Gondwana

Building and refining geometrically correct animations of continental movements has given new insight into the geological and tectonic evolution of the southern continents that once formed Gondwana..

Gondwana globe

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News - Earthworks in progress

Gravity survey and the origin of mankind

The Kalahari occupies an exceedingly flat tableland taking up much of the central part of southern Africa.  When the national gravity survey of Botswana was mooted in 1970, absolute heights above seal level for this remote, dry and thinly-populated area were unavailable and precision primary levelling was still in progress.  Earlier levelling work in pursuit of potential engineering work on river courses (Du Toit, 1926; Brind, 1955) had proved inconclusive.  A by-product of the national gravity survey (Reeves & Hutchins, 1976) was the first rough topographic contour map of Botswana dervied from about 2500 heights determined by barometric altimeters tied to the few available reliable datum points.  The lowest point in the inland drainage basin in the Makgadikgadi salt flats was determined as 903 (+/- 5) metres.  Almost all of northern Botswana lay below 1000 m with the only escape for water from the annual flooding of the Okavango delta in the NW of the country at about 930 m, located near the administratrive centre of Maun.

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African petroleum geologists meet again in London


How Mining Geophysics got started


Gondwana workshop in Rio

About Colin Reeves

Colin Reeves

Colin Reeves is an earth scientist with 40 years’ experience in the instigation, execution and interpretation of regio...

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About Earthworks

Earthworks bv

‘Global thinking in exploration geoscience’ states the ambition of Earthworks BV to set exploration projects in ...

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