摘要
冀北地区金、银多金属成矿作用研究表明，金、银等成矿元素除部分萃取自含矿围岩外，主要来自深源。幔枝构造是重要的热源释放体系，控制着深源含矿流体的迁移、聚集和成矿，从而构成了以幔枝构造为中心，内带为金、外带为银多金属的构造－岩浆成矿系列，并据此归纳出幔枝构造成矿模式。
A study of gold silver polymetallic mineralization in northern Hebei area reveals that tectonic activity seems to be the leading factor controlling the ore forming process. Besides being partly derived from ore bearing wall rocks, gold, silver and some other ore elements mainly came from the depth. Multistage evolution of mantle plume resulted in the formation of deep channelways for migration of ore materials. The tabular low velocity block in the upper part of Hehuai submantle material was decoupled below the orogenic belt. The incision of ductile shear zone along the Yanshanian axial part of orogenic belt caused depressurization and unloading of the deeper part , which in turn resulted in the ascending of anatectic magma and the formation of the third order mantle branching of mantle plume. The formation of mantle branch structure and the activity of anatectic magma derived from mantle branch were frequently controlled by sharply declined ductile shear zones in different directions. At surface, there appeared upwarped structure with the tectonomagmatic belt as the axis, in which the cover rocks of quickly upwarping segments were largely decoupled and the basement rocks were exposed, leading to the formation of typical metamorphic core complex. The mantle branch structure not only served as an important releasing system of thermal energy but controlled the migration and concentration of ore bearing fluids. Different typical deposits were formed in different locations of the mantle branch structure. According to multidisciplinary analysis, three large tectonomagmatic metallogenic series have been recognized, which are respectively related to mantle thermal fluid activity, ductile shear zone and tectonomagmatic zone. In addition, a typical mantle branch metallogenic model has been advanced in this paper.
出处
《矿床地质》
CAS
CSCD
北大核心
1996年第4期298-307,共10页
Mineral Deposits
基金
"八五"地质矿产部地质找矿科技
