Late Palaeozoic-early Mesozoic fore-arc basin Sedimentary rocks at the Pacific margin in Western Antarctica

IGCP 203 - Permo-Triassic events of eastern Tethys and their intercontinental correlation - focussed on the Permian-Triassic boundary sequences and in particular there was a consensus that the distinctive biological changes were associated with strong sea-level and tectonic change, strong volcanic activity and a harsh climate. These factors were connected with an important change in the environment and with the exception perhaps of the climate, reflected deep-seated changes within the earth. The project also resulted in improving the physical understanding of the sequences and their biostratigraphy and correlation.IGCP 272 was developed, and was approved in 1988, to apply these results to understanding the Late Palaeozoic and Early Mesozoic and was focussed on the Pacific as integration around this region seemed to offer especially fruitful possibilities.Working group meetings up to the end of 1991 have been held in Australia (Newcastle and Hobart), New Zealand (Dunedin), South America (Sao Paulo and Buenos Aires) and North America (Washington). Meetings are planned in North America, Japan, Eastern Siberia or Thailand and western Europe (France-Spain-Austria).Special cooperation has developed with the Carboniferous, Permian and Triassic Subcommissions of IUGS and with IGCP 214 - Global Bio-events. Using the more exact time correlations developed it has now been possible to show that major geological and biological events (of different levels of significance) are associated with major boundaries already recognized in the World Standard Stratigraphical Time Scale. These comprise the Carboniferous-Permian, the mid-Permian (twofold subdivision, the Permian-Triassic (already recognized in earlier work), the Lower-Middle and Middle-Upper Triassic and the Triassic-Jurassic boundaries.A special achievement of the project has been to show the similar significance of the Midian-Dzhulfian boundary within the Upper Permian but corresponding closely to the traditional Lower-Upper Permian of China and the Middle-Upper Permian of Japan.Although there are also other events at levels which have not been investigated by the project, those outlined all seem to reflect important changes within the earth.

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Late Palaeozoic — Early Mesozoic Plate Reorganization: Evolution and Demise of the Variscan Fold Belt

Pre-Mesozoic Geology in the Alps ◽

10.1007/978-3-642-84640-3_12 ◽

1993 ◽

pp. 203-216 ◽

Cited By ~ 13

Author(s):

P. A. Ziegler

Keyword(s):

Fold Belt ◽

Early Mesozoic ◽

Late Palaeozoic

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Late palaeozoic and early mesozoic hydrothermal events inthe northern Rhenish Massif results from fluid inclusion analyses and cathodoluminescence investigations

Journal of Geochemical Exploration ◽

10.1016/s0375-6742(03)00066-9 ◽

2003 ◽

Vol 78-79 ◽

pp. 531-535 ◽

Cited By ~ 3

Author(s):

Thomas Götte ◽

Detlev K. Richter

Keyword(s):

Fluid Inclusion ◽

Rhenish Massif ◽

Early Mesozoic ◽

Late Palaeozoic

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MESOZOIC TECTONICS OF THE OTWAY BASIN REGION: THE LEGACY OF GONDWANA AND THE ACTVE PACIFIC MARGIN—A REVIEW AND ONGOING RESEARCH

The APPEA Journal ◽

10.1071/aj94030 ◽

1995 ◽

Vol 35 (1) ◽

pp. 467 ◽

Cited By ~ 13

Author(s):

K.A. Hill ◽

D.M. Finlayson ◽

K.C. Hill ◽

G.T. Cooper

Keyword(s):

Ongoing Research ◽

Ridge Subduction ◽

The North ◽

Southern Margin ◽

The Pacific ◽

Half Graben ◽

Pacific Margin ◽

Mantle Processes ◽

Break Up ◽

Basin Region

Mesozoic extension along Australia's southern margin and the evolution and architecture of the Otway Basin were probably controlled by three factors: 1) changes in global plate movements driven by mantle processes; 2) the structural grain of Palaeozoic basement; and, 3) changes in subduction along Gondwana's Pacific margin. Major plate realignments controlled the Jurassic onset of rifting, the mid-Cretaceous break-up and the Eocene onset of rapid spreading in the Southern Ocean.The initial southern margin rift site was influenced by the northern limit of Pacific margin (extensional) Jurassic dolerites and the rifting may have terminated dolerite emplacement. Changed conditions of Pacific margin subduction (e.g. ridge subduction) in the Aptian may have placed the Australia-Antarctic plates into minor compression, abating Neocomian southern margin rifting. It also produced vast amounts of volcanolithic sediment from the Pacific margin arc that was funnelled down the rift graben, causing additional regional subsidence due to loading. Albian orogenic collapse of the Pacific margin, related to collision with the Phoenix Plate, influenced mid-Cretaceous breakup propagating south of Tasmania and into the Tasman Sea.Major offsets of the spreading axis during breakup, at the Tasman and Spencer Fracture zones, were most likely controlled by the location of Palaeozoic terrane boundaries. The Tasman Fracture System was reactivated during break-up, with considerable uplift and denudation of the Bass failed rift to the east, which controlled Otway Basin facies distribution. Palaeozoic structures also had a significant effect in determining the half graben orientations within a general N-S extensional regime during early Cretaceous rifting. The late Cretaceous second stage of rifting, seaward of the Tartwaup, Timboon and Sorell fault zones, left a stable failed rift margin to the north, but the attenuated lithosphere of the Otway-Sorell microplate to the south records repeated extension that led to continental separation and may be part of an Antarctic upper plate.

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