气候变化领域集成服务门户(CCPortal): Garnet sand reveals rock recycling processes in the youngest exhumed high- And ultrahigh-pressure terrane on Earth

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DOI	10.1073/pnas.2017231118
	Garnet sand reveals rock recycling processes in the youngest exhumed high- And ultrahigh-pressure terrane on Earth
	Baldwin S.L.; Schönig J.; Gonzalez J.P.; Davies H.; von Eynatten H.
发表日期	2021
ISSN	00278424
卷号	118 期号:3
英文摘要	Rock recycling within the forearcs of subduction zones involves subduction of sediments and hydrated lithosphere into the upper mantle, exhumation of rocks to the surface, and erosion to form new sediment. The compositions of, and inclusions within detrital minerals revealed by electron microprobe analysis and Raman spectroscopy preserve petrogenetic clues that can be related to transit through the rock cycle. We report the discovery of the ultrahigh-pressure (UHP) indicator mineral coesite as inclusions in detrital garnet from a modern placer deposit in the actively exhuming Late Miocene–Recent high- and ultrahigh-pressure ((U)HP) metamorphic terrane of eastern Papua New Guinea. Garnet compositions indicate the coesite-bearing detrital garnets are sourced from felsic protoliths. Carbonate, graphite, and CO2 inclusions also provide observational constraints for geochemical cycling of carbon and volatiles during subduction. Additional discoveries include polyphase inclusions of metastable polymorphs of SiO2 (cristobalite) and K-feldspar (kokchetavite) that we interpret as rapidly cooled former melt inclusions. Application of elastic thermobarometry on coexisting quartz and zircon inclusions in six detrital garnets indicates elastic equilibration during exhumation at granulite and amphibolite facies conditions. The garnet placer deposit preserves a record of the complete rock cycle, operative on <10-My geologic timescales, including subduction of sedimentary protoliths to UHP conditions, rapid exhumation, surface uplift, and erosion. Detrital garnet geochemistry and inclusion suites from both modern sediments and stratigraphic sections can be used to decipher the petrologic evolution of plate boundary zones and reveal recycling processes throughout Earth’s history. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Detrital garnet; Papua New Guinea; Rock cycle; Ultrahigh-pressure metamorphism
语种	英语
scopus关键词	carbon; carbon dioxide; carbonic acid; graphite; mineral; silicon dioxide; zirconium; Article; astronomy; chemical composition; controlled study; erosion; exhumation; garnet sand; geochemistry; metamorphosis; Miocene; Papua New Guinea; priority journal; rock; sand; stratigraphy
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180959
作者单位	Department of Earth and Environmental Sciences, Syracuse University, Syracuse, NY 13244-1070, United States; Department of Sedimentology and Environmental Geology, University of Göttingen, Göttingen, D-37077, Germany; Geology Department, University of Papua New Guinea, Port Moresby, 134, Papua New Guinea
推荐引用方式 GB/T 7714	Baldwin S.L.,Schönig J.,Gonzalez J.P.,et al. Garnet sand reveals rock recycling processes in the youngest exhumed high- And ultrahigh-pressure terrane on Earth[J],2021,118(3).
APA	Baldwin S.L.,Schönig J.,Gonzalez J.P.,Davies H.,&von Eynatten H..(2021).Garnet sand reveals rock recycling processes in the youngest exhumed high- And ultrahigh-pressure terrane on Earth.Proceedings of the National Academy of Sciences of the United States of America,118(3).
MLA	Baldwin S.L.,et al."Garnet sand reveals rock recycling processes in the youngest exhumed high- And ultrahigh-pressure terrane on Earth".Proceedings of the National Academy of Sciences of the United States of America 118.3(2021).