Open AccessSHORT EPISODES OF CRUST GENERATION DURING PROTRACTED ACCRETIONARY PROCESSES: EVIDENCE FROM CENTRAL ASIAN OROGENIC BELT, NW CHINA
Author(s) -
GongJian Tang,
SunLin Chung,
Chris J. Hawkesworth,
Peter A. Cawood,
Qiang Wang,
Derek A. Wyman,
YiGang Xu,
Zhenhua Zhao
Publication year - 2017
Publication title -
geodinamika i tektonofizika
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.336
H-Index - 8
ISSN - 2078-502X
DOI - 10.5800/gt-2017-8-3-0294
Subject(s) - geology , crust , continental crust , magma , paleozoic , geochemistry , central asia , china , petrology , seismology , physical geography , volcano , geography , archaeology
continental crust but the spatial and temporal distribution of crust generation within individual orogens remains poorly constrained. Paleozoic (~540–270 Ma) granitic rocks from the Alati, Junggar and Chinese Tianshan segments of the Central Asian Orogenic Belt (CAOB) have markedly bimodal age frequency distributions with peaks of ages at ~400 Ma and 280 Ma for the Altai segment, and ~430 Ma and 300 Ma for the Junggar and Chinese Tianshan segments. Most of the magma was generated in short time intervals (~20–40 Ma), and variations in magma volumes and in Nd–Hf isotope ratios are taken to reflect variable rates of new crust generation within a long-lived convergent plate setting