Guyana Geology & Mines Commission

The Mabura area is located close to a number of significant known mineral occurrences and mines such as Omai, Pott Falls and Winter’s Mine. Some areas have been mined or are now being mined for gold on a small scale using "Land Dredges". Soft material is washed into a pit using a water monitor, and pumped over a simple sluice. The area is now much more accessible than in the past, with upgrading of the road to Lethem, and logging roads made by Demerara Timbers Ltd.

This project was designed to investigate the extent of gold mineralisation in the area, and to determine whether any other types of mineralisation occur. Methods used included regional geochemical sampling, geological mapping, and air photo, Landsat and Slar interpretation, and integration of new data with all other available data. Fieldwork was done in May 2000. Assay results have recently been received, and the report is almost complete. Several gold anomalous areas are present, as well as a number of lower level Pd & Pt anomalies, apparently related to the presence of basic sills and dykes.

The geology of the area consists of basic and intermediate meta-volcanics / greenstones, intruded by younger granites and then by basic sills and dykes. Superficial quartz sand (White Sand) covers a significant part of the survey area, but appears to be at least in some places a locally derived residual deposit, rather than an alluvial sand cover. Presence of quartz sand results in dilution of any material eroded from the underlying hard rock, resulting in very subdued geochemical anomalies. Despite this work has resulted in identification of a number of areas with commercial potential. Blocks covering these areas will be auctioned on 22th August 2003. These include:

Two blocks (MAB01 & MAB02) covering low level drainage Au anomalies draining a circular feature in the Madrai Creek area, approximately 10-20km SSW of Omai. Two known areas with historical alluvial gold mining appear to be related to a NNE-SSW Lineament within this zone. The geology of the area consists of basic and intermediate meta-volcanics / greenstones, intruded by younger granites and then by basic sills and dykes. Some older granitoid intrusions similar to that hosting mineralisation at Omai may also be present.
Five blocks in the Pott Falls district. NW to WNW and N-S trending mineralised zones are thought to be hosted in Mazaruni Group meta-basic rocks, locally associated with porphyry dykes.

The following diagrams illustrate some of the more interesting features of this area.

REFERENCE : Heesterman, L.J.L, Kemp, A.W. & Nestor, G. Geology, Structure and Geochemistry in the Mabura Area. 2003. Mountains. Guyana Geology and Mines Commission, Geoservices Division Technical Report. – Report in preparation.