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Basement hydrocarbon reservoirs are widely distributed worldwide. In recent years, a major breakthrough has been made in basement-rock hydrocarbon exploration in the Qaidam Basin, and basement-rock reservoirs have become important exploration targets in the basin. Basement hydrocarbon reservoirs are a special type of oil and gas reservoirs. This type of reservoir requires not only the same formation conditions as conventional hydrocarbon reservoirs but also some unique reservoir conditions. In this study, several geochemical, geophysical, and geological methods are used to assess the hydrocarbon accumulation conditions and mechanisms of the basement-rock reservoirs found in the Qaidam Basin, and the main factors controlling the reservoirs are proposed. Major hydrocarbon-generation depressions controlled the overall basement-rock reservoir distribution, paleo-uplifts (or paleo-salients) and paleo-slopes controlled the hydrocarbon migration directions, faults and unconformities controlled hydrocarbon-migration channel systems, and weathered-crust reservoirs of basement rocks controlled hydrocarbon enrichment. In addition, a suitable cap rock is an important requirement for preservation. Suggestions for future explorations have been put forward in this study, which will be of significance for guiding petroleum exploration in the area. Promising future exploration areas include the western part of the Kunbei fault-terrace zone in the front of the Kunlun Mountains, the paleo-uplift in the western part of the Altun Mountains front, and the Pingtai and the Mahai–Dahonggou paleo-uplift in the front of the Qilian Mountains.

Thermochronological dating was used to study the thermal evolution of the Mesozoic plutons and uplift history of the Yanshan orogenic belt. The results show that the cooling history of the plutons is complicated, corresponding to the inhomogeneous uplift process of the Yanshan orogenic belt. The Panshan granite cooled fast during 226.48–204.95 Ma at a rate of 10.22°C/Ma after its emplacement at a depth of about 10 km, and its fast uplift occurred in about 96–35 Ma at an average rate of 0.115 mm/a. The Wulingshan pluton cooled fast during 132–127.23 Ma at a rate of 94.34°C/Ma, and its rapid uplift occurred in 86–45 Ma at an average rate of 0.186 mm/a. The Yunmengshan granite cooled fast during 143–120.99 Ma at a rate of 19.51°C/Ma, and its rapid uplift occurred in 106–103.95 Ma and 20–0.0 Ma at a rate of 1.06 mm/a and 0.15 mm/a respectively. The Sihetang granite-gneiss uplifted rapidly since 13 Ma at an average rate of 0.256 mm/a. The Badaling granite uplifted rapidly since 6 Ma at an average rate of 0.556 mm/a. The Cenozoic uplift of the Yanshan Mountains can be well correlated to the rifting process of the surrounding basins.

An earthquake of Ms 8 struck Wenchuan County, western Sichuan, China, on May 12th, 2008 and resulted in long surface ruptures (>300 km). The first-hand observations about the surface ruptures produced by the earthquake in the worst-hit areas of Yingxiu, Beichuan and Qingchuan, ascertained that the causative structure of the earthquake was in the central fault zones of the Longmenshan tectonic belt. Average co-seismic vertical displacements along the individual fault of the Yingxiu-Beichuan rupture zone reach 2.5-4 m and the cumulative vertical displacements across the central and frontal Longmenshan fault belt is about 5–6 m. The surface rupture strength was reduced from north of Beichuan to Qingchuan County and shows 2–3 m dextral strike-slip component. The Wenchuan thrust-faulting earthquake is a manifestation of eastward growth of the Tibetan Plateau under the action of continuous convergence of the Indian and Eurasian continents.

This paper discusses the seismic activity in Beijing Municipality and its adjacent areas (which are referred to as the Beijing region in the paper). By using fuzzy mathematics, the factors controlling regional crustal stability are transformed into fuzzy information and then a model of fuzzy diagnosis is established. A fuzzy comprehensive evaluation of regional crustal stability in the Beijing region is made according to the seismic and geological conditions of the region.

Using the reported new U-Pb age with the Sensitive High-Resolution Ion Microprobe (SHRIMP II), zircon U-Pb ages were obtained from two samples of K-feldspar felsic paragneiss and K-feldspar gneissoid trondhjemite on the southern margin of the Taihang Mountains in the North China Craton. The protolith of the K-feldspar felsic paragneiss is argillaceous-sandy clastic sedimentary rock, probably deposited in the Neoarchean. Most of the detritus zircons show heavy loss of Pb. Five spots of zircons near the upper point, yield a weighted mean 207Pb/206Pb age of 3399±8 Ma, representing an age of the sedimentary source. Two groups of zircons from the K-feldspar gneissoid trondhjemite give weighted mean 207Pb/206Pb ages of 2511±13 Ma and 2735±16 Ma respectively. The former represents the emplacement time of the pluton, while the latter is interpreted as the age of the inherited zircons. The new data support that the Archean geological body in the central zone has an affinity with those from the eastern block of the North China Craton.

This paper discusses the ground failures triggered by the surface wave (magnitude of 8.1) Central Kunlun Earthquake, northeast Tibet. It developed along the line of the Eastern Kunlun Active Fault Zone, which is known to experience left-lateral movements of 10–12 mm/year. The rupture zone was some 426 km long with left-lateral strike-slips of up to 16.3 m—one of the largest continental strike-slip rupture zones reported. The paper describes the fissures, ground dislocations, mole structures, depressions, scarps and liquefaction which occurred and discusses the risk of potential future movements for the Qinghai–Tibet railway, presently being constructed.

Since the beginning of the Cenozoic, north China has been fragmented by intensive intracontinental rifting and extensional tectonics, which resulted in the formation of two extensional domains: the graben systems around the Ordos block in the west and North China Plain in the east. How to link this Cenozoic extensional tectonics to plate kinematics has long been an issue of debate. This paper presents updated results of fault slip data sets collected in different zones in north China and addresses the changes in the direction of extensional stresses over the Cenozoic. A chronology of three successive extensions has been established and provides evidence for constraining the timing and location of either subduction-induced back-arc tectonics along the western Pacific or collision-related extrusion tectonics in Tibet. The oldest NW–SE trending extension occurred concomitantly with the early Tertiary rifting phase, which was initiated in a back-arc setting associated with westward subduction of the Pacific plate under the Asia continent. North China had been subjected, during the Miocene, to regional subsidence with widespread basalt flow, and the direction of extension changed to NE–SW to NNE–SSW, consistent with the spreading direction of the Japan Sea. The dynamic origin of this extension is poorly understood. Since the latest Miocene or earliest Pliocene, north China has been dominated by NW–SE extension resulting in the formation and development of the elongate graben systems around the rigid Ordos block. This extensional phase is accompanied by counterclockwise rotation of blocks such as Ordos, Taihangshan Massif etc., which are bounded to south by the left-lateral strike-slip Qinling fault system. The overall Pliocene-Quaternary deformation in north China accommodates an ESE-ward extrusion of the south China block relative to the Gobi-Mongolia plateau, as the consequence of late-stage India–Eurasia convergence.