地质通报2024，Vol.43Issue(12)：2272-2287,16.DOI:10.12097/gbc.2024.08.005
山西中条山2.5 Ga TTG岩石的暖俯冲成因
Warm subduction origin of 2.5 Ga TTG in Zhongtiao Mountains,Shanxi:Constraints from phase equilibrium modeling
摘要
Abstract
The tectonic transition that occurred around 2.5 Ga represents one of the most significant geological events in Earth's history,shaping the early processes of continental growth and cratonization.As the dominant component of the Archean continental crust,TTGs provide valuable insights into the dynamic mechanisms of Archean plate tectonics.However,the lack of data on the pressure-temperature(P-T)conditions during the water-bearing melting processes of TTGs limits our ability to fully identify the tectonic mechanisms involved.This study investigates the 2.5 Ga TTGs in the Zhongtiao Mountains,using 2.5 Ga metabasalt from Wenjiapo as the source rock.Quantitative forward modeling of TTG magmatism revealed that 25％water-bearing melting at a geothermal gradient of 900℃/GPa satisfies the conditions for the formation of the 2.5 Ga TTGs in the Zhongtiao Mountains.The findings suggest that these TTGs formed in a warm subduction environment,indicating that by 2.5 Ga,the North China Craton had already developed a horizontal growth mechanism,consistent with global plate growth events.Additionally,anomalies in certain geochemical indicators suggest that the tectonic mechanism was beginning to transition toward a modern plate subduction environment.关键词
太古宙/中条山/TTG岩石/暖俯冲/华北克拉通Key words
Archean/Zhongtiao Mountains/trondhjemite-tonalite-granodiorite(TTG)/warm subduction/North China Craton(NCC)分类
天文与地球科学引用本文复制引用
焦东晨,曲军峰..山西中条山2.5 Ga TTG岩石的暖俯冲成因[J].地质通报,2024,43(12):2272-2287,16.基金项目
中国地质科学院基本科研业务费专项经费(编号:JKYZD202309,YYMF201604) （编号:JKYZD202309,YYMF201604）
