云南中甸五村-移山晚三叠世沉积及盆地特征

五村-移山地区晚三叠世地层发育齐全，并在中咱地块边缘至甘孜-理塘结合带之间构成一个较为完整的沉积盆地。中甸、格咱和弥里淌三条平行控制性断裂将盆地由西向东依次横向分割成中咱微大陆五村台地边缘三角洲、哈工弧后断陷盆地、属都火山复理石盆地和尼汝弧前斜坡(盆地)。在上述4种构造-相区中沉积了各具特色的沉积物，具有不同基本层序结构、不同生物组合及沉积相特征。显示盆地经历下降-抬升-下降-抬升两个周期性演化过程。     

云南昆明寒武纪早期浅水相磷块岩的氧化还原环境及成因机制

磷是重要的营养元素,与古环境和生命演化密切相关。在埃迪卡拉纪—寒武纪之交,伴随着骨骼化动物的辐射,华南甚至全球广泛沉积了大量磷酸盐,这暗示磷是古环境的变化与生命演化之间关系的桥梁。然而,目前,磷块岩的沉积环境和形成机制尚不明确。为探究磷酸盐富集的沉积环境和形成机理,本文研究了华南寒武纪早期梅树村剖面磷块岩的磷酸盐聚集形式、黄铁矿形态学和稀土元素。磷块岩主要是由结晶氟磷酸钙、隐晶质氟磷酸钙和铁氧化物组成。稀土配分模式均为"帽型"配分模式,与沉积物中铁-锰还原带之中的稀土配分模式类似,表明稀土元素遭受了早期成岩的影响。磷块岩中没有草莓状黄铁矿和较低的Ce负异常(Ce/Ce~*=0.50～0.82,平均值为0.70),暗示磷块岩沉积于氧化/次氧化的沉积环境。Eu元素未发生异常(Eu/Eu~*=0.92～1.08,平均值为0.98),暗示磷块岩可能未受到热液作用的影响。较高的Y/Ho比值(55.3～74.5,平均值为63.6),与海水Y/Ho比值相似,表明磷块岩来源于海水。鉴于华南寒武纪早期广泛的氧化事件、缺氧分层的海水化学结构和上升流活动,本文认为磷块岩的形成源于氧化背景下较高的磷酸盐浓度和...     

The Oneka intrusive complex: a new structural type of large-scale manifestations of intrusive trap magmatism on the Siberian Platform

The Oneka intrusive complex, recognized on prospecting for hydrocarbons in the western Siberian Platform, in the northern half of the Bakhta megablock (Tunguska syneclise), holds a special position among the known and new large-scale manifestations of intrusive trap magmatism. During the process, original data on the distribution of traps in the 4.2 km thick platform cover were obtained. Diverse in morphology and size, the intrusions are of the same genesis, composition, and character of intrachamber differentiation and form a “framework” igneous complex in the northern half of the Bakhta megablock. This complex occupies an area of about 40,000 km². It is an intricate tectonomagmatic superstructure, with the volume of magmatic material estimated at 50,000 km³. Results of petrochemical and geochemical studies, multispectra and REE ratios, and isotope ratios ⁸⁷Sr/⁸⁶Sr (0.70558–0.70580) suggest that diverse rocks of the Oneka intrusive complex were, most likely, formed from a primary picritoid magma, which underwent deep-level differentiation and was slightly contaminated with rocks of the crust and platform cover. The comprehensive study of the massif and results of numerical modeling show that the formation of such tectonomagmatic structures is closely related to the processes of intraplate magma formation in the craton lithosphere. The large Oneka intrusive complex, like other similar manifestations of Permo-Triassic trap (and alkaline-ultrabasic) magmatism of the Siberian Platform, can be considered projections of hotspots recording the evolution of the Siberian superplume.     

南黄海地质及地震

南黄海属于华北地台及扬子准地台的一部分,是一个由隆起、拗陷组成的中、新生代大型复式盆地。海域内新构造运动以断裂、岩浆及差异性升、降活动为主,并且由现代活动断裂控制的地震频繁而活跃。南黄海的地震活动主要集中分布于南部拗陷与勿南沙隆起一带以及与江苏海岸相平行的浜岸断裂带上。今后较长时间内,南黄海的地震活动仍将沿着上述地带往复迁移     

吉林省石炭纪岩相古地理特征及沉积相模式

本文通过大量的实际资料分析对吉林省石炭纪沉积相进行了划分:早石炭世划分为两个相区,6个相带;晚石炭世划分为5个相区,8个相带,并建立了沉积相模式。     

系缆式水下自动升降平台

系缆式自动升降平台应用到水下定点测量系统中，可以用一套观测仪器完成全剖面的测量，和以往锚系系统单点分层测量方式相比，它具有连续进行剖面测量的先进性和经济性。文章介绍了系缆式水下自动升降平台的应用方式、升降原理、结构组成以及原理样机在实验室和千岛湖进行试验的情况。     

Eocene succession on the East Shetland Platform, North Sea

A sand-prone Middle Eocene sequence is recognized in three cored boreholes on the East Shetland Platform. Three lithostratigraphic divisions are recognized: Lower Sand Unit, Main Sand Unit and Upper Claystone Unit. The Lower Sand Unit is of fluvio-deltaic origin, occurring on the southern part of the East Shetland Platform. The Main Sand Unit represents the subsequent transgression of the delta. The unit comprises a set of highstand shelf systems tracts separated by glauconitic bands and reflected by palynological assemblage breaks. The presence of reworked palynofloras in sediments of late Middle Eocene age implies derivation of sediment from the north-west part of the East Shetland Platform. Although it is tempting to ascribe sea level changes to the sediment pattern, a tentative correlation with the Hampshire Basin only highlights the difficulties involved.     

贵州新民石门坎三叠系关岭组底部火山凝灰岩锆石U-Pb年龄及意义

华南地区三叠系地层发育,安尼阶底界（即下—中三叠统界线）附近广泛发育浅绿色火山凝灰岩或凝灰质碎屑岩,俗称 “绿豆岩”。国际安尼阶底界界线层型候选剖面——位于南盘江盆地内的贵州关刀剖面和广西湾头剖面,已获得可对比的“绿豆岩”锆石U-Pb年龄,但在相邻的上扬子台地上尚缺少对安尼阶底界测年的可对比数据。本研究采集了贵州省盘州市新民镇石门坎剖面三叠系关岭组底部的多层“绿豆岩”,利用LA-ICP-MS获得锆石的U-Pb年龄。结果显示,石门坎剖面关岭组底部的锆石结晶年龄为246.9±1.1 Ma,可与南盘江盆地内及上扬子台地区出露安尼阶底界的剖面相对比。其绝对年龄为上扬子台地区内的安尼阶底界年龄对比提供了参照,有助于限定中三叠世海生爬行动物群所代表的海洋生态系统的复苏时间。石门坎剖面地层沉积连续,未来有望继续开展综合地层学的研究。     

Helcionelloids from the Cambrian Fortunian of the Northern Yangtze Platform, China

A study of the morphological and microstructural characteristics of helcionelloids from the Nanjiang area (north Sichuan, China) at the northern Yangtze Platform was undertaken, in order to understand their phylogenetic position. Helcionelloids fossils from the Kuanchuanpu Formation of the Changtanhe–Maolinzi section include 7 genera and 11 species. There are distinct differences in the degree of shell bending, the apical morphology and apex position, the outline of the aperture and the height of the shell, all of which constitute important identification features. Although helcionelloid apices exhibit varying degrees of rotation towards the aperture, they do not show any signs of evident distortion. A pair of basally-symmetrical muscle scars are discovered on the shells of helcionelloids (such as Bemella simplex), showing a distinct difference when compared with those of the stem-group gastropod (e.g., Pelagiella). The prismatic shell layer of helcionelloids has been observed, which are common components in Cambrian molluscs, but differ significantly from the dense layer microstructure found in contemporary molluscs. The microstructures, muscle scars and morphological characteristics demonstrate that helcionelloids represent a stem-group of molluscs.     

华北地台前寒武纪变质基底的Sm－Nd同位素地质信息

华北前寒武纪变质基底的Ｓｍ－Ｎｄ同位素资料，主要来自冀东、辽东、内蒙古中部，五台－太行、河南和鲁西等地早前寒武纪以基性岩为主的表壳岩和深成酸性侵入体，也有少量副变质岩的分析结果。已搜集的华北地台前寒武纪变质基底的３０４个Ｓｍ－Ｎｄ分析资料表明，除同位素年龄信息外，作为壳－幔演化示踪剂，给出了岩石圈早期演化的重要信息：除已由Ｕ－ｐｂ法证实的冀东曹庄、辽东鞍山有≥３．８Ｇａ的地壳残留外，Ｓｍ－Ｎｄ资料还暗示吕粱和登封一带存在＞３．５Ｇａ的古老地壳。在华北地台上，除＞３．５Ｇａ的早期壳－幔分离事件外，３．２～３．６Ｇａ，２．６～３．０Ｇａ和２．０～２．２Ｇａ分别为三次造壳的高峰时间。来自华北不同地区的Ｓｍ－Ｎｄ资料还表明，在３．０Ｇａ以前即存在一个规模较大的古老地壳，加之晚太古的造壳规模，太古宙地壳规模之宏大已与现代地壳相近似。除壳－幔分离的造壳事件外，华北地台早前寒武纪地壳活化再造十分强烈。活化再造形成的酸性侵入体的Ｓｍ－Ｎｄ同位素资料显示Ｔ＿（ＤＭ）＝２．６～２．８Ｇａ是活化再造的最高峰时期。