The Duobaoshan Cu (Mo) deposit is one of the oldest super large porphyry deposits in the eastern part of the Central Asian orogenic belt. Although ore-forming processes have been extensively concerned, the post-mineralization ore preservation state was poorly focused on. In order to improve the ability of prospecting forecast, it is necessary to consider both deposit formation and deposit preservation. Here, we reported apatite fission track (AFT) data for the Duobaoshan porphyry copper deposits in the belt to reveal the cooling and exhumation history and evaluate ore preservation. The results show that the rapid cooling of the ore-hosting rock body occurred later than the surrounding rock body. The rapid cooling of the surrounding granodiorite occurred between 82 and 72 Ma, with the exhumation depth of 2.33–3.11 km and the exhumation rate of 0.25 mm/a, whereas the ore-hosting granodiorite porphyry was rapid cooling between 71.8 and 50.2 Ma, with the exhumation depth of 2.99–3.86 km and the exhumation rate of 0.22 mm/a. This differential exhumation and cooling event provide favorable geological conditions for the preservation of the ore body.
Abstract The development of Cenozoic basins in the northeast margin of the Tibetan Plateau is central to understanding the dynamics of plateau growth. Here we present a magnetostratigraphy from the Lanzhou Basin, dating the terrestrial deposits from the Eocene (~47 Ma) to the middle Miocene (~15 Ma). The stratigraphic observation, palocurrent, and sediment provenance analysis suggest that the Lanzhou Basin (subbasin of the Longzhong Basin) probably initiated as a topographically enclosed depression during Eocene to early Oligocene (~47–30 Ma). We suspect that right‐lateral transtensional deformation inherited from the Cretaceous may result in formation of the Lanzhou Basin at the Eocene. Subsequently, changes in paleocurrent, sandstone and conglomerate compositions and detrital zircon provenance reflect the pulsed growth of the West Qinling at ~30 Ma, which triggered not only the formation of new flexural subsidence to the north of the West Qinling, but also renewed subsidence of Lanzhou Basin into the broad foreland basin system. We compare this growth history with major NE Tibet deformation and suggest that it may result from northeastward extrusion of the Tibetan Plateau due to the onset of Altyn Tagh Fault activity at Oligocene.
By conducting relative permeability experiments of multi-cycle gas-water displacement and imbibition on natural cores, we discuss relative permeability hysteresis effect in underground gas storage during multi-cycle injection and production. A correction method for relative permeability hysteresis in numerical simulation of water-invaded gas storage has been worked out using the Carlson and Killough models. A geologic model of water-invaded sandstone gas storage with medium-low permeability is built to investigate the impacts of relative permeability hysteresis on fluid distribution and production performance during multi-cycle injection and production of the gas storage. The study shows that relative permeability hysteresis effect occurs during high-speed injection and production in gas storage converted from water-invaded gas reservoir, and leads to increase of gas-water transition zone width and thickness, shrinkage of the area of high-efficiency gas storage, and decrease of the peak value variation of pore volume containing gas, and then reduces the storage capacity, working gas volume, and high-efficiency operation span of the gas storage. Numerical simulations exhibit large prediction errors of performance indexes if this hysteresis effect is not considered. Killough and Carlson methods can be used to correct the relative permeability hysteresis effect in water-invaded underground gas storage to improve the prediction accuracy. The Killough method has better adaptability to the example model.
Research Article| April 01, 2011 Middle Miocene reorganization of deformation along the northeastern Tibetan Plateau Richard O. Lease; Richard O. Lease * 1Department of Earth Science, University of California–Santa Barbara, Santa Barbara, California 93106, USA *E-mail: rlease@crustal.ucsb.edu. Search for other works by this author on: GSW Google Scholar Douglas W. Burbank; Douglas W. Burbank 1Department of Earth Science, University of California–Santa Barbara, Santa Barbara, California 93106, USA Search for other works by this author on: GSW Google Scholar Marin K. Clark; Marin K. Clark 2Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109, USA Search for other works by this author on: GSW Google Scholar Kenneth A. Farley; Kenneth A. Farley 3Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA Search for other works by this author on: GSW Google Scholar Dewen Zheng; Dewen Zheng 4State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China Search for other works by this author on: GSW Google Scholar Huiping Zhang Huiping Zhang 4State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China Search for other works by this author on: GSW Google Scholar Geology (2011) 39 (4): 359–362. https://doi.org/10.1130/G31356.1 Article history received: 02 May 2010 rev-recd: 28 Oct 2010 accepted: 12 Nov 2010 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Richard O. Lease, Douglas W. Burbank, Marin K. Clark, Kenneth A. Farley, Dewen Zheng, Huiping Zhang; Middle Miocene reorganization of deformation along the northeastern Tibetan Plateau. Geology 2011;; 39 (4): 359–362. doi: https://doi.org/10.1130/G31356.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Temporal variations in the orientation of Cenozoic range growth in northeastern Tibet define two modes by which India-Asia convergence was accommodated. Thermochronological age-elevation transects from the hanging walls of two major thrust-fault systems reveal diachronous Miocene exhumation of the Laji-Jishi Shan in northeastern Tibet. Whereas accelerated growth of the WNW-trending eastern Laji Shan began ca. 22 Ma, rapid growth of the adjacent, north-trending Jishi Shan did not commence until ca. 13 Ma. This change in thrust-fault orientation reflects a Middle Miocene change in the kinematic style of plateau growth, from long-standing NNE-SSW contraction that mimicked the plate convergence direction to the inclusion of new structures accommodating east-west motion. This kinematic shift in northeastern Tibet coincides with expansion of the plateau margin in southeastern Tibet, the onset of normal faulting in central Tibet, and accelerated shortening in northern Tibet. Together these phenomena suggest a plateau-wide reorganization of deformation. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Abstract The Qilian Shan, at the northeastern frontier of the Tibetan Plateau, is a key area for studying the expansion mechanism of the Tibetan Plateau. Although previous thermochronology and paleomagnetic studies indicate Neogene northward expansion of the northern Qilian Shan, there is a distinct temporal gap in knowledge relative to the tectonic history of the southern Qilian Shan. This has hindered a complete understanding of the Cenozoic deformation pattern of the entire Qilian Shan. To study the growth history of the southern Qilian Shan, apatite fission track (AFT) data have been acquired from Zongwulong Shan and the Huaitoutala section. AFT thermal history modeling from the former shows a rapid cooling episode occurred at ~18–11 Ma, which is interpreted as marking the onset of intensive exhumation in the southern Qilian Shan. Within the Huaitoutala section, detrital grain up‐section shows progressively decreasing peak AFT ages followed by an age increase from midsection, implying that a sediment‐recycling event occurred at approximately 7 ± 2 Ma. Together with a shift in paleocurrent directions, this change marks the onset of Late Miocene deformation of the northern Qaidam Basin. Combined with previous studies on the deformation time of the Qilian Shan, our findings suggest that both the northern and southern Qilian Shan region grew outward synchronously in opposite directions during the Neogene. This resulted in the formation of a flower structure, which had an important impact on the deformation pattern of north Tibet. The synchronous outward expansion may have been triggered by the removal of mantle beneath north Tibet.
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