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Gondwana

About: Gondwana is a research topic. Over the lifetime, 6078 publications have been published within this topic receiving 263050 citations. The topic is also known as: Gondwanaland.


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Journal ArticleDOI
TL;DR: The pre-Late Cretaceous basement rocks of New Zealand are divided into a Western Province and an Eastern Province along a tectonic boundary called the Median Tectonic Line as discussed by the authors.
Abstract: The pre‐Late Cretaceous basement rocks of New Zealand are divided into a Western Province and an Eastern Province along a tectonic boundary called the Median Tectonic Line. The two provinces comprise assemblages of terranes of fundamentally different origin. The Western Province attained continental‐type thickness and structure by the end of the Carboniferous. The Eastern Province developed as a result of convergent margin crustal processes in the Permian‐Cretaceous. The boundary between the two is drawn in one of two positions in Nelson, either east or west of the Drumduan Terrane. The evidence presented so far on the affinities of the Drumduan Terrane is equivocal, and the suggested eastward extension of the Tuhua Orogen is not well supported. To the south, similar difficulties of interpretation occur, and it seems that between the Takaka Terrane in the west and the Brook Street Terrane in the east there is a belt of enigmatic rocks best termed the Median Tectonic Zone. In a broader context, th...

126 citations

Journal ArticleDOI
TL;DR: In this article, the authors presented two new tectonic maps of the Brasiliano and Pan-African structures of West Gondwana on which they identify ten piercing points that, if re-joined simultaneously, could facilitate quantification of a well-substantiated geologically economic fit and help retrace the evolution of its continental margins with greater accuracy than has been achieved.
Abstract: Abstract The concept of South America and Africa as rigid continents during the formation, growth and motion of their respective plates has frustrated reconstruction of a tight, geologically economic fit between these two fragments in their Gondwana framework. We recognize that (1) internal strains released during and following Gondwana break-up have distorted their actual shapes within Gondwana and (2) these two continents comprise mosaics of smaller microblocks, or platelets, of relatively undistorted Precambrian terrains that experienced modest, episodic relative motions along rift zones that separate them. This permits a fresh approach to quantitative reconstructions of palaeo-continents. Former geological ties forged at the time of Gondwana amalgamation, now exposed at the continental margins of the South Atlantic as piercing points, provide robust anchors for new paleo-cartographic experiments. We present two new tectonic maps of the Brasiliano and Pan-African structures of West Gondwana on which we identify ten piercing points that, if re-joined simultaneously, could facilitate quantification of a well-substantiated Gondwana fit and help retrace the evolution of its continental margins with greater accuracy than has been achieved until now. This has significant bearing on understanding the origin and evolution of passive continental margins, and the geodynamics of Gondwana break-up.

126 citations

Journal ArticleDOI
TL;DR: The geology of the metamorphic rocks of the Cordillera Real of Ecuador is described in terms of five informal lithotectonic divisions as discussed by the authors, and they deduce that during the Mesozoic repeated accretionary events occurred and that dextral transpression has been of fundamental importance in determining the tectonic evolution of this part of the Northern Andes.

126 citations

Journal ArticleDOI
TL;DR: T Tinker et al. as mentioned in this paper investigated the geomorphic origin and evolution of the tectonically unique interior highland of southern Africa, the Kalahari Plateau, and its flanking low-lying coastal planes, using abundant well data and a seismic reflection profile.

125 citations

Journal ArticleDOI
TL;DR: In this paper, the emplacement of kimberlites and related rocks in Southern Africa is analyzed using a framework of lineaments defined by combining geology, aeromagnetics, gravity and geomorphological data.
Abstract: Regional and local structural controls on the emplacement of 1326 Southern African kimberlites and related rocks (kimberlites sensu lato, 11% of which are dated) are analysed using a framework of lineaments defined by combining geology, aeromagnetics, gravity and geomorphological data. Spatial analysis of occurrences within clusters of kimberlites less than 100km across resolves variable trends, depending on the age and position of the cluster; but on a regional scale the distribution of these clusters is statistically controlled by four lineament trends: 040°, 096°, 134° and 165°. Similar regional trends are observed as aspect lineaments that can be followed over large distances from modelling the variation in dip direction of the Southern African topography. These observations suggest that different geological parameters exert a control on the distribution of kimberlites. Local structures may include en-echelon fault arrays, Riedel, R’-, P- or T-structures within trans-continental lithosphere structures (cryptic continental corridors). Many cryptic continental corridors are collinear with fracture zones along the Atlantic and Indian continental margins of Southern Africa, and may have found their origin in events resulting from plate reorganization during the break-up of the supercontinent Gondwana. Fault resistance may have rapidly changed the stress state of the African continent causing the deep lithospheric faults to be the loci of episodic extension, allowing kimberlite fluids to ascend through the faults and cluster within near-surface structures. A progressive age variation of kimberlite magmatism in Southern Africa may be attributed to stress propagation along deep lithospheric fractures.

125 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023269
2022497
2021307
2020281
2019293
2018230