内蒙古大黄花地区铜多金属矿地质特征及找矿建议

大黄花铜多金属矿区位于赤峰金银多金属成矿带南部,是在近年来开展1：5万数字化区域地质矿产调查野外工作中发现的.区内构造处于赤峰-开原深大断裂带中.含矿围岩主要为石炭系酒局子组地层,又叠加了中生代大规模的火山喷发作用及岩浆侵入活动,具有较好的成矿地质条件.     

内蒙古扎鲁特旗地区中侏罗统塔木兰沟组的厘定

扎鲁特旗地区发育的一套中性火山岩,前人曾将其置于二叠纪“大石寨组”、“青凤山组”,缺少古生物资料和测年数据.本次1：25万区域地质调查,在原1：20万划分的“大石寨组”、“青凤山组”的安山岩中采集了同位素测年样品,采用全岩激光⁴⁰Ar/³⁹Ar法测年,对火山岩样品进行了年代学研究,结果表明火山岩年龄为（172.7±2.0）~（165.2±1.3）Ma.鉴于这套火山岩地层岩石组合特征清楚,时代依据充分,在区域上具有一定的延展性和可填图性,故将这套火山岩地层重新厘定为中侏罗统塔木兰沟组.     

山东昌乐凹陷油页岩地球化学特征及成因探讨

山东昌乐凹陷油页岩出产于古近系五图群李家崖组,与济阳拗陷和潍北凹陷孔二段相当。利用有机地球化学方法对昌乐凹陷油页岩品质进行分析,结果显示该区油页岩有机质丰度较高、干酪根类型主要为Ⅰ型和Ⅱ₁型,处于未熟低熟阶段,具有较好的勘探开发前景。通过区域构造演化和气候变化分析,昌乐凹陷油页岩形成于郯庐断裂带左旋右旋转换期,构造活动强度较弱加之温暖湿润的气候环境促成了油页岩的发育。油页岩与煤共生于水进体系域和高水位体系域之中,油页岩成矿模式为断陷湖沼型。     

川西新场气田上三叠统须二、须四段相对优质储层成因差异性分析

川西新场地区须家河组储层埋藏深度大、成岩作用复杂、致密化程度高,但在整体超致密背景下,局部仍发育较多的相对优质储层.相对优质储层在埋深较大的须二段,往往发育较多的原生孔隙,和相对次要的次生孔隙;而埋深较小的须四段储层,次生孔隙占绝对优势,原生孔隙发育较少.造成这一现象的主要原因是须二、须四段原生孔隙保存和次生孔隙发育机制上的差异.须二段储层中较多刚性颗粒的存在和较为发育的包膜绿泥石是原生孔隙得到较好保存的主要原因;而其较大的单砂层厚度和较少的泥岩发育则导致了有机酸性流体的注入量较少,长石溶蚀有限.须四段塑性岩屑含量明显较高,储层原生孔隙在压实作用下几乎消失殆尽,但较薄的单砂层厚度和较多泥岩的叠置发育使长石在有机酸性流体作用下得到了充分溶蚀;这是须四段储层次生孔隙相对发育、长石含量很低、同时还有自生高岭石沉淀的主要原因.     

内蒙古扎鲁特旗地区更新世地层划分

根据孢粉组合特征及光释光测年结果,对分布在内蒙古东南部的第四系更新统做了进一步的划分和研究。研究结果表明,主要分布在内蒙古东南部的中更新统风积物,岩性为黄色亚砂土,含钙质结核,发育柱状节理,区域上称乌尔吉组,含Artemisia-Ephedra-Pinus孢粉组合,光释光测年结果为(40.4±1.9)~(110.0±7.5)ka; 下更新统沉积物,岩性为红褐色亚砂土及亚黏土,含钙质结核、砂砾透镜体,区域上称为赤峰黄土,含Artemisia-Polygonum-Betula孢粉组合,光释光测年结果为（200.9±9.6）~（220.4±13.2）ka。上述2套地层在内蒙古东南部广泛分布,更新世地层的划分为内蒙古东南部地区的第四系地层划分对比研究提供了基础地质资料。     

准噶尔西北缘玛北地区扇三角洲砂砾岩岩相分类及储集意义

准噶尔盆地西北缘三叠系处于大型逆冲推覆断裂带,盆地边缘同生断裂构造活动强烈,发育砂砾岩为主的扇三角洲沉积体系。通过对玛北地区三叠系百口泉组砂砾岩储层取芯段岩芯观察和描述、岩石薄片、扫描电镜、测井以及储层物性数据的分析,结合砂砾岩岩石构成、层理类型、沉积层序和测井曲线响应特征,对准噶尔盆地西北缘砂砾岩体岩性进行精细刻画,建立岩相模式,划分出同沉积相(微相)相符的11种岩相:其中扇三角洲前缘水下河道砂砾岩相、扇三角洲平原辫状河道砂砾岩相叠置连片展布,是最有利的储集体;扇三角洲前缘水下主河道砾岩相、水下河道末端砂岩相及河口坝—远砂坝砂岩相分布局限,储集性良好,为有利"甜点"区;水上泥石流砾岩相和水下泥石流砂砾岩相与扇三角洲平原和前缘分流河道间储集性较差的细粒砂泥岩相组成百口泉组油藏致密的顶底板;前扇三角洲粉砂岩相和泥岩相可作为良好的区域性盖层。不同的岩相类型及沉积条件提供了准噶尔西北缘百口泉组大规模低渗透岩性油气藏优良的储盖组合及顶底板条件。     

Transition from storm wave‐dominated outer shelf to gullied upper slope: The mid‐Pliocene Orinoco shelf margin,South Trinidad

Shelf‐edge deltas are a key depositional environment for accreting sediment onto shelf‐margin clinoforms. The Moruga Formation, part of the palaeo‐Orinoco shelf‐margin sedimentary prism of south‐east Trinidad, provides new insight into the incremental growth of a Pliocene, storm wave‐dominated shelf margin. Relatively little is known about the mechanisms of sand bypass from the shelf‐break area of margins, and in particular from storm wave‐dominated margins which are generally characterized by drifting of sand along strike until meeting a canyon or channel. The studied St. Hilaire Siltstone and Trinity Hill Sandstone succession is 260 m thick and demonstrates a continuous transition from gullied (with turbidites) uppermost slope upward to storm wave‐dominated delta front on the outermost shelf. The basal upper‐slope deposits are dominantly mass‐transport deposited blocks, as well as associated turbidites and debrites with common soft‐sediment‐deformed strata. The overlying uppermost slope succession exhibits a spectacular set of gullies, which are separated by abundant slump‐scar unconformities (tops of rotational slides), then filled with debris‐flow conglomerates and sandy turbidite beds with interbedded mudstones. The top of the study succession, on the outer‐shelf area, contains repeated upward‐coarsening, sandstone‐rich parasequences (2 to 15 m thick) with abundant hummocky and swaley cross‐stratification, clear evidence of storm‐swell and storm wave‐dominated conditions. The observations suggest reconstruction of the unstable shelf margin as follows: (i) the aggradational storm wave‐dominated, shelf‐edge delta front became unstable and collapsed down the slope; (ii) the excavated scars of the shelf margin became gullied, but gradually healed (aggraded) by repeated infilling by debris flows and turbidites, and then new gullying and further infilling; and (iii) a renewed storm wave‐dominated delta‐front prograded out across the healed outer shelf, re‐establishing the newly stabilized shelf margin. The Moruga Formation study, along with only a few others in the literature, confirms the sediment bypass ability of storm wave‐dominated reaches of shelf edges, despite river‐dominated deltas being, by far, the most efficient shelf‐edge regime for sediment bypass at the shelf break.     

High-resolution calcareous nannofossil biostratigraphy of the Santonian/Campanian Stage boundary,Western Interior Basin,USA

The base of the Campanian Stage does not have a ratified Global Stratotype Section and Point (GSSP); however, several potential boundary markers have been proposed including the base of the Scaphites leei III ammonite Zone and the base of the paleomagnetic Chron C33r. Calcareous nannofossil assemblages from the Smoky Hill Member of the Niobrara Formation in the central Western Interior Seaway, USA were analyzed from two localities to determine relevant biohorizons and their relationships to these potential boundary markers. In a previous study, the Aristocrat Angus 12-8 core (Colorado) was astrochronologically dated and constrained using macrofossil zonations and radiometric ages. The Smoky Hill Member type area (Kansas) provides an expanded interval with good to excellent nannofossil preservation.Five biohorizons are useful for recognition of the Santonian/Campanian transition within the Smoky Hill Member type area, and three are useful in the Aristocrat Angus 12-8 core. The first occurrences (FOs) of Aspidolithus parcus parcus and Aspidolithus parcus constrictus, as well as the last occurrences (LOs) of Zeugrhabdotus moulladei, Helicolithus trabeculatus specimens larger than 7 μm, and Zeugrhabdotus biperforatus are in close stratigraphic proximity to the base of the Scaphites leei III Zone and the base of Chron C33r.     

A new afrograptid (Diplostraca: Estheriellina) from the Lower Cretaceous of southern England

The Family Afrograptidae is a ‘conchostracan’ group with multiple radial costae reaching to the umbo on their carapaces. It comprises four described genera: Afrograpta, Camerunograpta, Congestheriella and Graptoestheriella with a total of thirteen described species which are occasionally reported from the Jurassic and the Cretaceous in Africa, Europe and South America (i.e. Afrograpta from the Upper Cretaceous of Cameroon; Camerunograpta from the Jurassic to Cretaceous of Cameroon; Congestheriella from the Jurassic to Upper Cretaceous of the Congo Basin, Brazil, Bulgaria, Venezuela and Argentina; and Graptoestheriella from the Upper Jurassic to Lower Cretaceous of Brazil). A new genus and a new species, Surreyestheria ockleyensis gen. et sp. nov., belonging to the Family Afrograptidae from the Lower Cretaceous (lower Barremian) Upper Weald Clay Formation of Ockley Village, Surrey County, southern England is described in this paper. The new genus mainly differs from the other four genera by the special reticulate ornamentation on its carapace. It indicates that the Family Afrograptidae was more diverse and more widely distributed in the late Mesozoic than previously supposed. Afrograptidae is a special branch of Estheriellina the latter originating in the late Palaeozoic and the former in the early Mesozoic. Afrograptids, as a whole had been widespread across Pangea in the Early Jurassic.     

Two rare taxa from the type area of the Devonian,south-west England

The rarity of certain taxa in the type Devonian, south-west England, may be real, but it is probably, in part, an artefact of preservation. In part this is a product of Variscan deformation, but disarticulation of multi-element skeletons into minute plates must also be a contributory factor. Echinoids are rare from these deposits and were hitherto limited to the Upper Devonian. A single radiole (=spine) from the Middle Devonian (Givetian) Lummaton Shell Beds, Torquay Limestone Formation, is referred to echinoid sp. indet. Although stromatoporoids are common in these same beds, true sponges were hitherto unknown. In the same rock specimen, a moderately well preserved siliceous spicule is referred to octactinellid sp. indet.