Lightning-induced remanent magnetization—the Vredefort impact structure, South Africa
نویسندگان
چکیده
منابع مشابه
Inversion of regional gravity gradient data over the Vredefort Impact Structure, South Africa
We present the results for 3D inversion of gravity gradiometry data over the Vredefort Impact Structure in South Africa. With the rapidly growing field of gravity gradiometry, an investigation into the extraction of information from multiple components is warranted. Though the gradient tensor has five independent components, any combination of the components can be used to invert for a structur...
متن کاملLightning medicine in South Africa.
South Africa has a rich history of lightning research; however, research on the clinical and pathological effects and features of lightning-related injury (keraunomedicine or lightning medicine) remains neglected locally. By providing an overview of keraunomedicine and focussing on South African perspectives, we hope to raise awareness and propose that a concerted and co-ordinated attempt be ma...
متن کاملRe-Os isotope and geochemical study of the Vredefort Granophyre: Clues to the origin of the Vredefort structure, South Africa
The origin of granophyric rock dikes (the Vredefort Granophyre) at the 2 Ga Vredefort structure in South Africa has been controversial. They have been interpreted as either impact melt or igneous intrusions. Most Vredefort Granophyre samples have considerably higher Os contents than the country rocks and Re/Os and Os/Os ratios that scatter about a 2 Ga isochron. Their initial Os/Os ratios (at 2...
متن کاملEvidence for high stress in quartz from the impact site of Vredefort, South Africa
A microstructural investigation of stishovite-bearing quartzite from the Vredefort meteorite impact site in South Africa reveals features that are attributed to shock deformation. These include abundant mechanically induced Dauphiné twinning, rhombohedral deformation lamellae and associated residual stresses. Mechanical twins were identified with SEM-EBSD. Residual stresses are derived from equ...
متن کاملDauphiné twinning as evidence for an impact origin of preferred orientation in quartzite: An example from Vredefort, South Africa
Large meteorite impacts cause great changes to geologic features on Earth, ranging from cratering and ejecta blankets to phase transformations in minerals. In this report we describe the effect of a shock wave on the crystallographic orientation of quartz crystals in quartzite from the Vredefort impact site in South Africa. Preferred orientation of bulk quartzite samples was measured by time-of...
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ژورنال
عنوان ژورنال: Geophysical Journal International
سال: 2013
ISSN: 1365-246X,0956-540X
DOI: 10.1093/gji/ggt230