Mike Benton Agrees with David Attenborough 

Many of you will have seen the recent programme "Dinosaurs: The Final Day" presented by David Attenborough which looked at the day the asteroid collided with Earth and at a place where the event was recorded in the fossil record. I wrote something about it in February and you can re-read that HERE.

The claims made are substantial. It is claimed that the site recorded the very day the asteroid arrived. But the announcements of the claims have not been made in peer-reviewed journals but in magazines. The academic papers did follow shortly afterwards. But we can wonder - are the claims true?

To settle the matter we can read THIS ARTICLE, by Bristol University's very own Mike Benton. And he agree's with David Attenborough and Robert DePalma, the site discoverer! So all is well.

Dave Green Lecture Course 

Dave Green has asked me to mention the following Lecture Course which sounds rather interesting.

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CLIMATE CHANGE THROUGH GEOLOGICAL TIME

This is a 10 week course, starting on Monday 25^th April and finishing on July 11^th (no meeting on 23rd or 30th May, but we will meet on the Bank holidays 3rd May). We are meeting in a new venue – the Beacon Hotel at the end of the road in Haresfield village, where there should be plenty of parking in the car park, or along the road. For those who are coming from some distance, the easiest approach is from Junction 12 on the M5, from where you should take the B4008 towards Stonehouse, turning first left after 200metres, then right at the next T junction, over the railway, and right into the village as the road turns sharply left. Each session will start at 7.30 and will last 2 hours, including a coffee break.

Course Outline:

1. Introduction: an overview of the subject of palaeoclimatology and its development. A summary of the development of Earth’s climate and its operation.

2. The tools of palaeoclimatology – how can we deduce past climates millions of years in the past? Week 1: Physical evidence preserved in rocks – Marine and Terrestrial fossils and lithologies.

3. The tools of palaeoclimatology 

Week 2 – Proxies – stable geochemical isotopes of Oxygen, Carbon, Strontium and Nitrogen. Climate modelling.

4. Pre Cambrian Climates 1 – the early atmosphere of Earth.

5. Pre Cambrian Climates 2 – Snowball Earth – the glaciations of the early and late Proterozoic.

6. The Lower Palaeozoic Greenhouse climate.

7. The Upper Palaeozoic Icehouse climate.

8. The Mesozoic to Early Cainozoic Greenhouse Climate.

9. The Late Cainozoic to Quaternary Icehouse climate.

10. The Anthropocene and future climate.

Useful Reading:  those with a * are in the linked Dropbox folder below and can be downloaded

“Earth’s Climate Evolution”* by Colin Summerhayes (2015, updated as “Palaeoclimatology” in 2020), explains the subject by charting its development , mainly through the later years of the 20^th century and into the 21^st .

“Paleoclimates”* by Thomas Cronin (2009) is a standard, well laid out and written textbook on the subject.

“A Brief History of the Earth’s Climate – Everyone’s Guide to the Science of Climate Change”*

Zalasiewicz J.,Williams M. – “The Goldilocks Planet:  The 4 Billion Year Story of Earth's Climate” *

(Frontiers in Earth Sciences) Gilles Ramstein et al- “Paleoclimatology”* (2021) the most up-to-date text

Ruddiman, William F – “Earth's climate_ past and future”* (2014)

C R Scotese et al (2021) “Phanerozoic paleotemperatures The earth’s changing climate during the last 540Ma”* An up-to-date summary of climate change in a review article.

Lawrence A. Frakes, et al – “Climate modes of the Phanerozoic_ the history of the earth's climate over the past 600 million years”* (1992)

https://www.dropbox.com/scl/fo/1fn5wa0s70n9e98d35717/h?dl=0&rlkey=o8f4jic5f0kkxqmpzgyos7lvd

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Another Look at the Cambrian Explosion 

I came across THIS ARTICLE on the Earthlogs website, a favourite of mine. It describes recent work on the Cambrian of Chengjian County, Yunnan, China. It is based on THIS PAPER.

The Cambrian Explosion is always associated with the Burgess Shale in the Canadian Rockies. But there the fossils are not found in the environment where they lived. There extraordinary good preservation is due to their being moved by some underwater avalanche to an anoxic environment.

The Chengjian Biota has more species than any other Cambrian fossil locality. But here has been, up to now, no consensus about the environment of the deposit. This is probably due to the rocks being highly weathered. To settle (possibly!) the matter a 130m boehole was drilled through the deposit and the conclusion was that the rocks were laid down in a deltaic environment.

The best preserved fossils are found in the prodelta. Here there is rapid deposition where the beasties were buried quickly, preserving them from predation, and in an anoxic environment. The quick burial may have been due to river floods moving the animals from the delta front.

Geology from Space 

A correspondent has brought THIS NASA WEBSITE to my attention, and in particular, THIS PAGE for its wonderful picture of part of Western Australia.

This is a false colour image, bringing out the geology, but the Google Maps picture is also rather good.

The article gives an explanation of the geology, which is interesting, but it is the beauty of the image which catches my eye.