Option Exercised at Earaheedy Zn Pb Project
Rumble's Managing Director, Mr Shane Sikora, said: "Rumble is pleased to exercise the option to acquire 75% of E69/3464 on renegotiated terms that were fair and reasonable for both parties. We look forward to continuing our strong relationship with Zenith Minerals as JV partners and Rumble shareholders as we progress the project.
"Historic and recent drilling had focused on Mississippi Valley Type (MVT) Zn-Pb mineralisation hosted within a mineralised dolomite unit defined over 20km's of strike. An exciting new development on the project has been identified in the recent drilling by Rumble, which discovered a previously unrecognised, mineralised Zn-Pb sandstone unit located above the mineralised dolomite unit. On review of the mineralisation intersected in drilling over the whole project, Rumble identified the dolomite unit hosted the lower grade MVT mineralisation whilst the higher-grade mineralised zones are hosted in the more porous mineralised sandstone unit above. The source of the Zn-Pb in the sandstone is from the underlying dolomite which hosts the Zn-Pb MVT mineralisation.
"Rumble now has a clearer understanding of the system and targets and believes the projects prospectivity has been significantly increased. Rumble's new target is large tonnage, flat lying, near surface (amenable to open cut mining), sandstone hosted Zn-Pb deposits which are typically metallurgical simple, making them high value propositions.
"As the sandstone unit hasn't previously been recognised and targeted, on the western margin of the project over 13km of shallow Zn-Pb mineralised sandstone units in two sub basins (see image 2 in link below) has been identified with no historic drilling where the units come to surface, making these first order drill target areas.
"Rumble will fast track exploration utilising a seismic geophysical survey that can potentially map the sandstone unit to surface and provide a valuable drill targeting tool. This survey will be followed by a wide spaced shallow vertical RC drilling program to test the two basins and the Zn-Pb bearing sandstone units".
Earaheedy Zn-Pb Project
The Earaheedy project is located approximately 110km north of Wiluna, Western Australia. Rumble now owns a 75% interest in E69/3464. Based on the newly identified mineralisation style, Rumble has applied for three (100% RTR) contiguous exploration licence applications ELA69/3743, ELA69/3745 and ELA69/3746, that cover the inferred unconformity contact between the overlying Frere Iron Formation and underlying Yelma Formation of the Palaeoproterozoic Earaheedy Basin - See image 2 and 3 in link below.
Earaheedy Zn-Pb Project - New Mineralisation Style
The new style of Zn-Pb mineralisation has been delineated on the unconformity contact between the overlying Frere Iron Formation and underlying Navajoh Dolomite and shale of the Yelma Formation. Both formations are part of the lower units of the Palaeoproterozoic Earaheedy Basin. Drilling intercepted a flat lying porous sandstone to grit unit that has been interpreted to be the basal unit of the Frere Iron formation that lies unconformably over the Yelma Formation. Sphalerite, galena and pyrite have replaced the matrix (pore) space within the porous sandstone grit host forming laterally extensive sulphide layers.
Large Tonnage Potential for Zn-Pb Deposits (image 2)
The flat lying Zn Pb bearing sandstone unit with over 13km of strike potential is a high tonnage target based on the average 7.5deg dip to the northeast. Image 2 highlights a target tonnage using the following assumptions:
o 1000m of strike (note there is over 13km of strike potential)
o 700m width (based on shallow 7.5deg and depth to 80m - typical large open cut mine scenario)
o 7m width of mineralisation (multiple intercepts with average true width of 7m)
o Specific Gravity (SG) of 2.5 (world average SG of sandstone - not accounting for metal)
The project has the potential for >12 million tonnes (plus metal) per 1km strike. Note over 13km of prospective strike has been identified.
Two sandstone sub basins dipping to the northeast between 5 - 10deg have been identified beneath the main Frere Iron Formation. The sub basins daylight under shallow sand cover along the regionally extensive Frere Iron Formation/Yelma Formation contact (unconformity) on the southwestern margin of project.
The larger sub basin (Main Sandstone Sub Basin) (See image 2 and 3) has an area of 8km by 2.5km and is open to the southeast. Within the Main Sandstone Sub Basin fifteen (15) diamond core and RC drill holes have intercepted the Zn Pb bearing sandstone unit. Over half of the drill holes did not pass through the sandstone and ended in mineralisation. Significant drill hole intercepts include:
o TDH20 - 7m @ 4.85% Zn + Pb from 103m EOH in sandstone
o TRC47 - 6m @ 3.91% Zn, 0.39% Pb from 210.5m in sandstone
The smaller sub basin (Northwest Sandstone Sub Basin) (see image 2) has an area of 5km by 2km and is completely open along strike (open to the southeast and open to the west). Within the Northwest Sandstone Sub Basin seven (7) diamond core and RC drill holes have intercepted the Zn - Pb bearing sandstone unit.
Significant drill hole intercepts include:
o TDH14 - 11m @ 3.6% Zn + Pb from 222.5m in sandstone
o TRC70 - 6m @ 2.52% Zn, 1.02% Pb from 126m EOH in sandstone
o TRC65 - 7m @ 1.18% Zn, 2.37% Pb from 60m in sandstone
Over 13km of prospective strike (see image 2) of potential shallow Zn-Pb mineralized sandstone has been identified where the unconformity comes to surface. The prospective strike is completely open. All previous exploration (drill holes) has focused on MVT (Mississippi Valley Type) Zn-Pb mineralisation hosted within the Navajoh Dolomite (upper unit of the Yelma Formation). No drill hole has tested the up-dip to surface expression of the Zn-Pb bearing sandstone unit within the sub basins.
The source of the Zn-Pb in the sandstone is from the underlying eroded dolomite which hosts the Zn Pb MVT mineralisation. With both sub basins, the Zn Pb (MVT) dolomite is completely eroded towards the southwest. Metal zonation is evident with Pb (Galena) increasing substantially (Zn:Pb ratio decreasing) towards the southwest. Mineralisation is sphalerite, galena and pyrite. The sandstone unconformity is often cavitated and fill of voids with large volumes of high salinity water present.
A series of diagrammatic longitudinal sections of the Main Sandstone Sub Basin (images 3 and 4) highlights the approximate depth and location of the prospective Zn Pb bearing sandstone as it nears the surface (up dip). Image 3 highlights Zn + Pb anomalism from previous soil sampling (partial leach geochemistry - iron) located close to the unconformity as it surfaces under shallow cover.
- Passive seismic traverses are planned in November 2019 to cover the Main and Northwest Sandstone Sub Basins to aid in understanding and locating the highly prospective sandstone unconformity as it comes to surface.
- Shallow vertical RC drilling is planned in December 2019 to test the up-dip position of the Zn Pb bearing sandstone unit. It is planned to drill on approximate 500m centres covering both the Main and Northwest Sandstone Sub Basins.
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About Rumble Resources Ltd
Rumble Resources Limited (ASX:RTR) (FRA:20Z) is an Australian based exploration company, officially admitted to the ASX on the 1st July 2011. Rumble was established with the aim of adding significant value to its current gold and base metal assets and will continue to look at mineral acquisition opportunities both in Australia and abroad.
Rumble Resources Ltd