TY - JOUR
T1 - The Crustal and Uppermost Mantle Vs Structure of the Middle and Lower Reaches of the Yangtze River Metallogenic Belt
T2 - Implications for Metallogenic Process
AU - Zhang, Yongqian
AU - Lü, Qingtian
AU - Shi, Danian
AU - Yang, Yingjie
AU - Afonso, Juan Carlos
AU - Xu, Yao
AU - Yan, Jiayong
AU - Gong, Xuejing
AU - Xu, Tao
N1 - Publisher Copyright:
© 2023. American Geophysical Union. All Rights Reserved.
PY - 2023/8
Y1 - 2023/8
N2 - The Middle and Lower Reaches of the Yangtze River metallogenic belt (MLYMB) is one of the most important Fe-Cu polymetallic belts in China. However, the mechanism and deep geodynamical process for the formation of this belt are still controversial. Here, we obtain the crustal and the uppermost mantle structures using ambient noise data from a dense seismic profile. A low velocity zone is revealed beneath the Moho of MLYMB, interpreted as the source of the deep mineralization materials. In addition, a low velocity layer (LVL) and a high velocity layer (HVL) are observed in the crust of the southern segment of the profile. The LVL is interpreted as a tectonic detachment layer between the upper and the lower crust, and the HVL is interpreted as the aggregation zone for mineralizing melts or crystallized magma chambers. Based on the observed velocity features, we propose a three-stage model for the formation of ore deposits in MLYMB. Our model suggests that an upwelling of asthenosphere triggered by the delamination of a previously thickened lithosphere leads to the partial melting of upper mantle rocks, which eventually ponders under the Moho. The magma then infiltrates through the ductile lower crust and reaches a depth of ∼7–13 km, forming a minerals-enriched magma chamber. Minerals-rich hot fluids originating from the magma chamber continue to move upward along the pre-existent faults and the minerals finally precipitate in dense veinlets when reaching shallow depths, forming the ore deposits in and around the MLYMB.
AB - The Middle and Lower Reaches of the Yangtze River metallogenic belt (MLYMB) is one of the most important Fe-Cu polymetallic belts in China. However, the mechanism and deep geodynamical process for the formation of this belt are still controversial. Here, we obtain the crustal and the uppermost mantle structures using ambient noise data from a dense seismic profile. A low velocity zone is revealed beneath the Moho of MLYMB, interpreted as the source of the deep mineralization materials. In addition, a low velocity layer (LVL) and a high velocity layer (HVL) are observed in the crust of the southern segment of the profile. The LVL is interpreted as a tectonic detachment layer between the upper and the lower crust, and the HVL is interpreted as the aggregation zone for mineralizing melts or crystallized magma chambers. Based on the observed velocity features, we propose a three-stage model for the formation of ore deposits in MLYMB. Our model suggests that an upwelling of asthenosphere triggered by the delamination of a previously thickened lithosphere leads to the partial melting of upper mantle rocks, which eventually ponders under the Moho. The magma then infiltrates through the ductile lower crust and reaches a depth of ∼7–13 km, forming a minerals-enriched magma chamber. Minerals-rich hot fluids originating from the magma chamber continue to move upward along the pre-existent faults and the minerals finally precipitate in dense veinlets when reaching shallow depths, forming the ore deposits in and around the MLYMB.
KW - 2024 OA procedure
KW - Metallogenic belt
KW - Metallogenic model
KW - Middle and lower reaches of the Yangtze River
KW - Shear wave velocity
KW - Ambient noise tomography
KW - ITC-ISI-JOURNAL-ARTICLE
U2 - 10.1029/2023JB026817
DO - 10.1029/2023JB026817
M3 - Article
AN - SCOPUS:85166749337
SN - 2169-9313
VL - 128
JO - Journal of Geophysical Research: Solid Earth
JF - Journal of Geophysical Research: Solid Earth
IS - 8
M1 - e2023JB026817
ER -