After our time in the Barberton Greenstone Belt we hope that our participants will have formulated some ideas about how the early-Earth functioned and how early continental crust formed. We now move on to the Pongola Supergroup, which provides an opportunity to investigate one of the earliest Archean volcano-sedimentary sequence deposited onto some stable continental margin.
For a geological overview of the Pongola Supergroup click here.
Overview of the various Pongola Supergroup geological stops
Stop 1
The first stop of the Pongola field trip will be to investigate the contact between the lowermost sequence of the Nsuze Group, i.e. the sandstone and volcanic rocks of the Matonga Formation and the pre-Pongola c. 3105 Ma TTG basement.
Stop 2
Thereafter, we will continue into the Archean TTG basement and investigate a Komatiitic remnant of the enigmatic, strongly mantle-depleted Commondale Greenstone Belt. Contact relationships of this greenstone sequence remains elusive.
Stop 3
The northern and southern domains of the Pongola Supergroup is largely separated by Karoo cover rocks. These particular lower Karoo rocks contain abundant coal reserves. We will therefore take some time to investigate some of these Karoo rocks near Vryheid.
Stop 4
Now, in the southern domain, we will investigate the Nsuze lavas, particularly the Agatha Formation, and discuss their features and implications on the development of this sequence.
Stop 5/6
Finally, we will investigate to contact relationship between the Nsuze and Mozaan Group. We will also discuss gold occurrences within the Mozaan and some of the mining history in this region. And, we will end this trip by looking at a major unconformity between the Pongola and Karoo Supergroups.
No comments:
Post a Comment