The optical features and hydrocarbon-generating model of “barkinite” from Late Permian coals in South China

Leping coal is known for its high content of “barkinite”, which is a unique liptinite maceral apparently found only in the Late Permian coals of South China. “Barkinite” has previously identified as suberinite, but on the basis of further investigations, most coal petrologists conclude that “barkinite” is not suberinite, but a distinct maceral. The term “barkinite” was introduced by (State Bureau of Technical Supervision of the People's Republic of China, 1991, GB 12937-91 (in Chinese)), but it has not been recognized by ICCP and has not been accepted internationally.In this paper, elemental analyses (EA), pyrolysis-gas chromatography, Rock-Eval pyrolysis and optical techniques were used to study the optical features and the hydrocarbon-generating model of “barkinite”. The results show that “barkinite” with imbricate structure usually occurs in single or multiple layers or in a circular form, and no definite border exists between the cell walls and fillings, but there exist clear aperture among the cells.“Barkinite” is characterized by fluorescing in relatively high rank coals. At low maturity of 0.60–0.80%R_o, “barkinite” shows strong bright orange–yellow fluorescence, and the fluorescent colors of different cells are inhomogeneous in one sample. As vitrinite reflectance increases up to 0.90%R_o, “barkinite” also displays strong yellow or yellow–brown fluorescence; and most of “barkinite” lose fluorescence at the maturity of 1.20–1.30%R_o. However, most of suberinite types lose fluorescence at a vitrinite reflectance of 0.50% Ro, or at the stage of high volatile C bituminous coal. In particular, the cell walls of “barkinite” usually show red color, whereas the cell fillings show yellow color under transmitted light. This character is contrary to suberinite.“Barkinite” is also characterized by late generation of large amounts of liquid oil, which is different from the early generation of large amounts of liquid hydrocarbon. In addition, “barkinite” with high hydrocarbon generation potential, high elemental hydrogen, and low carbon content. The pyrolysis products of “barkinite” are dominated by aliphatic compounds, followed by low molecular-weight aromatic compounds (benzene, toluene, xylene and naphthalene), and a few isoprenoids. The pyrolysis hydrocarbons of “barkinite” are mostly composed of light oil (C₆–C₁₄) and wet gas (C₂–C₅), and that heavy oil (C₁₅⁺) and methane (C₁) are the minor hydrocarbon.In addition, suberinite is defined only as suberinized cell walls—it does not include the cell fillings, and the cell lumens were empty or filled by corpocollinites, which do not show any fluorescence. Whereas, “barkinite” not only includes the cell walls, but also includes the cell fillings, and the cell fillings show bright yellow fluorescence.Since the optical features and the hydrocarbon-generating model of “barkinite” are quite different from suberinite. We suggest that “barkinite” is a new type of maceral.     

内蒙古北山重点成矿远景区主要地质特征与矿产资源潜力评价方向

本文根据北山地区区域地质背景、成矿地质条件及矿产分布特征,对北山地区初步划分出几个重点成矿远景区,建议作为今后进行区域固体矿产资源潜力评价的方向。     

Gravity and magnetic signatures of volcanic plugs related to Deccan volcanism in Saurashtra, India and their physical and geochemical properties

The Bouguer anomaly and the total intensity magnetic maps of Saurashtra have delineated six circular gravity highs and magnetic anomalies of 40-60 mGal (10⁻⁵m/s²) and 800-1000 nT, respectively. Three of them in western Saurashtra coincide with known volcanic plugs associated with Deccan Volcanic Province (DVP), while the other three in SE Saurashtra coincide with rather concealed plugs exposed partially. The DVP represents different phases of eruption during 65.5±2.5 Ma from the Reunion plume. The geochemical data of the exposed rock samples from these plugs exhibit a wide variation in source composition, which varies from ultramafic/mafic to felsic composition of volcanic plugs in western Saurashtra and an alkaline composition for those in SE Saurashtra. Detailed studies of granophyres and alkaline rocks from these volcanic plugs reveal a calc-alkaline differentiation trend and a continental tectonic setting of emplacement. The alkaline plugs of SE Saurashtra are associated with NE-SW oriented structural trends, related to the Gulf of Cambay and the Cambay rift basin along the track of the Reunion plume. This indicates a deeper source for these plugs compared to those in the western part and may represent the primary source magma. The Junagadh plug with well differentiated ring complexes in western Saurashtra shows well defined centers of magnetic anomaly while the magnetic anomalies due to other plugs are diffused though of the same amplitude. This implies that other plugs are also associated with mafic/ultramafic components, which may not be differentiated and may be present at subsurface levels. Paleomagnetic measurements on surface rock samples from DVP in Saurashtra suggest a susceptibility of 5.5×10⁻² SI units with an average Koenigsberger ratio (Q_n) of almost one and average direction of remanent magnetization of D=147.4° and I=+56.1°. The virtual geomagnetic pole (VGP) position computed from the mean direction of magnetization for the volcanic plugs and Deccan basalt of Saurashtra is 30°N and 74°W, which is close to the VGP position corresponding to the early phases of Deccan eruption. Modeling of gravity and magnetic anomalies along two representative profiles across Junagadh and Barda volcanic plugs suggest a bulk density of 2900 and 2880 kg/m³, respectively and susceptibility of 3.14×10⁻² SI units with a Q_n ratio of 0.56 which are within the range of their values obtained from laboratory measurements on exposed rock samples. The same order of gravity and magnetic anomalies observed over the volcanic plugs of Saurashtra indicates almost similar bulk physical properties for them. The inferred directions of magnetization from magnetic anomalies, however, are D=337° and 340° and I=−38° and −50° which represent the bulk direction of magnetization and also indicate a reversal of the magnetic field during the eruption of these plugs. Some of these plugs are associated with seismic activities of magnitude ≤4 at their contacts. Based on this analysis, other circular/semi-circular gravity highs of NW India can be qualitatively attributed to similar subsurface volcanic plugs.     

中外饭店区域集团化特征对比研究

随着饭店业全球化进程的发展，饭店之间的竞争日趋激烈，国际饭店集团的出现使国际旅游市场和饭店业都发生了极大的变化。与中国饭店集团相比，国际饭店集团具有诸多竞争优势，本文将以世界饭店集团300强为例，与中国饭店区域集团化特征进行对比分析，从而为中国饭店业借鉴国际饭店集团成功经验，应对其挑战提供启示。     

四川盆地白垩纪沙漠石英沙颗粒表面特征

石英具有较大的硬度和较高的化学稳定性，因而其颗粒表面特征能很好地反映沉积环境。而通过扫描电镜研究石英颗粒表面微细特征是分析沉积环境行之有效的方法。虽然多数人认为四川盆地白垩纪地层存在沙漠沉积(打儿凼组和夹关组)，但仍有人对沙漠沉积的存在持怀疑态度，并认为是河流成三角洲沉积。过去关于其沉积环境的判别主要是根据沉积结构和构造，并未对其石英沙颗粒表面特征进行过系统分析。笔者对采自四川盆地白垩系不同层位地层的样品进行了石英沙颗粒表面特征系统分析。结果表明，石英沙颗粒表面特征分析可以成功地将石英沙区分为风成和水成沉积。因此，本文从石英沙颗粒表面特征方面进一步肯定了四川盆地白垩纪古沙漠的存在。     

川西及松辽南部油气微渗漏动力学模拟

选择川西孝泉-新场气田和松辽南部后五家户气田为研究区,采集14口井井中化探样品,测试热释烃、酸解烃、荧光等指标,进行了烃类垂向微运移的研究.由于岩石物性的影响,热释烃、荧光等指标显示不同程度的正向梯度,但酸解烃指标在油气田井中局部层段垂向分布特征显示负向梯度,或与其它化探指标没有相关关系.建立相应的微渗漏模型,并进行动力学模拟,模拟结果和实测资料较吻合.     

塔里木板块南缘早古生代沉积特征及构造背景探讨

塔里木板块南缘早古生代时期继承了震旦纪的古地理格局，处于浅海陆棚—半深海环境，沉积了一套海相碳酸盐岩和碎屑岩地层。根据区域地层划分、古生物化石和最新的同位素测年数据，确定了塔里林板块南缘地层时代为早古生代。通过沉积学和地球化学方法初步分析，确定了该地区为早古生代的大地构造背景—具有被动大陆边缘性质。因此，系统研究塔里木板块南缘早古生代沉积地层，对于重塑早生代以来该区板块构造格局及演化历史有重要地质意义。     

青藏铁路抛石路基的温度特性研究

铁路道渣和片石铺层的对流换热为多孔介质的热传导问题，根据多孔介质中流体热对流的连续性方程、动量方程和能量方程，应用伽辽金法导出了多孔介质对流换热的有限元公式，并对抛石路基和传统道渣路基在未来25a创温度变化进行了预报分析和比较．计算结果表明，在150cm的抛石厚度，片石直径为10cm，年温度较差30℃的倩况下，在路基中心线y＝一5m处，抛石路基下的冻土温度要比传统路基的温度低2．45℃，抛石路基有对其下面的冻土提供冷能的制冷作用，可以保证冻土路基的稳定．因此，推荐该种路基作为青藏铁路高温冻土区的路基结构，可以最大限度地保护冻土区的铁路．