The Ediacarian-Cambrian uplift history of western Dronning Maud Land: New 40Ar-39Ar and Sr/Nd data from Sverdrupfjella and Kirwanveggan, the source of the Urfjell Group and tectonic evolution of Dronning Maud Land within the Kuunga Orogeny and Gondwana amalgamation

The West Siberian Basin (WSB) is one of the largest intracratonic Meso-Cenozoic basins in the world. Its evolution has been studied over the recent decades; however, some fundamental questions regarding the tectonic evolution of the WSB remain unresolved or unconfirmed by analytical data. A complete understanding of the evolution of the WSB during the Mesozoic and Cenozoic eras requires insights into the cooling history of the basement rocks as determined by low-temperature thermochronometry. We presented an apatite fission track (AFT) thermochronology study on the exposed parts of the WSB basement in order to distinguish tectonic activation episodes in an absolute timeframe. AFT dating of thirteen basement samples mainly yielded Cretaceous cooling ages and mean track lengths varied between 12.8 and 14.5 μm. Thermal history modeling based on the AFT data demonstrates several Mesozoic and Cenozoic intracontinental tectonic reactivation episodes affected the WSB basement. We interpreted the episodes of tectonic activity accompanied by the WSB basement exhumation as a far-field effect from tectonic processes acting on the southern and eastern boundaries of Eurasia during the Mesozoic–Cenozoic eras.

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Uplift history of the Sila Massif, southern Italy, deciphered from cosmogenic10Be erosion rates and river longitudinal profile analysis

Tectonics ◽

10.1029/2011tc003037 ◽

2012 ◽

Vol 31 (3) ◽

pp. n/a-n/a ◽

Cited By ~ 46

Author(s):

Valerio Olivetti ◽

Andrew J. Cyr ◽

Paola Molin ◽

Claudio Faccenna ◽

Darryl E. Granger

Keyword(s):

Southern Italy ◽

Profile Analysis ◽

Longitudinal Profile ◽

Erosion Rates ◽

History Of ◽

Uplift History

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Palaeozoic history of the Armorican Massif: Models for the tectonic evolution of the suture zones

Comptes Rendus Geoscience ◽

10.1016/j.crte.2008.11.009 ◽

2009 ◽

Vol 341 (2-3) ◽

pp. 174-201 ◽

Cited By ~ 167

Author(s):

Michel Ballèvre ◽

Valérie Bosse ◽

Céline Ducassou ◽

Pavel Pitra

Keyword(s):

Tectonic Evolution ◽

History Of ◽

Armorican Massif

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On the enigmatic birth of the Pacific Plate within the Panthalassa Ocean

Science Advances ◽

10.1126/sciadv.1600022 ◽

2016 ◽

Vol 2 (7) ◽

pp. e1600022 ◽

Cited By ~ 16

Author(s):

Lydian M. Boschman ◽

Douwe J. J. van Hinsbergen

Keyword(s):

Triple Junction ◽

Tectonic Evolution ◽

Plate Boundary ◽

Pacific Plate ◽

Plate Tectonic ◽

Point Location ◽

Marine Magnetic Anomalies ◽

The Pacific ◽

History Of ◽

Ridge System

The oceanic Pacific Plate started forming in Early Jurassic time within the vast Panthalassa Ocean that surrounded the supercontinent Pangea, and contains the oldest lithosphere that can directly constrain the geodynamic history of the circum-Pangean Earth. We show that the geometry of the oldest marine magnetic anomalies of the Pacific Plate attests to a unique plate kinematic event that sparked the plate’s birth at virtually a point location, surrounded by the Izanagi, Farallon, and Phoenix Plates. We reconstruct the unstable triple junction that caused the plate reorganization, which led to the birth of the Pacific Plate, and present a model of the plate tectonic configuration that preconditioned this event. We show that a stable but migrating triple junction involving the gradual cessation of intraoceanic Panthalassa subduction culminated in the formation of an unstable transform-transform-transform triple junction. The consequent plate boundary reorganization resulted in the formation of a stable triangular three-ridge system from which the nascent Pacific Plate expanded. We link the birth of the Pacific Plate to the regional termination of intra-Panthalassa subduction. Remnants thereof have been identified in the deep lower mantle of which the locations may provide paleolongitudinal control on the absolute location of the early Pacific Plate. Our results constitute an essential step in unraveling the plate tectonic evolution of “Thalassa Incognita” that comprises the comprehensive Panthalassa Ocean surrounding Pangea.

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Different Tectonic Evolution of Fast Cooling Ophiolite Mantles Recorded by Olivine-Spinel Geothermometry: Case Studies from Iballe (Albania) and Nea Roda (Greece)

Minerals ◽

10.3390/min12010064 ◽

2022 ◽

Vol 12 (1) ◽

pp. 64

Author(s):

Micol Bussolesi ◽

Giovanni Grieco ◽

Alessandro Cavallo ◽

Federica Zaccarini

Keyword(s):

Tectonic Evolution ◽

Early Stage ◽

Mineral Chemistry ◽

Northern Greece ◽

Present Contribution ◽

Cooling Rates ◽

History Of ◽

Ferrian Chromite ◽

Fast Cooling ◽

Subduction Setting

Mg-Fe2+ diffusion patterns in olivine and chromite are useful tools for the study of the thermal history of ultramafic massifs. In the present contribution, we applied the exponential modeling of diffusion patterns to geothermometry and geospeedometry of chromitite ores from two different ophiolite contexts. The Iballe ophiolite (Northern Albania) hosts several chromitite pods within dunites. Primary and re-equilibrated Mg#, estimated by using an exponential function, provided re-equilibration and primary temperatures ranging between 677 and 996 °C for chromitites and between 527 and 806 °C for dunites. Cooling rates for chromitites are higher than for dunites, suggesting a different genesis for the two lithologies, confirmed also by spinel mineral chemistry. Chromitites with MORB affinity formed in a SSZ setting at a proto-forearc early stage, explaining the higher cooling rates, while dunites, with boninitic affinity, were formed deeper in the mantle in a more mature subduction setting. At the Nea Roda ophiolite (Northern Greece) olivine in chromitites do not show Mg-Fe variations, and transformation into ferrian chromite produced “fake” diffusion patterns within chromite. The absence of diffusion patterns and the low estimated temperatures (550–656 °C) suggest that Nea Roda chromitites were completely re-equilibrated during an amphibolite-facies metamorphic event that obliterated all primary features.

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