Genesis Significance Of Clay Mineral Assemblage In The Upper Paleozoic, In Northeastern Inner Mongolia

Northeastern Inner Mongolia lies in eastern East Asia orogenic zone, geotectonic unit consists of EErGuNa and Xingan massif,SongNeng massif and JiaMuSi massif typically. Neopaleozoic formation makes up of a battery of marine deposit formation and partial continental deposit formation, rock are argillaceous rock(mudstone,silty mudstone,argillaceous siltstoue etc.)and carbonate etc., and it contains abundant hydrocarbon resources, which is the most promising area for finding marine exploration activity new area and new territory. The structure in this religion has NE structure and EW structure mainly. By means of XRD and TEM technique, predecessors analyzed and studied illite genesis sign among Neopaleozoic argillaceous rock, researched Neopaleozoic very low-grade metamorphism in Northeastern Inner Mongolia by illite crystallinity index and b0 value etc. and obtained the result that Neopaleozoic main layer in this religion was late diagenetic zone and low anchizone.This thesis studies varied feature of clay mineral content during different diagenic-very low-grade metamorphism intensity band in the upper Paleozoic, in Northeastern Inner Mongolia, according to illite crystallinity < 0.25( epimetamorphism band ),illite crystallinity 0.25-0.42 (low anchizone) illite crystallinity>0.42 ( late diagenetic zone),discusses varied tendency of clay mineral relative content,mixed layer clay mineral ratio,clay mineral assemblage etc. respectively,and probes into genesis significance of clay mineral assemblage.Our research demonstrate that clay mineral of argillaceous rock in the upper Paleozoic, in this area are illite,kaolinite,smectite,chlorite,illite / smectite mixed layer,chlorite/ smectite mixed layer etc.. Clay mineral distribution present feature in different time stratigraphic unit and diagenic-very low-grade metamorphism intensity belt as follows:①In Devonian anchizone, average illite crystallinity is 0.35, illite and chlorite are dominant among these clay mineral, content of kaolinite is very low, rate mixed-layer of smectite in mixed-layer mineral (illite / smectite mixed layer and chlorite/ smectite mixed layer) is lower relatively(25%);in diagenetic zone, average illite crystallinity is 0.48, illite and chlorite are dominant among these clay mineral, but content of kaolinite is higher relatively(6%), rate mixed-layer of smectite in mixed-layer mineral is higher relatively(34%).②In Carboniferous anchizone, average illite crystallinity is 0.37, relative content of illite is 66.50%, relative content of illite / smectite mixed layer is 16.00%;in diagenetic zone, average illite crystallinity is 0.58, relative content of illite is 62.00%, relative content of illite / smectite mixed layer is 26.17%.③In Permian anchizone, average illite crystallinity is 0.31, relative content of illite is 65.84%, relative content of illite / smectite mixed layer is 8.74%, rate mixed-layer of smectite in illite / smectite mixed layer and chlorite/ smectite mixed layer is 31.67% and 23.67%,the sum of them is 55.34%; in diagenetic zone, average illite crystallinity is 0.61, relative content of illite is 56.75%, relative content of illite / smectite mixed layer is 37.00%, rate mixed-layer of smectite in illite / smectite mixed layer and chlorite/ smectite mixed layer is 28.75% and 42.50%,the sum of them is 71.25%.④In region of interest, relative content of illite is negative related with illite crystallinity, coefficient of correlation is -0.206;relative content of chlorite is negative related with illite crystallinity, coefficient of correlation is -0.170; relative content of illite / smectite mixed layer is positive related with illite crystallinity, coefficient of correlation is 0.479.⑤There are correlation among these clay mineral,presenting positive correlation are kaolinite and chlorite/ smectite mixed layer,rate of illite / smectite mixed layer,rate of chlorite/ smectite mixed layer,chlorite/ smectite mixed layer and rate of illite / smectite mixed layer,rate of chlorite/ smectite mixed layer,rate of illite / smectite mixed layer and rate of chlorite/ smectite mixed layer; presenting negative correlation are illite / smectite mixed layer and illite, kaolinite and chlorite, chlorite and illite / smectite mixed layer,chlorite/ smectite mixed layer,rate of illite / smectite mixed layer,rate of chlorite/ smectite mixed layer.