T116 Time Machine: Earth’s Deep-Time Geography—Data, Reconstructions, Challenges (Posters)

Monday, 16 October 2023
8:00 AM - 5:30 PM
Hall B

TERRANE GENERATION AND ACCRETION SINCE 1 GA: A GLOBAL COMPILATION

Paper number: T116-2
Program: Technical Sessions
Time: 8:00 AM – 5:30 PM

Authors

Abstract

In this study, we integrated geology, plate reconstruction model and a global geochemical database to characterize the spatiotemporal patterns of global terranes including their compositions, areas, lifespans, and paleo-localities since 1 Ga. Our preliminary results show a significant surge in terrane formation during 600-400 Ma. Total present-day areas of these terrane formed during this interval is about 4.5x108 km2, occupying ~80% of the total areas of the terranes generated since 1 Ga. The terranes generated during this period predominantly have juvenile isotopic signatures (mean εHf(t)>0). The peak period of terrane accretion occurred in 300-200 Ma corresponding to the final assembly of the Pangea supercontinent. Throughout the dispersion of Pangea (180-0 Ma), many of these accreted terranes form the basements of the Late Mesozoic continental arcs, thereby influencing the isotopic signatures of global continental arc magmatism. The progressive accretion of the terranes to the continental margins since ~400 Ma could also cause orogenic events, contributing to an overall increasing in the global continental crust thickness. Our study highlights that roles of the terranes whose composition, generation, and accretion reflect the underlying dynamics of global tectonics, super-continental cycle, and crust growth.

Geological Society of America Abstracts with Programs. Vol. 55, No. 6

doi: 10.1130/abs/2023AM-392122

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