Sydney, Australia, July 29, 2026 - (ABN Newswire) - Terrain Minerals Limited (ASX:TMX) (OTCMKTS:TMXAF) (FRA:T4Y) provides the following update at the Lightning Gold Project, part of its 100% owned Smokebush Gold & Silver Project, 350km north of Perth, Western Australia.
The Lightning Maiden 'Starter' Mineral Resource Estimate (MRE) represents another significant milestone at Lightning Prospect. The Company intends to accelerate exploration activities aimed at upgrading the current MRE to the Indicated Mineral Resource category, while expanding the overall resource inventory through further drilling.
Importantly, this Starter MRE represents an initial foundation rather than the full extent of the Project's mineral endowment at Lightning. The Numerous look-alike gold targets across thebroader Project area, will continue to be advanced with the longer-term objective of defining a substantial gold resource inventory.
Key Points:
- Independent Inferred Mineral Resource Estimate ("MRE") for Lightning delivers 677,000 tonnes at 2.5g/t Au for 54,000oz.
- Resource is contained within an optimised pit shell, with economic assumptions applied for underground mining.
- Mineralisation starts from surface and remains open along strike and at depth.
- Infill & expansion drilling to capture mineralisation currently sitting outside of the MRE.
- Metallurgical stage one results due Q3 2026, with further work scheduled.
- Mineralisation at Lightning is high grade and shows both open pit and underground potential.
Independent geological consultancy Apex Geoscience completed the MRE, which is constrained within an optimised pit shell and economic assumptions for underground. The resource extends from surface and remains open at depth and is under-drilled to the north of the main orebody.
Terrain Executive Director Justin Virgin said:
"The Maiden 'Starter' Mineral Resource Estimate at Lightning represents another major milestone for Terrain and provides an exciting foundation for the Company's future growth. Importantly, a significant amount of known mineralisation remains outside the current MRE, highlighting the strong potential to expand the resource through further drilling."
"Our next drilling campaign will focus on both infill and extensional drilling to convert and grow the existing resource, while also testing several new priority targets that our technical team has developed across the project. With mineralisation remaining open along strike and at depth, we believeLightning has considerable upside and is well positioned to deliver further resource growth."
"Terrain will also focus on evaluating the silver potential of the Monza structure, as only 28% of historical drill holes were not tested for multi elements which also tests for silver. This presents an opportunity to assess the potential for additional silver mineralisation within the existing drilled footprint."
Material Information Summary - Mineral Resource Estimation (as per ASX LR 5.8.1)
The Company provides the following summary of Material Information for the Lightning Mineral Resource Estimation in accordance with ASX Listing Rule 5.8.1 requirements. (Further information is provided in the JORC Code Table 1 *).
Location:
The Lightning Deposit is located on the northern portion of the Smokebush Project. The Smokebush project is located approximately 350 km north of Perth, Western Australia. The Project can be accessed via the unsealed Warriedar Coppermine Road. The nearest services are in Perenjori or in the town of Morawa, 10 km north of Perenjori.
The Project area has highly variable topography with significant outcropping ridges and rocky ranges transitioning to flat low-lying areas with thick transported and regolith cover. The project is located adjacent to large scale tungsten molybdenum resources that are associated with the Mt Mulgine Granite. Several stockwork gold deposits peripheral to the tungsten molybdenum system have been developed inrecent years and form an analogue for the Smokebush Gold Project.
Geological Interpretation:
The Smokebush Project resides on the south-eastern portion of the fold belt, straddling the greenstone boundaries with the Mt Mulgine Granite. The Mt Mulgine Granite forms the core of the Mt Mulgine Anticline, which hosts several molybdenum-tungsten deposits and small-scale stockwork gold deposits.
The stratigraphy of mafic volcanic and sedimentary successions is similar in the major fold belts of the region. There are broadly recognized to be four associations of supracrustal volcanics and sediments preserved in the supracrustal fold belts (Lipple et al., 1983):
- The lower mafic volcanic association
- The lower sedimentary association
- The upper mafic volcanic association
- Intrusion of post-tectonic granitoid masses in the region
Locally the Lightning Deposit, gold mineralisation is hosted within a shear zone developed in a north northeast-trending felsic-intruded structure within a dolerite sequence. Mineralisation occurs in variably altered dolerite characterised by silica +/- sericite +/- muscovite +/- biotite +/- chlorite alteration adjacent to felsic porphyry and pegmatite intrusions. Higher grade mineralisation (>0.5 g/t Au) is associated with the most intensely altered intervals containing minor concentrations of sulphides, including pyrite, pyrrhotite, arsenopyrite, chalcopyrite and stibnite. These high-grade zones are enclosed within broader envelopes of weaker alteration and sulphide mineralisation that contain lower-grade gold mineralisation (>0.1 g/t Au), indicating the potential for wider mineralised zones.
The defined mineralised system has a strike length of approximately 850m, trending at approximately 355deg and dips steeply east at predominantly 80deg and has been defined to depths ranging between 75m and 175m below surface.
Drilling Techniques:
A total of 98 drill holes have been completed at the Lightning prospect, comprising 94 RC (16,173 m) and 4 diamond drill holes (328 m). Of this 11 RC holes were completed by Minjar Gold between 2013-2014, with the remainder of the drilling completed by Terrain Minerals from 2020 onwards.
The RC drilling was completed using a face sampling 5 1/2 inch hammer while the diamond drilling was NQ size diamond core. Collar positions were picked up by DGPS where possible with 72 of the 98 drillholes picked up with a DGPS. The remainder of the holes were establishedusing a hand held GPS (+/-5m). All but 28 of the holes had down hole surveys collected at regular intervals (between 5m to 30m) down the drillhole using a north seeking gyro tool. The majority of the drilling was completed at -60deg toward 250deg in orientation, which is perpendicular to mineralisation.
Sampling and Sub Sampling Techniques:
The RC samples were split using a rig-mounted cone splitter at 1m intervals to obtain an approximate 3kg sample for analytical test work. All 1m samples were submitted for gold analysis. Approximately 28% of the samples were sent for multi element analysis.
The diamond drilling was completed using NQ size drill equipment, Core was sampled to geological contacts or one metre intervals. All core was cut in half and sent for analysis. Sample size varied from 0.3 to 1.2 m in size. Core recovery was excellent with geologists noting little to no core loss.
Sample Analysis Method:
Samples were sent to different commercially certified laboratories over the project life. Samples were typically dried at 105deg then crushed and pulverised to a nominal 85% passing 75um. These include Bureau Veritas where samples underwent 40g Fire Assay (FA40/AAS), ALS for 50g Fire Assay (Au-AA26) and Intertek for 50g Fire Assay. The multi element analysis was conducted by Intertek (4A/MS48) and Bureau Veritas Ultrarace (ICP-AES) using a 4-Acid digestion with a 48 element analysis.
Quality control data was used throughout the drillingprograms with the regular insertion of blank, certified standards/CRM's and field duplicates. These were routinely reviewed for laboratory performance. Review of this data concluded that the results were satisfactory for the use in a Mineral Resource Estimation.
Grade Top cut/Capping:
To prevent metal grades from being overestimated due to outlier values, composite grades are capped to specific maximum values. Potential outliers are first identified using log-probability plots, which highlight composite values that deviate significantly from the expected distribution. These outliers are then examined in 3D to determine if they are part of a consistent high-grade trend. Gold capping levels ranged from 11 to 19g/t, and silver ranged from 10.5 to 87 g/t Ag. Only five composites were capped for both gold and silver.
Estimation Methodology:
Independent geological consultancy Apex Geoscience was contracted to conduct the maiden MRE. Apex Geoscience has supervised all ofTerrain's drilling activities since 2020. The mineralised domains were interpreted using a nominal 0.5g/t Au lower cut of grade with a minimum composite interval of 2m was used. The mineralisation interpretation was extrapolated to the nominal 25mspaced drill sections and terminated halfway to the next drill section where mineralisation terminated.
Ordinary Kriging (OK) was used to estimate metal grades for the 2026 Lightning MRE block model.
Only blocks that intersect the estimationdomains were estimated. Grades were estimated into a 3m (X) x 3m (Y) x 3m (Z) block. Hard boundaries were applied between domains. Variography was conducted on the larger domains to determine the ranges used in the multi staged estimation runs.
Blocks were only estimated into parent blocks.
The samples that were not assayed for silver were given a 0.00 g/t Ag grade to prevent over estimation. Silver has been treated as a by-product of the gold MRE.
A multiple-pass estimation method is used to control Kriging's smoothing effect, ensuring accurate block-scale grade and tonnage estimates above the reporting cutoff. With each pass the number of composites used and number of drill holes decreased as the search distance increased.
Resource Classification:
Resource classification was considered on the basis of drill hole spacing and continuity of mineralisation. Other factors considered were the amount of composites that had silver analysis conducted, topographic control and collar/ downhole survey control. The Lightning MRE has been classified as Inferred.
Cut-Off Grades/Reasonable Prospects of Economic Extraction:
Due to the high grade and shallow nature of mineralisation, the Lightning deposit has reasonable prospects of economic extraction via a small, high grade, open pit and underground mine. The open pit resource has been reported at a 0.5g/t Au cut-off using -60deg wall angles, AUD$35/tonne for mining ore and waste, G&A cost of AUD$9/tonneand a recovery of 93% recovery at a AUD$6000/oz gold price. The Underground reportable resource has been calculated using a AUD$100/tonne ore/waste mining cost at a minimum of 3m wide zones. These cost assumptions are similar to mining costs usedby other operations/companies in the goldfields. These include Capricorn Metals Ltd - Mt Gibson operation, West Gold - Southern Goldfield operations, Ramelius - Rebbecca Roe operation for Open Pit assumptions and Meeka Metals - Murchison Gold Project, Rox Resources - Youanmi project and Ramelius Rebbecca Roe operation for underground assumptions.
Density:
Four diamond holes were drilled into the Lightning deposit in order to obtain accurate density data for the use in the MRE. A density sample was collected every metre from the top of the diamond core to the bottom of the hole using the air/water emulsion method. A total of 324 samples were collected. A nominal value of 2.60 g/cm3 and 2.95 g/cm3 was applied to the transitional and fresh rock (respectively) profiles.
Metallurgy:
At the time of calculating the Lightning MRE, no metallurgical test work was completed at Lightning. Samples have been submitted for initial metallurgical test work but results are pending. Assumptions on recovery (93% for gold) have been based on similar deposits in the area.
Modifying Factors:
No modifying factors were applied to the MRE. Parameters reflecting the mining dilution, ore loss and metallurgical recoveries will beconsidered during the mining evaluation.
Forward Programme - Advancement activities
With the maiden Lightning MRE completed, the Company is now focused on growing and defining additional mineralisation to add to the existing resource inventory. Key forward activities are: - September 2026: Commence RC drilling program to define (infill) and extend existing resources along strike and along depth. - Third Quarter 2026: Completion of first pass metallurgical test work to determine potentialgold recoveries.
District Context
The Lightning Gold Project is located within an established and active gold corridor in the Murchison region of Western Australia. The project sits northeast of the operating Rothsay Gold Mine and within a corridor that includes Capricorn Metals' Mt Gibson Gold Project (4.5-million-ounce Mineral Resource) and Warriedar Resources' gold projects within the same mineral field.
Lightning is 100% owned by Terrain Minerals and held under a granted MiningLease (M59/0796), positioning the project for orderly progression through resource definition and study work.
*To view tables and figures, please visit:
https://abnnewswire.net/lnk/6375PJQV
About Terrain Minerals Limited:
Terrain Minerals Ltd (ASX:TMX) is an exploration company with a portfolio of projects across Western Australia and Queensland. The company's primary focus is advancing the flagship Smokebush Gold & Silver Project toward resource definition, where the Lightning delivered its maiden Mineral Resource Estimate (MRE) in July 2026 and Wildflower area represents the next phase of district-scale discovery. The company's portfolio approach provides upside optionality in copper, gallium, rare earths, and lithium while maintaining disciplined capital allocation to the gold-focused core. The Company main focus is on advancing its flagship Smokebush gold/silver project.
Contact:
Justin Virgin
Executive Director
Email: terrain@terrainminerals.com.au
Phone: +61 8 9381 5558
Source:
Terrain Minerals Limited
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