Salt Lake Potash #SO4 – Exploration targets reveal World Class scale potential

Salt Lake Potash Limited (SLP or the Company) is pleased to announce results of an initial estimate of Exploration Targets for eight of the nine lakes comprising the Company’s Goldfields Salt Lakes Project (GSLP). The ninth lake, Lake Wells, already has a Mineral Resource reported in accordance with the JORC code.

The total “stored” Exploration Target for the GSLP is 290Mt – 458Mt of contained Sulphate of Potash (SOP) with an average SOP grade of 4.4 – 7.1kg/m³ (including Lake Wells’ Mineral Resource of 80-85Mt). On a “drainable” basis the total Exploration Target ranges from 26Mt – 153Mt of SOP. The total playa area of the lakes is approximately 3,312km².

	Area	Average Grade (kg/m3)		Stored (Mt)		Drainable (Mt)
Lake	(km2)	SOP (min)	SOP (max)	SOP (min)	SOP (max)	SOP (min)	SOP (max)
Ballard	626	3.5	4.7	42	53	3.1	18
Barlee	350	1.9	4.3	10	21	0.8	8.1
Irwin	306	4.8	8.1	25	43	1.9	15
Marmion	339	3.0	5.1	20	34	1.6	11
Minigwal	567	3.8	8.3	45	98	3.4	31
Noondie	386	4.2	6.0	35	50	2.8	16
Raeside	89	2.1	7.0	6	20	0.4	5.4
Way	172	5.6	15.5	28	54	2.7	19
Wells	477	8.7	8.8	801	851	92	292
Total	3,312	4.4	7.1	290	458	26	153

1.     Incorporating Lake Wells’ stored Mineral Resource Estimate previously reported.

2.     Lake Wells Mineral stored Mineral Resource Estimate converted to drainable equivalent.

Table 1: GSLP Exploration Target

The combined resources and exploration targets in the GSLP comprise a globally significant Project in the SOP sector, potentially sustaining one of the world’s largest SOP production operations for many decades.

CEO Matt Syme commented “These initial exploration targets allow us for the first time to quantify the real scale of the long term opportunity at the Goldfields Salt Lakes Project. We have already made very substantial progress in revealing the outstanding potential at Lake Wells and these Exploration Targets illustrate how the broader Project has a multiple of that potential. This places the GSLP asset at the leading edge of world scale SOP development opportunities.”

The Company’s long term plan is to develop an integrated SOP operation, producing from a number (or all) of the lakes within the GSLP, after confirming the technical and commercial elements of the Project through construction and operation of a Demonstration Plant producing up to 50,000tpa of SOP. 

The Company’s recent Memorandum of Understanding with Blackham Resources Limited (see ASX Announcement dated 12 March 2018) offers the potential for an expedited path to development at Lake Way, possibly the best site for a 50,000tpa Demonstration Plant in Australia.

The GSLP has a number of very important, favourable characteristics:

Ø  Very large paleochannel hosted brine aquifers, with chemistry amenable to evaporation of salts for SOP production, extractable from both  low cost trenches and deeper bores;

Ø  Over 3,300km² of playa surface, with in-situ clays suitable for low cost on-lake pond construction;

Ø  Excellent evaporation conditions;

Ø  Excellent access to transport, energy and other infrastructure in the major Goldfields mining district;

Ø  Lowest quartile capex and opex potential based on the Lake Wells Scoping Study;

Ø  Clear opportunity to reduce transport costs by developing lakes closer to infrastructure and by capturing economies of scale;

Ø  Multi-lake production offers operational flexibility and protection from localised weather events;

Ø  The very high level of technical validation already undertaken at Lake Wells substantially applies to the other lakes in the GSLP; and

Ø  Potential co-product revenues, particularly where transport costs are lowest.

Salt Lake Potash will progressively explore the lakes in the portfolio with a view to estimating resources for each Lake, in parallel with the development of the Demonstration Plant. Exploration of the lakes will be prioritised based on likely transport costs, scale, permitting pathway and brine chemistry.

THE GOLDFIELDS SALT LAKES PROJECT

The nine lakes comprising the GSLP were selected for scale, potential brine volume, known hypersaline brine characteristics, and the potential for production from both shallow trenches and deeper paleochannel aquifer bores. Each has a large surface area, a flat and bare surface playa and proximity to the important transport and energy infrastructure and engineering expertise available in the Western Australian Goldfields. 

The GSLP has a number of very important, favourable characteristics:

Paleochannel Hosted Brine Aquifers

The GSLP salt lakes are each part of typical Western Australian paleovalley environments. Ancient hydrological systems incised paleovalleys into Palaeozoic or older basement rocks, which were then infilled by Tertiary-aged sediments, typically comprising a coarse-grained fluvial basal sand, overlain by paleovalley clay with some coarser grained interbeds. The clay is overlain by recent Cainozoic material including lacustrine sediment, calcrete, evaporite and aeolian deposits. 

There are two methods of extracting brine from aquifers. Firstly, low cost trenching from the surface aquifer and the secondly, extraction from the paleochannel basal aquifer via bores.

All the lakes in the GSLP offer very large paleochannel hosted brine aquifers, with brine chemistry amenable to evaporation of salts for SOP production.

Large Playa Surface

The lakes included in the GSLP have a surface area averaging 370km² and totaling over 3,300km². This large surface area and the occurrence of impermeable clays near the surface, provides the potential for constructing low cost, on-lake, unlined evaporation ponds.

As demonstrated at Lake Wells (refer to ASX Announcement dated 16 October 2017), this provides significant potential capex savings. The results from the evaporation pond trial at Lake Wells exceeded expectations and strongly validated SLP’s model for construction of on-lake, unlined evaporation ponds. Net seepage of 2.4mm per day in a test scale pond extrapolates to less than 0.125mm per day in a 400ha Demonstration Plant scale halite pond, a negligible inefficiency in the context of overall pond operations.

Preliminary excavation and sampling at Lakes Ballard, Irwin and Way also indicate the presence of clays amenable for pond construction near the lake surface.

Excellent Evaporation Conditions

The Goldfields has very favourable arid climatic conditions with annual Class A pan evaporation in the region around ~3,000mm per year. This compares favourably with other global brine projects currently in production.

Access to Transport, Energy and Other Infrastructure

The lakes of the GSLP are strategically located close to the regional transport and energy infrastructure corridor. Transport from site to port is the single largest cost factor for (export oriented) Australian salt lake SOP projects, and the GSLP has a considerable advantage in this regard, with excellent proximity to the Kalgoorlie-Leonora rail line and the Goldfields Highway. The Company has made substantial progress in understanding and optimising its transport proposition, with major economies of scale to be achieved as the production volume increases.

The table below sets out the straight-line and existing road distances to the nearest railhead for each lake.

Lake	Railhead	Straight-line Distance to Rail line (km)	Likely Road Haul Distance (km)
Lake Wells	Malcolm	270	318
Lake Way	Leonora	230	281
Lake Irwin	Leonora	85	170
Lake Ballard	Menzies	2	20
Lake Marmion	Menzies	20	47
Lake Minigwal	Kookynie	130	172
Lake Raeside	Leonora	20	20
Lake Noondie	Leonora	110	198
Lake Barlee	Menzies	130	133
Average		111	151

Table 2: Transportation Distances of the GSLP

The Goldfields Gas Pipeline also intersects the GSLP, passing close to a number of lakes, offering potential energy cost savings.

Multi-Lake Production

There is substantial potential for integration, economies of scale, operating synergies and overhead sharing in the GSLP across a number of producing lakes.

There is also the possibility of some important elements of the SOP production process such as compaction, agglomeration and packaging being centralised, probably adjacent to rail loading facilities.

The flexibility of multi-lake production is also appealing for a natural production process which is subject to climate variability, where the operating risk of individual high rainfall events is diminished over a portfolio of production lakes.

Technical Validation Already Undertaken at Lake Wells

At Lake Wells, the Company has tested and verified all the major technical foundations for production of SOP from Lake Wells brine to a standard previously unseen in Australia under actual site conditions and across all seasons.

These key technical achievements at Lake Wells will have significant application across the other lakes in the GSLP, given the similar geology, brine chemistry and climate conditions.

Lowest Quartile Capex and Opex

The Scoping Study on Lake Wells released in August 2016 (see ASX announcement dated 29 August 2016) highlighted the outstanding potential economics of extracting hypersaline brine by trenches and bores for solar evaporation of salts and processing to produce premium SOP. The Scoping Study indicates Lake Wells would be firmly in the lowest cost quartile for any SOP Project in Australia and around the world, with relatively low transport costs being a major advantage.

	Stage 1	Stage 2
Annual Production (tpa) – steady state	200,000	400,000
Capital Cost *	A$191m	A$39m
Operating Costs **	A$241/t	A$185/t
* Capital Costs based on an accuracy of -10%/+30% before contingencies and growth allowance but including EPCM. Stage 1 Capital Costs include most of the main capital items for 400,000tpa production. ** Operating Costs based on an accuracy of ±30% including transportation & handling (FOB Esperance) but before royalties and depreciation.

Table 3: Lake Wells Scoping Study

Lake Way is likely to offer material economic advantages even over Lake Wells due to proximity and availability of transport and other infrastructure and potential cost saving with the Matilda-Wiluna Gold Operation.

Production of Valuable Co-Products

Brine modelling and evaporation testwork has demonstrated that Lakes Wells, Irwin, Ballard and Way can produce potassium and magnesium salts amenable to conversion to SOP and also potentially other valuable co-products.

Kieserite (MgSO₄.H₂O) and Epsom salts (MgSO₄.7H₂O) are valuable fertiliser products for both the domestic and export markets, with particular application in the tropical crop regions in South East Asia, South America and Africa.

While magnesium nutrients have lower market value than SOP, they are potentially valuable co-products, particularity where transport costs are lowest, for example Lakes Ballard and Marmion.

Exploration Targets for MgSO₄.7H₂O (Epsom Salt) were calculated at the each lake, except Lake Wells, as follows:

	Stored (Mt)		Drainable (Mt)		Average Grade (kg/m3)
Lake	MgSO4 (min)	MgSO4 (max)	MgSO4 (min)	MgSO4 (max)	MgSO4 (min)	MgSO4 (max)
Ballard	667	949	51	320	58	82
Barlee	158	431	13	163	31	84
Irwin	145	304	11	106	27	57
Marmion	355	712	27	235	53	107
Minigwal	668	1,462	50	469	57	124
Noondie	308	488	23	154	37	58
Raeside	86	358	6	98	30	126
Way	151	339	15	125	49	105
Total	2,538	5,043	196	1,670	46	92

MgSO₄ = the molar mass of MgSO₄.7H₂0 based on a conversion ratio of 10.14 of Mg to MgSO₄.7H₂O.

Table 4: Magnesium Sulphate Exploration Target

APPENDIX 1 – EXPLORATION TARGET METHODOLOGY AND RESULTS

GSLP Exploration Targets:

Exploration Target calculated using Total Porosity:

Lake	Playa Area	Estimated Paleochannel Length	Sediment Volume	Brine Volume	Average Potassium Concentration kg/m3		SOP Tonnage Mt
	Km2	Km	Mm3	Mm3	Lower Estimate	Upper Estimate	Lower Estimate	Upper Estimate
Ballard	626	55	26,370	11,487	1.6	2.1	42	53
Barlee	350	60	11,455	5,107	0.8	1.9	10	21
Irwin	306	22	11,942	5,236	2.1	3.6	25	43
Marmion	339	35	15,294	6,626	1.3	2.3	20	34
Minigwal	567	100	27,166	11,716	1.7	3.7	45	98
Noondie	386	75	19,412	8,345	1.9	2.7	35	50
Raeside	89	35	6,775	2,844	0.9	3.1	6	20
Way	172	25	8,044	3,475	3.6	7.0	28	54
Wells	477	60	24,723	9,639	3.9		80	85
Total	3,312	467	151,181	64,474			290	458

Table 5: Exploration Target calculated using Total Porosity

Exploration Target calculated using Drainable Porosity:

Lake	Sediment Volume	Weighted Average Drainable Porosity 1		Brine Volume		Average Potassium Concentration		SOP Tonnage
				Mm3		kg/m3		Mt
	Mm3	Sy Lower	Sy Upper	Lower Estimate	Upper Estimate	Lower Estimate	Upper Estimate	Lower Estimate	Upper Estimate
Ballard	26,370	0.03	0.15	882	3,913	1.6	2.1	3.1	18
Barlee	11,455	0.04	0.17	404	1,931	0.8	1.9	0.8	8
Irwin	11,942	0.03	0.15	408	1,844	2.1	3.6	1.9	15
Marmion	15,294	0.03	0.14	501	2,192	1.3	2.3	1.6	11
Minigwal	27,166	0.03	0.14	877	3,783	1.7	3.7	3.4	31
Noondie	19,412	0.03	0.14	619	2,645	1.9	2.7	2.8	16
Raeside	6,775	0.03	0.11	198	778	0.9	3.1	0.4	5
Way	8,044	0.04	0.15	299	1,196	2.8	7.1	2.7	19
Wells2	24,723	0.04	0.14	1,074	3,355	3.9		9	29
Total	151,181	0.03	0.14	5,262	21,637			26	153

1.   Drainable Porosity was assigned to each geological unit per Table 9 Porosity Estimates.  The volume weighted average value is presented here.

2.   Incorporating Lake Wells’ total Mineral Resource Estimate previously reported.

Table 6: Exploration Target calculated using Drainable Porosity

The Company engaged an independent hydrogeological consultant with substantial salt lake brine expertise, Groundwater Science Pty Ltd, to complete the Exploration Targets for all the lakes in the GSLP.

Scope

The Exploration Target is a statement or estimate of the exploration potential of a mineral deposit in a defined geological setting where the statement of estimate, quotes as a range of tones and a range of grade (or Quality), relative to mineralisation for which there has been insufficient exploration to estimate a Mineral Resource. The potential quantity and grade is conceptual in nature and there has been insufficient exploration to estimate a Mineral Resource and it is uncertain if further exploration will result in the estimation of a Mineral Resource.

The Exploration Targets are reported in accordance with

•          the JORC Code 2012,

•          the draft Guidelines for Resource and Reserve Estimation for Lithium and Potash Brines, developed by the Australia  Association of Mining and Exploration Companies (AMEC), and

•          the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Best Practice Guidelines for Resource and Reserve Estimation for Lithium Brines.

A Mineral Resource Estimate for Lake Wells has been reported (refer to ASX Announcements dated 11 November 2015 and 22 February 2016), comprising a total of 85Mt SOP. This estimate was calculated as the total in-situ resource based on the total porosity of the brine host aquifer. The resource has been re-calculated for this study based on the estimates of drainable porosity that are detailed below. The aim is to provide an estimate of mineralisation that is comparable to the proposed Exploration Targets and collate an inventory of the entire GSLP project.

Data sources

An exploration target for each lake has been defined by review of:

·      All historic exploration data that has been released for the tenement, including drilling and geophysics;

·      All public geology and hydrogeology reports, maps and data;

·      Company hydrogeological reports obtained from the Western Australia Department of Water and Environmental Regulation via freedom of information request;

·      Surface brine samples from test pits; and

·      Test Pits, test excavation, and geophysical survey, undertaken by SLP.

Geology

Each playa lake exhibits reasonably consistent Tertiary paleovalley morphology as described in detail by Bell et al. (2012)^[1], Johnson et al. (1999)^[2], and DeBroekert and Sandiford (2005)^[3]. Paleovalleys are incised into the Palaeozoic or older basement rocks. These are then infilled by Tertiary-aged sediment typically comprising a coarse-grained fluvial Basal Sand overlain by Paleovalley Clay with some coarser grained interbeds. The clay is overlain by Cainozoic Alluvium, that includes lacustrine clay, calcrete, evaporite and aeolian deposits.

Geological Unit	Inferred age	Description	Hydrogeological Attributes
Lake surface and islands	Recent	Clay sediments with some sandy, evaporite and calcrete horizons containing variable abundance of evaporite minerals, particularly gypsum.	Minor aquifer. Highly variable permeability and moderate drainable porosity.
Alluvium	Cainozoic	Unconsolidated silt, sand and clay sediments.	Minor aquifer.  Moderate permeability and moderate drainable porosity
Paleovalley clay	Tertiary (Miocene)	Stiff to plastic clay.  Minor silt and sand interbeds	Aquitard. Low permeability and low drainable porosity
Basal sand	Tertiary (Eocene)	Typically fining upwards sequence of sand with silt, clay and lignitic interbeds.	Major aquifer.  High to moderate permeability and High to moderate drainable porosity

Table 7: Geological Units

Geological Model

At each playa lake, the extent and thickness of each geological unit has been inferred from the available data. Differentiating each geological unit is important because each unit exhibits specific hydrogeological properties, permeability and drainable porosity as described below.

Area

The area of each playa lake was calculated by digitising the lake surface and removing area covered by islands. These areas are used to calculate the volume of the lake sediments. The extent of the brine body hosted by alluvium has been defined by the extent of the lake playa.  Extension of the brine body beyond the lake playa edge in shallow sediment is possible but unsupported by data at this stage. Studies on other playa lakes have demonstrated that brine concentration quickly diminishes with distance from the playa edge. The mechanism for lower brine grade off the playa is understood to be dilution by rainfall infiltration and the absence of the intense evaporation that occurs on the playa surface.

The extent of the lower Paleovalley Clay and Basal Sand is based on the mapped distribution of paleovalleys across the Northern Goldfields by Johnson et al. (1999) and other studies. This has been used as the basis for determining paleovalley length. There has been additional geophysics undertaken at Lakes Ballard, Irwin and Marmion that provides a more accurate interpretation. At Lake Way, exploration drilling for the Mt Keith Borefield (AGC Woodward Clyde, 1992) has further confirmed the paleochannel extent and presence of the Basal Sand.   

Thickness

Lake Sediments (Upper Alluvium)

The lake sediments are dominated by clay lacustrine deposits with abundant evaporite minerals, such as gypsum. The thickness of this unit is poorly resolved. An average thickness of 10m has been assumed. The 10m thickness of Lake sediments are also the maximum depth of dilution calculated beneath islands on the Playa Surface.

Alluvium

The alluvium comprises a mixed sequence of sheetwash, calcrete and aeolian deposits that underlie the lake sediments. It has been mapped by Johnson et al. (1999) as a channel fill deposit being similar in nature to that found in present-day outwash alluvial fans and minor creeks, and it extends and is present beyond the lake margins. The thickness is highly variable and is up to 60m thick in parts of the Raeside Paleovalley. An average thickness of 15m has been applied for the exploration target estimation.

Paleochannel Clay

The paleochannel clay is a stiff clay that confines the basal paleochannel sand. It has a variable thickness depending on whether a site is within a trunk (thicker) or tributary (thinner) paleovalley. The width is dependent on the basement material with wider channels in granitoid basement and narrower channels in greenstone lithologies. For the resource estimation, the thickness and width was determined based on nearby geological transects from Langford (1997) and Johnson et al. (1999), or other company drilling in the case of Lake Way.

Basal Sand

The basal sand is present in the deepest section of the paleovalley. It has a variable thickness with some sand sections being up to 40 m thick. The development of the sand is dependent on proximity to granitoid catchments with less sand thickness in catchments dominated by greenstone lithologies. As with the paleochannel clay, the thickness and width was determined based on nearby geological transects from Langford (1997) and Johnson et al. (1999), or other company drilling in the case of Lake Way. As an example, the conceptual model applied to a cross section at Lake Ballard developed by Langford (1997). 

Brine Concentration

Brine concentration has been defined based on samples taken from test pits excavated into the Alluvium by SLP in 2017 (Appendix 3), and from historic drilling data where available. Minimum and Maximum values have been defined as the mean value +/- one standard deviation for sample sets of more than 10 samples. For sample sets of less than 10 samples, the minimum and maximum values have been used.

Where no brine chemistry data is available for the paleochannel sediments, brine concentration is assumed to be constant with depth. This assumption is supported by SLP’s experience at Lake Wells, other company reports for comparable paleochannel hosted brine in the Goldfields region, and work by Water and Rivers Commission and others. Proving this assumption by drilling and sampling is a priority for progressing evaluation of these targets. 

Hydrogeological Attributes

Hydrogeological attributes assigned to each geological unit are summarised in Table 8. 

The permeability of the Lake Sediments and Alluvium is expected to be variable. Permeability is dependent on the lithology of the sediment, development of evaporite minerals that can enhance permeability, and the development of calcrete minerals that can be extremely permeable.

Paleovalley Clay is a low permeability aquitard, brine held in this unit will not be drained by bores; however, some fraction of the brine stored in this unit might be accessed by leakage into the underlying basal sand. 

Basal Sand is typically permeable, and brine is expected to be extracted by pumping from bores.

Geological Unit	Hydrogeological Properties
Lake Sediments	Highly variable aquifer dependent on lithology and evaporite formation
Alluvium	Highly variable aquifer dependent on lithology and evaporite formation
Paleovalley Clay	Aquitard low permeability
Basal Sand	Aquifer high permeability

Table 8: Hydrogeological Attributes

Porosity

Total porosity (Pt) relates to the volume of brine-filled pores contained within a unit volume of aquifer material. A fraction of this pore volume can by drained under gravity, this is described as the drainable porosity (or specific yield). The remaining fraction of the brine, which is held by surface tension and cannot be drained under gravity, is described as the specific retention (or un-drainable porosity).

A resource calculated as the product of drainable porosity is still not completely recoverable by gravity drainage to trenches or bores.

The reported mineral tonnage represents the brine with no recovery factor applied. It will not be possible to economically extract all the contained brine by pumping. The amount that can be extracted depends on many factors including the permeability of the sediments, adjacent groundwater composition, and the recharge dynamics of the aquifers. Brine projects typically recover a small fraction of the in-situ resource.

The total and drainable porosity of each geological unit has been estimated from lithology and benchmarking against other studies completed in comparable geological settings. A summary of the porosity assigned to each geological unit and the source of the estimates is presented in Table 9.

Benchmarking of the porosity applied in this study to other Australian salt lakes is presented in Table 10.

Geological Unit	Total Porosity (%)	Drainable Porosity (%)
Lake Sediments	0.46	0.04-0.2
Alluvium	0.46	0.04-0.2
Paleovalley Clay	0.4	0.01-0.05
Basal Sand	0.4	0.1-0.2

Table 9: Porosity Estimates

 

		Project
		WA Salt Lake 1 Mineral Resource Estimate	WA Salt Lake 2 Mineral Resource Estimate	WA Salt Lake 3 Mineral Resource Estimate	WA Salt Lake 4 Exploration Target	GSLP
Lake Sediments and Alluvium	Total Porosity	0.39	0.47	0.45	0.42-0.53	0.46
	Drainable Porosity	0.16	0.17	0.064	0.13-0.15	0.04-0.20
Clay	Total Porosity	0.47	0.5	–		0.4
	Drainable Porosity	0.06	0.03	–		0.01-0.05
Basal Sand	Total Porosity	0.4	0.4	–		0.4
	Drainable Porosity	0.23	0.28	–		0.1-0.20

Source: Company releases

Table 10: Porosity Benchmarks

Brine Hydrology and Water Balance

The brine hydrology and water balance of each playa lake is not yet defined at this early stage of project evaluation.

All the playa lakes are understood to flood intermittently following large rainfall events. This is based on information derived from a Geoscience Australia dataset that presents the frequency of inundation for the Australian continent based on analysis of Landsat TM images compiled since 1984 (GA, 2017)^[4].

Flooding and direct infiltration of rainfall will recharge the lake sediments and contribute to the water balance of the brine system.

Pumping from confined paleochannels results in depressurisation of the paleochannel and subsequent slow leakage of groundwater from the overlying clay aquitard and lateral inflow from the adjacent weathered basement aquifer. Studies of long-term water supply abstraction from the Roe paleochannel suggest sustainable water yields of around 1GL/year per 10km of paleochannel are possible (Johnson, 2007)^[5].

Neighbouring properties and temporal effects

Neighbouring properties and temporal effects have not been evaluated at this early stage of project development.

Treatment of Islands

Many of the salt lake playas contain islands on the playa surface. These islands generally comprise gypsiferous dunes and often exhibit some vegetation.  They are more common in playas that are less frequently inundated Bowler, (1986)^[6],presumably due to the erosion that occurs through wave action during periods of inundation. Research on other playas has shown that the brine beneath islands is typically diluted close to the surface. The mechanism is understood to be dilution by infiltration of rainfall through the islands, without the subsequent intense evaporation that occurs on the playa surface. This dilution effect diminishes with depth.

Shallow dilution beneath islands is considered in the Exploration Target estimate by defining the area occupied by islands and reducing brine concentration beneath the islands by a factor of 3 to a depth of 10m.

Mineralisation Extent

Mineralisation is calculated for the area beneath the salt lake playa and islands only. There is in-sufficient data at each site to infer continuity of the mineralisation beyond the playa extent.

A summary of the geological and hydrogeological data review undertaken at each playa lake is presented below.

 

APPENDIX 2 – GSLP GEOLOGICAL AND HYDROGEOLOGICAL DATA REVIEW 

LAKE BALLARD

Previous Exploration

A large amount of historical exploration work has been undertaken surrounding Lake Ballard focusing on gold, nickel and uranium. There has been limited exploration on the lake surface with most exploration associated with uranium exploration in the upper 10 m.  Soil sampling was undertaken on the lake, as well as a number of geophysical surveys and shallow drilling activities. The Company has reviewed multiple publicly available documents to provide an understanding of the geology and hydrogeology in the Lake Ballard paleodrainage.

Esso Australia (1977) completed ground-based gravity and seismic geophysical survey at western end of lake suggesting the presence of the palaeovalley. Uranerz Australia (1977) undertook airborne spectrometric and ground-based scintillometric surveys that was followed by auger drilling with 81 holes being completed to depths of up to 30 m bgl, which suggested the shallow alluvium is dominated by clay lithologies and some drill holes encountered the top of the paleochannel clay. Uranoz Ltd (2007) completed an airborne gravity survey over the eastern portion of Lake Ballard and eastward over the northern portion of Lake Marmion that broadly mapped the distribution of the paleochannel thalweg.

The most useful hydrogeological data relates groundwater exploration undertaken by the Geological Survey of Western Australia (GSWA) in 1987. Three north-south transects were drilled between Lake Ballard and Lake Marmion to explore for the main trunk paleodrainage that originates to the west of Lake Ballard and flows to the east beneath Lakes Marmion and Rebecca. Drill holes were cased where possible; however, most holes into the deeper paleochannel sediments couldn’t be cased owing to running sands. There are some drill sites with multiple bores and different screen intervals. A bore completion report details the drilling and bore construction (Nidagal, 1992), while a description of the hydrogeology between the two lakes is provided by Langford (1997).

Geology

The Lake Ballard paleodrainage is incised into the Archean basement and now in-filled with a mixed sedimentary sequence. There is a shallow sedimentary sequence comprising lake sediments overlying alluvium and colluvium that concealed a deeper sedimentary sequence of plastic clay and basal sand. The paleochannel sands occur only in the deepest portion.

The lake sediments are thin being less than 2 to 3 m thick, which tend to interfinger and grade downward into an upper, iron-stained sequence of alluvium and colluvium (up to 30 m thick). This upper sequence appears to be more clayey with noticeably less sandy horizons, when compared with other paleodrainages to the north. Between Lakes Ballard and Marmion, there are clay layers (up to 20 m thick) being separated by sandy clay to clayey sand beds.

The understanding of the deep stratigraphy in the paleovalley is limited to three drilling transects between Lakes Ballard and Marmion. The lower Tertiary-aged paleochannel sequence comprises dense plasticine clay (60m thick) and basal sands (up to 20m thick). In places, there are silcrete and sandy intervals within the plasticine clay providing a different stratigraphy to other paleodrainages.

Hydrogeology

The upper alluvium and colluvium is likely to be a minor aquifer associated with Lake Ballard, and in some places may form an aquitard. The basal sands are confined beneath the plastic clay and comprise fine to coarse-grained quartz sand, which forms a deeper aquifer being about 80m bgl in the west (estimated from ground-based geophysics) and about 110m bgl at the east of Lake Ballard. There has been no hydraulic testing of the shallow or deep aquifers at Lake Ballard; however, bore yields will be higher from the basal sands.

References

Esso Exploration and Production Australia Inc, 1977, 1999 Annual (Final) Report, Lake Ballard – Project 650, Mineral Claims 29/2988-3000, 29/3059 and 3060, 30/1249-1253, and 30/1266-1270 – unpublished report by Esso Australia, WAMEX A7536.

Langford, R., 1997, Hydrogeology of part of the Rebecca Palaeodrainage between Lake Ballard and Lake Marmion in the northeastern Goldfields of Western Australia, unpublished thesis for Master of Science (Applied Geology) at Curtin University.

Nidagal, V., 1992, Lake Ballard palaeodrainage groundwater investigation bore completion reports, Western Australia Geological Survey, Hydrogeology Report 1989/18, unpublished.

Uranerz Australia, 1977, Final Report covering the period from 10/12/1976 to 1/11/1977, Temporary Reserve No 6400H, unpublished report by Uranerz Australia, WAMEX A7330.

Uranoz Ltd, 2007, E59/599 – Goongarrie Project, Annual Technical Report, Period Ending December 18, 2007: Report compiled by Mark Gordon of Gondor Geoconsult Pty Ltd in December 2007, unpublished report for Uranoz Ltd, WAMEX A76810.

LAKE BARLEE

Previous Exploration

There has been limited exploration on the lake surface with most exploration associated with uranium exploration in the upper 10m. Soil sampling was undertaken on the lake, as well as a number of geophysical surveys and shallow drilling activities (Jervois Mining, 2013; Northern Uranium, 2008). The Company has reviewed multiple publicly available documents to provide an understanding of the geology and hydrogeology in the Lake Barlee paleodrainage.

Recent potash exploration work by Parkway Minerals on their tenements to the north of SLP tenements suggest the presence of a paleochannel feature (Parkway Minerals, 2017). There has been no drilling to date, but geophysics results indicate the combined depth of the paleovalley is about 75m (Parkway Minerals, 2017) being shallower than other paleodrainages as it is close to its headwaters.

Geology

There is little known about the stratigraphy in the Barlee Paleodrainage, as there has been no regional assessment undertaken. The paleovalley becomes shallower towards its headwaters in the west and south; as such it is possible that it is about 50m deep beneath the SLP tenements.

The paleodrainage is incised into the Archean basement and now in-filled with a mixed sedimentary sequence. Lake sediments are thin being less than 2 to 3m thick, which tend to interfinger and grade downward into an upper, iron-stained sequence of alluvium and colluvium (up to 30m thick). This shallow sedimentary sequence may conceal a deeper sedimentary sequence of plastic clay and basal sand. The presence of the paleochannel sands is unknown; however, if present they will occur in the deepest portion.

Hydrogeology

The upper alluvium and colluvium is likely to be a minor aquifer, and in some places may form an aquitard. Basal sands comprise fine to coarse-grained quartz sand may be confined beneath plastic clay and form a deeper aquifer. There has been no hydraulic testing of the shallow or deep aquifers at Lake Barlee; however, bore yields are likely to be higher from the basal sands.

References

Jervois Mining, 2013, Bulga Project, Final Surrender Report for period 6th September to 22nd May 2013, unpublished report, WAMEX A98133.

Northern Uranium, 2008, Annual Report for the Lake Barlee Project, Exploration Licence E77/1331, unpublished report, WAMEX A77895.

Parkway Minerals, 2017, Parkway Minerals announces seismic survey at Lake Barlee confirms deep paleo-channels, ASX announcement by Parkway Minerals, 17 October 2017.

LAKE IRWIN

Previous Exploration

Significant historical exploration work has been completed in the Lake Irwin area focusing on nickel and gold. This exploration work was largely undertaken in the basement lithologies surrounding the lake; however, there has been no substantial exploration on the lake.

The most useful stratigraphic and hydrogeological data relates to groundwater exploration undertaken by the Water and Rivers Commission (WRC) in 1997 and 1998. Three investigation transects were completed surrounding and across Lake Irwin. Transect B located across the middle of the lake failed to encounter the main trunk paleodrainage and is somewhat inconclusive. Transect C in the northwest encountered a palaeotributary with basal sand between 80 and 90 m bgl. Transect D located to the north of the lake encountered the basal sand between 110 and 140 m bgl. A bore completion report details the drilling and bore construction (Johnson et al., 1998), while a regional description of the hydrogeology is provided by Johnson et al. (1999).

Geology

The Carey paleodrainage, passing beneath Lake Irwin, is incised into the Archean basement and now in-filled with a mixed sedimentary sequence. There is a shallow sedimentary sequence comprising lake sediments overlying alluvium and colluvium that concealed a deeper sedimentary sequence of plastic clay and basal sand. The paleochannel sands occur only in the deepest portion.

The stratigraphy comprises thin lake sediments overlying an upper interbedded sequence of alluvium and colluvium (30m thick), and a lower Tertiary-aged paleochannel sequence of dense plasticine clay (50 to 60m) and basal sands (20 to 30m thick) that is surrounded by Archaean granite and greenstone basement.

Hydrogeology

The upper alluvium and colluvium is considered a minor aquifer owing to the fine-grained nature of the sediments and lack of thick sandy / gravel horizons. This aquifer is present beneath the entire lake surface. Direct hydraulic testing is limited; however, bore yields are likely to be low in the order of 1 to 2 L/sec and up to 5 L/sec in some cases. It is utilised by the pastoral industry for stock watering with bores and wells.

The deeper paleochannel sand is an important regional aquifer that is widely developed by the mining industry for meeting process water requirements. The thalweg of the trunk paleochannel appears to be about 1 to 2 km northeast of the lake, and only paleotributaries on the western side are present the current lake surface. In these paleotributaries, there are two production borefields (Charlie Well and Greymare) operated by Minara Resources’ Murrin Murrin operation. Long-term bore yields are commonly between 10 and 15 L/sec with up to 20 L/sec in the thickest thalweg sections.

References

Johnson, S., Mohsenzadeh, H., Yesterener, C., and Koomberi, H., 1998, Northern Goldfields regional groundwater assessment bore completion reports: Western Australia Water and Rivers Commission, Hydrogeology Report 107, unpublished.

Johnson, S., Commander, D., and O’Boy, C., 1999, Groundwater resources of the Northern Goldfields, Western Australia: Western Australia Water and Rivers Commission, Hydrogeological Record Series, Report HG2, 57p.

LAKE MARMION

Previous Exploration

A large amount of historical exploration work has been undertaken surrounding Lake Marmion focusing on gold, nickel and uranium. There has been limited exploration on the lake surface with most exploration associated with uranium exploration in the upper 10m. The Company has reviewed multiple publicly available documents to provide an understanding of the geology and hydrogeology in the paleodrainage beneath Lake Marmion.

Reports from previous tenement holders detailing mineral exploration programs provided useful data on the location of the paleochannel, and thickness / nature of the lake sediments. There have been a range of exploration activities including wide-spaced gravity surveys and some drilling at the western and eastern lake margins.

There have been several gravity surveys across the lake that have provided an understanding of the distribution of the paleochannel. The most recent surveys by Uranoz Ltd (2007a, b and c), Nickleore Ltd (2008) and Siburan Resources (2011a, b, c and 2012) suggest that the main trunk drainage takes a meandering path beneath the northern parts of the lake that merges with a large palaeotributary from the south.

Geology

There have been no regional studies on the Ballard-Marmion-Rebecca Paleodrainage – unlike the paleodrainages to the north (Johnson et al., 1999) and to the south (Commander et al., 1992).  Despite this, there is high level of confidence that the main trunk drainage traverses the northern portion of the lake from Lake Ballard to Boomerang Lake / Lake Rebecca in the east, and there is also a large paleotributary from the south. The stratigraphy seems to broadly align with other paleodrainages in the northern Goldfields.

Lake sediments are probably thin being less than 2 to 3m thick, which tend to interfinger and grade downward into an upper, iron-stained sequence of alluvium and colluvium (up to 30m thick). This upper sequence may be more clayey with noticeably less sandy horizons, when compared with other paleodrainages to the north. Between Lakes Ballard and Marmion, there are clay layers (up to 20m thick) being separated by sandy clay to clayey sand beds.

The understanding of the deep stratigraphy is based on the drilling undertaken at the lake margins. In the northwest, one incomplete and shallow drilling transect was completed by AFMECO (1978 a and b) and three drilling transects were completed by the GSWA between Lakes Ballard and Marmion with detailed lithological descriptions in the bore completion reports (Nidagal, 1992) and interpreted stratigraphy for each transect (Langford, 1997). This drilling suggests a total thickness of about 80m with 20m of alluvium / colluvium overlying 45m of plasticine clay and 15m of basal sands. There are silcrete and sandy intervals at the base of the alluvium / colluvium and throughout the plasticine clay that provides a different stratigraphy to other paleodrainages.

Hydrogeology

The upper alluvium and colluvium is considered a minor aquifer owing to the dominance of clay lithologies and lack of thick sandy / gravel horizons. It is present beneath the entire lake surface. There has been no direct hydraulic testing with bore yields to be very low, less than 1 L/sec. In places, discrete bodies of calcrete are present that form localised aquifers; however, these bodies are less common near Menzies when compared with areas to the north. Groundwater resources in this shallow aquifer will be more likely accessed via leakage rather than direct abstraction.

The deeper paleochannel sand is an important regional aquifer that is widely developed by the mining industry to the north; however, there has been no utilisation in the vicinity of Lake Marmion. Long-term bore yields are commonly between 10 and 15 L/sec with up to 20 L/sec in the thickest thalweg sections.

References

AFMECO, 1978a, Yilgarn Drainage, Temporary Reserve 6402H, West Lake Marmion, Annual Report, Report WA 275F, February 1978, unpublished report, WAMEX 7573.

AFMECO, 1978b, Yilgarn Drainage, Temporary Reserve 6402H, West Lake Marmion, Final Report, Report WA 275F, July 1978, unpublished report, WAMEX 7945.

Commander, D.P., Kern, A.M. and Smith, R.A., 1992, Hydrogeology of the Tertiary Palaechannels in the Kalgoorlie Region (Roe Palaeodrainage): Western Australia Geological Survey, Record 1991/10.

Johnson, S., Commander, D., and O’Boy, C., 1999, Groundwater resources of the Northern Goldfields, Western Australia: Western Australia Water and Rivers Commission, Hydrogeological Record Series, Report HG2, 57p.

Langford, R., 1997, Hydrogeology of part of the Rebecca Palaeodrainage between Lake Ballard and Lake Marmion in the northeastern Goldfields of Western Australia, unpublished thesis for Master of Science (Applied Geology) at Curtin University.

Nickleore Ltd., 2008, E29/634 (Lake Marmion), 2008 Annual Report, 12 April 2007 to 11 April 2008, unpublished report, WAMEX 79044.

Nidagal, V., 1992, Lake Ballard palaeodrainage groundwater investigation bore completion reports, Western Australia Geological Survey, Hydrogeology Report 1989/18, unpublished.

Siburan Resources, 2011a, Lake Marmion Project, Annual Report, Exploration Licence E29/756, Western Australia, Reporting period 19 August 2010 to 18 August 2011, unpublished report, WAMEX 91660.

Siburan Resources, 2011b, Lake Marmion Project, Annual Report, Exploration Licence E29/757, Western Australia, Reporting period 18 November 2010 to 17 November 2011, unpublished report, WAMEX 92276.

Siburan Resources, 2011c, Gravity surveys outline new uranium prospective paleochannels at Lake Marmion Project, ASX announcement.

Siburan Resources, 2012, Lake Marmion Project, Annual Report, Exploration Licences E29/637, E29/756-757, E29/773, E29/778-780, E29/782, E31/939-940, E31/976-977, Reporting period 5 July 2011 to 4 July 2012, unpublished report, WAMEX 95065.

Uranoz Ltd., 2007a, Goongarrie Project, E59/598, Annual Technical Report, Period Ending November 14, 2007: Report prepared by Mark Gordon of Gondor Geoconsult Pty Ltd in December 2007, unpublished report, WAMEX 76809.

Uranoz Ltd., 2007b, Goongarrie Project, E59/599, Annual Technical Report, Period Ending December 18, 2007: Report prepared by Mark Gordon of Gondor Geoconsult Pty Ltd in December 2007, unpublished report, WAMEX 76810.

Uranoz Ltd., 2007c, Goongarrie Project, E59/600, Annual Technical Report, Period Ending December 18, 2007: Report prepared by Mark Gordon of Gondor Geoconsult Pty Ltd in December 2007, unpublished report, WAMEX 76811.

LAKE MINIGWAL

Previous Exploration

A large amount of historical exploration work has been undertaken in the area to the north of Lake Minigwal focusing on gold, nickel and uranium. The Company has reviewed multiple publicly available documents to develop an understanding of the geology and hydrogeology in the paleodrainage beneath the lake itself.

Mineral exploration has been undertaken surrounding the lake margins with minimal activity on or beneath the lake surface. There has been some drilling near the eastern portion of the lake (Uranerz, 1983); however, there was no reporting of lithology in these drill holes. Uranerz Pty Ltd (1987) focused on a tributary near Jasper Hill that flows in Lake Minigwal with a drill hole encountering shallow paleochannel sediments. An AEM (airborne electromagnetic) survey has been undertaken over the project area by Camuco Pty Ltd (2008): however, there were issues with near-surface conductivity masking. It was concluded that there is limited data from geophysical surveys and drilling activities that contribute to paleochannel interpretation at Lake Minigwal.

Geology

There is limited understanding of the deep stratigraphy beneath Lake Minigwal. In the available dataset, there are no drill holes that fully penetrate the Tertiary sequence with the deepest holes being about 60m bgl that were ceased in paleochannel clay. Granny Smith Mines (1999) noted that there are 120m deep paleochannels beneath Lake Carey near Wallaby deposit and it is assumed that this is the same paleochannel beneath Lake Minigwal.

Beneath 20 to 30m of alluvium and colluvium, there is a Tertiary-aged paleochannel sequence comprising dense plasticine clay (50 to 60m) and basal sands (10 to 20m thick) that are incised into the Archaean granite and greenstone basement. In places, there may be silcrete and sandy intervals within the plasticine clay. The basal sands are commonly fine to coarse-grained sand.

Hydrogeology

The upper alluvium and colluvium is considered a minor aquifer, which is present beneath the entire lake surface. There has been no direct hydraulic testing with bore yields to be low, less than 3 L/sec. In places, there may be discrete bodies of calcrete that form localised aquifers. Groundwater resources in this shallow aquifer may be directly abstracted from sandy intervals, but more likely via downward leakage.

The deeper paleochannel sand is an important regional aquifer that is widely developed by the mining industry to the north, in particular Granny Smith Mines at Lake Carey. Production bores are screened in the permeable basal sand and gravels. Long-term bore yields are commonly between 10 and 15 L/sec with up to 20 L/sec in the thickest thalweg sections

References

Camuco Pty Ltd, 2008, Annual Report for the Minigwal Project comprising ELs 39/1185, 39/1186, 39/1187, unpublished report, WAMEX A77594.

Granny Smith Mines, 1999, Lake Carey Project, E38/447, E38/448, E38/457, E39/387, E39/389 & E39/483, Mount Margaret Mineral Field, Western Australia, Sixth Annual Report on Exploration, Period ending 30th June 1999, Ref: M7959, unpublished report, WAMEX A59288.

Uranerz Pty Ltd, 1983, Final report on Exploration Licence 38/13, Rason Lake Area, Western Australia, Covering the Period 30 March 1983 to 4 November 1983, unpublished report, WAMEX A12985.

Uranerz Pty Ltd, 1987, Surrender Report on Exploration Licence 39/87, Lake Minigwal, Western Australia, Covering the period 23 March 1986 to 22 March 1987, unpublished report, WAMEX A20809.

LAKE NOONDIE

Previous Exploration

Previous diamond, gold and uranium exploration has been conducted in the vicinity of Lake Noondie. There has been limited exploration on the lake surface with most exploration associated with uranium exploration in the upper 10m.  Soil sampling was undertaken on the lake, as well as a number of geophysical surveys and shallow drilling activities (Hemisphere, 2010, 2011; Mindax, 2008). The Company has reviewed multiple publicly available documents to provide an understanding of the geology and hydrogeology in the Lake Noondie paleodrainage.

Geology

There is little known about the stratigraphy in the Noondie Paleodrainage, as there have been no regional studies unlike the paleodrainages to the east (Johnson et al., 1999). The closest drill transect (Transect R) completed by the Water and River Commission (Johnson et al., 1999) is about 40km to the east. This drilling suggests the presence of a full paleochannel stratigraphy with a combined thickness of 130m.

The paleodrainage is incised into the Archean basement and now in-filled with a mixed sedimentary sequence. Lake sediments are thin being less than 2 to 3m thick, which tend to interfinger and grade downward into an upper, iron-stained sequence of alluvium and colluvium (up to 30m thick). This shallow sedimentary sequence conceals a deeper sequence of plastic clay and basal sand. The paleochannel sands will occur in the deepest portion and may be 20 to 30m thick.

Hydrogeology

The upper alluvium and colluvium is likely to be a minor aquifer associated with Lake Noondie. Basal sands comprise fine to coarse-grained quartz sand that are confined beneath plastic clay and form a deeper aquifer. There has been no hydraulic testing of the shallow or deep aquifers at Lake Noondie; however, bore yields will be higher from the basal sands.

References

Hemisphere Resources Ltd., 2010, Combined reporting group C61/2009, Bulga Downs Project, Exploration Licences E57/720, E57/721, E57/722, E57/762, E57/763, E57/781 and E57/782, Western Australia, Annual Report for the year ended 13 April 2010, unpublished report, WAMEX A87235.

Hemisphere Resources Ltd., 2011, Combined reporting group C61/2009, Bulga Downs Project, Exploration Licences E57/720, E57/721, E57/722, E57/762, E57/763, E57/781 and E57/782, Western Australia, Annual Report for the year ended 13 April 2011, unpublished report, WAMEX A90598.

Johnson, S., Commander, D., and O’Boy, C., 1999, Groundwater resources of the Northern Goldfields, Western Australia: Western Australia Water and Rivers Commission, Hydrogeological Record Series, Report HG2, 57p.

Mindax Ltd, 2008, Lake Noondie Project, Combined Annual Report for Exploration Licenses E57/602 (Lake Noondie West), E57/603 (Lake Noondie East) and E57/619 (Bill Well), Black Range District, East Murchison Mineral Field for the period 1st January 2007 and 31st December 2007, unpublished report, WAMEX A77744.

LAKE RAESIDE

Previous Exploration

A large amount of historical exploration work has been undertaken in the vicinity of Lake Raeside focusing on gold, limestone, nickel and uranium. There has been limited exploration on the lake surface with most exploration associated with limestone and uranium exploration in the upper 10m at the lake margins. Soil sampling was undertaken on the lake, as well as a number of geophysical surveys and shallow drilling activities. The Company has reviewed multiple publicly available documents to develop an understanding of the geology and hydrogeology in the paleodrainage beneath the lake itself.

The Water and Rivers Commission completed a regional groundwater resource assessment of the paleodrainages in the Northern Goldfields in 1997 and 1998. As part of this assessment, a drilling transect (Transect Q) was installed about 5 km north of Lake Raeside along the Ida Valley Road that encountered a full paleochannel stratigraphy with a combined thickness of 130 m (Johnson et al., 1999).

Geology

The paleodrainage is incised into the Archean basement and now in-filled with a mixed sedimentary sequence. Lake sediments are thin being less than 2 to 3 m thick, which tend to interfinger and grade downward into an upper, iron-stained sequence of alluvium and colluvium (up to 30 m thick). This shallow sedimentary sequence conceals a deeper sequence of plastic clay and basal sand. The paleochannel sands occur in the deepest portion, may be 20 to 30 m thick, and are present beneath the current lake surface

Hydrogeology

The upper alluvium and colluvium is likely to be a minor aquifer, and in some places may form an aquitard. The presence of calcrete at the margins suggests that there may be calcrete aquifer horizons within the upper 10 m. Beneath the plastic clay, basal sands comprise fine to coarse-grained quartz sand that forms a potential deeper aquifer. There has been no hydraulic testing of the shallow or deep aquifers at Lake Raeside; however, bore yields will be higher from the basal sands.

References

Johnson, S., Commander, D., and O’Boy, C., 1999, Groundwater resources of the Northern Goldfields, Western Australia: Western Australia Water and Rivers Commission, Hydrogeological Record Series, Report HG2, 57p.

LAKE WAY

Previous Exploration

Significant historical exploration work has been completed in the Lake Way area focusing on nickel, gold and uranium. The Company has reviewed multiple publicly available documents including relevant information on the Lake Way’s hydrogeology and geology.  

Groundwater exploration was undertaken in the early 1990s by AGC Woodward Clyde to locate and secure a process water supply for WMC Resources Limited’s Mt Keith nickel operation.  There was a wide and extensive program of exploration over 40km of paleodrainage that focused on both the shallow alluvium and deeper paleochannel aquifers.

The comprehensive drilling program comprised 64 air-core drill holes totalling 4,336m and five test production bores (two of which were within SLP’s exploration licences). The aquifers identified were a deep paleochannel sand unit encountered down the length of the Lake Way investigation area and a shallow mixed alluvial aquifer from surface to a depth of approximately 30m.

Geology

The Lake Way drainage is incised into the Archean basement and now in-filled with a mixed sedimentary sequence, the paleochannel sands occurring only in the deepest portion. The mixed sediments include sand, silts and clays of lacustrine, aeolin, fluvial and colluvial depositional origins. The surficial deposits also include chemical sediments comprising calcrete, silcrete and ferricrete. These sediments provide a potential reservoir for large quantities of groundwater.

The deep paleochannel sand aquifer is confined beneath plasticine clay up to 70m thick. The sand comprises medium to coarse grained quartz grains with little clay – it is approximately 30m thick and from 400m to 900m in width.

Hydrogeology

The shallow aquifer comprises a mixture of alluvium, colluvium and lake sediments extending beyond the lake playa and continuing downstream. Five test production bores were developed, of which two are within SLP’s tenements. CRT bore yields ranged from 520 kL/day up to 840 kL/day in permeable coarse-grained sand.

References

AGC Woodward-Clyde Pty Ltd, 1992, Mt Keith Process Water Supply, Lake Way Area, Volume 1, Contained within WMC Resources, Partial Surrender Report for the period 8 December 1992 to 7 December 1995, unpublished report, WAMEX A48586.

 

 

Tenements

The GSLP tenements are detailed in the Table below:

Project

Status

License Number

Area       (km2)

Term

Grant Date

Date of First Relinquish-ment

Interest

Western Australia

Lake Wells

Central

Granted

E38/2710

192.2

5 years

05-Sep-12

4-Sep-17

100%

South

Granted

E38/2821

131.5

5 years

19-Nov-13

18-Nov-18

100%

North

Granted

E38/2824

198.2

5 years

04-Nov-13

3-Nov-18

100%

Outer East

Granted

E38/3055

298.8

5 years

16-Oct-15

16-Oct-20

100%

Single Block

Granted

E38/3056

3.0

5 years

16-Oct-15

16-Oct-20

100%

Outer West

Granted

E38/3057

301.9

5 years

16-Oct-15

16-Oct-20

100%

North West

Granted

E38/3124

39.0

5 years

30-Nov-16

29-Nov-21

100%

West

Granted

L38/262

113.0

20 years

3-Feb-17

2-Feb-38

100%

East

Granted

L38/263

28.6

20 years

3-Feb-17

2-Feb-38

100%

South West

Granted

L38/264

32.6

20 years

3-Feb-17

2-Feb-38

100%

South

Application

L38/287

95.8

–

–

–

100%

South Western

Granted

E38/3247

350.3

5 years

25-Jan-18

24-Jan-23

100%

South

Application

M38/1278

87.47

–

–

–

100%

Lake Ballard

West

Granted

E29/912

607.0

5 years

10-Apr-15

10-Apr-20

100%

East

Granted

E29/913

73.2

5 years

10-Apr-15

10-Apr-20

100%

North

Granted

E29/948

94.5

5 years

22-Sep-15

21-Sep-20

100%

South

Granted

E29/958

30.0

5 years

20-Jan-16

19-Jan-21

100%

South East

Granted

E29/1011

68.2

5 years

11-Aug-17

10-Aug-22

100%

South East

Granted

E29/1020

9.3

5 years

21-Feb-18

20-Feb-23

100%

South East

Granted

E29/1021

27.9

5 years

21-Feb-18

20-Feb-23

100%

South East

Granted

E29/1022

43.4

5 years

21-Feb-18

20-Feb-23

100%

Lake Irwin

West

Granted

E37/1233

203.0

5 years

08-Mar-16

07-Mar-21

100%

Central

Granted

E39/1892

203.0

5 years

23-Mar-16

22-Mar-21

100%

East

Granted

E38/3087

139.2

5 years

23-Mar-16

22-Mar-21

100%

North

Granted

E37/1261

107.3

5 years

14-Oct-16

13-Oct-21

100%

Central East

Granted

E38/3113

203.0

5 years

14-Oct-16

13-Oct-21

100%

South

Granted

E39/1955

118.9

5 years

14-Oct-16

13-Oct-21

100%

North West

Application

E37/1260

203.0

–

–

–

100%

South West

Application

E39/1956

110.2

–

–

–

100%

Lake Minigwal

West

Granted

E39/1893

246.2

5 years

01-Apr-16

31-Mar-21

100%

East

Granted

E39/1894

158.1

5 years

01-Apr-16

31-Mar-21

100%

Central

Granted

E39/1962

369.0

5 years

8-Nov-16

7-Nov-21

100%

Central East

Granted

E39/1963

93.0

5 years

8-Nov-16

7-Nov-21

100%

South

Granted

E39/1964

99.0

5 years

8-Nov-16

7-Nov-21

100%

South West

Application

E39/1965

89.9

–

–

–

100%

Lake Way

Central

Granted

E53/1878

217.0

5 years

12-Oct-16

11-Oct-21

100%

South

Application

E53/1897

77.5

–

–

–

100%

Lake Marmion

North

Granted

E29/1000

167.4

5 years

03-Apr-17

02-Apr-22

100%

Central

Granted

E29/1001

204.6

5 years

03-Apr-17

02-Apr-22

100%

South

Granted

E29/1002

186.0

5 years

15-Aug-17

14-Aug-22

100%

West

Granted

E29/1005

68.2

5 years

11-Jul-17

10-Jul-22

100%

Lake Noondie

North

Application

E57/1062

217.0

–

–

–

100%

Central

Application

E57/1063

217.0

–

–

–

100%

South

Application

E57/1064

55.8

–

–

–

100%

West

Application

E57/1065

120.9

–

–

–

100%

East

Application

E36/932

108.5

–

–

–

100%

Lake Barlee

North

Application

E49/495

217.0

–

–

–

100%

Central

Granted

E49/496

220.1

5 years

17-Dec-17

16-Dec-22

100%

South

Granted

E77/2441

173.6

5 years

09-Oct-17

08-Oct-22

100%

Lake Raeside

North

Application

E37/1305

155.0

–

–

–

100%

Northern Territory

Lake Lewis

South

Granted

EL 29787

146.4

6 years

08-Jul-13

7-Jul-19

100%

North

Granted

EL 29903

125.1

6 years

21-Feb-14

20-Feb-19

100%

 

Competent Persons Statement

The information in this report that relates to Exploration Results, Exploration Targets or Mineral Resources is based on information compiled by Mr Ben Jeuken, who is a member Australian Institute of Mining and Metallurgy. Mr Jeuken is employed by Groundwater Science Pty Ltd, an independent consulting company. Mr Jeuken has sufficient experience, which is relevant to the style of  mineralisation and type of deposit under consideration and to the activity, which he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Mr Jeuken consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.

Forward Looking Statements

This announcement may include forward-looking statements. These forward-looking statements are based on Salt Lake’s expectations and beliefs concerning future events. Forward looking statements are necessarily subject to risks, uncertainties and other factors, many of which are outside the control of Salt Lake, which could cause actual results to differ materially from such statements. Salt Lake makes no undertaking to subsequently update or revise the forward-looking statements made in this announcement, to reflect the circumstances or events after the date of that announcement.

 

APPENDIX 2A – LAKE RAESIDE BRINE CHEMISTRY ANALYSIS

HOLE ID	East	North	From  (m)	To (m)	K (mg/L)	Cl (mg/L)	Na (mg/L)	Ca (mg/L)	Mg (mg/L)	SO4 (mg/L)	TDS (g/L)
S700001	315501	6807912	0	1	2,270	138,200	82,000	1,020	5,420	10400	241
S700005	311513	6809765	0	1	1,440	73,000	44,000	1,500	3,390	8400	133
S700007	307959	6811061	0	1	2,180	115,350	68,700	1,060	5,330	11500	208
S700011	300035	6813662	0	1	2,240	149,850	87,900	603	8,690	17600	273
S700013	278641	6810996	0	1	3,140	167,950	96,900	409	12,400	27400	317
S700015	281725	6810666	0	1	950	55,550	34,100	600	3,130	8730	104
S700017	287751	6812747	0	1	2,230	124,500	74,100	789	6,510	15400	228

APPENDIX 2B – LAKE NOONDIE BRINE CHEMISTRY ANALYSIS

HOLE ID	East	North	From  (m)	To (m)	K (mg/L)	Cl (mg/L)	Na (mg/L)	Ca (mg/L)	Mg (mg/L)	SO4 (mg/L)	TDS (g/L)
N700004	713808	6828889	0	1	2,630	131,000	78,600	785	5,310	13,700	232
N700008	720566	6832676	0	1	2,350	125,050	75,300	822	5,230	13,900	223
N700010	727256	6836907	0	1	2,390	125,050	75,400	796	4,950	14,300	222
N700012	734532	6837014	0	1	2,740	130,150	80,400	821	4,370	13,400	231
N700014	740408	6837916	0	1	2,030	121,050	71,500	802	5,330	12,900	212
N700016	741574	6840505	0	1	1,900	92,800	54,900	522	3,700	8,640	162
N700018	750994	6847653	0	1	2,340	135,400	76,600	754	5,870	14,200	234
N700020	754948	6851513	0	1	2,470	111,750	67,700	949	4,240	12,100	197
N700022	765001	6857294	0	1	2,600	128,550	73,600	1,050	4,810	10,200	222
N700024	781493	6855076	0	1	2,030	101,200	58,600	1,390	3,800	8,490	172

APPENDIX 2C – LAKE MINIGWAL BRINE CHEMISTRY ANALYSIS

HOLE ID	East	North	From  (m)	To (m)	K (mg/L)	Cl (mg/L)	Na (mg/L)	Ca (mg/L)	Mg (mg/L)	SO4 (mg/L)	TDS (g/L)
M700002	462878	6753653	0	1	1,900	154,200	96,600	706	5,900	14,300	267
M700004	465178	6751680	0	1	2,160	168,450	104,000	658	5,710	12,900	288
M700006	516470	6735650	0	1	2,270	143,150	89,300	523	7,210	23,000	261
M700008	518949	6731636	0	1	1,850	138,950	87,100	594	7,580	20,500	250
M700010	520783	6728495	0	1	1,990	145,100	91,700	499	8,110	24,300	267
M700011	477839	6749646	0	1	2,470	176,750	106,000	539	7,030	15,700	311
M700013	482455	6738102	0	1	2,610	165,500	103,000	310	7,290	31,800	323
M700015	488600	6734506	0	1	2,040	126,450	75,300	648	6,120	19,200	237
M700017	507653	6736762	0	1	1,750	134,000	79,600	526	8,160	23,200	257
M700019	527552	6726613	0	1	1,750	149,850	84,800	549	7,890	18,300	274
M700023	505953	6742473	0	1	3,810	167,750	92,400	375	11,700	26,700	316
M700025	509570	6745818	0	1	2,850	151,400	80,300	456	10,900	23,900	285
M700027	504869	6753891	0	1	3,800	133,450	78,800	500	7,990	24,900	259
M700029	504869	6753891	0	1	3,740	149,300	82,700	402	12,500	32,100	292

 

APPENDIX 2D – LAKE BARLEE BRINE CHEMISTRY ANALYSIS

HOLE ID	East	North	From  (m)	To (m)	K (mg/L)	Cl (mg/L)	Na (mg/L)	Ca (mg/L)	Mg (mg/L)	SO4 (mg/L)	TDS (g/L)
E700003	766001	6706841	0	1	1920	146800	81100	726	8180	13400	250500
E700005	764573	6716740	0	1	1680	145950	81500	677	8470	14200	250900
E700011	761574	6746205	0	1	1720	132450	78700	1000	5680	10900	228850
E700013	754538	6747013	0	1	1150	93300	54500	477	3890	7200	158200
E700017	758045	6747653	0	1	1400	98400	59000	978	3480	7680	169350
E700021	737684	6727502	0	1	860	65750	38800	554	3110	6060	113950
E700023	742095	6731966	0	1	1460	129100	76900	990	5400	11000	223650

APPENDIX 2E – LAKE WAY BRINE CHEMISTRY ANALYSIS

“Lake Way” series Chemistry data extracted from AGC Woodward-Clyde Pty Ltd, 1992, Mt Keith Process Water Supply, Lake Way Area, Volume 1, Contained within WMC Resources, Partial Surrender Report for the period 8 December 1992 to 7 December 1995, unpublished report, WAMEX A48586.

HOLE ID	Aquifer	East	North	K (mg/L)	Cl (mg/L)	Na (mg/L)	Ca (mg/L)	Mg (mg/L)	SO4 (mg/L)	TDS (g/L)
Lake Way 2/4	Paleochannel	255050	7020250	5,200	120,000	68,000	600	6,700	6,700	220
Lake Way 3/4	Paleochannel	247700	7032150	6,300	130,000	83,000	520	8,200	8,200	260
Lake Way 3/5	Paleochannel	247700	7032150	3,400	75,000	49,000	510	5,000	5,000	160
Lake Way 3/14	Paleochannel	245050	7029800	5,300	130,000	70,000	440	7,400	7,400	240
Lake Way 5/6	Paleochannel	241750	7035300	6,100	130,000	77,000	570	7,000	7,000	240
Lake Way 2/4	Clay	255050	7020250	3,800	78,000	49,000	930	3,400	3,400	150
Lake Way 2/6	Clay	254250	7019550	3,400	64,000	38,000	1,100	2,500	2,500	120
Lake Way 2/7	Clay	253300	7018850	3,000	56,000	37,000	930	2,900	2,900	120
Lake Way 3/1	Clay	248420	7032900	1,500	42,000	28,000	450	3,400	3,400	88
Lake Way 3/4	Clay	247700	7032150	2,200	49,000	31,000	750	3,900	3,900	110
Lake Way 5/7	Clay	242800	7034250	6,000	130,000	73,000	510	7,100	7,100	240
Y700002	Surficial	237500	7031600	8,110	149,750	86,800	359	8,930	30,600	288
Y700004	Surficial	235968	7036128	6,950	124,750	74,200	503	7,280	28,000	240
Y700006	Surficial	237015	7039115	6,980	132,800	79,200	445	8,470	31,800	258
Y700008	Surficial	240508	7036136	6,440	142,100	78,300	407	12,000	33,000	274
Y700010	Surficial	241352	7031891	7,210	127,200	72,800	593	6,630	22,500	238
Y700012	Surficial	241855	7026999	7,090	114,750	67,000	638	5,450	21,900	216
Y700020	Surficial	245022	7027585	6,930	123,700	73,000	624	6,440	22,100	231
Y700022	Surficial	246105	7024796	5,160	109,300	59,700	803	6,670	17,300	201

APPENDIX 3 – JORC TABLE ONE

Section 1: Sampling Techniques and Data

Criteria	JORC Code explanation	Commentary
Sampling techniques	Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. Aspects of the determination of mineralisation that are Material to the Public Report. In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information.	Sampling was undertaken using test pits excavated into the playa surface to a depth of approximately 1m.
Drilling techniques	Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc).	Not Applicable
Drill sample recovery	Method of recording and assessing core and chip sample recoveries and results assessed. Measures taken to maximise sample recovery and ensure representative nature of the samples. Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material.	Brine samples were obtained from all test pits
Logging	Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. The total length and percentage of the relevant intersections logged.	All pits were geologically logged by a qualified geologist, noting moisture content of sediments, lithology, colour, induration, grainsize, matrix and structural observations. A digital drill log was developed specifically for this project.
Sub-sampling techniques and sample preparation	If core, whether cut or sawn and whether quarter, half or all core taken. If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. For all sample types, the nature, quality and appropriateness of the sample preparation technique. Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples. Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. Whether sample sizes are appropriate to the grain size of the material being sampled.	Geological logs are recorded in the field based on inspection of cuttings. Geological samples are retained for each hole in archive. Sub-sampling was not undertaken. Sample bottles are rinsed with brine which is discarded prior to sampling. All brine samples taken in the field are split into three sub-samples: primary, potential duplicate, and archive.
Quality of assay data and laboratory tests	The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established.	Primary samples were sent to Bureau Veritas Minerals Laboratory, Perth.  Brine samples were analysed using ICP-AES for K, Na, Mg, Ca, with chloride determined by Mohr titration and alkalinity determined volumetrically. Sulphate was calculated from the ICP-AES sulphur analysis
Verification of sampling and assaying	The verification of significant intersections by either independent or alternative company personnel. The use of twinned holes. Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. Discuss any adjustment to assay data.	Data entry is done in the field to minimise transposition errors. Brine assay results are received from the laboratory in digital format to prevent transposition errors and these data sets are subject to the quality control described above. Independent verification of significant intercepts was not considered warranted given the relatively consistent nature of the brine.
Location of data points	Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Specification of the grid system used. Quality and adequacy of topographic control.	Hole co-ordinates were captured using hand held GPS. Coordinates were provided in GDA 94_MGA Zone 51. Topographic control is obtained using Geoscience Australia’s 3-second digital elevation product. Topographic control is not considered critical as the salt lakes are generally flat lying and the water table is taken to be the top surface of mineralisation.
Data spacing and distribution	Data spacing for reporting of Exploration Results. Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. Whether sample compositing has been applied.	Data spacing is variable and is not on an exact grid due to the irregular nature of the salt lake shape and difficulty obtaining access to some part of the salt lake.
Orientation of data in relation to geological structure	Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material.	Not Applicable
Sample security	The measures taken to ensure sample security.	All brine samples were marked and kept onsite before transport to the laboratory.  All remaining sample and duplicates are stored in the Perth office in climate-controlled conditions. Chain of Custody system is maintained.
Audits or reviews	The results of any audits or reviews of sampling techniques and data.	Data review is summarised in Quality of assay data and laboratory tests and Verification of sampling and assaying. No audits were undertaken.

Section 2: Reporting of Exploration Results

Criteria	JORC Code explanation	Commentary
Mineral tenement and land tenure status	Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. The security of the tenure held at the time of reporting along with any known impediments to obtaining a licence to operate in the area.	Details are presented in the report.
Exploration done by other parties	Acknowledgment and appraisal of exploration by other parties.	Details are presented in the report.
Geology	Deposit type, geological setting and style of mineralisation.	Salt Lake Brine Deposit
Drill hole Information	A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes: o   easting and northing of the drill hole collar o   elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar o   dip and azimuth of the hole o   down hole length and interception depth o   hole length. If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case.	Details are presented in the report.
Data aggregation methods	In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (eg cutting of high grades) and cut-off grades are usually Material and should be stated. Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. The assumptions used for any reporting of metal equivalent values should be clearly stated.	Details are presented in the report.
Relationship between mineralisation widths and intercept lengths	These relationships are particularly important in the reporting of Exploration Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (eg ‘down hole length, true width not known’).	The brine resource is inferred to be consistent and continuous through the full thickness of the sediments.
Diagrams	Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views.	Addressed in the announcement.
Balanced reporting	Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results.	All results have been included.
Other substantive exploration data	Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples – size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances.	All material exploration data reported.
Further work	The nature and scale of planned further work (eg tests for lateral extensions or depth extensions or large-scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive.	Aircore / RC drilling to defined paleovalley structure and provide brine samples with depth. Hydraulic testing be undertaken, for instance pumping tests from bores and/or trenches to determine, aquifer properties, expected production rates and infrastructure design (trench and bore size and spacing). Diamond Core drilling to obtain sample for porosity determination. Lake recharge dynamics be studied to determine the lake water balance and subsequent production water balance. For instance, simultaneous data recording of rainfall and subsurface brine level fluctuations to understand the relationship between rainfall and lake recharge, and hence the brine recharge dynamics of the lake.

 

For further information please visit www.saltlakepotash.com.au or contact:

Matt Syme/Sam Cordin	Salt Lake Potash Limited	Tel: +61 8 9322 6322
Jo Battershill	Salt Lake Potash Limited	Tel: +44 (0) 20 7478 3900
Colin Aaronson/Richard Tonthat	Grant Thornton UK LLP (Nominated Adviser)	Tel: +44 (0) 20 7383 5100
Derrick Lee/Beth McKiernan	Cenkos Securities plc (Joint Broker)	Tel: +44 (0) 131 220 6939
Jerry Keen/Toby Gibbs	Shore Capital (Joint broker)	Tel: +44 (0) 20 7468 7967