The First Discovery of the Easternmost Jehol Biota from Southeastern Jilin,China     

LI Yunfeng  HUANG Wei  WANG Hongshan  David L. DILCHER  TAN Xiao  LI Tao  NA Yuling  SUN Chunlin 《《地质学报》英文版》2018,92(4):1649-1650

正Objective The Jehol Biota,a world-famous Early Cretaceous fossil Lagerst?tte characterized by the traditional Eosestheria-Ephemeropsis-Lycoptera(EEL)assemblage,has a wide distribution over most parts of northern China,the coastal area of southeastern China,southeastern Mongolia,Transbaikalian area of Russia,Korea and Japan(Shao et al.,2017).The Baishan Basin,situated in  相似文献   

印度尼西亚苏门答腊北部巽地外弧脊     

Harb.  NA 俞保祥 《世界地质》1994,13(2):69-80

  相似文献   

辽宁北部红透山地区太古宙绿岩带的多期变形     

杨振升  俞保祥 《吉林大学学报(地球科学版)》1984,(1)

辽宁北部是我国太古宙绿岩带发育较好的地区之一。本区绿岩带是由变粒岩——斜长角闪岩组合所构成。它在区域地质图上呈规模不等、形状不同的包体分布在太古宙花岗岩系中(见附图1)。著名的红透山铜锌矿区就是上述绿岩带包体中的一个区段。多年来,不少地质单位在本区做了大量有关物质成分方面的基础地质研究工作,取得了许多  相似文献   

辽宁歪头山变质——沉积铁矿构造变形研究     

杨振升  俞保祥  高德华 《吉林大学学报(地球科学版)》1983,(2)

歪头山地区是辽东鞍山群出露较好的地区,歪头山铁矿就赋存于鞍山群茨沟组中。对该地区鞍山群的研究不仅有助于查明鞍山式铁矿的层位、类型、空间分布;而且对解决南北鞍山群铁矿对比,鞍山群地层层序都有着重要意义。由于本区变质杂岩经历了复杂的演化历史,不同时期的地质事件都可以在其中找到影响的信息。因此,如何正确认识和查明这些作用结果的主要关键之一是变质岩构造问题。 通过一九八○年的野外工作和室内整理,歪头山一带至少经历了三期变形作用,其中以第一期变形最为突出,表现最强烈,我们称为强期变形作用。这次变形是鞍山运动造成的结果,第二期变形可能是辽河群变形期迭加的表现,而第三期变形有可能属中生  相似文献   

The Insect Oviposition Firstly Discovered on the Middle Jurassic Ginkgoales Leaf from Inner Mongolia,China     

NA Yuling  SUN Chunlin  LI Tao  LI Yunfeng 《《地质学报》英文版》2014,88(1):18-28

Although the evidence of insect oviposition on plant organs has been reported from the late Paleozoic to the Miocene, record from the middle Jurassic is still blank. This paper reports a significant evidence of insect oviposition on plant leaf from the middle Jurassic for the first time. The ovipositional scar is distributed on the abaxial surface of Sphenobaiera leaf（Ginkgoales） from the middle Jurassic Daohugou Formation of Inner Mongolia, China. A new ichnospecies Paleoovoidus venustus sp. nov. is described. The scar is elliptic to oval, arranged in longitudinal rows between leaf veins with almost regular distance, with its long axis paralleling to the leaf venation. This discovery adds new information to the morphology of insect endophytic oviposition probably produced by Odonata existed in a terrestrial ecosystem ~165 Ma ago. The new materials also provide important data for the study of insect reproductive biology, plant-insect interaction and coevolution, as well as understanding the paleoclimate and palaeoenvironment during that time in northeast China.  相似文献   

Assessment of long term change in sediment condition after organic enrichment: defining recovery     

Macleod CK  Crawford CM  Moltschaniwskyj NA 《Marine pollution bulletin》2004,49(1-2):79-88

Sediment condition at an Atlantic salmon (Salmo salar) culture site in S.E. Tasmania, Australia was evaluated to determine the rate and extent of recovery after removal of farmed fish. By local standards the cage sediment at the start of this survey was markedly degraded but comparison with results from impact studies in Scotland, Canada and Norway suggests that the sediments were considerably less impacted than in northern temperate areas. The impact at the cages diminished rapidly with both time and distance; after only 2 months conditions were markedly improved. The macrobenthos indicated a slower recovery than chemical measures, after 36 months the benthic faunal community structure under the cages still differed from reference conditions even though other sediment measures had recovered. This study highlighted two other key issues in relation to monitoring and management of sediment recovery. First, techniques used to determine impact may not be appropriate for evaluation of recovery. Second, establishment of local baseline standards is extremely important to ensure appropriate evaluation of both impact and recovery.  相似文献   

The distribution and inventory of total and methyl mercury in Kuwait Bay     

Butayban NA  Preston MR 《Marine pollution bulletin》2004,49(11-12):930-937

Sediment (surface and core) sampling was conducted during the period from August 96-December 98 from intertidal and offshore areas in Kuwait Bay. The highest (and most variable) concentrations of total mercury (T-Hg; 36500+/-34930 ng g(-1)) are encountered around the previous industrial outfall where sediments are disturbed by shipping activities. The concentrations of T-Hg are lower in the Shuwaikh Port area (650+/-210 ng g(-1)) and continue to decrease towards the northern coastline of Kuwait Bay (average concentrations in the wider Bay region are 50+/-30 ng g(-1)). These values are still above background concentrations of 15-20 ng g(-1). Calculation of the total inventory of mercury in all the surface sediments of the studied area indicates that approximately 22.5 ton is present which is similar to the estimated industrial discharges of approximately 20 ton suggesting that the contamination is largely confined to the Bay and that releases to the wider Gulf region are small. The distributions of MeHg are similar to those of T-Hg and represent ranges between 0.23% and 0.5% of the T-Hg indicating that surface sediments within Kuwait Bay contain approximately 80 kg of this chemical.  相似文献   

Evaluation of short-term fallowing as a strategy for the management of recurring organic enrichment under salmon cages     

Macleod CK  Moltschaniwskyj NA  Crawford CM 《Marine pollution bulletin》2006,52(11):1458-1466

Rotation of cages within fish farm leases and the subsequent fallowing of areas of seabed is commonly used to allow recovery of infaunal communities following periods of organic enrichment. To investigate the effect of different background environmental conditions on recovery response, two Atlantic salmon (Salmo salar) fish farm sites in southeast Tasmania were sampled over two commercial fallowing cycles. Despite similar stocking levels and feed input there were significant differences in the way in which sediment at each farm responded to the cessation of fish stocking. Sediments at both farms showed some improvement in the community structure over a three month fallow period, but the community structure only recovered to that present before stocking not to that at the reference sites. The similarity of the impact sites to the reference sites increased from ca. 25% to 31% at one site and 11% to 27% at the other after fallowing. Rate and extent of recovery were affected by farm location, initial impact of the sediments, and length of fallow period. Initial recovery was faster at the more sheltered site than at the more exposed site, possibly reflecting differences in environmental resilience with the more sheltered location better able to assimilate organic inputs. Accordingly general fallowing management protocols may need to be adapted to reflect differences between sites. The findings of this study suggest that the recovery response of benthic communities can be predicted once baseline conditions are understood.  相似文献   

Macrobenthic community structure in the northern Saudi waters of the Gulf, 14 years after the 1991 oil spill   总被引：1，自引：0，他引：1  

Joydas TV  Qurban MA  Al-Suwailem A  Krishnakumar PK  Nazeer Z  Cali NA 《Marine pollution bulletin》2012,64(2):325-335

The 1991 Gulf oil spill heavily impacted the coastal areas of the Saudi waters of the Arabian Gulf and recent studies have indicated that even 15 years after the incident, macrobenthos had not completely recovered in the sheltered bays in the affected region such as, Manifa Bay. This study investigates the community conditions of macrobenthos in the open waters in one of the impacted areas, Al-Khafji waters, about 14 years after the spill. Diversity measures and community structure analyses indicate a healthy status of polychaete communities. The BOPA index reveals that oil sensitive amphipods were recolonized in the study area. This confirms that the benthic communities of the oil spill impacted area had taken only <14 years to recover in the open waters of the impacted areas. The study also reveals the existence of three distinct polychaete communities along the depth and sediment gradients.  相似文献   

Early Cambrian Mollusc Watsonella crosbyi: A Potential GSSP Index Fossil for the Base of the Cambrian Stage 2     

LI Guoxiang  ZHAO Xin  Alexander GUBANOV  ZHU Maoyan  NA Lin 《《地质学报》英文版》2011,85(2):309-319

The mollusc Watsonella crosbyi was studied on the basis of material from the lower Cambrian Dahai Member of the Zhujiaqing Formation in eastern Yunnan, China and the Pestrotsvet Formation of the Aldan River region in the Siberian Platform. This fossil had been excessively described under different names in the literature, such as Heraultia varensalensis Cobbold, 1935, H. sibirica Missarzhevsky, 1974, Heraultipegma yunnanensis He and Yang, 1982, H. yannanese He and Yang, 1982, Watsonella yunnanensis, W. crosbyi Grabau, 1900, etc. Taxonomic revision shows that other species are junior synonyms of W. crosbyi. Analysis of functional morphology implies that W. crosbyi may be rather a helcionelloid than a rostroconch since its univalved conch is untorted endogastric and lacks a rostrum and a true internal pegma. Replicas of the original microstructures preserved on the surfaces of phosphatic internal moulds confirm that the shell consists of two layers. The inner layer is lamello-fibrillar, and the outer layer is spherulitic prismatic. The widespread geographical occurrences in both siliciclastic and carbonate rocks of the late Terreneuvian indicate that W. crosbyi is an important index fossil for global correlations and subdivision of the Cambrian Series 1 (Terreneuvian). The first appearance datum (FAD) of W. crosbyi is suggested to be a potential GSSP (Global Boundary Stratotype Section and Point) candidate marker for defining the base of the Cambrian Stage 2.  相似文献