摘要
盆-山耦合关系是当今地学研究的前沿课题。但是,在几何学上,成对盆山耦合论述较多。而华北东部裂陷盆地则西与太行造山带、北与燕山造山带、东与胶辽山地、南与大别造山带均构成盆-山耦合,即中心裂陷盆地与外围各造山带均为耦合关系。研究表明:中心裂陷与华北地幔亚热柱的形成密切相关,由于地幔亚热柱强烈上隆,在岩石圈底部受阻,使华北东部岩石圈发生热减薄-断陷的同时,向外拆离的地幔岩在盆地外围形成一系列次级隆起(太行、燕山、胶辽、大别造山带),即地幔热柱多级演化的第三级单元———幔枝构造。各幔枝构造(造山带)间具有明显的可比性,并共同与中心裂陷盆地构成盆-山耦合关系。与此同时,随地幔热柱-亚热柱-幔枝构造向上迁移的成矿元素,亦以气态-气液混合态-含矿流体的形式向上迁移,并最终在幔枝构造的有利聚集部位成矿,形成张宣、冀东、辽东、胶东、鲁西、小秦岭、阜平等幔枝构造成矿集中区。
The coupling relationship between basin and mountains is a frontier hot topic for geoscience today, and it is generally considered that fracture systems serves as the coupling links among tectonic groups, such as between extensional orogenic belts and rifting basins, between compressional orogenic belts and foreland basins, as well as between orogenic belts and strike-slip basins. The rifting basins in the east of North China are coupled with Taihang orogen in the west, with Yanshan orogen in the north, with Jiaoliao Mountains in the east and with Dabie orogen in the south, which means that the coupling relationships exist between the rifting basin in the center and each orogen in the peripheral regions. Our research indicates that the central rifting is closely related to formation of the mantle sub-plume in North China, this is because the intense underplating of mantle sub-plume was resisted at the bed of the lithosphere, which results in thermal thinning - rifting of the lithosphere in the east of North China, and meanwhile, formation of a series of secondary upheavals （Taihang, Yanshan, Jiaoliao, Dabie orogens） , i. e. , third grade units - mantle branch structures, in the peripheral regions of the basin by the pyrolite that was detached toward the outside. Here the mantle branch structures （orogens） can be compared with one another and are coupled jointly with the central rifting basin. At the same time, the ore-forming elements in the mantle plume - sub-plume - mantle branch structures migrate upward in forms of gas, gas-liquid, or ore-bearing fluid, etc. , which finally leads to formation of ores in favorable positions of mantle branch structures, such as ore-concentrated districts at Zhangxuan, Jidong, Liaodong, Jiaodong, Luxi, Xiaoqinling and Fuping.
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2006年第3期331-342,共12页
Geotectonica et Metallogenia
基金
国家自然科学基金(40272088
40372103)
中国科学院知识创新项目(KZCX107)
中国地质调查局(200110200038)项目资助.
关键词
盆-山耦合
地幔热柱
幔枝构造
裂陷盆地
造山带
成矿作用
华北地区
coupling relationship between basin and mountains
mantle plume
mantle branch
rifting basin
orogenic belt
mineralization
North China
