May 15, 2013
To make up for missing the last two Monday Geology Picture posts, here’s another guest post by my husband Jackie Gauntlett. This post shares more pictures from his recent mining / exploration geology field trip in South Africa.
The Barberton Mountainland in north-eastern South Africa is underlain by the some of the oldest and best preserved rocks in the world – the Barberton Greenstone Belt. The rocks of this unique area allow geologists to peer into the world of 3.5 billion years ago. The variety of rocks making up this ancient belt provide some of the earliest evidence for deep bodies of water (pillow lavas – Figure 1), running water and fluvial systems (conglomerate beds and cross-bedding (Figures 2 and 3)), tidal systems (symmetrical ripples, Figure 4) and…our ancestors. The oldest form of life was discovered here, a bacterial micro fossil Archaeospheroides barbertonis and has been identified as being 3.2 billion years old (Figure 5).
The Barberton Makhonjwa Geotrail is an amazing initiative, and I urge anyone passing through to spend a day absorbing this unique and spectacular part of South Africa. Check out a description of the trail here.