Meridian Mining UK. S Reports 7Km Copper in Stream Anomaly At Its Jauru Project, Brazil
Jauru District Technical Note: Meridian's Jauru database draws on an intensive phase of "frontier" exploration in the 1980's by BPM when the belt was initially discovered, during which time the BP Minerals regional team grew from a reconnaissance staff of around seventy people to over two hundred ahead of the commissioning of the Cabaçal Mine. BPM drilling was heavily focussed on Cabaçal and Santa Helena, leaving their near mine and regional targets at a reconnaissance stage, after the mine was closed in the early 1990's. This left significant exploration upside. Meridian, with its in-house suite of modern geophysical equipment and local knowledge, can follow on from where BPM left off, and define new drill targets for the future. The Jauru portfolio of exploration assets spans positions along a Paleoproterozoic greenstone belt that is considered coeval with the Cabaçal Belt to the east. Geological mapping has been conducted by the state geological survey at 1:100,000 scale, and that of BPM at a more detailed scale again of 1:50,000. The more detailed scale of mapping in the Jauru Belt shows an exhalative unit extending over a strike length of 9km, contained wholly within the Company's licence applications. This unit is structurally truncated to the north against a sequence of undifferentiated granites-gneisses, and to the south, it passes laterally to a sequence of acid metavolcanics. The geological units of the belt have a dominant gentle southerly plunge, and the unit may project further below surface along the southern continuation of the Company's licences. A strong copper-in-stream anomaly is evident over at least a 7km strike extent over this exhalative unit. Basaltic metavolcanics are developed in the footwall of the exhalative unit to the east, and a metasedimentary unit is present to the west in the hangingwall. The copper-in-stream response increases rapidly from background values over the metavolcanic-sedimentary package, to form a coherent strike-extensive anomaly over the exhalative unit, increasing to peak values of up to 240ppm Cu. For context, peak copper values for the stream anomaly that led to definition of the Cabaçal target were in the order of 34 - 56ppm Cu, and for Santa Helena, 20 - 36ppm Cu. The exhalative position also exhibits more localized elevated responses in other base metals. Zinc-in-stream values are typically greater than 40ppm Zn, up to a peak of 144ppm Zn: twice to 10-fold that of background in bounding lithologies. This compares to peak values at Cabaçal of 44 - 60ppm Zn, and Santa Helena of 41 - 149ppm Zn. Lead-in-stream values are more subdued, with a peak of 21ppm Pb over the exhalative unit, compared to peak values at Cabaçal of 8 - 20ppm Pb, where lead is restricted to the far northern periphery of the deposit, and at Santa Helena of 68 - 90ppm Pb. Gold anomalism was measured by panning a set volume of channel alluvium (5 litres) and counting the gold grains in the heavy mineral concentrate.