Brading geology

A lot of space is given in reference 2 (advertised at reference 1) to something called the KT boundary, that is to say the place in the sequence of sedimentary rocks - marine or fluvial - marking the boundary between the end of the Cretaceous period and the start of the Triassic period, roughly 65mya. A time associated with a mass extinction, with lots of plants and animals not making the cut.

It seems that there was a great debate about all this at the end of the last century, with many academic careers made and many academic careers broken. Was it a sudden event, perhaps caused by an asteroid hitting us, or was it a slow event, perhaps caused by climate change? A great debate which ended in a complete victory for the asteroid camp - who then went on to overreach themselves by claiming any extinction in sight for the asteroids.

This morning, it occurred to me that this boundary might run through the middle of the Isle of Wight, from Culver Point in the east to the Needles in the west. Out with the map from British Geological Survey, to find that the cottage we were staying in in Brading was maybe just 50 yards north of the boundary between the upper chalk (Cretaceous) and the Reading beds (Palaeocene), with the beds of the relevant rocks being near vertical. All confirmed by the slim volume at reference 4, once the property of and bound by Dorset County Library.

It's a small world!

PS: Wikipedia tells me at reference 3 tells me that I should really be talking about the KPg boundary. K from the German for the Cretaceous period and Pg for the Paleogene period, of which the first epoch was the aforementioned Palaeocene.

Reference 1: https://psmv4.blogspot.com/2019/08/advertisement.html.

Reference 2: Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future - Peter D. Ward - 2007.

Reference 3: https://en.wikipedia.org/wiki/Cretaceous–Paleogene_boundary.

Reference 4: British Regional Geology: The Hampshire basin and adjoining areas - C.P. Chatwin, M.Sc. - 1948. HMSO.