Based on the study of tens of geophysical profiles (seismic, geothermal flow and magnetotelluric sounding profiles) and 3-D shear wave velocity structures of the Chinese continent and its neighbouring regions, this pa...Based on the study of tens of geophysical profiles (seismic, geothermal flow and magnetotelluric sounding profiles) and 3-D shear wave velocity structures of the Chinese continent and its neighbouring regions, this paper describes the 3-D crustal and upper mantle structures and discusses briefly the deep geophysical background of superlarge ore deposits in the Chinese continent. Superlarge deposits are usually very few in number, but they are distributed still in certain forms such as “point”, “zone” and “area”. Most of the large-, medium- and small-sized deposits occur near the margins of different tectonic units; while the superlarge endogenic polymetallic deposits occur mostly in thinned mantle lithosphere, uplifts of the asthenosphere (vertical low-velocity zones) and the transformation zones of lateral inhomogeneity (weak zones) in the upper mantle. The superlarge endogenic polymetallic deposits are almost unevenly distributed in three major ore zones in China, corresponding to the boundaries of inhomogeneous regions in the asthenosphere.展开更多
Recent seismic studies reveal a sharp velocity drop mostly at^70–100 km depth within the thick mantle keel beneath cratons, termed the mid-lithosphere discontinuity(MLD). The common presence of the MLD in cratonic re...Recent seismic studies reveal a sharp velocity drop mostly at^70–100 km depth within the thick mantle keel beneath cratons, termed the mid-lithosphere discontinuity(MLD). The common presence of the MLD in cratonic regions indicates structural and property layering of the subcontinental lithospheric mantle(SCLM). The nature and origin of the MLD, and many issues associated with the layering of the SCLM are essential to understand the formation and evolution of continents, and have become frontier subjects in the Earth sciences.展开更多
The lithospheric mantle is one of the key layers controlling the stability of continents.Even a small amount of water can influence many chemical and physical properties of rocks and minerals.Consequently,it is a pivo...The lithospheric mantle is one of the key layers controlling the stability of continents.Even a small amount of water can influence many chemical and physical properties of rocks and minerals.Consequently,it is a pivotal task to study the distribution of water in the continental lithosphere.This paper presents a brief overview of the current state of knowledge about(1)the occurrence of water in the continental lithospheric mantle,(2)the spatial and temporal variations of the water content in the continental lithospheric mantle,and(3)the relationship between water content and continent stability.Additionally,suggestions for future research directions are briefly discussed.展开更多
文摘Based on the study of tens of geophysical profiles (seismic, geothermal flow and magnetotelluric sounding profiles) and 3-D shear wave velocity structures of the Chinese continent and its neighbouring regions, this paper describes the 3-D crustal and upper mantle structures and discusses briefly the deep geophysical background of superlarge ore deposits in the Chinese continent. Superlarge deposits are usually very few in number, but they are distributed still in certain forms such as “point”, “zone” and “area”. Most of the large-, medium- and small-sized deposits occur near the margins of different tectonic units; while the superlarge endogenic polymetallic deposits occur mostly in thinned mantle lithosphere, uplifts of the asthenosphere (vertical low-velocity zones) and the transformation zones of lateral inhomogeneity (weak zones) in the upper mantle. The superlarge endogenic polymetallic deposits are almost unevenly distributed in three major ore zones in China, corresponding to the boundaries of inhomogeneous regions in the asthenosphere.
基金supported by the National Natural Science Foundation of China (41225016, 41688103, 91414301)Chinese Academy of Sciences
文摘Recent seismic studies reveal a sharp velocity drop mostly at^70–100 km depth within the thick mantle keel beneath cratons, termed the mid-lithosphere discontinuity(MLD). The common presence of the MLD in cratonic regions indicates structural and property layering of the subcontinental lithospheric mantle(SCLM). The nature and origin of the MLD, and many issues associated with the layering of the SCLM are essential to understand the formation and evolution of continents, and have become frontier subjects in the Earth sciences.
基金supported by the National Natural Science Foundation of China (91014007, 90714009 and 40673028)
文摘The lithospheric mantle is one of the key layers controlling the stability of continents.Even a small amount of water can influence many chemical and physical properties of rocks and minerals.Consequently,it is a pivotal task to study the distribution of water in the continental lithosphere.This paper presents a brief overview of the current state of knowledge about(1)the occurrence of water in the continental lithospheric mantle,(2)the spatial and temporal variations of the water content in the continental lithospheric mantle,and(3)the relationship between water content and continent stability.Additionally,suggestions for future research directions are briefly discussed.
