新疆罗布泊地区第四纪环境演变

新疆罗布泊干湖盆中的Ｋ１钻孔揭示了该区第四纪沉积地层。孢粉分析表明,早更新世,当地发育森林－草原植被,中更新世以来,荒漠草原与荒漠交替出现,湖泊的发育可上溯至更新世。     

通天河上游墩日含煤岩系地层时代的新认识

墩日含煤岩系时代原定为晚三叠世。该岩系的岩性、岩相、煤质、孢粉组合等诸多特征均反映了下侏罗统的沉积特点,故应将其厘定为早侏罗世。     

Bio-reef-chert suite and superlarge ore deposits

The bio-reef-chert suite is an important ore-bearing rock assemblage and one of the metallogenic rock suites of superlarge ore deposits. It is formed as a fixed and ordered suite in space and time, and composed of different rocks formed by different geological processes. It is the product of basin evolution at special stage in a special geological setting. It is also the comprehensive product of normal sedimentary process, biological process in basin, hydrothermal sedimentary process under basin base and magmatic process in the deep lithosphere.     

Hydrothermal sedimentation characteristics of the Dajiangping superlarge pyrite deposit, Yunfu, Guangdong

The Dajiangping pyrite deposit is hosted in a carbonate-clastic rock series which is characterized by a bioreef-chert suite in its middle part.Conformable lenses of various sizes constitute the orebodies which often branch transitionally into the surroundings.Syngenetic deformation fabrics can be observed in orebody NO.3.Orebody No.4 is composed almost entirely of massive pyrite,with conspicuous hydrothermal sedimentation and bacterium-alga features.The hydrothermal sedimentation origin is also reflected by simple chemistry of the ore (predominated by quartz and pyrite),the presence of U and Th,and the REE compositions of pyrite and ankerite.The ores are rich in organic matter and the difference in organic content between the banded ores and the massive ores is mainly owing to the difference in the clastic components they contain rather than to the subsequent processes of reworking .Co/Ni rations in the ore may reflect the temperature pattern during hydrothermal sedimentation.     

海平面升降旋回中的生物响应

通过滇东寒武系筇竹寺阶和曲靖志留纪盆地的层序地层学、生物地层学研究,发现生物与海平面变化之间有一定的规律可寻。（１）物种形态响应：在滇东寒武系筇竹寺阶三叶虫演化序列中,这种响应反映为海平面下降过程有利于形成土著（原地）物种;而海平面上升则导致异地物种的迁入。（２）群落响应：每一个海平面变化旋回都要产生底栖海相群落的重组,形成新的生物组合。（３）种群响应：种群对海平面变化的响应通常表现为种群大小的波动,实质上是种群在不同生存环境中的不同表现。     

汤原断陷第三纪地层研究新进展

主要从生物地层学、年代地层学和地球物理地层学三个方面,对汤原断陷近几年来地层研究的最新成果进行了简要论述,建立了１９个化石组合、亚组合,认为本区存在古新统和上新统;获得了１１个裂变径迹年龄数据;在地层倾角测井上识别出了４种沉积相变化模式;完善了本区第三系地层层序。     

北京西山灵岳寺古冰川沉积物何在?

北京西山灵岳寺附近的第四纪沉积物不是真正的古冰川沉积物。该处山腰凹地中一套以粗大砾石为主的混杂堆积是较典型的复式稀性泥石流堆积体,其时代为晚更新世之前,而不是晚更新世末期产物。所谓晚更新世末期的冰川堆积体和冰蚀地貌,实际上是不存在的。晚更新世时期,北京西山地区属冰缘环境,而非冰川环境。     

呼伦湖、乌伦古湖全新世植物群发展与气候环境变化

于１９９０－１９９３年分别对呼伦湖及乌伦古湖进行了调查，并对其剖面及钻孔进行了孢粉分析，结合＾１４Ｃ测年、介形类、硅藻分析资料，对两区孢粉植物群演替、气候与湖泊环境变迁进行了比较。结果表明，１０．０ｋａＢ．Ｐ．前，西北地区湖水位变化与冰川融水有关，东北湖区温凉湿润气候受季风环境影响所致；１０．０－７．０ｋａＢ．Ｐ．及５．０－３．０ｋａＢ．Ｐ．间，气候干旱，两者受西风带控制；７．０－５．０ｋａＢ．Ｐ     

Seasonal and ontogenetic patterns of habitat use in coral reef fish juveniles

We investigated the diversity of patterns of habitat use by juveniles of coral reef fishes according to seasons and at two spatial scales (10–100 m and 1–10 km). We conducted underwater visual censuses in New Caledonia's Lagoon between 1986 and 2001. Co-inertia analyses highlighted the importance of mid-shelf habitats at large spatial scale (1–10 km) and of sandy and vegetated habitats at small spatial scale (10–100 m) for most juveniles. Among all juvenile species, 53% used different habitats across seasons (e.g. Lutjanus fulviflamma and Siganus argenteus) and 39% used different habitats as they grow (e.g. Lethrinus atkinsoni and Scarus ghobban). During their ontogeny, at large and small scales, respectively, 21% and 33% of the species studied showed an increase in the number of habitats used (e.g. L. fulviflamma, L. atkinsoni), 10% and 3% showed a decrease in the number of habitats used (e.g. Amphiprion melanopus, Siganus fuscescens), 23% and 3% showed a drastic change of habitat used (e.g. S. ghobban, Scarus sp.) whereas 46% and 61% showed no change of habitat used (e.g. Lethrinus genivittatus, Ctenochaetus striatus). Changes in habitat use at both small and large spatial scales occurred during the ontogeny of several species (e.g. S. ghobban, Scarus sp.). Results pointed out the different spatial and temporal scales of juvenile habitat use to account for in conservation decisions regarding both assemblage and species-specific levels.