Geothermal energy has been recognized as an important clean renewable energy. Accurate assessment... more Geothermal energy has been recognized as an important clean renewable energy. Accurate assessment of geothermal resources is an essential foundation for their development and utilization. The North Jiangsu Basin (NJB), located in the Lower Yangtze Craton, is shaped like a wedge block of an ancient plate boundary and large-scale carbonate thermal reservoirs are developed in the deep NJB. Moreover, the NJB exhibits a high heat flow background because of its extensive extension since the Late Mesozoic. In this study, we used the Monte Carlo method to evaluate the geothermal resources of the main reservoir shallower than 10 km in the NJB. Compared with the volumetric method, the Monte Carlo method takes into account the variation mode and uncertainties of the input parameters. The simulation results show that the geothermal resources of the sandstone thermal reservoir in the shallow NJB are very rich, with capacities of (6.6–12) × 1020 J (mean 8.6 × 1020 J), (5.1–16) × 1020 J (mean 9.1 ...
The study of thermal conductivity anisotropy is of great importance for more accurate heat flow c... more The study of thermal conductivity anisotropy is of great importance for more accurate heat flow calculations, geodynamic studies, development and utilization of hot dry rock, and simulation of heat transfer in geological reservoirs of nuclear waste, and so on. To study the thermal conductivity anisotropy of rocks, 1158 cores from 60 boreholes in East China were tested for thermal conductivity, including thermal conductivity values parallel to (λ∥) and perpendicular to (λ⊥) structural planes of basalt, mudstones, gneisses, sandstones, carbonates, evaporites, and metamorphic rocks. The thermal conductivity anisotropy is not obvious for sand, clay, and evaporate, and the average anisotropic factors of 1.19 ± 0.22, 1.18 ± 0.17, and 1.18 ± 0.17 for tuff/breccia, granitoid and contact metamorphic rocks, respectively, indicate that these three rocks have strong anisotropy characteristics. Finally, the effect of thermal conductivity anisotropy on heat flow is studied and discussed in detail...
The study of thermal conductivity anisotropy is of great importance for more accurate heat flow c... more The study of thermal conductivity anisotropy is of great importance for more accurate heat flow calculations, geodynamic studies, development and utilization of hot dry rock, and simulation of heat transfer in geological reservoirs of nuclear waste, and so on. To study the thermal conductivity anisotropy of rocks, 1158 cores from 60 boreholes in East China were tested for thermal conductivity, including thermal conductivity values parallel to (λ∥) and perpendicular to (λ⊥) structural planes of basalt, mudstones, gneisses, sandstones, carbonates, evaporites, and metamorphic rocks. The thermal conductivity anisotropy is not obvious for sand, clay, and evaporate, and the average anisotropic factors of 1.19 ± 0.22, 1.18 ± 0.17, and 1.18 ± 0.17 for tuff/breccia, granitoid and contact metamorphic rocks, respectively, indicate that these three rocks have strong anisotropy characteristics. Finally, the effect of thermal conductivity anisotropy on heat flow is studied and discussed in detail...
The thermal conductivity of a stratum is a key factor to study the deep temperature distribution ... more The thermal conductivity of a stratum is a key factor to study the deep temperature distribution and the thermal structure of the basin. A huge expense of core sampling from boreholes, especially in offshore areas, makes it expensive to directly test stratum samples. Therefore, the use of well logging (the gamma-ray, the neutron porosity, and the temperature) to estimate the thermal conductivity of the samples obtained from boreholes could be a good alternative. In this study, we measured the thermal conductivity of 72 samples obtained from an offshore area as references. When the stratum is considered to be a shale–sand–fluid model, the thermal conductivity can be calculated based on the mixing models (the geometric mean and the square root mean). The contents of the shale and the sand were derived from the natural gamma-ray logs, and the content of the fluid (porosity) was derived from the neutron porosity logs. The temperature corrections of the thermal conductivity were performe...
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Rheological properties of continental lithosphere are key controls on the behavior of continental... more Rheological properties of continental lithosphere are key controls on the behavior of continental deformation. Using thermal structure, constrained by surface heat flow data and measured thermal properties of rocks, the present study calculates different thermo-rheological structure scenarios for the ocean-continent transition (OCT) at the northern margin of the South China Sea, using two different models: a conventional model, taking into account frictional sliding and powerlaw creep, and a model that additionally includes a high-pressure brittle-fracture mechanism. Two compositions of the lower part of the lithosphere are considered: a soft case with felsic granulite lower crust and wet peridotite lithospheric mantle, and a hard case with mafic granulite lower crust and dry peridotite lithospheric mantle. The former scenario shows a major rheological change from a "jelly sandwich" to a "Christmas tree" type of rheology from north to south along the margin. This complex rheological structure explains lateral changes in earthquake distribution and geometries of extensional faults of the OCT at the northern margin of the South China Sea. Further, our analyses indicate that the initial lithospheric rheology profile probably has only one ductile layer in the lower part of upper crust. Such an initial lithospheric rheology model predicts focused extension to form asymmetric margins, which is the case for the SCS.
• This compilation of terrestrial heat flow includes almost 70,000 measurements • Global heat los... more • This compilation of terrestrial heat flow includes almost 70,000 measurements • Global heat loss based on measurements only ranges between 40-42 TW, close to previous estimates using conductive cooling models (45-47 TW) • A generalized similarity method is used to map global variations of surface heat flow on a 0.5 • x 0.5 • grid. The best prediction is obtained for 14 observables.
Systemic administration of free chemotherapeutic drugs leads to severe toxic effects, and physiol... more Systemic administration of free chemotherapeutic drugs leads to severe toxic effects, and physiological characteristics of solid tumors restrain the drugs from reaching the hypoxic regions. Nissle 1917 (EcN) has been known to penetrate the barrier and proliferate in the interface between the viable and necrotic regions of tumors. This study aimed to fabricate a nanoscale minicell via genetic engineering of EcN for targeted delivery of chemotherapeutic drugs to the hypoxic regions of tumors for cancer therapy. A large number of minicells were produced by knocking out the gene and enhancing the expression in EcN. Then, a pH (low) insertion peptide (pHLIP) was displayed on the membrane surface through protein display technology to endow the cells with the ability to target the acidic microenvironments of tumors. The acidic-microenvironment targeting ability and therapeutic effect of the engineered minicells with chemotherapeutic drugs was thoroughly evaluated by using breast cancer cel...
Development and utilization of deep geothermal resources, especially a hot dry rock (HDR) geother... more Development and utilization of deep geothermal resources, especially a hot dry rock (HDR) geothermal resource, is beneficial for both economic and environmental consideration in oilfields. This study used data from multiple sources to assess the geothermal energy resource in the Daqing Oilfield. The temperature logs in boreholes (both shallow water wells and deep boreholes) and the drilling stem test temperature were used to create isothermal maps in depths. Upon the temperature field and thermophysical parameters of strata, the heat content was calculated by 1 km × 1 km × 0.1 km cells. The result shows that in the southeastern part of Daqing Oilfield, the temperature can reach 150 • C at a depth of 3 km. The heat content within 3-5 km is 24.28 × 10 21 J, wherein 68.2% exceeded 150 • C. If the recovery factor was given by 2% and the lower limit of temperature was set to be 150 • C, the most conservative estimate for recoverable HDR geothermal resource was 0.33 × 10 21 J. The uncertainties of the estimation are mainly contributed to by the temperature extrapolation and the physical parameter selections.
Journal of Geophysical Research: Solid Earth, 2014
A large part of the southeastern Tibetan Plateau (TP) is characterized by low-relief surfaces at ... more A large part of the southeastern Tibetan Plateau (TP) is characterized by low-relief surfaces at high elevations (>3.5 km). The origin of these landscapes and their geodynamic implications with regard to evolution of the southeastern TP has been the subject of considerable debate. Focusing on this topic, this study utilizes fission track and (U-Th)/He thermochronology to reconstruct the thermal history of the Late Triassic Daocheng granite, on which a low-relief high-elevation landscape has developed. Results suggest that the plateau surface experienced widespread Late Jurassic to Early Cretaceous cooling (at a rate of~1-2°C/Ma), followed by minimal regional cooling (~0.3°C/Ma) and Early Miocene enhanced cooling (~2-3°C/Ma) along deep valleys at the southern edge of the landscape. Given the subdued Late Jurassic to Early Cretaceous crustal deformation in the study area, we relate the coeval cooling to crustal refrigeration and exhumation triggered by northward subduction of the Meso-Tethys Ocean along the Bangong suture. Subsequent Late Cretaceous to Cenozoic minimal cooling supports arguments for the formation of a low-elevation landform prior to uplift of the southeastern TP. The enhanced cooling commenced at the Early Miocene (~15-22 Ma) along deep valleys and heralded the onset of river incision and surface uplift of the southeastern TP. This finding does not support previous proposals claiming that high elevations of the southeastern TP were formed in Late Miocene time resulting from lower crustal flow but rather supports a model highlighting continental subduction and extrusion along the large Tanggula-Yushu-Batang-Red River fault system. Debate continues as to the origin of these low-relief landscapes and the geodynamic implications with respect to the evolution of the TP. Fielding et al. [1994] and Clark et al. [2006] suggested that flatness of the TP was formed by elevating a preexisting flat near sea level "peneplain" through shallow crustal isostatic compensation to vertical thickening and lateral flow of the lower crust [Bird, 1991; Royden et al., 1997]. Brozović et al. [1997] argued that the widespread low-relief surfaces in the northwest Himalaya were formed in Quaternary time by efficient kilometer-scale glacial erosion at high elevations. Shackleton and Chang [1988] reported that in the central TP, low-relief landscapes cut across folded Eocene strata and mid-Miocene granites but were displaced by major faults before the Pliocene and consequently suggested that they were formed by Middle to Late Miocene pediplanation (a relief-reducing process related to scarp retreat and TIAN ET AL.
Synchronous response of river erosion to surface uplift is often assumed by studies using thermoc... more Synchronous response of river erosion to surface uplift is often assumed by studies using thermochronometer-constrained erosion histories to estimate changes in landscape and tectonics. We have tested this assumption by studying river incision histories at two sites (Heishui and Lianghekou) located in the westernmost inland part of the deeply incised eastern Tibetan Plateau. Apatite fission track age-elevation plots for the two sites show clear late Miocene inflection points, marking the time when apparent erosion rates increased fourfold to eightfold to 300-800 m/Myr. This timing is further refined as 10-12 Ma by thermal history modeling and overlaps within analytical uncertainties with that recorded from the eastern Tibetan Plateau margin~150-200 km to the east, demonstrating that river incision propagated rapidly from the margin to the interior in less than~2 Ma. Such synchronous regional river incision is consistent with regional surface uplift generated by crustal extrusion along a detachment at depth. 2. Morphotectonic Setting and Previous Studies The high eastern TP (~3000-4000 m) is incised deeply by the Dadu and Min Rivers (Figure 1b). Topographic relief is about 2-3 km in areas within a distance of~150-200 km west of the eastern plateau margin (the Longmen Shan). Further west, however, topographic relief decreases rapidly to <500-1200 m (Figures 1b-1d), and no evident Cenozoic erosion has occurred [Tian et al., 2014b]. To the east of the Longmen Shan, TIAN ET AL.
ABSTRACT The timing of the transition of a peripheral foreland basin from underfilled to overfill... more ABSTRACT The timing of the transition of a peripheral foreland basin from underfilled to overfilled provides important insights into the post-orogenic dynamics of its coupled orogenic wedge. Such information is lacking in the Mesozoic foreland basins surrounding the Qinling Orogen, central China, such as the Daba Shan Foreland Basin (DSFB), the northeastern part of the Sichuan Basin. In an effort to constrain the timing of maximum burial and onset of denudation, we report detrital zircon (U–Th)/He (ZHe) data from four deep boreholes in the DSFB. Results show that ZHe ages from the oldest foreland basin formations (Upper Triassic–lower Middle Jurassic) are mostly younger than their depositional age, whereas non-reset ZHe ages characterize younger strata. This suggests that the oldest strata attained maximum temperatures between ~ 130 °C and 200 °C (ZHe partial retention zone), which is consistent with previous independent paleotemperatures (organic matter reflectance and illite crystallinity) reported in two of the boreholes and another nearby. The fully reset ages apparently show the youngest peaks at ~ 80 Ma and ~ 100 Ma, which are interpreted as the minimum constraints on the timing of maximum basinal burial and subsequent denudation. Considering that the regional deposition has lasted to Aptian time, it is proposed that the onset of the basin exhumation in the DSFB started at Aptian–Albian time (~ 100–125 Ma), heralding the termination of regional tectonic shortening in the hinterland (Southern Qinling).
The crystalline terrane of the Tongbai-Dabie region, central China, comprising the Earth's larges... more The crystalline terrane of the Tongbai-Dabie region, central China, comprising the Earth's largest ultrahigh-pressure (UHP) exposure was formed during Triassic collision between the Sino-Korean and Yangtze cratons. New apatite fission-track (AFT) data presented here from the UHP terrane, extends over a significantly greater area than reported in previous studies, and includes the (eastern) Dabie, the Hong'an (northwestern Dabie) and Tongbai regions. The new data yield ages ranging from 44 ± 3 to 142 ± 36 Ma and mean track lengths between ∼10 and 14.4 μm. Thermal history models based on the AFT data taken together with published 40 Ar/ 39 Ar, K-Ar, apatite and zircon (U-Th)/He and U-Pb data, exhibit a three-stage cooling pattern that is similar across the study region, commencing with an Early Cretaceous rapid cooling event, followed by a period of relative thermal stability during which rocks remained at temperatures within the AFT partial annealing zone (∼60-110°C) and ending with a possible renewed phase of accelerated cooling during Pliocene to Recent time. The first cooling phase followed large-scale transtensional deformation between ∼140 and 110 Ma and is related to Early Cretaceous eastward tectonic escape and Pacific back arc extension. Between this phase and the subsequent slow cooling phase, a transition period from ∼120 to 80 Ma (to ∼70 to 45 Ma along the Tan-Lu fault) was characterised by a relatively low cooling rate (∼3-5°C/Ma). This transition is likely related to a tectonic response associated with the mid-Cretaceous subduction of the Izanagi-Pacific plate as well as lithospheric extension and thinning in eastern Asia. The present regional AFT age pattern is therefore basically controlled by the Early Cretaceous rapid cooling event, but finally shaped through active Cenozoic faulting. Following the transition phase the subsequent slow cooling phase pattern implies a net reduction in horizontal compressional stress corresponding to increased extension rates along the continental margin due to the decrease in plate convergence. Modelling of the AFT data suggests a possible Pliocene-Recent cooling episode, which may be supported by increased rates of sedimentation observed in adjacent basins. This cooling phase may be interpreted as a response to the far-field effects of the frontal India-Eurasia collision to the west. Approximate estimates suggest that the total amount of post ∼120 Ma denudation across the UHP orogen ranged from ∼2.4 to 13.2 km for different tectonic blocks and ranged from ∼0.8 to 9.7 km during the Cretaceous to between ∼1.7 and 3.8 km during the Cenozoic.
ABSTRACT [1] Contrasting models of upper crustal shortening versus lower crustal flow have been p... more ABSTRACT [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.
The Chinese Continental Scientific Drilling (CCSD) Project offers a unique opportunity for studyi... more The Chinese Continental Scientific Drilling (CCSD) Project offers a unique opportunity for studying the thermal regime of the Dabie-Sulu ultrahigh-pressure metamorphic belt. In this paper, we report measurements of borehole temperature, thermal conductivity, and radiogenic heat production from the 5158 m deep main hole (CCSD MH). We have obtained six continuous temperature profiles from this borehole so far. The temperature logs show a transient mean thermal gradient that has increased from 24.38 to 25.28 K km À1 over a period of about 1.5 years. We measured thermal conductivities and radiogenic heat productions on more than 400 core samples from CCSD MH. The measured thermal conductivities range between 1.71 and 3.60 W m À1 K À1 , and the radiogenic heat productions vary from 0.01 mW m À3 to over 5.0 mW m À3 , with a mean value of 1.23 ± 0.82 mW m À3 for the upper 5-km layer of the crust. The heat productions in CCSD MH appear to be more rock-type than depth-dependent and, over the depth range of CCSD MH, do not fit the popular model of heat production decreasing exponentially with increasing depth. The measured heat flow decreases with depth from $75 mW m À2 near the surface to $66 mW m À2 at a depth of 4600 m. High heat flow anomalies occur at $1000 and $2300 m, and low anomalies occur at 3300-4000 m. A preliminary two-dimensional numerical model suggests that both radiogenic heat production and thermal refraction due to structural heterogeneity are at least partially responsible for the vertical variation of heat flow in CCSD MH.
Apatite fission track data are used to evaluate the thermal and tectonic history of the central B... more Apatite fission track data are used to evaluate the thermal and tectonic history of the central Brooks Range and the North Slope foreland basin in northern Alaska along the northern leg of the Trans-Alaska Crustal Transect (TACT). Fission track analyses of the detrital apatite grains in most sedimentary units resolve the timing of structures and denudation within the Brooks Range, ranging in scale from the entire mountain range to relatively small-scale folds and faults. Interpretation of the results indicates that rocks exposed within the central Brooks Range cooled rapidly from paleotemperatures 110 ø to 50øC during discrete episodes at ~ 100+5 Ma, ~60+4 Ma, and ~24+3 Ma, probably in response to kilometer-scale denudation. North of the mountain front, rocks in the southern half of the foreland basin were exposed to maximum paleotemperatures 110øC in the Late Cretaceous to early Paleocene as a result of burial by Upper Jurassic and Cretaceous sedimentary rocks. Rapid cooling from these elevated paleotemperatures also occurred due to distinct episodes of kilometer-scale denudation at -60+4 Ma, 46+3 Ma, 35_+2 Ma, and ~24+3 Ma. Combined, the apatite analyses indicate that rocks exposed along the TACT line through the central Brooks Range and foreland basin experienced episodic rapid cooling throughout the Late Cretaceous and Cenozoic in response to at least three distinct kilometer-scale denudation events. Future models explaining orogenic events in northern Alaska must consider these new constraints from fission track thermochronology. contraction resulted in the initiation of the Late Jurassic to Late Cretaceous Brookian orogeny [e.g., Mull, 1982, 1985]. During deformation and denudation of the Brooks Range, material was shed northward and deposited into the North Slope foreland basin [e.g., Bird, 1987; Mayfield et al., 1988; Bird and Molenaar, 1992; Moore et al., 1994]. Sediments derived from the Brooks Range and deposited along the southern flank of the foreland basin were subsequently uplifted and deformed as the result of continued advancement of the Brooks Range fold and thrust belt, presumably during the Late Cretaceous [e.g., Ma)field et al., 1988]. Then prior to the Cenozoic, denudation within the Brooks Range and foreland
The Songpan-Ganze terrane (SGT), formed by Early Mesozoic closure of the Paleo-Tethys Ocean, occu... more The Songpan-Ganze terrane (SGT), formed by Early Mesozoic closure of the Paleo-Tethys Ocean, occupies a large area of the central-eastern Tibetan Plateau. Late Mesozoic and Cenozoic strike-slip deformation has been identified in the surrounding terranes and faults (e.g., western Qinling, Altyn Tagh, and Kunlun faults); however, the coeval evolution of the SGT has not been well explored. We report apatite fission track and apatite and zircon (U-Th)/He data from a >7 km deep borehole and outcrop samples covering an area of >150 3 150 km in the eastern SGT. Thermal history modeling suggests a distinct phase of Late Jurassic-Early Cretaceous (150-100 Ma) cooling, followed by a prolonged stage of slow cooling, for all samples despite of their differences in depositional age (Mid-Late Triassic time) and locality within a large area. The ubiquitous Late Jurassic-Early Cretaceous cooling implies little differential deformation in the eastern SGT and is best explained by regional rock uplift resulting from the transpressional strain field created by the contemporaneous Lhasa-Qiangtang collision to the south. Projecting the contemporaneous deformation surrounding the SGT onto an Early Cretaceous paleogeographic terrane reconstruction results in a new tectonic model. The model relates the Lhasa-Qiangtang collision to tens to hundreds of kilometers of shearing along the Altyn Tagh and Kunlun faults, which transferred strain into central Asia (e.g., Qinling-Dabie orogen). Results of this study suggest a rigid behavior for the eastern SGT and highlight the important role of crustal strength discontinuities in accommodating and transferring crustal deformation. Components: 12,068 words, 9 figures, 4 tables.
The migration of fluid petroleum gas, described as fluid potential, depends only on gravity, flui... more The migration of fluid petroleum gas, described as fluid potential, depends only on gravity, fluid pressure controlled by depression and capillary force during tectonically stable period; but on tectonic stress during the tectonically active period with severe compression. This method is applied in the Junggar Basin, showing that the migration of Jurassic gas during Cretaceous and Eocene and the migration of Permian gas from Jurassic till the present are determined by capillary force and fluid pressure (including overpressure) which is controlled by depression; the migration of Jurassic gas from Eocene till the present and the migration of Permian gas during Triassic are controlled by tectonic stress.
Geothermal energy has been recognized as an important clean renewable energy. Accurate assessment... more Geothermal energy has been recognized as an important clean renewable energy. Accurate assessment of geothermal resources is an essential foundation for their development and utilization. The North Jiangsu Basin (NJB), located in the Lower Yangtze Craton, is shaped like a wedge block of an ancient plate boundary and large-scale carbonate thermal reservoirs are developed in the deep NJB. Moreover, the NJB exhibits a high heat flow background because of its extensive extension since the Late Mesozoic. In this study, we used the Monte Carlo method to evaluate the geothermal resources of the main reservoir shallower than 10 km in the NJB. Compared with the volumetric method, the Monte Carlo method takes into account the variation mode and uncertainties of the input parameters. The simulation results show that the geothermal resources of the sandstone thermal reservoir in the shallow NJB are very rich, with capacities of (6.6–12) × 1020 J (mean 8.6 × 1020 J), (5.1–16) × 1020 J (mean 9.1 ...
The study of thermal conductivity anisotropy is of great importance for more accurate heat flow c... more The study of thermal conductivity anisotropy is of great importance for more accurate heat flow calculations, geodynamic studies, development and utilization of hot dry rock, and simulation of heat transfer in geological reservoirs of nuclear waste, and so on. To study the thermal conductivity anisotropy of rocks, 1158 cores from 60 boreholes in East China were tested for thermal conductivity, including thermal conductivity values parallel to (λ∥) and perpendicular to (λ⊥) structural planes of basalt, mudstones, gneisses, sandstones, carbonates, evaporites, and metamorphic rocks. The thermal conductivity anisotropy is not obvious for sand, clay, and evaporate, and the average anisotropic factors of 1.19 ± 0.22, 1.18 ± 0.17, and 1.18 ± 0.17 for tuff/breccia, granitoid and contact metamorphic rocks, respectively, indicate that these three rocks have strong anisotropy characteristics. Finally, the effect of thermal conductivity anisotropy on heat flow is studied and discussed in detail...
The study of thermal conductivity anisotropy is of great importance for more accurate heat flow c... more The study of thermal conductivity anisotropy is of great importance for more accurate heat flow calculations, geodynamic studies, development and utilization of hot dry rock, and simulation of heat transfer in geological reservoirs of nuclear waste, and so on. To study the thermal conductivity anisotropy of rocks, 1158 cores from 60 boreholes in East China were tested for thermal conductivity, including thermal conductivity values parallel to (λ∥) and perpendicular to (λ⊥) structural planes of basalt, mudstones, gneisses, sandstones, carbonates, evaporites, and metamorphic rocks. The thermal conductivity anisotropy is not obvious for sand, clay, and evaporate, and the average anisotropic factors of 1.19 ± 0.22, 1.18 ± 0.17, and 1.18 ± 0.17 for tuff/breccia, granitoid and contact metamorphic rocks, respectively, indicate that these three rocks have strong anisotropy characteristics. Finally, the effect of thermal conductivity anisotropy on heat flow is studied and discussed in detail...
The thermal conductivity of a stratum is a key factor to study the deep temperature distribution ... more The thermal conductivity of a stratum is a key factor to study the deep temperature distribution and the thermal structure of the basin. A huge expense of core sampling from boreholes, especially in offshore areas, makes it expensive to directly test stratum samples. Therefore, the use of well logging (the gamma-ray, the neutron porosity, and the temperature) to estimate the thermal conductivity of the samples obtained from boreholes could be a good alternative. In this study, we measured the thermal conductivity of 72 samples obtained from an offshore area as references. When the stratum is considered to be a shale–sand–fluid model, the thermal conductivity can be calculated based on the mixing models (the geometric mean and the square root mean). The contents of the shale and the sand were derived from the natural gamma-ray logs, and the content of the fluid (porosity) was derived from the neutron porosity logs. The temperature corrections of the thermal conductivity were performe...
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Rheological properties of continental lithosphere are key controls on the behavior of continental... more Rheological properties of continental lithosphere are key controls on the behavior of continental deformation. Using thermal structure, constrained by surface heat flow data and measured thermal properties of rocks, the present study calculates different thermo-rheological structure scenarios for the ocean-continent transition (OCT) at the northern margin of the South China Sea, using two different models: a conventional model, taking into account frictional sliding and powerlaw creep, and a model that additionally includes a high-pressure brittle-fracture mechanism. Two compositions of the lower part of the lithosphere are considered: a soft case with felsic granulite lower crust and wet peridotite lithospheric mantle, and a hard case with mafic granulite lower crust and dry peridotite lithospheric mantle. The former scenario shows a major rheological change from a "jelly sandwich" to a "Christmas tree" type of rheology from north to south along the margin. This complex rheological structure explains lateral changes in earthquake distribution and geometries of extensional faults of the OCT at the northern margin of the South China Sea. Further, our analyses indicate that the initial lithospheric rheology profile probably has only one ductile layer in the lower part of upper crust. Such an initial lithospheric rheology model predicts focused extension to form asymmetric margins, which is the case for the SCS.
• This compilation of terrestrial heat flow includes almost 70,000 measurements • Global heat los... more • This compilation of terrestrial heat flow includes almost 70,000 measurements • Global heat loss based on measurements only ranges between 40-42 TW, close to previous estimates using conductive cooling models (45-47 TW) • A generalized similarity method is used to map global variations of surface heat flow on a 0.5 • x 0.5 • grid. The best prediction is obtained for 14 observables.
Systemic administration of free chemotherapeutic drugs leads to severe toxic effects, and physiol... more Systemic administration of free chemotherapeutic drugs leads to severe toxic effects, and physiological characteristics of solid tumors restrain the drugs from reaching the hypoxic regions. Nissle 1917 (EcN) has been known to penetrate the barrier and proliferate in the interface between the viable and necrotic regions of tumors. This study aimed to fabricate a nanoscale minicell via genetic engineering of EcN for targeted delivery of chemotherapeutic drugs to the hypoxic regions of tumors for cancer therapy. A large number of minicells were produced by knocking out the gene and enhancing the expression in EcN. Then, a pH (low) insertion peptide (pHLIP) was displayed on the membrane surface through protein display technology to endow the cells with the ability to target the acidic microenvironments of tumors. The acidic-microenvironment targeting ability and therapeutic effect of the engineered minicells with chemotherapeutic drugs was thoroughly evaluated by using breast cancer cel...
Development and utilization of deep geothermal resources, especially a hot dry rock (HDR) geother... more Development and utilization of deep geothermal resources, especially a hot dry rock (HDR) geothermal resource, is beneficial for both economic and environmental consideration in oilfields. This study used data from multiple sources to assess the geothermal energy resource in the Daqing Oilfield. The temperature logs in boreholes (both shallow water wells and deep boreholes) and the drilling stem test temperature were used to create isothermal maps in depths. Upon the temperature field and thermophysical parameters of strata, the heat content was calculated by 1 km × 1 km × 0.1 km cells. The result shows that in the southeastern part of Daqing Oilfield, the temperature can reach 150 • C at a depth of 3 km. The heat content within 3-5 km is 24.28 × 10 21 J, wherein 68.2% exceeded 150 • C. If the recovery factor was given by 2% and the lower limit of temperature was set to be 150 • C, the most conservative estimate for recoverable HDR geothermal resource was 0.33 × 10 21 J. The uncertainties of the estimation are mainly contributed to by the temperature extrapolation and the physical parameter selections.
Journal of Geophysical Research: Solid Earth, 2014
A large part of the southeastern Tibetan Plateau (TP) is characterized by low-relief surfaces at ... more A large part of the southeastern Tibetan Plateau (TP) is characterized by low-relief surfaces at high elevations (>3.5 km). The origin of these landscapes and their geodynamic implications with regard to evolution of the southeastern TP has been the subject of considerable debate. Focusing on this topic, this study utilizes fission track and (U-Th)/He thermochronology to reconstruct the thermal history of the Late Triassic Daocheng granite, on which a low-relief high-elevation landscape has developed. Results suggest that the plateau surface experienced widespread Late Jurassic to Early Cretaceous cooling (at a rate of~1-2°C/Ma), followed by minimal regional cooling (~0.3°C/Ma) and Early Miocene enhanced cooling (~2-3°C/Ma) along deep valleys at the southern edge of the landscape. Given the subdued Late Jurassic to Early Cretaceous crustal deformation in the study area, we relate the coeval cooling to crustal refrigeration and exhumation triggered by northward subduction of the Meso-Tethys Ocean along the Bangong suture. Subsequent Late Cretaceous to Cenozoic minimal cooling supports arguments for the formation of a low-elevation landform prior to uplift of the southeastern TP. The enhanced cooling commenced at the Early Miocene (~15-22 Ma) along deep valleys and heralded the onset of river incision and surface uplift of the southeastern TP. This finding does not support previous proposals claiming that high elevations of the southeastern TP were formed in Late Miocene time resulting from lower crustal flow but rather supports a model highlighting continental subduction and extrusion along the large Tanggula-Yushu-Batang-Red River fault system. Debate continues as to the origin of these low-relief landscapes and the geodynamic implications with respect to the evolution of the TP. Fielding et al. [1994] and Clark et al. [2006] suggested that flatness of the TP was formed by elevating a preexisting flat near sea level "peneplain" through shallow crustal isostatic compensation to vertical thickening and lateral flow of the lower crust [Bird, 1991; Royden et al., 1997]. Brozović et al. [1997] argued that the widespread low-relief surfaces in the northwest Himalaya were formed in Quaternary time by efficient kilometer-scale glacial erosion at high elevations. Shackleton and Chang [1988] reported that in the central TP, low-relief landscapes cut across folded Eocene strata and mid-Miocene granites but were displaced by major faults before the Pliocene and consequently suggested that they were formed by Middle to Late Miocene pediplanation (a relief-reducing process related to scarp retreat and TIAN ET AL.
Synchronous response of river erosion to surface uplift is often assumed by studies using thermoc... more Synchronous response of river erosion to surface uplift is often assumed by studies using thermochronometer-constrained erosion histories to estimate changes in landscape and tectonics. We have tested this assumption by studying river incision histories at two sites (Heishui and Lianghekou) located in the westernmost inland part of the deeply incised eastern Tibetan Plateau. Apatite fission track age-elevation plots for the two sites show clear late Miocene inflection points, marking the time when apparent erosion rates increased fourfold to eightfold to 300-800 m/Myr. This timing is further refined as 10-12 Ma by thermal history modeling and overlaps within analytical uncertainties with that recorded from the eastern Tibetan Plateau margin~150-200 km to the east, demonstrating that river incision propagated rapidly from the margin to the interior in less than~2 Ma. Such synchronous regional river incision is consistent with regional surface uplift generated by crustal extrusion along a detachment at depth. 2. Morphotectonic Setting and Previous Studies The high eastern TP (~3000-4000 m) is incised deeply by the Dadu and Min Rivers (Figure 1b). Topographic relief is about 2-3 km in areas within a distance of~150-200 km west of the eastern plateau margin (the Longmen Shan). Further west, however, topographic relief decreases rapidly to <500-1200 m (Figures 1b-1d), and no evident Cenozoic erosion has occurred [Tian et al., 2014b]. To the east of the Longmen Shan, TIAN ET AL.
ABSTRACT The timing of the transition of a peripheral foreland basin from underfilled to overfill... more ABSTRACT The timing of the transition of a peripheral foreland basin from underfilled to overfilled provides important insights into the post-orogenic dynamics of its coupled orogenic wedge. Such information is lacking in the Mesozoic foreland basins surrounding the Qinling Orogen, central China, such as the Daba Shan Foreland Basin (DSFB), the northeastern part of the Sichuan Basin. In an effort to constrain the timing of maximum burial and onset of denudation, we report detrital zircon (U–Th)/He (ZHe) data from four deep boreholes in the DSFB. Results show that ZHe ages from the oldest foreland basin formations (Upper Triassic–lower Middle Jurassic) are mostly younger than their depositional age, whereas non-reset ZHe ages characterize younger strata. This suggests that the oldest strata attained maximum temperatures between ~ 130 °C and 200 °C (ZHe partial retention zone), which is consistent with previous independent paleotemperatures (organic matter reflectance and illite crystallinity) reported in two of the boreholes and another nearby. The fully reset ages apparently show the youngest peaks at ~ 80 Ma and ~ 100 Ma, which are interpreted as the minimum constraints on the timing of maximum basinal burial and subsequent denudation. Considering that the regional deposition has lasted to Aptian time, it is proposed that the onset of the basin exhumation in the DSFB started at Aptian–Albian time (~ 100–125 Ma), heralding the termination of regional tectonic shortening in the hinterland (Southern Qinling).
The crystalline terrane of the Tongbai-Dabie region, central China, comprising the Earth's larges... more The crystalline terrane of the Tongbai-Dabie region, central China, comprising the Earth's largest ultrahigh-pressure (UHP) exposure was formed during Triassic collision between the Sino-Korean and Yangtze cratons. New apatite fission-track (AFT) data presented here from the UHP terrane, extends over a significantly greater area than reported in previous studies, and includes the (eastern) Dabie, the Hong'an (northwestern Dabie) and Tongbai regions. The new data yield ages ranging from 44 ± 3 to 142 ± 36 Ma and mean track lengths between ∼10 and 14.4 μm. Thermal history models based on the AFT data taken together with published 40 Ar/ 39 Ar, K-Ar, apatite and zircon (U-Th)/He and U-Pb data, exhibit a three-stage cooling pattern that is similar across the study region, commencing with an Early Cretaceous rapid cooling event, followed by a period of relative thermal stability during which rocks remained at temperatures within the AFT partial annealing zone (∼60-110°C) and ending with a possible renewed phase of accelerated cooling during Pliocene to Recent time. The first cooling phase followed large-scale transtensional deformation between ∼140 and 110 Ma and is related to Early Cretaceous eastward tectonic escape and Pacific back arc extension. Between this phase and the subsequent slow cooling phase, a transition period from ∼120 to 80 Ma (to ∼70 to 45 Ma along the Tan-Lu fault) was characterised by a relatively low cooling rate (∼3-5°C/Ma). This transition is likely related to a tectonic response associated with the mid-Cretaceous subduction of the Izanagi-Pacific plate as well as lithospheric extension and thinning in eastern Asia. The present regional AFT age pattern is therefore basically controlled by the Early Cretaceous rapid cooling event, but finally shaped through active Cenozoic faulting. Following the transition phase the subsequent slow cooling phase pattern implies a net reduction in horizontal compressional stress corresponding to increased extension rates along the continental margin due to the decrease in plate convergence. Modelling of the AFT data suggests a possible Pliocene-Recent cooling episode, which may be supported by increased rates of sedimentation observed in adjacent basins. This cooling phase may be interpreted as a response to the far-field effects of the frontal India-Eurasia collision to the west. Approximate estimates suggest that the total amount of post ∼120 Ma denudation across the UHP orogen ranged from ∼2.4 to 13.2 km for different tectonic blocks and ranged from ∼0.8 to 9.7 km during the Cretaceous to between ∼1.7 and 3.8 km during the Cenozoic.
ABSTRACT [1] Contrasting models of upper crustal shortening versus lower crustal flow have been p... more ABSTRACT [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.
The Chinese Continental Scientific Drilling (CCSD) Project offers a unique opportunity for studyi... more The Chinese Continental Scientific Drilling (CCSD) Project offers a unique opportunity for studying the thermal regime of the Dabie-Sulu ultrahigh-pressure metamorphic belt. In this paper, we report measurements of borehole temperature, thermal conductivity, and radiogenic heat production from the 5158 m deep main hole (CCSD MH). We have obtained six continuous temperature profiles from this borehole so far. The temperature logs show a transient mean thermal gradient that has increased from 24.38 to 25.28 K km À1 over a period of about 1.5 years. We measured thermal conductivities and radiogenic heat productions on more than 400 core samples from CCSD MH. The measured thermal conductivities range between 1.71 and 3.60 W m À1 K À1 , and the radiogenic heat productions vary from 0.01 mW m À3 to over 5.0 mW m À3 , with a mean value of 1.23 ± 0.82 mW m À3 for the upper 5-km layer of the crust. The heat productions in CCSD MH appear to be more rock-type than depth-dependent and, over the depth range of CCSD MH, do not fit the popular model of heat production decreasing exponentially with increasing depth. The measured heat flow decreases with depth from $75 mW m À2 near the surface to $66 mW m À2 at a depth of 4600 m. High heat flow anomalies occur at $1000 and $2300 m, and low anomalies occur at 3300-4000 m. A preliminary two-dimensional numerical model suggests that both radiogenic heat production and thermal refraction due to structural heterogeneity are at least partially responsible for the vertical variation of heat flow in CCSD MH.
Apatite fission track data are used to evaluate the thermal and tectonic history of the central B... more Apatite fission track data are used to evaluate the thermal and tectonic history of the central Brooks Range and the North Slope foreland basin in northern Alaska along the northern leg of the Trans-Alaska Crustal Transect (TACT). Fission track analyses of the detrital apatite grains in most sedimentary units resolve the timing of structures and denudation within the Brooks Range, ranging in scale from the entire mountain range to relatively small-scale folds and faults. Interpretation of the results indicates that rocks exposed within the central Brooks Range cooled rapidly from paleotemperatures 110 ø to 50øC during discrete episodes at ~ 100+5 Ma, ~60+4 Ma, and ~24+3 Ma, probably in response to kilometer-scale denudation. North of the mountain front, rocks in the southern half of the foreland basin were exposed to maximum paleotemperatures 110øC in the Late Cretaceous to early Paleocene as a result of burial by Upper Jurassic and Cretaceous sedimentary rocks. Rapid cooling from these elevated paleotemperatures also occurred due to distinct episodes of kilometer-scale denudation at -60+4 Ma, 46+3 Ma, 35_+2 Ma, and ~24+3 Ma. Combined, the apatite analyses indicate that rocks exposed along the TACT line through the central Brooks Range and foreland basin experienced episodic rapid cooling throughout the Late Cretaceous and Cenozoic in response to at least three distinct kilometer-scale denudation events. Future models explaining orogenic events in northern Alaska must consider these new constraints from fission track thermochronology. contraction resulted in the initiation of the Late Jurassic to Late Cretaceous Brookian orogeny [e.g., Mull, 1982, 1985]. During deformation and denudation of the Brooks Range, material was shed northward and deposited into the North Slope foreland basin [e.g., Bird, 1987; Mayfield et al., 1988; Bird and Molenaar, 1992; Moore et al., 1994]. Sediments derived from the Brooks Range and deposited along the southern flank of the foreland basin were subsequently uplifted and deformed as the result of continued advancement of the Brooks Range fold and thrust belt, presumably during the Late Cretaceous [e.g., Ma)field et al., 1988]. Then prior to the Cenozoic, denudation within the Brooks Range and foreland
The Songpan-Ganze terrane (SGT), formed by Early Mesozoic closure of the Paleo-Tethys Ocean, occu... more The Songpan-Ganze terrane (SGT), formed by Early Mesozoic closure of the Paleo-Tethys Ocean, occupies a large area of the central-eastern Tibetan Plateau. Late Mesozoic and Cenozoic strike-slip deformation has been identified in the surrounding terranes and faults (e.g., western Qinling, Altyn Tagh, and Kunlun faults); however, the coeval evolution of the SGT has not been well explored. We report apatite fission track and apatite and zircon (U-Th)/He data from a >7 km deep borehole and outcrop samples covering an area of >150 3 150 km in the eastern SGT. Thermal history modeling suggests a distinct phase of Late Jurassic-Early Cretaceous (150-100 Ma) cooling, followed by a prolonged stage of slow cooling, for all samples despite of their differences in depositional age (Mid-Late Triassic time) and locality within a large area. The ubiquitous Late Jurassic-Early Cretaceous cooling implies little differential deformation in the eastern SGT and is best explained by regional rock uplift resulting from the transpressional strain field created by the contemporaneous Lhasa-Qiangtang collision to the south. Projecting the contemporaneous deformation surrounding the SGT onto an Early Cretaceous paleogeographic terrane reconstruction results in a new tectonic model. The model relates the Lhasa-Qiangtang collision to tens to hundreds of kilometers of shearing along the Altyn Tagh and Kunlun faults, which transferred strain into central Asia (e.g., Qinling-Dabie orogen). Results of this study suggest a rigid behavior for the eastern SGT and highlight the important role of crustal strength discontinuities in accommodating and transferring crustal deformation. Components: 12,068 words, 9 figures, 4 tables.
The migration of fluid petroleum gas, described as fluid potential, depends only on gravity, flui... more The migration of fluid petroleum gas, described as fluid potential, depends only on gravity, fluid pressure controlled by depression and capillary force during tectonically stable period; but on tectonic stress during the tectonically active period with severe compression. This method is applied in the Junggar Basin, showing that the migration of Jurassic gas during Cretaceous and Eocene and the migration of Permian gas from Jurassic till the present are determined by capillary force and fluid pressure (including overpressure) which is controlled by depression; the migration of Jurassic gas from Eocene till the present and the migration of Permian gas during Triassic are controlled by tectonic stress.
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Papers by Shengbiao Hu