| Literature DB >> 33741949 |
He Li1,2,3,4, Richard J Arculus5, Osamu Ishizuka6,7, Rosemary Hickey-Vargas8, Gene M Yogodzinski9, Anders McCarthy10,11, Yuki Kusano6, Philipp A Brandl12,13, Ivan P Savov14, Frank J Tepley15, Weidong Sun16,17,18.
Abstract
The magmatic character of early subduction zone and arc development is unlike mature systems. Low-Ti-K tholeiitic basalts and boninites dominate the early Izu-Bonin-Mariana (IBM) system. Basalts recovered from the Amami Sankaku Basin (ASB), underlying and located west of the IBM's oldest remnant arc, erupted at ~49 Ma. This was 3 million years after subduction inception (51-52 Ma) represented by forearc basalt (FAB), at the tipping point between FAB-boninite and typical arc magmatism. We show ASB basalts are low-Ti-K, aluminous spinel-bearing tholeiites, distinct compared to mid-ocean ridge (MOR), backarc basin, island arc or ocean island basalts. Their upper mantle source was hot, reduced, refractory peridotite, indicating prior melt extraction. ASB basalts transferred rapidly from pressures (~0.7-2 GPa) at the plagioclase-spinel peridotite facies boundary to the surface. Vestiges of a polybaric-polythermal mineralogy are preserved in this basalt, and were not obliterated during persistent recharge-mix-tap-fractionate regimes typical of MOR or mature arcs.Entities:
Year: 2021 PMID： 33741949 PMCID： PMC7979767 DOI： 10.1038/s41467-021-21980-0
Source DB: PubMed Journal: Nat Commun ISSN： 2041-1723 Impact factor: 14.919