MagNetZ with Andy Herries (2021/07/14) - Magnetic reversals in Africa
Channel: MagNetZ
Date: 2021-07-14

The video is also available for download at: https://earthref.org/ERDA/2477/
and can be referenced with the doi: 10.7288/V4/ERDA/2477

Title: Either side of Olduvai: high resolution reversals in archaeological and fossil bearing volcanic and palaeocave sequences from Kenya and South Africa
Author: Andy Herries from La Trobe University, Australia
Author Website: http://www.archaeomagnetism.com/

Work over the last 20 years has established that magnetic reversals and events often occur in flowstone speleothem from early human fossil bearing palaeocave deposits in South Africa. Resolution within these reversals and events is often low due to the nature of sampling the flowstones. However, developments in uranium-lead dating over this same time period now allows such reversals and events to be directly dated with the magnetic signal being locked in rapidly during precipitation of the speleothem. Recent work at Drimolen Cave has identified for the first time a high-resolution magnetic reversal within palaeocave sediments and associated flowstone that has been correlated to the base of the Olduvai SubChron. Similar high-resolution reversals can also be identified in fossil and archaeological bearing volcanic sequences in eastern Africa, dated by argon-argon. Preliminary work at the site of Kilombe in Kenya has identified such a sequence that covers the reversal at the end of the Olduvai SubChron. Together these two sites span either side of the Olduvai SubChron and highlight the potential for such sequences in resolving the nature and dating of magnetic reversals and excursions.