车排子凸起与沙湾凹陷过渡带的构造模型

车排子凸起位于准噶尔盆地扎伊尔山前,是夹持在南部四棵树凹陷和东部沙湾凹陷之间的三角构造带。然而对这个三角构造带是原地掩伏构造,山前推覆构造,还是走滑构造控制形成的认识存在争议。目前对于车排子凸起与沙湾凹陷过渡带的构造变形特征以及变形机制的认识尚不清楚。而过渡带是研究该区构造变形与演化的良好区域,精细研究该区域构造几何学与运动学对于揭示其构造变形机制以及认识盆山之间的关系具有积极作用,并对于该区油气勘探具有重要意义。本文以研究区的连片三维地震资料为基础,运用不整合面识别、轴面分析及平衡剖面等方法,对车排子凸起与沙湾凹陷过渡带进行精细的构造解析、建模与构造复原。研究表明,过渡带发育下二叠统（P₁j-P₁f）,中二叠统（P₂x-P₂w）,上二叠统（P₃w）,三叠系（T）,侏罗系（J）,白垩系（K）与古近系-第四系（E-Q）7个构造变形层序。发育佳木河组底部及石炭系内部滑脱层。深部（前二叠系）构造楔发育于整个过渡带,其个数和几何学形态的变化直接影响了上覆背斜形态。构造楔在早二叠世开始楔入,挤压作用持续至三叠纪末期。晚三叠世发育生长地层,显示了P-T构造层褶皱变形的时间,随后三叠纪末期,过渡带受到来自西北缘造山带方向的逆冲推覆构造的叠加作用,表现在后缘发育一系列叠瓦构造,推覆距离约为8 km,南部逆冲断层上盘二叠系-三叠系被剥蚀完全,北部残余少量下二叠统佳木河组。     

准噶尔盆地腹部地区生烃增压定量化评价——东道海子北凹陷为例

目前准噶尔盆地腹部地区超压演化过程仅提供了相对时间、概念、定性的认识,并未达到定量化。本文以东道海子北凹陷为例,基于流体包裹体、单井一维和剖面二维烃源岩成熟生烃史模拟技术,采用生烃增压模型定量化评价了侏罗纪八道湾组顶部和底部烃源岩的生烃增压演化过程。研究结果表明侏罗纪八道湾组为东道海子北凹陷主力烃源岩,具有幕式排烃的特点。八道湾组底部烃源岩经历了3 次超压增加和两次超压释放的过程,顶部烃源岩经历了两次超压增加和一次超压释放的过程。八道湾底部烃源岩3 次超压增加的时间分别为距今170～70 Ma、55～23 Ma、10～0 Ma,对应最大压力系数均为2.0,最大剩余流体压力50 MPa,两次超压释放的时间分别为70～55 Ma、23～10 Ma;八道湾组顶部烃源岩两次超压增加的时间分别为130～40 Ma、23～0 Ma,对应流体最大压力系数最大亦可达2.0 左右,最大剩余流体压力44 MPa,超压释放的时间为40～23 Ma。     

Garnet-Pyroxenite-Derived End-Member Magma Type in Kamchatka: Evidence from Composition of Olivine and Olivine-Hosted Melt Inclusions in Holocene Rocks of Kekuknaisky Volcano

Late Quaternary volcanoes of Sredinny Range (Kamchatka) attract geoscientists’ attention by their unusual geochemical features and geodynamic setting. They produced volcanic rocks that are enriched relative to N-MORB in most of incompatible trace elements (except HREE), including strong enrichment in large-ion lithophile elements, and show a negative Nb–Ta anomaly, which is typical for rocks formed in supra-subduction settings. However, modern subduction of the Pacific Plate does not reach the most part of Sredinny Range, as inferred by mapping of Wadati–Benioff zone or seismic tomography. We constrain the source of parental magmas for Sredinny Range volcanic rocks by combining major and trace element geochemical data for olivine and naturally quenched olivine-hosed melt inclusions for Holocene tephra layers of the Kekuknaisky field. Composition of the most magnesian olivine (Ni > 2000 ppm, Fe/Mn ≈ 75 at Mg# ~ 84–85 mol %) and geochemical characteristics of the most primitive melts (FC3MS = 0.61 ± 0.04 (2s)) are consistent with their derivation from a pyroxenite source, while elevated LREE/HREE ratios in lavas indicate that it contained garnet. This garnet-bearing pyroxenite likely originated from the lower crust or lithospheric mantle. Its melting could have occurred due to delamination and sinking into the hotter mantle.     

Phase Relations in the Harzburgite–Hydrous Carbonate Melt at 5.5–7.5 GPa and 1200–1350°С

Phase relations are studied experimentally in the harzburgite–hydrous carbonate melt system, the bulk composition of which represents primary kimberlite. Experiments were carried out at 5.5 and 7.5 GPa, 1200–1350°С, and \({{X}_{{{\text{C}}{{{\text{O}}}_{2}}}}}\) = 0.39–0.57, and lasted 60 hours. It is established that olivine–orthopyroxene–garnet–magnesite–melt assemblage is stable within the entire range of the studied parameters. With increase of temperature and \({{X}_{{{\text{C}}{{{\text{O}}}_{2}}}}}\) in the system, Ca# in the melt and the olivine fraction in the peridotite matrix significantly decrease. The composition of silicate phases in run products is close to those of high-temperature mantle peridotite. Analysis of obtained data suggest that magnesite at the base of subcontinental lithosphere could be derived by metasomatic alteration of peridotite by asthenospheric hydrous carbonate melts. The process is possible in the temperature range typical of heat flux of 40–45 mW/m², which corresponds to the conditions of formation of the deepest peridotite xenoliths. Crystallization of magnesite during interaction with peridotite matrix can be considered as experimentally substantiated mechanism of CO₂ accumulation in subcratonic lithosphere.     

Biostratigraphy and Sedimentary Settings of the Middle Devonian Succession of the Yuryung-Tumus Peninsula,Khatanga Gulf of the Laptev Sea

The age of the Paleozoic sedimentary successions of the Yuryung-Tumus Peninsula in the Khatanga Gulf is determined as Middle Devonian, late Eifelian, and the beginning of the early Givetian on the basis of the study of brachiopods, ammonoids, nautiloids, bactritoids, gastropods, and conodonts, and in the terminology of the standard conodont succession, these deposits are not older than the late Eifelian Tortodus kockelianus Zone, but include the terminal Eifelian Polygnathus ensensis Zone and the first Givetian Polygnathus hemiansatus Zone and are no younger than the beginning of the early Givetian Polygnathus varcus Zone. The Middle Devonian sedimentary successions of the Yuryung-Tumus Peninsula show the level of the global sedimentary Ka?ak Event. The areas of distribution of the Devonian sedimentary deposits in the Yuryung-Tumus Peninsula in the Khatanga Gulf should be considered as one of the fragments of the regional geological structures of a remote (isolated?) region of the Taymyr Fold System rather than a component of the structures of the northern Siberian Platform.     

Jurassic and Early Cretaceous Radiolarians of Siliceous Sequences of the Vaamychgyn–Podgornaya Interfluve,Econai Zone,Koryak Highland

The assemblages of the Early Jurassic (Hettangian–Pliensbachian) and Late Jurassic–Early Cretaceous (Tithonian–Berriasian) radiolarians were described for the first time in the eastern part of the Ekonai Zone of the Koryak Highland. The Hettangian–Pliensbachian assemblage was found in siliceous rocks of the Ionai Nappe and this finding expands the stratigraphic interval of its siliceous sequences from the Carboniferous to the Early Jurassic. The Tithonian–Berriasian assemblage was found in volcanosiliceous rocks of the Yanranai accretionary complex. Both assemblages contain taxa abundant in the Tethyan regions.     

Age and Provenance Areas of Terrigenous Rocks of the Dzhida Terrane: Results of U—Th—Pb (LA-ICP-MS) Geochronological Study of Detrital Zircons

The results of U—Th—Pb (LA-ICP-MS) geochronological studies of detrital zircons from terrigenous rocks of the Dzhida terrane of the Central Asian Fold Belt (CAFB) are presented. The data obtained allow us to distinguish the following age maxima (Ma): 578 and 634 (Vendian); 720, 823, and 919 (Late Riphean); 1922, 2090, 2225, and 2321 (Early Proterozoic). A number of zircons have Late Archean age in the interval of 2670–2980 Ma. Taking into account Late Cambrian age (504–506 Ma) of intrusive rocks that intruded the Dzhida terrane, a possible sedimentation period of sequences of this terrane is estimated to be in the interval of 580–510 Ma (from Vendian to Late Cambrian). The possible provenance areas of terrigenous sediments are proposed and the previously proposed models of geodynamic evolution of the Dzhida terrane are correlated with new geochronological data.     

Kampelite,Ba3Mg1.5Sc4(PO4)6(OH)3·4H2O,a new very complex Ba-Sc phosphate mineral from the Kovdor phoscorite-carbonatite complex (Kola Peninsula,Russia)

Mineralogy and Petrology - Kampelite, Ba3Mg1.5Sc4(PO4)6(OH)3·4H2O, is a new Ba-Sc phosphate from the Kovdor phoscorite-carbonatite complex (Kola Peninsula, Russia). It is orthorhombic, Pnma,...     

Club convergence and spatial distribution dynamics of carbon intensity in China’s construction industry

Climate change caused by carbon emissions continuously threatens sustainable development. Due to China’s immense territory, there are remarkable regional differences in carbon emissions. The construction industry, which has strong internal industrial differences, further leads to carbon emission disparity in China. Policymakers should consider spatial effects and attempt to eliminate carbon emission inequality to promote the sustainable development of the construction industry and realize emission reduction targets. Based on the classic Markov chain and spatial Markov chain, this paper investigates the club convergence and spatial distribution dynamics of China’s carbon intensity in the construction industry from 2005 to 2014. The results show that the provincial carbon intensity in the construction industry is characterized by “convergence clubs” during the research period, and very low-level and very high-level convergence clubs have strong stability. Moreover, the carbon intensity class transitions of provinces tend to be consistent with that of their neighbors. Furthermore, the transition of carbon intensity types is highly influenced by their regional backgrounds. The provinces with high carbon emissions have a negative influence on their neighbors, whereas the provinces with low carbon emissions have a positive influence. These analyses provide a spatial interpretation to the “club convergence” of carbon intensity.     

鄂尔多斯盆地西峰和姬塬油田长81段低渗透储层迥异性

利用岩芯、薄片、测井等资料,从储层特征及孔隙演化角度对比分析了西峰和姬塬油田长8₁低渗透储层的迥异性。分析结果表明,两地区长8₁储层的共性为:1）储层砂体为浅水三角洲前缘的多期叠加的水下分流河道厚层砂体,且在空间上具有良好的连续性;2）砂体为岩屑长石砂岩和长石岩屑砂岩,属于细砂岩和极细砂岩,分选以较好为主;3）储层孔隙类型以粒间孔和溶蚀孔为主,原始孔隙度约38%,压实作用、胶结作用孔隙损失率约35%,最终储层孔隙度约7%。两地区长8₁储层存在以下差异:1）姬塬地区长8₁水下分流河道砂体叠加期次不明显,为"连续退积式"沉积模式,而西峰地区具有明显的垂向加积特征,为"顶牛"沉积模式;2）粒间孔、岩屑溶孔、晶间孔姬塬地区低于西峰地区,而溶蚀孔姬塬地区高于西峰地区;3）储层后期成岩演化过程中,姬塬和西峰地区长8₁砂体平均胶结孔隙度损失率为13.87%和11.99%,姬塬地区胶结孔隙度损失程度高于西峰地区,而溶蚀增孔率分别为3.71%和2.79%,姬塬地区溶蚀增孔率高于西峰地区。