49th Percy Evans Lecture: Snowballs in the Desert – A Glacial History of Oman

given by Ross Garden, Reading Geological Society
Ross is kindly standing in for the scheduled speaker Dr Haydon Bailey. Haydon’s talk will now given at a later date.

The Earth has experienced repeated major icehouse periods through its history.  Across the UK, we have many examples of the Plio-Pliestocene ice age deposits and in Scotland we see evidence of Pre-Cambrian Snowball Earth glaciations.  Sowhat might the Sultanate of Oman on the eastern margin of the arid Arabian Peninsula offer?

Oman lies on the Tropic of Cancer and the current climate is hot and arid with midday winter temperatures in the mid 20’s and summer temperatures reaching 40° C and above.  The arid climate, together with the relative ease of movement and hospitality of the Omani people provides a geological wonderland.  There are many geological delights in Oman, but the area provides a variety of geology resulting from previous glaciations.  We can see evidence for Proterozoic marine glaciations together with lacustrine deposits from the Permo-Carboniferous ice ages.  The lack of vegetation and long geological history of the area provides good out crops of the glacial formations and allows examination of lateral facies variations that typify these deposits.

But the Oman also contains evidence of the impact of high latitude glaciations on land masses at low latitudes.  The Omani Plio-Pliestocene history is characterised by ice driven sea level falls and rises, compressed climatic zones and cooler and wetter periods.  As Arabia is situated between Africa and Asia these climatic changes are likely to have impacted the migration of homids out of Africa.