丽江古都塘锰矿

古都塘锰矿床由晚二叠世海底基性火山喷发及含锰喷气活动提供主要锰质来源，在海底槽形洼地内沉积形成的海相沉积锰矿床，并叠加了表生氧化富集作用。矿体赋存于二叠统猴子坡组（P2ho）灰岩夹层中，严格受层位、岩性控制。     

Shear wave splitting in the Eastern Alps observed at the TRANSALP network

Data from the temporary TRANSALP seismic network were analysed to investigate the seismic anisotropy in the upper mantle beneath the Eastern Alps. We operated mostly short period and some broadband stations in a dense linear array, which transects the Eastern Alps at 12° E longitude. Recorded SKS and SKKS phases with different backazimuths were used simultaneously to calculate the splitting parameters of delay time and fast axis direction for each seismic station. While we found variations in the delay times between 0.8 and 2.0 s, the determined fast axis directions prove to be rather consistent along the profile (60°–70° N). They coincide well with the trend of the Eastern Alps, thus suggesting orogen-parallel flow in the upper mantle. Our findings support the earlier proposed idea that the Adriatic indenter which was forced northwards into the European plate during the late stage of the Alpine orogeny, triggered an escape movement to the less constrained Pannonian basin to the east.     

鄂尔多斯盆地中西部延长组长6油层组物源分析

根据砂岩颗粒类型及特征、石英阴极发光、重矿物组合、砂体展布方向以及岩相古地理格局,对鄂尔多斯盆地中西部上三叠统延长组长6油组进行了物源分析。分析结果表明,酸性岩浆岩和中低级变质岩、浅海相碎屑岩及碳酸盐岩为研究区延长组主要的母岩类型,东北、西北、西部、西南和南部为5个主要的物源方向,且东北和西南影响范围最大;形成了东北安边三角洲沉积体系、西北盐定三角洲沉积体系、西部环县三角洲沉积体系、演武三角洲沉积体系、西南镇原辫状河三角洲沉积体系和南部固城-合水浊积扇沉积体系。     

Variations of Eu/Eu* ratio in Vendian shales of the Volga-Ural region and the boundary traced between the Redkino and Kotlin Horizons

Variations of Eu/Eu* ratio in shales from the upper Vendian Kairovo and Shkapovo groups of the Shkapovo-Shikhan depression, the Volga-Ural region, are considered. Shales in the lower part of the Karlin Formation are established to be similar in geochemistry to the shale member with abnormally low Eu/Eu* ratios at the base of the Upper Vendian Kotlin Horizon of the East European Platform. According to these data, the studied formation appears to be a lithostratigraphic unit of the Kotlin Horizon, while the Baikibashevo, Staropetrovo and Salikhovo formations belong to the Redkino Horizon of the upper Vendian.     

漠河盆地上侏罗统沉积特征与构造背景

对晚侏罗世漠河盆地的沉积特征进行了分析,并探讨了其构造类型和成因机制。详细的沉积学研究表明:晚侏罗世漠河盆地主要发育冲积扇、扇三角洲和湖泊相沉积,属于前陆盆地的陆相磨拉石部分。晚侏罗世漠河盆地的物源来自南北两个方向,具有典型前陆盆地双向物源特点:北部物源区是蒙古-鄂霍茨克造山带,位于西伯利亚板块南缘;南部物源区是下伏板块基底,位于大兴安岭北部。根据沉积特征、区域大地构造背景和俄罗斯上阿穆尔盆地有关资料认为:晚侏罗世漠河盆地为漠河-上阿穆尔前陆盆地的南半部分,形成和演化受蒙古-鄂霍茨克造山带制约;晚侏罗世二十二站期和额木尔河期是漠河盆地的主要成盆期,该时期湖泊面积广阔、暗色泥岩发育,是烃源岩的重要形成期。     

漠河盆地上侏罗统物源分析及其地质意义

为了探讨晚侏罗世漠河盆地的构造类型,笔者等对其物源特征进行了系统分析。通过古水流分析、母岩成分分析和源区构造背景分析认为:①晚侏罗世漠河盆地的物源来自南北两个方向;②北部物源区位于西伯利亚板块南缘,为蒙古—鄂霍茨克造山带,母岩成分主要为花岗岩、变质岩、中酸性火山岩、中基性火山岩和沉积岩;③南部物源区位于大兴安岭北部,为下伏板块基底,母岩成分主要为花岗岩、变质岩和沉积岩;④北部造山带物源区的构造背景为早中生代的活动大陆边缘。晚侏罗世漠河盆地具有典型前陆盆地的双向物源特征,一方面来自北部造山带,一方面来自盆地下伏板块基底。根据物源特征、区域大地构造背景和俄罗斯上阿穆尔盆地(黑龙江在俄罗斯称为阿穆尔河)有关资料认为晚侏罗世漠河盆地可能为漠河—上阿穆尔周缘前陆盆地的南半部分,其形成和演化受蒙古—鄂霍茨克造山带制约。     

Quaternary Moraines vs Catastrophic Rock Avalanches in the Karakoram Himalaya, Northern Pakistan

A history and conception of glacial events for the central Karakoram Himalaya, proposed some 80 years ago by Giotto Dainelli, are largely accepted today. However, certain deposits identified as terminal moraine complexes marking glacial episodes were actually emplaced by rock avalanches. In the Skardu and Shigar intermontane basins of Baltistan, at least 15 rock avalanche events were previously mapped as moraine or till. Criteria used for distinguishing these catastrophic landslide deposits emphasize homogeneous lithology of rubble and matrix, clast shape, facies characteristics, the large scale unity of emplacement, and morphological relations to valley topography. The deposits of three events, at Katzarah, Satpura, and the north end of Shigar Valley, have been reconstructed in detail. Thick supraglacial debris does not result in similar deposits. Extensive valley fills, river terraces, large sediment fans, and lacustrine sediments formerly attributed to late-glacial conditions are reinterpreted as postglacial events involving rock avalanches that interrupted fluvial development. Existing reconstructions of glaciations are left in doubt, especially late-glacial events in the central Karakoram, as are the roles assigned to Karakoram, main Indus Valley, and western Himalayan ice.     

中上扬子地区二叠纪缺氧环境

中上扬子地区二叠纪缺氧环境较为发育,缺氧沉积的岩石类型主要有黑色泥页岩、黑色薄层硅岩, 深灰色-灰黑色中-薄层泥晶石灰岩和含泥石灰岩。前 3种岩石类型常形成暗色泥页岩-薄层硅岩-泥晶石灰 岩组合,而含泥石灰岩则主要为眼球状石灰岩的 “ 眼皮”部分。分别对这两种组合的岩石特征、古生物特征及 地球化学特征进行了研究,并分析了各自的沉积环境以及缺氧环境的成因。分析认为暗色泥页岩-薄层硅岩- 泥晶石灰岩组合为盆地、盆地边缘或斜坡环境的产物,其缺氧环境主要为大规模的海侵形成;眼球状石灰岩的 “ 眼皮”部分应为碳酸盐岩台地的产物,其缺氧环境应为上升流作用形成。     

鄂尔多斯盆地临兴地区下石盒子组不同粒级砂岩成岩演化及孔隙定量研究

利用鄂尔多斯盆地临兴地区下石盒子组铸体薄片、扫描电镜、阴极发光、包裹体分析,地球化学等资料,通过统计与计算等方法,对研究区下石盒子组不同粒级砂岩的岩石学特征,成岩演化序列以及埋藏过程中孔隙的定量演化进行研究。结果表明:①岩石学组成中,粗砂岩刚性颗粒含量高,塑性颗粒则多集中在细砂岩中;粗砂岩中硅质胶结、碳酸盐胶结含量较高,中、细砂岩以高岭石胶结为主。②成岩演化阶段中,粗砂岩经历的成岩作用较为完全,而细砂岩在早成岩B期就已经基本致密化,中砂岩则为二者的过渡型。③二叠世-中晚三叠世为准同生-早成岩B阶段,成岩作用以压实为主,其对细砂岩孔隙度影响最大;晚三叠世-中侏罗世为中成岩A阶段,成岩作用以溶蚀和胶结为主,粗砂岩溶蚀作用较强,孔隙度较高,细砂岩基本不发育溶蚀和胶结作用;中侏罗世之后,成岩阶段达到了中成岩B,以亚铁碳酸盐胶结为主,粗砂岩受到胶结作用较强,降低了一定孔隙度,但物性依然较好,粗、中、细砂岩最终孔隙度分别为11.07%、6.08%及2.60%。综上所述,粗砂岩由于压实作用较弱,溶蚀作用较强,可以形成良好的储集空间,中砂岩主要受控于压实和胶结作用的双重影响,形成次一级的储集空间,而细砂岩以压实破坏为主,物性相对最差。     

西秦岭北缘武山地区上白垩统沙漠相沉积特征

西秦岭广泛但不连续分布着一套晚白垩世红层地层。这套红层地层所代表的原型沉积盆地是西秦岭中生代陆内造山期发育的相互孤立的山间盆地拟或是整体统一红层盆地新生代以来地壳隆升侵蚀破坏的残留一直存在争议。这个争议问题即关乎到对西秦岭中生代末期的构造地貌状态的认识,也关乎到现今青藏高原东北缘新生代以来地壳隆升初始地质背景。通过对西秦岭北缘武山地区上白垩统红层沉积地层中发育的一套砖红色砂岩的沉积序列、沉积构造、粒度分布等宏观地质特征的较详细研究,结合对这套砂岩的矿物成分和显微结构以及石英颗粒SEM表面结构特征的研究,表明这套砖红色砂岩具有如下特征:1）发育典型的大型风成交错层理;2）粒度均匀,分选好,以中-细砂、极细砂组分为主,缺乏粉砂-黏土颗粒组分;3）石英颗粒磨圆度好,表面发育碟形和新月形坑、溶蚀坑、硅质薄膜等风成砂颗粒具有的独特表面特征。据此提出这套砖红色砂岩是典型的沙漠相沉积的新认识,并根据沙漠相沉积类型的识别标志将其分为沙丘沉积和丘间沉积两种沉积类型。秦岭北缘武山地区晚白垩世沙漠相沉积的存在,结合西秦岭腹地同时代的哈达铺、岷县西江等地分布在山顶面的晚白垩世红层地层中存在类似的沙漠相沉积分析,提出了西秦岭晚白垩世不仅处于干旱炎热气候环境,而且曾呈现出地形相对平缓的泛盆地构造地貌状态。这套红层沉积反映了西秦岭晚白垩世为统一红层沉积盆地而非孤立的山间盆地,现今多不连续分布在山顶面之上是新生代以来地壳不均匀隆升和侵蚀共同作用的结果。