Diagenesis and very low grade metamorphism in a 7,012?m-deep well Hongcan 1, eastern Tibetan plateau

This study uses clay mineral assemblages, illite ??crystallinity?? (IC), chlorite ??crystallinity?? (CC), illite polytypes, the b cell-dimension of K-white mica, mineral geothermo-geobarometers and homogenization temperatures of fluid inclusions to investigate the transition from diagenesis to metamorphism in a 7?km thick Triassic flysch sequence in the well Hongcan 1, eastern Tibetan plateau. The 7,012.8?m deep borehole penetrated flysch of Upper to the Middle Triassic age and represents a unique chance to characterize low temperature metamorphic processes in an unusually thick sedimentary sequence developed on thickened continental crust. Mineral assemblage analysis reveals a burial metamorphic pattern with kaolinite and chlorite/smectite mix-layer phases present in the upper 1,500?m, and illite/smectite mixed-layer phases extending to a depth of 3,000?m. The metamorphic index mineral, graphite, was detected in sedimentary rock below 5,000?m using Raman spectroscopy. There exists a good correlation between IC and CC within the prograde burial sequence; with CC anchizonal boundaries of 0.242 and 0.314°2?? (upper and lower boundaries, respectively) corresponding to Kübler??s IC limits at 0.25 and 0.42°2??. Illite polytypism also shows an increase in the 2M ₁ polytype with increasing depth, with ca. 60?% 2M ₁ abundance compared to the 1M type at the surface, to 100?% 2M ₁ at the bottom of the borehole. Fluid inclusion analysis show HHC-rich bearing fluids correspond to the diagenetic zone, CH₄-rich bearing fluids appear at transitional zone from diagenetic to low anchizone and H₂O-rich bearing fluids mark the high anchizone to epizone. Based on chlorite chemical geothermometer, calcite?Cdolomite geothermo-barometers as well as homogenization temperature of fluid inclusions, a paleotemperature range of 118?C348?°C is estimated for the well with a pressure facies of low to intermediate type.     

成烃贡献值及其在烃源岩评价中的应用

烃源岩评价是油气勘探的关键工作之一。为了更加合理、直观和有效地评价烃源岩,以辽东湾地区为例,通过对烃源岩常规评价参数的分析,提出了考虑有机质丰度、类型和热演化程度的综合指标——成烃贡献值,并利用该指标对辽东湾地区烃源岩进行了评价。从个体评价和整体评价两方面,与常规评价方法的结论进行对比研究。结果表明,辽东湾地区辽中凹陷沙河街组烃源岩对成烃的贡献比东营组大,中洼烃源岩比北洼好。由此可见,用成烃贡献值评价烃源岩,不仅可以达到常规评价的要求,而且比常规方法更加合理和直观。     

东北及内蒙古东部地区显生宙构造演化的有关问题

以国家油气资源战略选区项目研究成果为基础,结合近年来该区积累的大量区域地质调查资料和已发表的数据,对东北及内蒙古东部地区早古生代以来的大地构造性质及其演化进行综合对比分析。东北地区晚古生代以来的构造演化以稳定的大陆地块为主体,而非两大板块间多岛洋演化形成的造山带。东北地区的各地块均具有前寒武纪—早前寒武纪、甚至是太古宙的古老基底,它们在早古生代早期(490～510Ma)同时遭受了区域变质作用和花岗质岩浆侵入。350～450Ma,各地块均处于相对稳定的构造环境,以普遍缺失这一时期的花岗质岩浆活动记录为标志。从早古生代晚期开始,东北及内蒙古东部地区至少已存在2个早古生代早期固结的微陆块,即额尔古纳—兴安微陆块和松嫩—佳木斯微陆块,这2个微陆块向北分别与俄罗斯境内的额尔古纳微陆块和布列亚微陆块相连。二者在早石炭世沿北北东向展布的开鲁—嫩江—黑河—诺拉—索霍提(Nora-Soukhotin)一线碰撞拼合,形成统一的东北亚晚古生代大陆板块。西拉沐伦河断裂西端被北北东向构造所截,向东延至开鲁—嫩江断裂,并没有延伸到松辽盆地内,说明西拉沐伦河断裂可能与开鲁—嫩江碰撞带的形成有关。从晚石炭世开始,东北亚大陆板块整体处于伸展构造背景,至少在中国境内具有北陆南海的构造-沉积古地理格局,早期发育以火山岩为主的断陷盆地,到中二叠世演化成一个规模巨大的海相沉积盆地。中生代以来,东北地区的构造体制转换及物质成分演化不仅仅是古亚洲洋构造域和西太平洋构造域叠加转换的结果,蒙古—鄂霍茨克构造域的演化对该区现今构造体制的形成也具有重要影响。地质和地球物理综合证据显示,大兴安岭北部的得尔布干断裂、内蒙古中部的贺根山断裂和黑龙江省东部的跃进山断裂可能并不是具有一定深度规模的构造分区断裂。东北地区的中、新生代盆地之下并非都是变质结晶基底,而是存在一个规模巨大的晚古生代海相沉积盆地。     

煤矿瓦斯抽放井一次成井工艺及技术效果

煤矿瓦斯抽放井要求垂直精度高、井径大,通常采用常规钻探工艺时,需进行3-4次扩孔才能达到最终孔径,施工时间较长,钻进效率较低。此次在端氏煤矿施工的大口径瓦斯抽放井,采用了的一次成井钻进技术及工艺方法,钻进口径达到φ660mm,选用了江汉735型和715型系列镶齿牙轮钻头,采用塔式加重钻具控制并保证了钻井的重直度,采用密度较大的化学泥浆和保持大泵量排渣,避免了井底牙轮钻头的重复破碎,确保了钻进效果。与传统的扩孔工艺相比,缩短了施工周期,成井质量高,提高了钻进效率,降低了钻进成本。     

层序古地理背景下河南省二_1煤聚集规律研究

对河南省晚石炭世-早二叠世含煤岩系(太原组中部碎屑岩段、上部灰岩段和山西组二1煤层段、大占砂岩段)进行层序分析,共识别出以胡石砂岩底面、二1煤底面、大占砂岩底面和香炭砂岩底面为代表的4个层序界面,将该层段含煤岩系划分为3个三级层序。通过对层序S1和层序S3岩相古地理图和二1煤厚度等值线图耦合分析发现,障壁岛-潟湖沉积环境为二1煤的聚集提供一个较好的前期环境,分流间湾沉积环境为二1煤的保存提供一个较好的后期环境,而分流河道对二1煤的保存起到了破坏性的作用。     

http://www.sciencedirect.com/science/article/pii/S1674987111001150

The Erlangmiao granite intrusion is located in the eastern part of the East Qinling Orogen.The granite contains almost 99 vol.％ felsic minerals with accessory garnet,muscovite,biotite,zircon,and Fe-Ti ...     

Petroleum pollution and evolution of water quality in the Malian River Basin of the Longdong Loess Plateau,Northwestern China

The possible sources of water pollution and the evolution of water quality in the Malian River Basin of China’s Longdong Loess Plateau were studied based on chemical analysis. Concentrations of major chemicals in the river were related to the distance downstream from the source of the river and the surface water in the upstream had good quality, while the river from Southern Huanxian County to Qingcheng County was seriously polluted. Groundwater quality was generally good in the phreatic aquifer beneath the loess plateau, with bicarbonate and calcium dominant, but salinity was high and petroleum pollution was present in many parts of the study area. Both surface water and groundwater quality have declined rapidly during the past 20 years, leading to much of the water unsafe to drink and unsuitable for use in irrigation. The substances released into the water included industrial wastes, domestic sewage, organic and inorganic fertilizers, and pesticides, as well as a range of other substances that are harmful to humans. However, petroleum contamination caused by the oil industry in the Longdong oilfield is the largest source of pollution that infiltrates surface water and groundwater, leading to deterioration of water quality. It is recommended that oilfield management must be improved and the petroleum products and wastes must be disposed carefully to reduce the risk of further spills and pollution.     

Geochemistry and genotoxicity of the heavy metals in mine-abandoned areas and wasteland in the Hetai goldfields,Guangdong Province,China

The article presents the geochemical and biogeochemical characteristics of heavy metal elements within the soil–plant system in the Hetai mine-abandoned areas and wasteland, China. The cytogenetic toxic effects of gold mine wastelands environment on the chromosome and micronucleus were analyzed by genetic methods. The results showed that abundances of Au and Au-associated heavy metal elements such as Cu, As, Cd, Pb and Hg in soils, plants and the pigments in those abandoned mine areas were much higher than those in the background region. The cell structures of the plants in the abandoned mine areas were anomalous and aberrant, and there were many nano-metal particles diffused in the cells. Moreover, the heavy metal elements in those abandoned mine areas had entered the ultrastructure and caused toxicities to the organism.     

工程测量数据共享机制研究

北京市测绘设计研究院(简称北京院)是全国最大的城市测绘院,每年约完成5000余件工程测量任务,其对工程测量数据共享的需求具有代表性.在调研北京市测绘设计研究院各部门工程测量数据情况的基础上,首先对院内工程测量数据的现状和共享现状进行了分析,然后分析了共享中存在的问题,并提出了工程测量数据共享机制的建议,供领导在决策过程...