On geophysical background of superlarge deposits in the Chinese continent

Citation
C. Peng et al., On geophysical background of superlarge deposits in the Chinese continent, ACT GEO S-E, 73(2), 1999, pp. 193-200
Citations number
11
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
ACTA GEOLOGICA SINICA-ENGLISH EDITION
ISSN journal
1000-9515 → ACNP
Volume
73
Issue
2
Year of publication
1999
Pages
193 - 200
Database
ISI
SICI code
1000-9515(199906)73:2<193:OGBOSD>2.0.ZU;2-X
Abstract
Based on the study of tens of geophysical profiles (seismic, geothermal flo w and magnetotelluric sounding profiles) and 3-D shear wave velocity struct ures of the Chinese continent and its neighbouring regions, this paper desc ribes the 3-D crustal and upper mantle structures and discusses briefly the deep geophysical background of superlarge ore deposits in the Chinese cont inent. Superlarge deposits are usually very few in number, but they are dis tributed still in certain forms such as "point", "zone" and "area". Most of the large-, medium- and small-sized deposits occur near the margins of dif ferent 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 inhomo geneity (weak zones) in the upper mantle. The superlarge endogenic polymeta llic deposits are almost unevenly distributed in three major ore zones in C hina, corresponding to the boundaries of inhomogeneous regions in the asthe nosphere. The authors argue that the lithospheric structure is to some extent in agre ement with the geotectonic units, suggesting that the crust structure is in fluenced and restricted by the lithosphere, and that the crust and upper ma ntle both exhibit low-velocity nature. Therefore, vertical low-velocity zon es of seismic waves are considered to be a favourable environment for endog enic polymetallic ore belts.