贵州遵义晚二叠世长兴组的介形类

本文首次报道了贵州遵义晚二叠世长兴组介形类化石，计14属24种（其中4新种、4未定种）。这些介形类化石的发现，不但为该区地层划分与对比提供了新的依据，而且对二叠系与三叠系的界线研究也具有一定意义。     

第四纪湖相介形类组合的古气候与古环境意义:以洞庭盆地介形类现生种为例

本文在分析国内外第四纪湖相介形类组合古气候与古环境意义研究现状基础上,初步研究了洞庭湖湘阴近岸介形类现生种分布与生态特征.国外在第四纪湖相介形类古气候与古环境研究方面做了大量工作,取得了丰富成果.而国内该方面工作仅主要集中青藏高原及其邻区,其它地区鲜见.国外在详细介形类现生种生态调查基础上,建立基于其的环境参数转换函数,并在第四纪古气候与古环境定量重建中发挥了重要作用.然而我国现生种生态调查依然薄弱,主要表现在1)仅主要集中青藏高原等少数地区,其它地区还很少;2)生境数据绝大多为定性或半定量,很少定量;3)很少按季节采样.洞庭湖湘阴近岸包含3个属种,分别为未定种、Metacypris bellareticulata及Darwinula sp.,它们的生态要求为电导率240μs/cm,溶氧量10.45 mg/L,p H值8.1,水深0.5-1 m,水温10℃.     

青藏高原通天河盆地五道梁组介形虫壳体Mg/Ca和Sr/Ca地球化学特征及古环境意义

中新世早期青藏高原腹地曾经发育了面积巨大的古大湖,此时恰逢青藏高原的快速隆升关键时期.为研究高原腹地在此期间环境的演化,对五道梁组中介形虫壳体的Mg/Ca 和Sr/Ca的值进行了测试.通天河盆地五道梁组地层中的介形虫壳体的Mg/Ca 和Sr/Ca数值的特征,结合剖面岩性特征,反映了23.8～21.8 Ma前该湖泊区域气候由湿润-干旱-暖湿的演化趋势.其气候的变化可能是此时期青藏高原从快速隆升到剥蚀夷平后高原北部构造隆升活动的结果.该研究为进一步了解青藏高原腹地的古环境探索了一条新的途径.     

渭河盆地渭南段古三门湖的盐度估算

目的研究古三门湖的盐度数值。方法在渭河盆地渭南部分地区的古三门湖沉积地层中采集泥岩样品,分析了样品中的B元素,然后利用有关公式求得古三门湖的盐度。结果渭河盆地渭南段三门组盐度变化范围大致为1.66%~1.88%,游河组盐度变化范围大致为1.38%~2.06%。结论渭南段三门组为低盐度沉积,游河组为低盐度—半咸水沉积。     

Discovery of the budding phosphatized globular fossils from the Neoproterozoic Doushantuo Formation at Weng’an, Guizhou Province, China

There is much debate on biological affinities of the phosphatized globular fossils from the Neoproterozoic Doushantuo phosphorites at Weng’an, Guizhou Province. Here we report for the first time the budding structures of some of these globular fossils, which have previously been interpreted as the resting eggs and early cleavage embryos of metazoans. The budding structures are similar to the germinating tubes of the spore and zygote of living algae, suggesting that some globular fossils from the Doushantuo phosphorites bear affinity with algae. The present new information indicated various biological affinity of the phosphatized globular fossils from the Doushantuo phosphorites.     

Vermicular fossils in the Early Cambrian Xidashan Formation in the Quruqtagh region of Xinjiang, China

Large amounts of vermicular fossils and a minor amount of sponge animal fossils have been found in the Early Cambrian Xidashan Formation in the region of Quruqtagh, Xinjiang. Vermicular fossils are generally more than 50 mm long and 0.3?1.4 mm wide; their wrinkled lamellae are microfine with 3?10 pieces within the length of every each millimeter. The fossils are considered to be Sabellidites cambriensis Sokolov (1965). The Xidashan Formation is the highest stratum in which Sabellidites occur, as has been so far reported.     

Discovery of marine fossils in the upper part of the Permian Linxi Formation in Lopingian, Xingmeng area, China

Two important geological issues have a long history of debate in the Xingmeng area. The first concerns the final closure of the North China plate, Siberia plate and several intermediate massifs in the area, and the other con- cerns the folding and lifting of the Xingmeng Trough. Dis- agreements arise because of issues involving the tectonic- palaeogeographical environment of the Upper Permian deposits of the Linxi Formation. The Linxi Formation （Upper Permian） is generally considered to be either an exclusively continental deposit or separated into marine- terrigenous facies deposited during the Lower to Middle Linxi Period and continental deposits in the Upper Linxi Period. However, in this study, large numbers of bryozoan and sponge spicule fossils were discovered for this first time in the thick limestone layers and lenses of the upper part of the Linxi Formation found in the Guandi section of Linxi county in eastern Inner Mongolia. At the same time, abun- dant bryozoan fossils were also found in sedimentary tuff slices that were collected from the upper part of the Tao- huayingzi Formation from the Taohuayingzi section in Ar Horqin Banner, and abundant small connecting body crinoid stem fossils were found in the dark shale of the Yangjiagou Formation from the Yangjiagou section of Jiutai county, Jilin Province. These marine fossils provide the first evidence that the Xingmeng area was still a marine or mainly marine environment at the end of the late Permian. This not only provides conclusive evidence for the recognition of the above two major geological issues but also promotes chan- ges in the approach towards research, exploration and development of oil and gas, shale gas （oil）, and other mineral resources that are preserved in the late Permian layers of the Northeast-Xingmeng area.     

冈底斯西段第四纪钾质火山岩的发现及赛利普组的建立

冈底斯西段赛利普一带分布有大面积的钾质火山岩,以前曾被划归上新世-早更新世赛利普群.作者对这套火山岩地层进行了详细野外调查并重新测制了火山岩地层剖面,在该套火山岩下伏及层间湖相碎屑沉积层中获得ESR年龄0.268 Ma与0.349 Ma.岩石学、岩石化学研究表明,这套火山岩是以安粗质熔岩为主的钾玄岩系列-钾质碱性玄武岩系列火山岩,岩石类型及岩石组合稳定,岩层产状平缓,岩石新鲜,层位相对清楚,故将其命名为赛利普组,属第四纪早-中更新世.这一发现对研究冈底斯构造带新生代以来岩浆活动、构造演化,进而探讨青藏高原隆升机制有着重要的地质意义.     

A new discovery of macroscopic fossils from the Ediacaran Doushantuo Formation in the Yangtze Gorges area

The Ediacaran section in the Yangtze Gorges area, South China, is one of the most important in the worldand contains abundant fossils[1-4]. The earliest discov- ery of macrofossils in 1984, including macroscopic algal fossils from the uppermost Doushantuo…     

济阳坳陷东部新近系馆陶组下段辫状河三角洲沉积研究

根据水下沉积的标志 (泥岩颜色和富存的古生物化石 )和湖泊水流作用的标志 (岩性和结构、沉积构造、粒度分析、岩石的成分与结构成熟度、岩心的沉积相序以及砂体的平面形态等 ) ,证实了济阳坳陷新近系馆陶组下段为辫状河三角洲 ,而不是陆上河流或冲积扇沉积。通过解剖济阳坳陷东部某油田馆陶组的沉积序列发现 ,在馆下段沉积时期 ,辫状河三角洲发育水下辫状河道、河口砂坝以及前缘席状砂等微相 ,这为渤海湾盆地新近纪古湖泊研究和济阳坳陷新近系油气勘探提供了新的思路