Red Mountain Mining has identified a new high-grade gold target at the Lobo prospect of the Batangas project in southern Luzon. Rock chip sample results of up to 32.7 grams/tonne gold have been returned from the Signal target, which is about 1.5km west of Lobo’s South West Breccia (SWB) deposit.
The surface rock chip sample result sits midway between previous surface rock chip sample results of 72.6 grams/tonne and 42.6 grams/tonne, forming part of a linear northeast trending zone over 500 metres-long. The structure is interpreted to then pass to the northeast under younger limestone cover then under a zone of siliceous material, or a silica cap, that is interpreted to overlay potentially the main area of gold mineralization.
The discovery of a high-grade gold lode trend at Signal coincides with the development of a new target model for the SWB high-grade epithermal gold deposit and other targets at Lobo. The target model is based on similarities between the Lobo prospect and other epithermal gold and copper-gold deposits including the large Lepanto-Far South East porphyry/epithermal gold-copper ore system 250km to the north of Lobo.
At Lepanto-Far South East, and other epithermal systems worldwide, including the Maclaughlin epithermal gold deposit in California, where the silica cap is remarkably well preserved, high grade gold mineralization is capped by an early formed silica cap or silica sinter. It is interpreted that later, gold-bearing, hydrothermal fluids were constrained by this cap and high grade gold mineralization concentrated beneath it.
Red Mountain’s SWB deposit is another such example where the high-grade hydrothermal breccia is exposed and a remnant silica cap has been mapped on surrounding ridges, indicating that a siliceous cap once sat above the deposit and has since been eroded.
The Signal high-grade trend appears to pass under a preserved silica cap. Anomalous soil geochemistry is observed on the down slope margins of the siliceous zone and limited sampling within the silica cap has produced rock chip sample results of up to 4.47 grams/tonne gold and high silver grades of up to 55 grams/tonne, 90.7 grams/tonne and 150 grams/tonne. The high silver-copper values concentrated in the siliceous cap material are interpreted to lie above the gold mineralization, a vertical zonation observed in similar epithermal deposits, including at the old Lobo mine above the new resource at West Drift.
Based on this new model, the high grade trend and the existence of an intact Silica Cap with anomalous silver-copper-gold geochemistry at the Signal target, and other prospective areas with the Lobo prospect, indicates potential to locate a number of ‘blind’ and intact high grade gold shoots similar to or better than the SWB mineralization. www.redmm.com.au