Advanced Materials Research Vols. 1010-1012

Abstract: The Longmenshan fault zone has been a research hotspot, but fewer scholars have paid attention to its transverse faults. According to the analysis of regional tectonic, seismic activities, geomorphic features, remote sensing images, and deep geophysical data, combined with field studies, the existence, distribution and type of the transverse faults in the Longmenshan fault zone were demonstrated. Research shows that there are 9 transverse faults that lie parallel to each other approximately at ~50km intervals in the Longmenshan fault zone. And transverse faults can be divided into regional transverse faults and localized transverse faults with NW strike, nearly EW strike and nearly SN strike.

Abstract: It is of great importance in classifying reservoirs and establishing the relationship of pore structure and productivity for formation evaluation and reserves estimation. In this study, based on the morphological characteristics and the difference of pore structure evaluation parameters acquired from mercury injection capillary pressure (MICP) data, which were obtained from the experimental results of 20 core samples drilled from Chang 6 tight sandstone Formation of north Ordos basin, the Chang 6 formation is classified into three types, and the corresponding average MICP curves of every types are obtained. These were usable in determining the potential target formation and predicting the productivity in tight sandstone reservoirs.

Abstract: Firstly, the evaluation system of the priority sequence of mineral resources development was constructed from five aspects as mineral resources endowment, market conditions, technical conditions, social and economic conditions and environmental protection conditions. Then, the priority sequence model of mineral resources development based on grey correlation analysis was proposed. Further, taken the mineral resources in Hebei province as an example, the empirical analysis of the above model was made. Results show that the suitability of the province's mineral development from big to small is, in order, molybdenum ore, cement-used limestone, iron ore, gold ore, silver ore, coal, and etc. The algorithm is not only simple and intuitive, but also improves the efficiency and accuracy of the prioritize division of mineral resource development.

Abstract: Subtle fault zones are caused by the weak deformation generated in the sedimentary cover of a sag due to the influence of regional or local stress fields or basement faults. They are too subtle to be easily identified by conventional exploration methods and technologies and are thus usually ignored. Research results prove that there are two basement faults in the Jinhu sag referred to as the NE-and NW-trending basement faults. Parts of the NE-trending basement fault are intense enough to control sag formation and evolution (such as the faults in Yangcun and Shigang, etc.). However, the NW-trending and the rest of the NE-trending basement faults show weak activity and exert little influence on sedimentary cover deformation. These faults merely yield some weakly-deformed trend zones in the sedimentary cover, such as small en-echelon faults, small faults intermittently distributed along fixed directions, buried alluvial fans, zonal or stringy oil-gas traps, or linear structures (such as local folds, narrow and deep half-grabens, etc.). Apart from the two aforementioned types of subtle fault zones, intermittent and stringy NS-trending subtle fault zones are also induced by the EW-trending extrusion stress component in the sag generated by the regional dextral stress field. Keywords: Jinhu sag; basement faults; subtle fault zones; tectonic evolution; en-echelon; trap distribution

Abstract: The Tianshan Orogenic Belt, which is located in the southwestern part of the Central Asian Orogenic Belt (CAOB), is an important component in the reconstruction of the tectonic evolution of the CAOB. In order to examine the evolution of the Tianshan Orogenic Belt, we performed macroscopic, microscopic structure observations analyses with deformed rocks along orogen-perpendicular transects pass Wuwamen in the South Tianshan orogenic belt of south west China, and we propose that the South Tianshan Orogenic belt enterwent a high temperature deformation in Wuwamen area during the plate interactions in Late Paleozoic.

Abstract: It is discussed characteristic and dominant factors of lower-middle Ordovician cave-reservoir in southern Tahe oilfield by analyzing data such as core, well drilling, logging, and seismic systematically, and by applying reservoir identifying, wells comparing, section of seismic analyzing, and ancient physiognomy recovering technology in this article. Three cave layers effected by the early hercynian karstification have been discovered in the study area. In single well section, the cave layer with strong heterogeneity corresponds with the Karst cycle with six combinations. The cave layers dominated by the early hercynian unconformity concentrate under0-200metre of the unconformity surface. The nearer to the unconformity surface, the more caves are filled. With effecting of fracture, the caves layers, especially larger cave, are often discovered in fractures concentrated zone. With effecting of ancient physiognomy, the caves layers are often in gentle carbonate slope. The unconformity, regional fractures and ancient physiognomy are the dominant factors of lower-middle Ordovician cave-reservoir in southern Tahe oil field.

Abstract: Kanggurtag-Yamansu ductile shear zone is the largest ductile shear zone in the East Tianshan orogenic belt. Deformation characteristics and structural associations of the shear zone suggest that the shear zone was formed by Nearly N-S compression duing late Carboniferous-early Permian. Which confirmed that the Eastern Tianshan mountains along the southern edge of the Turpan Basin were the results of plate interactions in Late Paleozoic.

Abstract: The Structural and deformational features of fold-thrust belt in the north margin of Kashi，southern Tian Shan were disclosed based on various data such as two dimensional seismic profile and field geologic survey. The results show that the fold-thrustbelt can be divided into several rows of anticlines, includingKalaboketuoer-Wenguer, Tuopa-Kangxiweier, Atushi and Kashi on plane,and the development of Atushi anticlines and its north side was controlled by the activity of the thrust system originated along the middle Cambrian Awatage Group from north to south. The fold-thrust belt can be divided into two different spatial levels: the shallow tectonic is a large scale imbricate thrust system, the detachment surface is uplifted from Cambrian system to Neogene system; the deep structure is a buried duplex structure system, the fault in floor and fault in roof are located at gypsic horizon in Cambrian and Neogene systemrespectively. Based on structural deformation analyzing and balanced section technology, the distribution of each anticlinal belt and the structure style of the low and deep thrust systems are confirmed. In this area the distance is shortened by 32.64～49.1km from north to south since Pliocene with the scalage of 40.5%～50.51%，and its average crustal shortening rate is 9.11～13.71mm/a.

Abstract: Shale of rich organic matter presents in Upper Carboniferous in Qaidam Basin, Northwest of China. Carboniferous shale thickness is between 100 ~ 300m in the Qaidam Basin, the shale includes silty mudstone shale, calcareous mudstone, shale and carbonaceous shale, and it is very favorable lithology type for shale gas. According to the shale organic geochemical analysis, the abundance of organic matter reaching the middle - good degree of hydrocarbon source rocks; the type of organic matter is mainly II₂ and III type. The maturity of organic matter is mainly between 1 % -1.3 %. The Upper Carboniferous shale thermal evolution is in mature oil and gas stage. The Upper Carboniferous hydrocarbon-rich shale distribute stability, with great thickness. Shale gas potential in Upper Carboniferous is quite large.

Abstract: The occurrence and homogenization temperature of fluid inclusions as well as salinity measurement and Laser Raman test, etc. from Tumengela Formation of Upper Triassic in Woruo Mountain area of North Qiangtang Basin are analyzed in this paper. Which indicating that the inclusions of the study area are mostly in small size with rules and developed in strips or groups. The GOI of the inclusions is especially high, and the homogenization temperature shows two peak values. Besides, the organic inclusions fluorescent display is extremely weak or even nothing. It is believed by combining of the analysis of the host mineral diagenesis stages and salinity of brine in the inclusions that there existed two large scale processes of hydrocarbon generation and migration. Namely, early one is in a small scale with oil migration, later one is in a large scale with gas migration.