Terrane

About: Terrane is a research topic. Over the lifetime, 11025 publications have been published within this topic receiving 442596 citations. The topic is also known as: tectonostratigraphic terrane.

Tectonic evolution of the southern margin of Laurasia in the Black Sea region

Abstract: The Black Sea region comprises Gondwana-derived continental blocks and oceanic subduction complexes accreted to Laurasia. The core of Laurasia is made up of an Archaean–Palaeoproterozoic shield, whereas the Gondwana-derived blocks are characterized by a Neoproterozoic basement. In the early Palaeozoic, a Pontide terrane collided and amalgamated to the core of Laurasia, as part of the Avalonia–Laurasia collision. From the Silurian to Carboniferous, the southern margin of Laurasia was a passive margin. In the late Carboniferous, a magmatic arc, represented by part of the Pontides and the Caucasus, collided with this passive margin with the Carboniferous eclogites marking the zone of collision. This Variscan orogeny was followed by uplift and erosion during the Permian and subsequently by Early Triassic rifting. Northward subduction under Laurussia during the Late Triassic resulted in the accretion of an oceanic plateau, whose remnants are preserved in the Pontides and include Upper Triassic eclogites. The C...

Archaean–Cambrian crustal development of East Antarctica: metamorphic characteristics and tectonic implications

Abstract: The East Antarctic Shield consists of a variety of Archaean and Proterozoic-Cambrian high-grade terranes that have distinct crustal histories and were amalgamated at various times in the Precambrian-Cambrian. High-grade Pan-African tectonism at 600–500Ma is recognized from four distinct belts: the Dronning Maud Land, Lutzow-Holm Bay, Prydz Bay and Denman Glacier Belts. These high-grade belts juxtapose distinct Mesoproterozoic and Neoproterozoic crustal provinces (Maud, Rayner and Wilkes), the Rauer Terrane, and have also marginally affected Archaean cratonic remnants in the Napier Complex and southern Prince Charles Mountains. The Wilkes Province experienced its principal tectonothermal events prior to 1130Ma and was not affected by the younger events that characterize the Maud Province (1150 and 1030–990Ma), the Rayner Province (990–920Ma) and the Rauer Terrane (1030–990Ma). These differences between the isotopic/event records of the basement provinces now separated by the Pan-African belts require that the older provinces were not formerly parts of a continuous ‘Grenville’ belt as proposed in the SW US-East Antartic model. East Antarctica was not a single unified crustal block within either East Gondwana or Rodinia until the Cambrian, which is now demonstrated to be the key phase of high-grade and ultrahigh-temperature (UHT) metamorphism associated with supercontinent assembly. The high-grade Pan-African tectonism is characterized by extensive infracrustal melting, clock-wise P-T paths, rapid post-peak exhumation along isothermal decompression paths to shallow- or mid-crustal levels by 500 Ma and the generation, at least locally, of UHT conditions. A significant flux of heat from the mantle into the deep and initially overthickened crust is required to produce these observed metamorphic effects. Whilst the thermal evolution can be explained by models that invoke the removal of most of the lithospheric mantle following crustal thickening and prior to rapid extension of the remaining crust, these one-dimensional models are inconsistent with present crustal thicknesses of 25–35km in the Pan-African domains of the East Antarctic Shield.