热水沉积成矿盆地的热状态及热演化分析与研究思路——热水沉积成矿盆地分析与研究之四

Analysis and approach on geothermal state and evolution of hydrothermal depositional sedimentary basin

根据对秦岭泥盆纪沉积盆地的构造成盆 -后期构造变形特征研究 ,秦岭造山带泥盆纪热水沉积成矿盆地中构造 -热流体地质事件可初步厘定如下 :1中泥盆世伸展构造成盆 -热水同生沉积成矿事件 (D1)。2晚泥盆世 -石炭纪伸展变形 -深源热流体叠加事件 (D2 )。3印支期挤压收缩变形 -热改造事件 (D3 )。 4燕山期逆冲推覆构造改造 -深源热流体叠加及脆性变形事件 (D4 )。 5喜玛拉雅山期脆性变形 (D5)。从盆地热状态及热演化研究角度看 ,盆地内充填地层体中有机质及矿物可以记录热状态及热演化历史 ,利用盆地内充填地层体中有机质及矿物温度计可以反演盆地内充填地层体形成时盆地热状态和盆地底部热流。认为热水沉积成矿盆地热状态及热演化主要研究方法有主要矿物流体包裹体测温、镜质体反射率 (R0 )法、氧同位素地质温度计法等。

According to research on tectonic basin formation and post tectonic deformation of the Devonian sedimentary, the geothermal events of tectonic hydrothermal fluid in the Devonian hydrothermal deposition basins in the Qinling orogen can be, roughly speaking, recognized as follows: 1 the geothermal event of the Devonian basin formation of extensional tectonism hydrothermal deposition (D 1); 2 the geothermal event of the end of the Late Devonian to the Carboniferous extensional deformation of basin superimposing of deep source hot fluids(D 2);3 the geothermal event of compression deformation of basin superimposing of hydrothermal fluids in the Indo Chinese orogen(D 3);4 the geothermal event of nappe thrust deformation of the basin in the Early Yanshanian orogen and superimposing of deep source hydrothermal fluids and brittle deformation of the basin in the Late Yanshanian orogen (D 4); 5 the geoevent of brittle deformation of the basin in the Himalayan (D 5) In the coarse of sedimentary basin formation and evolution, geothermal regime is variable in the basin but still can be recovered on the basis of special approach In the recovery of geothermal state and geothermal evolution in the hydrothermal deposition basin, fluid inclusion of mineral, maturity grade of organism, thermometer of minerals and oxygen isotope can be employed to reconstruct paleo temperature of hydrothermal activities in the basin