摘要
松辽盆地南部遭受了多期不同性质的断裂构造运动,形成了多种形式的断裂反转构造。在断陷期,断裂反转构造主要表现为正断层;反转期,断裂反转构造发生逆冲,并在断裂的上盘形成了反转背斜带。在局部反转背斜构造上,由于地层褶皱隆升,形成了剥蚀构造天窗。其中,反转断裂切割了基岩至嫩江组地层,导致深部沙河子组、营城组等烃源岩所形成的油气、CO2和煤成气等还原性流体沿反转断裂向上运移,引起浅部较为疏松的泉头组和姚家组红色砂体发生后生还原蚀变,形成有利于铀成矿的灰色砂岩目的层。同时,反转作用形成的剥蚀构造天窗,使目的层裸露于地表,接受含氧含铀水的渗入和氧化作用,为层间氧化带及其铀矿化的形成创造了有利条件。
The faults in the south of Songliao basin suffered multiple distinct tectonic movements and some kinds of reversal structure were developed. At the period of fault subsidence, these structures acted as normal fault. At the period of reverse, they occured thrusting and cause the hanging wall of the faults to form reverse anticlinal belt. Due to the folding and uplifting, scuttle structure of ablation was shaped at some part of the anticlinal belt. Among them, the reversal faults dissected the layers from base rock to Nenjiang group, caused the reductive fluids such as oil, carbon dioxide, coal derived gas migrating upward, which was generated by oil source rock of Shahezi and Yingcheng group from the lower layer. These fluids made the loose red sand body reduced exogeneously and create some gray sandstone which are favour of uranium mineralization. At the same time, the scuttle structure of ablation shaped by the reverse process lead the layer of interest exposed to the air to suffer oxidation and infiltration of urania, which is favourable to interlayer oxidation and mineralization of uranium.
出处
《铀矿地质》
CAS
CSCD
2008年第4期195-200,共6页
Uranium Geology
关键词
断裂反转构造
剥蚀构造天窗
砂岩型铀矿
松辽盆地
reversal faulted structure
scuttle structure of ablation
sandstone type uranium deposit
Songliao basin
