| The scope of the study area mainly Xilinguole and Xing'an League from East to western region. Xilin Gol League is located in the middle of the Mongolia—Autonomous Region,The study area is located in east longitude 115°13'-ll7°06 ', latitude 43°02'-44°52', are mainly located in Erlian Basin, Songliao basin and Hailar Basin. The study area and adjacent areas is located in the south of the great arc tectonic belt, between North China Platform and the Siberian plate Paleozoic orogenic belt in Inner Mongolia。By the North China platform, the ancient Mongolia and the Siberian plate oceanic crust at subduction multi-phase, the effects of collision and docking, Paleozoic volcanic - sedimentary rocks are widely distributed, the Late Paleozoic strata in the study area are mainly dominated by marine limestone strata and there are also a small amount of clastic rock which contain many kinds of fossils, and a great deal of biological reef; there is a progressive change that the lithostratigraphic units become younger from north to south, the strike direction is latitudinal direction or almost latitudinal direction. Late Paleozoic strata area of Mongolia is good land continental margin sediments. Inner Mongolia marine deposit is the main body of the Devonian which have a vast distribution in the north area, the area exposed strata are Paramisgurnus River Group, Hanau oboo group Taerba gete groups, such as Ingres Yam Wulashan Group . Carboniferous strata exposed mud basin, as opposed to less Shaximiao bulag, bumbat group. The lithologic character is mainly terrigenous clastic deposition under neritic facies, partial see undersea volcanic eruptions and clastic sedimentary rocks output interbedded. The important Permian strata in this area are under the EC tolgoi Al group and the philosophy of the EC group and the puerarin oboo Linxi group.In this paper, by the study of the measured field profile analysis, mineral composition of the research and illite crystallinity, then come to a discussion of the study area to determine the intensity of contact metamorphic reactions and the extent of, and determine the mineral into the temperature and pressure, discussed he temperature and pressure relationship between the low level of contact metamorphism and metamorphic very low-grade metamorphism. Use the typical contact metamorphic halo to identify typical metamorphic facies.According to the study on the metamorphic belt ,contact metamorphic belt and illite crystallinity to determine the intenses thermal contact metamorphism of the igneous body. Combined with previous studies, summed up the contact metamorphism degree in the central and western Inner Mongolia, and have a further study on the reconstruction of the late Paleozoic strata in the central and western regions of Inner Mongolia which caused by contact metamorphism.According to the degree of metamorphic rock, from the outward-looking in can be divided into three metamorphic belt: Spotted slate belt, andalusite, biotite with cordierite hornfels belt angle, the contact metamorphic belt in the most affected area 300—500 meters, there has been andalusite actinolite metamorphic minerals, etc., on behalf of low-grade metamorphism, but the metamorphic minerals from the rock in places closer to the general rock mass at a distance of 70-100 meters in the field of rock metamorphism Although there have been , But it is not clear, for example, in the sandstone of the cement, such as occurred in sericite, are very low metamorphic grade, the majority were spotted with slate and mineral characteristics are not clear, temperature about 350°in the following, which and the back we have to introduce the metamorphic minerals of the illite crystallinity and concluded that the same, this article summarizes the study area in the Late Paleozoic of the intensity of contact metamorphism, the overall in biotite - andalusite zone and spotted slate belt, the former the scope of the impact of the smaller, most of the contact metamorphic rocks are in the latter, as well as illite crystallinity provides the premise of the discussion.Because of the constrains of the technical means and methods , this article only study the clay mineral assemblages and illite crystallinity in order to discuss Late Paleozoic stratigraphy and development of the degree of dynamic metamorphism in Inner Mongolia. In this paper, select 0.215 and 0.40 illite crystallinity values, respectively, as the diagenetic zone, the last metamorphic belt and shallow metamorphic belt line. We select 26 samples in order to study the illite crystallinity analysis where the contact metamorphism took place ,the major samples are from late Carboniferous and Devonian, come to the illite crystallinity is 0.36 and 0.31 on average, than region on the illite crystallinity values below 0.56 and 0.41 shows that the SP Late Paleozoic magmatic activities on the West Inner Mongolia, Late Paleozoic strata have been modified. However, despite the impact of the magmatic activity, the degree of contact metamorphism zone is not high, the degree of metamorphic rock are still grapes - green stone with defibrillators. Although the measurements show that a number of sections of rock in the vicinity of the contact zone of the metamorphic minerals such as andalusite, but occurred in the overall profile or very low-grade metamorphism. Therefore, this transformation is still very limited.
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