First identification of a Cathaysian continental fragment beneath the Gagua Ridge, Philippine Sea, and its tectonic implications
| Autor: | Serge Lallemand, Daniel P. Miggins, Xiaozhi Zhang, Chiyue Huang, Jonny Wu, Huaiyang Zhou, Alexander R. L. Nichols, Shengping Qian |
|---|---|
| Přispěvatelé: | Tongji University, University of Houston, Géosciences Montpellier, Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS), University of Canterbury [Christchurch], National Cheng Kung University (NCKU), Oregon State University (OSU) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences Subduction Geology 010502 geochemistry & geophysics 01 natural sciences Continental fragment Cretaceous Paleontology Basement (geology) Oceanic crust [SDU]Sciences of the Universe [physics] Magmatism Oceanic basin 0105 earth and related environmental sciences Zircon |
| Zdroj: | Geology Geology, Geological Society of America, 2021, 49, ⟨10.1130/G48956.1⟩ |
| ISSN: | 0091-7613 |
| Popis: | The tectonic history of the Philippine Sea plate is an essential piece in understanding the tectonic evolution of Southeast Asia, but it is still unclear and controversial. We present the first geochemical data obtained from lavas from the Gagua Ridge (GR) within the Philippine Sea. The GR lavas exhibit geochemical signatures typical of subduction-related arc magmatism. Plagioclase Ar-Ar ages of ca. 124–123 Ma and subduction-related geochemical signatures support the formation of GR lavas in the vicinity of an arc during the Early Cretaceous induced by subduction of the oceanic plate along East Asia. The ages of trapped zircon xenocrysts within the GR lavas cluster at 250 Ma, 0.75 Ga, and 2.45 Ga and match well the ages of zircons recovered from the Cathaysian block, southern China. Our results imply that the GR basement is partially composed of continental material that rifted away from the Eurasian margin during opening and spreading of the Huatung Basin. The depleted mantle wedge-derived magmas evolved and picked up the continental zircons during ascent. The youngest zircon ages and the GR lava Ar-Ar ages (ca. 124–123 Ma) presented in this study newly constrain an Early Cretaceous age for the Huatung Basin. Our study provides further evidence that the Huatung Basin is a remnant of a Mesozoic-aged ocean basin that dispersed from southern China during the Cretaceous. Transport of continental slivers by growth and closure of marginal seas along the East Asia margin may have been more prevalent than previously recognized. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|