环渤海地区油气资源探查的思考

回顾过去渤海勘探实践的经验，对于指导今后的研究工作是十分重要的。40年来渤海地区发现大量新老第三纪陆相石油资源，成为中国的重要产油区，也积累了丰富的勘探经验。深化环渤海地区油气资源的探查，首先应考虑前新生代海相油气资源。但其勘探是高难度的，前景是诱人的。应该认真贯彻下列认识原则：（1）区域指导局部；（2）深部制约浅层；（3）在地震处理解释创新的同时，大力发展综合地质地球物理研究。     

中扬子区寒武纪层序地层研究

笔者建立了中扬子区寒武系层序地层格架，研究了中扬子区层序界面和体系域特点，分析了中扬子区层序样式的基本类型及其特征。共划分出2个二级层序、14个三级层序。寒武系下统划分了1个二级层序(SS3)、6个三级层序(SQ1—SQ6)，平均延时约5．0Ma；体系域颜色普遍较深，泥质含量较高，是一套良好的烃源岩。寒武系中上统划分出1个二级层序(SS4)、8个三级层序(SQ7—SQ14)，平均延时约2．9Ma；体系域颜色普遍较浅，云质含量较高，是一套良好的储集层。总体上H型样式为主，T型样式和TH型样式数量相当，反映寒武纪水体中等。二级层序体系域和三级层序体系域都表现出明显的南北向差异性。     

广东大亚湾底质重金属分布特征与环境质量评价

大亚湾是粤东的大型海湾，毗邻深港，其环境质量现状及发展趋势颇受关注。对大亚湾海域45个表层站位、1口浅钻及2个柱状样重金属元素Hg、As、Cd、Cu、Pb、Cr、Zn进行分析，并对底质环境质量进行定量评价。其结果：①大亚湾海域Hg、As、Cu的污染指数Pi值均小于1．0，超标率为0，表明全区未受这些因子污染；②Cd、Zn、Pb、Cr的污染指数Pi值部分大于1．0，表明受到这些因子不同程度的污染，其中Pb的超标率最高，达93．3％，污染指数Pi值为0．83～2．25，为良好—中等污染，总体为轻微污染；Zn的超标率为76．9％，pf值为0．25～2．63，变化较大，总体为轻微污染；Cd的超标率为60．0％，Pi值为0．50～1．78，良好—轻微污染；Cr的超标率为17．8％，Pi值为0，49～1．90，良好—轻微污染；③综合污染指数为1．08～2．21，平均1．37，表明本区均不同程度地受重金属污染，总体属轻微污染，其中范和港污染最为严重，SQI值多在1．5以上，其次为中央列岛附近海域。湾口和澳头—霞涌近岸海域污染较轻。从钻孔及柱状样的重金属含量分布来看，在表层没有明显增多的趋势。     

浅论新疆海相火山热水沉积矿床的分带及其找矿意义

新疆海相火山热水沉积矿床，一般在时间上没有明显的集中生长期。空间上依附于活动大陆边缘火山岛弧带，它在区域上和矿床本身具有矿种转化、类型转换、配套与分带特征。以块状氧化物、块状碳酸盐和块状硫化物转换序次来研究该类矿床。利用铁木尔特铅锌矿上部铅锌下部铜金，预须开普台铁矿上铁下铜；莫托沙拉铁锰矿上锰下铁中间铅锌重晶石等矿种转化规律和由块状氧化物和块状碳酸盐向块状硫化物成生过渡特点，预测诸如蒙库铁矿、赤龙峰火山盆地中铁矿和喀喇昆仑山各铁矿床(点)外围与深部转换、发展成为铜金矿的成矿前景。     

鄂尔多斯盆地奥陶系马家沟组溶斑形成机理

鄂尔多斯盆地中部气田奥陶系马家沟组属蒸发边缘海相地层,其风化壳是中部气田的主要产气层段。该层中广泛发育毫米级、厘米级的溶斑,这些溶斑的产状、大小、成分以及溶孔内的充填物十分复杂,有的具多期充填,充填物为石膏、石英、方解石、白云石、高岭石、黄铁矿等多种矿物。溶斑中下半部残留的岩石经溶蚀后的白云石晶粒形成的渗流砂示底构造十分明显。研究表明,溶斑的形成不仅具有适宜的岩相古地理环境和其复杂的生成演化史,而且与原始沉积以及不同地史阶段的岩溶作用相关。     

A review of the physics and ecological implications of the thermal bar circulation

Following recent applications of numerical modelling and remote sensing to the thermal bar phenomenon, this paper seeks to review the current state of knowledge on the effect of its circulation on lacustrine plankton ecosystems. After summarising the literature on thermal bar hydrodynamics, a thorough review is made of all plankton observations taken in the presence of a thermal bar. Two distinct plankton growth regimes are found, one with production favoured throughout the inshore region and another with a maximum in plankton biomass near the position of the thermal bar. Possible explanations for the observed distributions are then discussed, with reference to numerical modelling studies, and the scope for future study of this interdisciplinary topic is outlined.     

Simulation of marine boundary layer characteristics using a 1-D PBL model over the Bay of Bengal during BOBMEX-99

The characteristic features of the marine boundary layer (MBL) over the Bay of Bengal during the southwest monsoon and the factors influencing it are investigated. The Bay of Bengal and Monsoon Experiment (BOBMEX) carried out during July–August 1999 is the first observational experiment under the Indian Climate Research Programme (ICRP). A very high-resolution data in the vertical was obtained during this experiment, which was used to study the MBL characteristics off the east coast of India in the north and south Bay of Bengal. Spells of active and suppressed convection over the Bay were observed, of which, three representative convective episodes were considered for the study. For this purpose a one-dimensional multi-level PBL model with a TKE-ε closure scheme was used. The soundings, viz., the vertical profiles of temperature, humidity, zonal and meridional component of wind, obtained onboard ORV Sagar Kanya and from coastal stations along the east coast are used for the study. The temporal evolution of turbulent kinetic energy, marine boundary layer height (MBLH), sensible and latent heat fluxes and drag coefficient of momentum are simulated for different epochs of monsoon and monsoon depressions during BOBMEX-99.The model also generates the vertical profiles of potential temperature, specific humidity, zonal and meridional wind. These simulated values compared reasonably well with the observations available from BOBMEX.     

Architecture of coastal and alluvial deposits in an extensional basin: the Carboniferous Joggins Formation of eastern Canada

Abstract The Joggins Formation was deposited in the Cumberland Basin, which experienced rapid mid‐Carboniferous subsidence on bounding faults. A 600 m measured section of coastal and alluvial plain strata comprises cycles tens to hundreds of metres thick. The cycles commence with coal and fossiliferous limestone/siltstone intervals, interpreted as widespread flooding events. These intervals are overlain by coarsening‐upward successions capped by planar‐based sandstone mounds, up to 100 m in width that represent the progradation of small, river‐generated delta lobes into a standing body of open water developed during transgression. The overlying strata contain sand‐rich heterolithic packages, 1–8 m thick, that are associated with channel bodies 2–3 m thick and 10–50 m wide. Drifted plant debris, Calamites groves and erect lycopsid trees are preserved within these predominantly green‐grey heterolithic sediments, which were deposited on a coastal wetland or deltaic plain traversed by channel systems. The cycles conclude with red siltstones, containing calcareous nodules, that are interbedded with thin sandstones and associated with both single‐storey channel bodies (1–1·5 m thick and 2–3 m wide) and larger, multistorey channels (3–6 m thick) with incised margins. Numerous channel bodies at the same level suggest that multiple‐channel, anastomosed river systems were developed on a well‐drained floodplain. Many minor flooding surfaces divide the strata into parasequences with dominantly progradational and aggradational stacking patterns. Multistorey channel bodies are relatively thin, fine grained and modestly incised, and palaeosols are immature and cumulative. The abundance and prominence of flooding surfaces suggests that base‐level rise was enhanced, whereas the lack of evidence for abrupt basinward stepping of facies belts, coupled with the absence of strong fluvial incision and mature palaeosols, suggests that base‐level fall was suppressed. These architectural features are considered to reflect a tectonic architectural signature, in accordance with the high‐subsidence basinal setting. Evidence for restricted marine influence and variation in floral assemblages suggests modulation by eustatic and climatic effects, although their relative importance is uncertain.     

Petrographic of Northwestern Sudan

The sedimentology of the Northwestern Sudan consists of lower, middle and upper cycles. The lower and upper cycles are composed of intercalated fluvial and shallow marine facies, whereas the middle cycle consists entirely of fluvial and glaciofluvial facies. The petrographic analysis shows that the lower and upper cydes consist of quartz and lithic arenite sandstones, whereas the middle cycle consists of arkosic and lithic arenite sandstones. The lower and upper cycle sandstones reflect derivation mainly from recycled orogens with minor contribution from craton interior provenances. However, the middle cycle sandstones indicate derivation from basement uplift, transitional and mainly recycled orogens provenances.     

沉积地质学研究现状和进展在第30届国际地质大会上的反响

根据第３０届国际地质大会上专家发言及提供大会交流的部分论文摘要，从沉积环境，海相沉积，旋回地层和层序地层，古地理和盆地分析四个方面，窥视自第２９届国际地质大会以后沉积地质学的进展概况。