The Archaean Geology of the Kaapvaal Craton, Southern Africa

The Archaean Geology of the Kaapvaal Craton, Southern Africa
Author: Alfred Kröner
Publisher: Springer
Total Pages: 312
Release: 2019-02-20
Genre: Science
ISBN: 3319786520

This book provides a comprehensive overview of the evolution of one of the oldest and best-exposed Archaean cratons on this planet. There is currently a renewed interest in the early Earth, and the Kaapvaal craton has long served as a model for early crustal evolution. This unique multidisciplinary resource features information on geology, tectonics, geochemistry, and geochronology. It offers a wealth of new data on various aspects of the craton as well as contributions on the various crustal units by international specialists.

Processes on the Early Earth

Processes on the Early Earth
Author: W. U. Reimold
Publisher: Geological Society of America
Total Pages: 418
Release: 2006-01-01
Genre: Science
ISBN: 0813724058

"This Special Paper presents a collection of 19 papers contributed to a joint Field Forum organized by the Geological Society of America and the Geological Society of South Africa in July 2004 in the Barberton Greenstone Belt and the Vredefort Dome, South Africa. The papers cover a wide variety of themes, including Archean and Proterozoic crust formation and geodynamics (with an appraisal of evidence of Archean subduction processes); the significance of impacts in the evolution of the early Earth's crust; traces of early life in Archean environments of Australia and South Africa and related studies of depositional environments; and processes affecting the giant Witwatersrand gold deposit."--Publisher's website.

A Tale of Two Cratons

A Tale of Two Cratons
Author: A. G. Jones
Publisher: Gulf Professional Publishing
Total Pages: 522
Release: 2004-03-11
Genre: Science
ISBN: 9780444516145

Given the established nature of geoscientific knowledge of the Kaapvaal craton compared to the Slave craton, and given the exciting new interdisciplinary results coming from the Kaapvaal Project and from Slave craton studies, scientists working on both cratons were brought together in a workshop to compare and contrast the nature of these two cratons. Of the 54 papers presented at the workshop, 24 are included in this volume. There are clearly major similarities and differences between these two Archean cratons. The crust of both was predominantly formed in the Mesoarchean. Both contain crustal sections consisting of terranes of different ages welded together by Archean accretionary events. Both crustal sections are underlain by lithospheric mantle sections consisting of peridotites that experienced extensive partial melt extraction between 2.9 Ga and 3.2 Ga, but this is where the similarities between the cratons end. One of the most striking differences between the Slave and Kaapvaal cartons is the apparent seismic homogeneity of the Kaapvaal craton's SCLM whereas the Slave craton is seismically layered. The seismic layering in the centre of the craton correlates laterally and with depth with electrical layering and geochemical layering. Taken together, these differences suggest that SCLM formation was different for the two cratons, implying that the search for a single causative formation process is bound to fail. Reprinted from the journal Lithos Volume 71, numbers 2-4.

Evolution of Early Earth's Atmosphere, Hydrosphere, and Biosphere

Evolution of Early Earth's Atmosphere, Hydrosphere, and Biosphere
Author: Stephen E. Kesler
Publisher: Geological Society of America
Total Pages: 350
Release: 2006-01-01
Genre: Science
ISBN: 0813711983

"The history of Earth's early atmosphere, hydrosphere, and biosphere, from Hadean through Proterozoic time, is one of geology's enduring puzzles. Ore deposits provide important insights into this history because they contain elements and minerals that are highly sensitive to the geochemical environment in which they form. Just what these minerals tell us remains a matter of considerable debate, however. When and how did life develop, an oxygen-rich atmosphere form, and sulfate dominate the ocean? This volume contains reports on these questions from both sides of the aisle for iron and manganese formations, uranium paleoplacers and hydrothermal deposits, and exhalative sulfides and oxides."--Publisher's website.

A Scientific Bibliography of the Far Northern Drakensberg

A Scientific Bibliography of the Far Northern Drakensberg
Author: Rodney Moffett
Publisher: UJ Press
Total Pages: 334
Release: 2023-04-14
Genre: Nature
ISBN: 1776434137

This Scientific Bibliography of the “Far Northern Drakensberg” is a continuation by the Afromontane Research Unit of the University of the Free State (ARU) to document published and other similar works on the mountains of the summer rainfall area of South Africa. It follows “A Scientific Bibliography of the Drakensberg, Maloti and Adjacent Lowlands” which was published in 2020 (Moffett 2020), and which covered the area between the North-Eastern Cape and the North-Eastern Free State. The current work extends this northward by including articles and publications dating back to 1875 (E.Cohen, on the Lydenburg goldfields) reaching as far as the Wolkberg and Woodbush near Tzaneen in Limpopo Province. Figure 1 shows the boundary of the area covered, and although referred to as the Far Northern Drakensberg in this work, it is identical to that described as the LMEE, Limpopo, Mpumalanga & Eswatini Escarpment by Clarke et al (2022). Although slightly separate from the “lower” escarpment, the mountainous Barberton and adjacent Eswatini area, as well as the Leolo Mountains in eastern Sekhukhuneland are also included. Details on how the boundary in figure 1 was determined are given in Clark et al (2022). Bibliographies on two further ranges in the summer rainfall area, viz. the Magaliesberg in Gauteng province and the Soutpansberg in Limpopo province are to be the subject of future compilations.

Meteorite Impact!

Meteorite Impact!
Author: Wolf Uwe Reimold
Publisher: Springer Science & Business Media
Total Pages: 338
Release: 2010-06-02
Genre: Science
ISBN: 3642104649

PART I CHAPTER 1 T E — , , . . . . . . . . . 15 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Geological change — the answers within, and without. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Man on the Moon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Back to the beginning — from the Big Bang to early Earth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Impact — the ubiquitous process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 The oldest rocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Time to cool — birth of the Kaapvaal continent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Old crust in the Vredefort Dome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Rifting, oceans, volcanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Mountains, fire and ice. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 The unique Bushveld magmatic event. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 CHAPTER 2 C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Extinction or survival — our restless Earth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Meteorite-impact catastrophes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Normal (background) versus mass extinctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 A brief look at the impact record in the Solar System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 What are the projectiles capable of causing an impact catastrophe?. . . . . . . . . . . . . . . . . . . . . . . 87 What is an impact crater? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 How can we identify impact structures? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Shock metamorphism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 CHAPTER 3 T A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Tswaing meteorite crater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Does Tswaing have a twin? (Kalkkop Crater, Eastern Cape Province) . . . . . . . . . . . . . . . . . . . . . . . 108 South Africa’ s other Giant Impact Morokweng impact structure, — North West Province . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Our southern African neighbours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Testimony of earliest impact catastrophe — Barberton and the Northern Cape Province . . 113 Traces of catastrophe in the Karoo?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 6 CHAPTER 4 V : T W . . . 117 The Vredefort Structure revealed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Getting to know the giant: By road through the Vredefort Structure . . . . . . . . . . . . . . . . . . . 120 Traversing the outer parts of the Vredefort Dome (Fochville to Parys) . . . . . . . . . . . . . . . . . . 12 5 The geology of the Vredefort Dome. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .