Krakatoa Resources Limited (ASX: KTA) believes it may have unlocked the potential mineral prospectivity at its 100% owned Belgravia Project in the Lachlan Fold Belt of NSW.
Executive Chairman, Colin Locke, said the recent maiden aircore drilling programme – combined with recent geological mapping – has significantly improved geological understanding at Belgravia.
Mr Locke said drilling confirmed the presence of (high potassium) shoshonitic rocks at Belgravia. Shoshonites and other alkaline rocks have been established as being closely related to certain types of gold and base metal deposits, including epithermal Au and porphyry Cu-Au deposits. Sillitoe (1997) points out that about 20% of the large gold deposits are associated with shoshonitic and alkaline rocks.
The drilling also revealed prospective stratigraphy beneath younger regolith outlining two distinct zones of diorite/monzodiorite intrusion. These zones respectively correspond with the edges of the Larras Lake and Copper Hill Intrusive Complexes and lie close to a northwest-trending structure that separates the complexes.
The margins of major intrusive complexes can form a primary control on the location of porphyry and epithermal mineralisation. For example, historical RAB/Aircore drilling by MIM Exploration located gold and copper mineralisation along the southern margin of the Larras Lake Intrusion, 400m to the west of EL8153. The extensive halo of low-grade mineralisation extends onto the northwest flank of the Belgravia Project.
The drilling objective at Belgravia was to locate patterns of zoned alteration, and mineralisation halos like that found at Larras Lake and Cadia.
Drilling successfully intersected hydrothermal alteration featuring a propylitic assemblage including epidote, chlorite, Fe-carbonate, calcite, hematite-dusting and also variable amounts of vein quartz.
The company hopes the alteration in conjunction with any returned anomalous metal values relate to mineralisation located at depth (like at Cadia Valley). The combination of rock and alteration-type, along with returned assay results will outline targets for anticipated deeper drilling.
Mr Locke said the presence of the world class Cadia Valley porphyry district, 35km due south of Belgravia, attests to the prospectivity for large scale porphyry gold- copper deposits within the MVB.
