| 1. | The hard coats of spores and pollen grains are preserved better , forming microfossils 孢子和花粉粒的坚硬外壳被完好保留下来形成微化石。 |
| 2. | In the summer of 2003 we began to zero in on one microfossil type whose complex morphological characteristics particularly intrigued us 2003年夏天,我们开始瞄准一种微化石的类型,其复杂的形态特徵特别引起我们兴趣。 |
| 3. | Based on the researches of neogene calcareous nannofossils from the pearl river mouth basin , this paper briefly reviews the researching and developing process 摘要根据珠江口盆地新近系钙质超微化石研究文献,综述了研究内容及发展过程。 |
| 4. | Our initial probes suggested that a relatively thin sedimentary layer , which is black in color , would be the most promising for finding a variety of microfossils 我们的初步探查显示,有一层黑而薄的沉积,最有希望找到各式各样的微化石。 |
| 5. | The study of foraminifera , ostrocoda , radiolaria and calcareous nannofossil plays an important , indispensable and useful role in the marine geology research 其中有孔虫、介形虫、放射虫、超微化石等海洋微体生物壳体是海洋地质研究不可缺少和替代的重要部分。 |
| 6. | The latest studies show that these rocks are older than the ediacara biota , most likely 580 million to 600 million years old , and thus that the microfossils they contain lived 40 million to 55 million years before the cambrian 最新研究显示,此沉积比艾迪卡拉生物群还早,很有可能介于6亿到5亿8000万年前,也就是说,里面微化石的生存年代比寒武纪还早了4000万到5500万年左右。 |
| 7. | This study is a post - cruise study of this leg , calcareous nannofossil samples from sites 1146 , 1147 and 1148 of leg 184 were analyzed to provide a high - resolution biostratigraphy for this leg and to investigate morphological variation of coccolith genus gephyrocapsa . the main results of this study are : 1 . 12 late pliocene to pleistocene bio - events were recognized and 6 zones of martini ( 1971 ) were determined for the upper sediment sequences of sites 1146 and 1148 本文作为大洋钻探项目船下后续研究的一部分,对184航次中的1146站位和1147 、 1148站位的样品进行了分析和研究,在船上科学家已经建立起的地层框架的基础上进一步加密采样,对生物事件标志化石类别进行数量统计,进一步确定了12个生物事件在钻孔中的深度,建立起了两个站位的高分辨率的钙质超微化石生物地层框架。 |
| 8. | The origin and evolution of land plants was an important event in the history of earth life and has affected all other lives on the earth and global environment . during the past two decade , the new discoveries of fossil plants microfossils and megafossils from the mid - ordovician through all silurian to the lower devonian improved knowledge of the origin of land plants , provided a time framework of the basal groups for the land plants and the early evolution diversity of vascular plants . three new plant based epochs have been recognized . on the other hand , molecular sequence studies have provided insights into the phylogeny and early branches of land plants . a phylogenetic tree has been established by the joint of a study of comparative morphology and gene sequences . this paper summarizes recent advances and new knowledges , comments on the phylogenetic studies based on the cladistic analysis 陆生植物的起源和演化是地球生命中的重大事件,它影响到地球上所有的其他生命和全球环境。在过去的20年中,从中奥陶世历经整个志留纪至早泥盆世的岩层中,化石植物微化石和大化石的新发现改变了人们对陆生植物起源的认识,并且为陆生植物和维管植物早期演化分异提供了基部类群分化的时间框架。据此人们识别出地史中的3个陆生植物的时代:始胚植物时代始维管植物时代和真维管植物时代。 |
| 9. | The results improve our understanding of the utility of tl as an indicator of sedimentary environment and provide insight into what types of ocean sediments are amenable for study . the comparison of the 18o with the tl cycles indicates that the tl dose display the expected coupling relation with interglacial and glacial climate cycles 尤以位于东经90海岭上的以远洋沉积作用为主的md81349岩芯最为理想,陆源剥蚀产物在其沉积记录中所占比例较少,有孔虫和超微化石为代表的远洋成因的灰白色生物软泥构成主要的沉积组分。 |
| 10. | The study of neogene calcareous nannofossils from the pearl river mouth basin in the last two decades could be subdivided into two stages ( 1 ) from the beginning period of the 80 ' s to early of the last century , the studies focused on the calcareous nannofossil zones and the descriptions of main genera and species ; ( 2 ) from the middle and late period of the 90 ' s of the last century to the present , the researches concentrated on the high - resolution calcareous nannnofossil biostratigraphy 纵观二十多年来珠江口盆地新近系钙质超微化石的研究历史,大致可分成两个阶段: ( 1 )上世纪80年代初至90年代初,侧重于化石带的报道及主要化石属种的描述; ( 2 )上世纪90年代中后期至今,主要为高分辨率钙质超微生物地层研究阶段。 |