Regional Geology Map of Guyana

The Regional Geological map of Guyana at the scale 1:1,000,000 includes the compilation of geological mapping work from 1898 to 1987 made by Walrond (1987). The digital version of the map was made in 1999 and the last update in 2010 (Heesterman and Nadeau, 2010). The geological formations of Guyana are displayed by different color reflecting their age and rock composition.

The digital map of Guyana at the scale 1:1,000,000 in paper format or on CD is sold at the price of GUY$5,000 (US$25.00).

Mineral Occurrence Map of Guyana

The Mineral Occurrence Map of Guyana at the scale 1: 1,000,000 includes a compilation by Geologists and Mines Officers of GGMC of mineral deposits and occurrences of: gold, diamonds, manganese, columbite-tantalite, uranium, Rare Earth Elements, and semi-precious stones.

Old workings of previous mining activities and occurrences, deposits are shown with various symbols and colors.

1. Workings:
   1. Gold (red dot, yellow area)
   2. Diamond (purple diamond and purple area)
   3. Columbite-tantalite (blue circle with a dot, blue area)
   4. Manganese (black square, grey area)
2. Mines: 2 picks (black)

Regional Geochemical Surveys 

The figure shows the location of all Regional Geochemical Surveys performed by GGMC since 1999. A list of the project name of all the regional geochemical projects are given in the legend.

The Regional Geochemical Surveys Project Areas Map of Guyana at the scale 1: 1,000,000 includes regional geochemical sampling program of stream sediments, rocks samples and more rarely soil samples between 1999 and 2014. The regional geological and geochemical surveys (N=35) have covered a total area of approximately 35 throughout Guyana.  Sampling and analytical methods used are the same for each of these projects which are also combined in the construction of a geochemical Atlas of Guyana. 

Geochemical sampling techniques employed are those commonly used in wet tropical areas, with bulk -30 mesh stream sediments samples taken using a flocculent in the field. A -80 mesh fraction split of the samples is separated in the laboratory. All sample processing and analysis is currently being done by Actlabs in Canada. A 2 kg split of the – 30 mesh is analysed for Au, Ag, Cu, Pd and Pt using a cyanide leach method (BLEG). The -80 mesh split fraction is analysed for "Au plus 48 chemical elements" using INAA (Instrumental Neutron Activation Analysis) and ICP-OES (Inductively Couple Plasma-Optical Emission Spectrometry).

Completed reports of the geology, geochemistry, and structure are available as paper copies and as CD's (price: single report GUY $25,000; double report GUY$50,000). For reports that are not yet completed, their geochemical data could be bought at the same price as completed report and when the final report is produced a copy of the full report and data are sent free of charge on a CD. 

Geological Timescale

The geological timescale figure contains the various supereons, eons, era, and periods of the Earth simplified from the detailed geological timescale figure from the International Commission on Stratigraphy (2009).

Information of the age of rocks from Guyana in Millions of Years (My) are indicated in red (text and arrow). Oldest ages obtained in zircon of Australia, Canada and Brazil and of the Moon also included in black (text and arrow) for comparison with Guyana. Ages of animal species and man are also shown.