Up for Grabs ... flint. What is it and how did it get here

30 Aug 2011

In response to Gary Gilligan's ideas about flint (see his web site, www.gks.uk.com) and the significance of the study at http://swansea.academia.edu/CarolynGravesBrown/Papers/847861/The_Biologi... ... a rather interesting paper on the role of flint as an attribute of the Gods, I thought I might look up the orthodox view of how it was made. This perforce has to be from a UK perspective - not from Egypt. Flint probably formed somewhat differently there as they do not have the chalk hills of southern Britain and northern France, but even here there is a huge question mark around the formation of flint - and exactly how it came to be what it is. In fact, the theories are just that, theories that are accepted by some geologists but not by others. 

We have plenty of flint in a local context where I live, and flint stones are the most common ones encountered when digging holes in the garden. At www.bucksgeology.org.uk/whiteleaf.html there is a nice explanation. Whiteleaf quarry is on the escarpment above Princes Risborough and was mined for its hard chalk. Its face shows a distinct layering pattern and it is self evident the flint was laid down periodically and on many occasions - some of it in bands of nodules and some of it in distinct bedding planes, known as laminate. Flint is quartz and appears to have been soft and jelly like when first formed as long cylindrical nodules are often where it has percolated into burrows in the bottom sediment of the sea. Nodular flint is also found encompassing sea creatures such as sponges - and the sea creatures are preserved with their soft parts intact (or a hole in the flint is left in the shape of the absent creature). The flat laminate bedding plane of flint looks visually something like slate - which is made of compressed layers of mud. It formed on the sea bed as a distinct layer. The theory is that flint forms just beneath the surface of the sediment where quartz is in solution in the sea water - but it needs a trigger to form. This is thought to be primarily a lack of oxygen - possibly a sudden lack of oxygen. Does flint have a catastrophic origin and if so what might that be?