The Texas silver project, located in Southern Queensland, comprises a turn-key heap leach operation for silver extraction and existing large low grade JORC 2012 silver resources, published by Moreton Resources Limited (ASX:MRV), at the Twin Hills and Mt Gunyan deposits (refer to table 1 below for list of previous Reserve and Resource announcements for each deposit).
The Texas District has had a long mining and exploration history. Between 1892 to 1925 (and 1952, 1970 and 1976) approximately 100kt of ore was extracted from the Silver Spur underground mine producing 2.19 Moz silver, 990 t of copper, 1050 t of lead, 690 t of zinc and 4,516 oz of gold. Between 2006 to 2013 Macmin Silver Ltd (“Macmin”) and Alcyone Resources Ltd (“Alcyone”) produced approx. 1.4 Moz silver from an open pit heap leach operation from the Twin Hills deposit.
In 2013 Alcyone presented the results of an exploration targeting report for the Texas district highlighting a series of compelling silver, copper and base metal targets. The majority of the targets highlighted were not tested or remain under drilled.
Moreton Resources Limted (“Moreton”) reported JORC 2012 Measured, Indicated and Inferred resources in 2016 for Twin Hills and Mt Gunyan deposits, but did not carry out any new hard rock mining, instead focusing its efforts on a brief restart of the silver heap leaching of the existing pads. Moreton did not carry out any exploration drilling prior to suspending heap leach operations in late 2019.
Location and Geology
The Texas district is hosted by the early Permian age Silver Spur sedimentary basin. The Texas mineral district is developed over 50 sq. km area containing a diverse range of silver – gold, copper and base metal deposits styles including:
- Silver Spur deposit which is thought to be an early Permian age (300 – 295 Ma?) stratiform silver base metal massive sulphide deposit.
- Twin Hills and Mt Gunyan Ag Au Zn Pb deposits that host the current 2012 JORC silver -gold resources formed during the middle Triassic (244.6 +/- 6.1Ma) and are thought to be epigenetic disseminated and fracture veinlet low sulphidation polymetallic deposits. These deposits formed broadly contemporaneously with emplacement ages of a suite granitic intrusive including Tingha and Gilgai granites located approximately 135 km to the SE of the Texas district. These granites are thought to be the source of the metals responsible for the formation of Thomson’s Webbs and Conrad deposits as well as a number of significant tin – silver- base metal deposits in the region.
|Texas||Heap Leach Pad Resource – JORC 2012||ASX:MRV - 21 April 2017, MRV Metals Pty Ltd Re-release of Heap leach Stockpiles Data|
|Twin Hills Resource – JORC 2012||ASX:MRV - 19 September 2016, MRV Metals Pty Ltd|
|Confirms significant Resources in Twin Hills Mine|
|Mt Gunyan Resource – JORC 2012||ASX:MRV - 5 October 2016, MRV Metals Pty Ltd|
|Confirms JORC Resource - Mt Gunyan|