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[1] Contrasting models of upper crustal shortening versus lower crustal flow have been proposed to explain the formation of thickened crust in the Longmen Shan (LMS), eastern Tibetan Plateau (TP) margin. These models require different structural kinematics along the LMS, whose structural geometry is defined by three parallel NW-dipping fault zones. From foreland (southeast) to hinterland (northwest), they are the Guanxian-Anxian Fault, Yingxiu-Beichuan Fault (YBF), and Wenchuan-Maowen Fault (WMF). Newly derived and previously published low-temperature thermochronology data from the LMS were synthesized to constrain the spatial exhumation and test previous models. The results show that (1) exhumation increases abruptly across the range-bounding YBF, suggesting the fault being the main thrust boundary between the LMS and the Sichuan Basin to the east; (2) Younger Late Cenozoic cooling ages are found on the hinterland WMF, where a dichotomy of ages on the hanging wall versus footwall suggests Late Cenozoic thrust activity; and (3) toward the hinterland to the west, exhumation rates decrease twofold over a distance of~30-40 km. This exhumation pattern indicates a westward decrease of tectonic uplift, providing the regional topography approached a steady state, whereby exhumation is in balance with tectonic uplift. The observed exhumation estimates support an upper crustal configuration where thrusts in the LMS merge gradually into a gentle detachment seated at a depth of~20-30 km. Results of this study support a revised upper crustal thrusting model.

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Correction added after online publication 3 August 2010 -'prelate' has been changed to 'pre-late' throughout the text]. Using apatite fission track and (U-Th-Sm)/He thermochronology, we report the low-temperature thermal history of the Mesozoic Micang Shan Foreland Basin system, central China. This system, comprising the Hannan Dome hinterland, the northern Sichuan Foreland Basin and the intermediate frontal thrust belt (FB), shares a common boundary with three major tectonic terrains -Mesozoic Qinling-Dabie Orogen, Mesozoic Sichuan Foreland Basin and Cenozoic elevated Tibetan Plateau. Results show: (1) a relatively rapid pre-late Cretaceous cooling episode in the Hannan Dome; (2) a mid-Cenozoic cooling phase (ca. 50°C at ca. 30 ± 5 Ma) within the northern Sichuan Basin; and (3) possible late Cenozoic cooling (ca. 25°C at ca. 16 ± 4 Ma) within the Hannan Dome-FB, a phase which has also been reported previously from adjacent regions. The pre-late Cretaceous cooling episode in the Hannan Dome is attributed to coeval tectonism in nearby regions.Mid-Cenozoic cooling in the northern Sichuan Basin can possibly be attributed to either one of or a combination of shortening of the basin, onset of the Asian monsoon and drainage adjustment of the Yangtze River system, all of which are related to growth of the Tibetan Plateau. Possible late Cenozoic cooling in the hinterland and nearby regions is also probably related to the northeastward growth of the Tibetan Plateau. However, previous studies suggest a northeastward propagation for onset of cooling from the eastern Tibetan Plateau to western Qinling in response to northeastward lower crust flow from the central Tibetan Plateau. The timing of apparent late Cenozoic cooling in the Hannan Dome hinterland, at an intermediate locality, is not consistent with this trend, and supports a previous model suggesting northeastern growth of the Tibetan Plateau through reactivation of WE trending strike-slip faults.

Based on temperature logging of 9 boreholes and thermal conductivity measurement of 297 samples in Sichuan basin, 9 terrestrial heat‐flows of high quality are reported and thermal conductivity stratigraphic column is suggested as well. The contour maps of geothermal gradient and heat flow are presented after combining with previously available data. The variation of thermal conductivity of sedimentary rocks in Sichuan basin is mainly controlled by the lithology, rather than the current burial depths. At present, the geothermal gradient ranges from 17.7 to 33.3 °C/km with an average value of 22.8 °C/km in the basin, and the heat flow ranges from 35.4 to 68.8 mW/m2 with an average of 53.2 mW/m2, which are typical of cratonic basins with medium‐low heat flows. In regard to the areal distribution of heat flows, they are relatively higher in the southwestern and central part and lower in the northern part of the Sichuan basin. The heat flows are apparently dependent upon tectonic settings of the basement.

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Geothermal energy potential in China is high, and although they currently lead the way in direct heat production, geothermal power generation is still low. Hot spring analysis and surface heat flux data indicate significant potential resources for the major industrial province of Guangdong, South China. This pilot study investigates the Heyuan Fault, Guangdong, as a potential site for a geothermal power plant. Here we line out (i) preferred locations of possible hot spots on fault intersections, (ii) the possible sources of the heat anomalies, (iii) potential pathways for hot fluid circulation in the upper crust, (iv) available hot spring data and (v) the future work plan to investigate the geothermal hot spots. We find that hot springs occur along the NE trending Heyuan Fault, clustering where NNW striking faults crosscut the Heyuan. The increased heat flow can be explained partly by radioactive decay of a large granite pluton beneath the fault, however, additional heat sources may need to be considered to explain the heat flow maxima of above 85 mWm-2. We postulate that advective (topographically driven) and convective (deep fluids ponding at the brittle-ductile transition) processes may be operating to generate these heat anomalies. Expansive quartz reef systems exposed on the Heyuan Fault, are proposed here, to represent uplifted sections of these deep fluid circulation patterns. A detailed systematic analysis of reef structures will reveal (i) the fluid provenance, (ii) precipitation conditions and (iii) deformation mechanisms, which will ultimately help us understand how fault intersection relations control fluid flow; which is of key significance if it can be utilised for targeting geothermal energy.

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