Neoproterozoic tectonics of the Jiangnan orogen: The magmatic record of continental growth by arc and slab-failure magmatism from 1000 to 780 Ma

2021 ◽  
Vol 362 ◽  
pp. 106319
Author(s):  
Wan Le ◽  
Timothy M. Kusky ◽  
Jin Wei ◽  
Yang Jie ◽  
Zeng Zuoxun
Keyword(s):  
1974 ◽  
Vol 85 (12) ◽  
pp. 1913 ◽  
Author(s):  
JOHN J. W. ROGERS ◽  
B. C. BURCHFIEL ◽  
E. W. ABBOTT ◽  
J. K. ANEPOHL ◽  
A. H. EWING ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
José Joaquín Jara ◽  
Fernando Barra ◽  
Martin Reich ◽  
Mathieu Leisen ◽  
Rurik Romero ◽  
...  

AbstractThe subduction of oceanic plates beneath continental lithosphere is responsible for continental growth and recycling of oceanic crust, promoting the formation of Cordilleran arcs. However, the processes that control the evolution of these Cordilleran orogenic belts, particularly during their early stages of formation, have not been fully investigated. Here we use a multi-proxy geochemical approach, based on zircon petrochronology and whole-rock analyses, to assess the early evolution of the Andes, one of the most remarkable continental arcs in the world. Our results show that magmatism in the early Andean Cordillera occurred over a period of ~120 million years with six distinct plutonic episodes between 215 and 94 Ma. Each episode is the result of a complex interplay between mantle, crust, slab and sediment contributions that can be traced using zircon chemistry. Overall, the magmatism evolved in response to changes in the tectonic configuration, from transtensional/extensional conditions (215–145 Ma) to a transtensional regime (138–94 Ma). We conclude that an external (tectonic) forcing model with mantle-derived inputs is responsible for the episodic plutonism in this extensional continental arc. This study highlights the use of zircon petrochronology in assessing the multimillion-year crustal scale evolution of Cordilleran arcs.


2017 ◽  
Author(s):  
Wenchao Cao ◽  
Sabin Zahirovic ◽  
Nicolas Flament ◽  
Simon Williams ◽  
Jan Golonka ◽  
...  

Abstract. Paleogeographic reconstructions are important to understand Earth's tectonic evolution, past eustatic and regional sea level change, hydrocarbon genesis, and to constrain and interpret the dynamic topography predicted by time-dependent global mantle convection models. Several global paleogeographic maps have been compiled and published but they are generally presented as static maps with varying temporal resolution and fixed spatial resolution. Existing global paleogeographic maps are also tied to a particular plate motion model, making it difficult to link them to alternative digital plate tectonic reconstructions. To address this limitation, we developed a workflow to reverse-engineer global paleogeographic maps to their present-day coordinates and enable them to be linked to any tectonic reconstruction. Published paleogeographic compilations are also tied to fixed input datasets. We used fossil data from the Paleobiology Database to identify inconsistencies between fossils paleo-environments and published paleogeographic maps, and to improve the location of inferred terrestrial-marine boundaries by resolving these inconsistencies. As a result, the overall consistency ratio between the paleogeography and fossil collections was improved from 76.9 % to 96.1 %. We estimated the surface areas of global paleogeographic features (shallow marine environments, landmasses, mountains and ice sheets), and reconstructed the global continental flooding history since the late Paleozoic based on the amended paleogeographies. Finally, we discuss the relationships between emerged land area and total continental crust area through time, continental growth models, and strontium isotope (87Sr/86Sr) signatures in ocean water. Our study highlights the flexibility of digital paleogeographic models linked to state-of-the-art plate tectonic reconstructions in order to better understand the interplay of continental growth and eustasy, with wider implications for understanding Earth's paleotopography, ocean circulation, and the role of mantle convection in shaping long-wavelength topography.


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