辽宁西部上侏罗统义县组研究新认识

根据丰富的，最新的野外地质资料，对辽宁西部锦州和义县地区晚侏罗世义县组的岩石地层划分和对比中的重要问题进行了补充和修正。以《国际地层指南》的多重地层划分观点为基础，建立了一套完整的义县组岩石岩层单位。根据最新的原始鸟类以及昆虫，鱼，爬行类等生物化石研究结果，认为义县组的形成时期限于晚侏罗世晚期。     

腾冲上新统芒棒组地质时代及沉积环境

摘要：腾冲地区新生代地层分布广泛，其中又以芒棒组出露较为完整，由河流相、湖泊相及沼泽相碎屑岩夹火山岩中火山沉积岩组成，含丰富的植物化石和硅藻化石。依据化石研究及用K-Ar、Rh-Sr法测获同位素年龄，芒棒组应属新近纪上新世。植物化石显示腾冲地区上新世时期气候，比现今亚热带炎热干燥气候较温凉而湿润，反映该区从新近纪上新世至第四纪，气候有从凉变暖的演变趋势。     

云南景洪上泥盆统南光组沉积环境新议

云南景洪东南地区出露一套泥盆系,前人将其以粗粒碎屑岩为特征的部分命名为怕当组,根据腕足类化石鉴定其地质时代为中泥盆世;以碎屑岩、凝灰岩为特征的部分被命名为南光组,根据植物化石斜方薄皮木（Lepotophloeum rhombicum）划归晚泥盆世。对其沉积环境尚存在陆相和海陆交互相、浅海陆架相、半深海-深海相沉积环境的不同认识。本研究发现,粗粒碎屑岩层序中也发现有晚泥盆世标准植物化石斜方薄皮木（Lepotophloeum rhombicum）,并且粗粒碎屑岩层序位于剖面上部,南光组位于剖面下部,说明两者的地质时代均为晚泥盆世。故建议废除怕当组,将两者合并为上泥盆统南光组。南光组具有典型的鲍马序列特征,含有放射虫等海洋环境生物化石,属于深海浊流沉积层序。     

贵州独山中泥盆统碎屑岩地层的遗迹化石及其沉积环境

本文研究产自贵州独山中泥盆统碎屑岩地层（大河口组、独山组宋家桥段）中的遗迹化石，并分析了这些遗迹化石所代表的沉积环境，分属于Ｓｅｉｌａｃｈｅｒ的Ｓｃｏｙｅｎｉａ遗迹相、Ｓｋｏｌｉｔｈｏｓ遗迹相和Ｃｒｕｚｉａｎａ遗迹相。其中，独山县巴年地区独山组宋家桥段下部发现的以Ｓｃｏｙｅｎｉａ为主的遗迹化石具陆相沉积环境特征。这一发现将促进我国Ｓｃｏｙｅｎｉａ遗迹相的研究．     

在黑龙江省上侏罗统中发现新遗迹化石

本文所描述的遗迹化石系笔者于1980年夏,随同长春地质学院的老师赴黑龙江省参加黑龙江省东部龙爪沟群专题研究时,在密山地区过关山附近上侏罗统云山组中所发现的。化石保存在一层巨厚的滨浅海相黑色泥岩里。经研究,确定它是一个新遗迹属。在研究过程中,承蒙门凤岐和杨式溥老师在百忙中给予了亲切的指导和帮助;我所照像室陈殿丰技师摄制图片,在此一并表示衷心的感谢!     

兰州盆地渐新统化石山杨（Populus davidiana Dode）数据化初探

本文试用平台式扫描仪和GetData Graph Digitizer软件相结合的方法,对产于兰州盆地渐新统二维形态的化石山杨（Populus davidiana Dode）叶片进行数字化,获得其叶相的主要基本参数数据。然后用Golden Software Grapher软件对数据进行检验,重建的化石形态与原叶片宏观特征吻合程度很好。这表明：对于二维形态的叶化石,利用相关软件获取图形数据是一种可行的方法,这也可为叶片化石形态定量化分析和重建3D化石图像用于博物馆展览和科普宣传提供基础的数据。     

基于岩石薄片分析的介形类化石赋存状态及地质意义——以济阳坳陷始新统泥页岩为例

首次利用岩石薄片观察和统计介形类化石的赋存状态,对济阳坳陷页岩的沉积环境及层序进行了研究。根据介形类化石在层面上的分布特征,将化石分布形式分为均匀分布、零星分布、条带状分布三种,按其保存状况分为双瓣、单瓣、破碎及压扁变形四种类型,化石丰度分为丰富(100瓣/4cm2)、中等(30~100瓣/4cm2)和稀少(30瓣/4cm2)三种。介形类化石的赋存状态与古盐度、岩相、层序及页岩中碳酸盐含量密切相关。研究表明:1济阳坳陷古近系沙河街组四段纯下亚段(Es4cx)——古近系沙河街组三段下亚段(Es3x)沉积期水体环境经历了由咸变淡的过程,盐度变化与化石丰度变化一致;2碳酸盐含量处于50%~60%范围内,最有利于介形类化石的保存;3纹层状灰质泥岩相和纹层状泥质灰岩相化石丰度高,但纹层状构造形成时期沉积速率慢,沉积基底较坚实,不利于介形虫死亡后的埋藏和保存,因此化石多以破碎为主。4介形类化石的盛衰与地层层序关系密切,一个层序内化石丰度呈现为出现-繁盛-衰退三个阶段,分别对应于低位体系域、湖扩展体系域和高位体系域。该方法解决了常规分析中难以观察到的化石原始保存和分布状态的问题,实现化石信息获取的最大化。     

东海瓯江凹陷下第三系层序地层学研究

运用威尔(P. R. Val)等人层序地层学的新慨念,对瓯江凹陷下第三系进行了层序地层分析和研究,确定了四个区域不整合面,三套层序,每一套层序又可划分出低水位体系域,海进体系域,高水位体系域。每个体系域,在钻井上可以发现相应的各种沉积相和生物化石。沉积环境的变化,生物化石带的演变反映了海平面变化的控制作用,并能同全球海平面变化对比。     

中国最早人类化石地层年龄的测定——巫山下更新统磁性地层学研究

四川巫山大庙龙骨坡是新发现的重要人类化石点,地层属下更新统,含人类化石层位正对应于留尼汪I 极性亚时,年龄应为2.04—2.01MaB.P。它是我国迄今发现的最早的人类化石。本研究还揭示中国第四纪下限至少早于2.0MaB.P.。     

综合地层滂的系统层次结构

本文在分析地层客分支科学研究内容，出发点和相互关系的基础上，从系统科学观点出发阐述了综合地层学在研究地层体时空工分布规律中以岩石地层学为基础，以沉积地层学，火山地层学，磁性地层学，构造地层学等为基本层次，以生物地层学，同位素年龄地层学，年代地层为学主层层次系统结构特点。综合地层学就是要以这种系统结构为基本指导思想，最大限度地利用包括地层的岩石组合，化石，变形变质，物理化学属性和侵入地层中的岩脉及它     

High-resolution last deglaciation record from the Congo fan reveals significance of mangrove pollen and biomarkers as indicators of shelf transgression

High abundances of mangrove pollen have been associated with transgressive cycles on tropical margins, but the detailed relations between systems tracts and the taphonomy of the pollen are unclear. We report here the occurrence and high abundance of Rhizophora pollen, in association with taraxerol, a Rhizophora-sourced biomarker, from a high-resolution Congo fan core covering the last deglaciation. An age model based on ¹⁴C dates enables the temporal changes in taraxerol content and the percentage frequencies and flux (pollen grains (pg) cm⁻² (10³ yr)⁻¹) of mangrove pollen to be compared quantitatively with the lateral rate of transgression across the flooding surface (derived from glacio-hydro-isostatic model output and the bathymetry of the margin). Rhizophora pollen concentrations and taraxerol content of the sediment are very strongly positively correlated with the lateral rate of transgression and indicate, independently of any sequence stratigraphic context, that mangrove pollen spikes are associated with the transgressive systems tract rather than the highstand systems tract or maximum flooding surface. Lower-resolution longer-term records from this margin indicate an association between taraxerol concentrations and transgressive rather than regressive phases. The flux of these materials to the Congo fan is interpreted as a function of the erosion of flooded mangrove swamp on the shelf and, less importantly, changing extent of mangrove habitat, during sea-level rise. Congo River palaeoflood events also result in reworking of mangrove pollen and supply to the fan, but this mechanism is subdominant. Rhizophora pollen has been underestimated in many palynological studies undertaken on cores from the African margin because of inappropriate sieve mesh size used during laboratory preparation.     

Impacts of rapid sea‐level rise on mangrove deposit erosion: application of taraxerol and Rhizophora records

We investigated a well‐dated marine sediment core from the tropical SE Atlantic covering the last 25 kyr, applying taraxerol and Rhizophora pollen as organic geochemical and palynological proxies for mangrove, respectively. Taraxerol records are positively correlated with Rhizophora pollen records, showing an enhanced supply of mangrove materials into deep‐sea environments during the last deglaciation (Termination I). Sedimentation rates peaked during Meltwater Pulses 1A and 1B, which were associated with the maxima of taraxerol and Rhizophora pollen. This study supports the view that mangrove input was dominantly controlled by erosion of mangrove‐rich shelf sediments during the transgressions. Whether reworked materials were penecontemporaneous or from much older deposits formed during previous sea‐level cycles is discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

Taraxerol and Rhizophora pollen as proxies for tracking past mangrove ecosystems

Angola Basin and Cape Basin (southeast Atlantic) surface sediments and sediment cores show that maxima in the abundance of taraxerol (relative to other land-derived lipids) covary with maxima in the relative abundance of pollen from the mangrove tree genus Rhizophora and that in the surface sediments offshore maxima in the relative abundance of taraxerol occur at latitudes with abundant coastal mangrove forests. Together with the observation that Rhizophora mangle and Rhizophora racemosa leaves are extraordinarily rich in taraxerol, this strongly indicates that taraxerol can be used as a lipid biomarker for mangrove input to the SE Atlantic. The proxy-environment relations for taraxerol and Rhizophora pollen down-core show that increased taraxerol and Rhizophora pollen abundances occur during transgressions and periods with a humid climate. These environmental changes modify the coastal erosion and sedimentation patterns, enhancing the extent of the mangrove ecosystem and/or the transport of mangrove organic matter offshore. Analyses of mid-Pleistocene sediments show that interruption of the pattern of taraxerol maxima during precession minima occurs almost only during periods of low obliquity. This demonstrates the complex environmental response of the interaction between precession-related humidity cycles and obliquity-related sea-level changes on mangrove input.     

The Holocene shallowing‐upward parasequence of north‐west Andros Island,Bahamas

Many pre‐Mesozoic records of Earth history are derived from shallow water carbonates deposited on continental shelves. While these carbonates contain geochemical proxy records of climate change, it is the stratal architecture of layered carbonate units that often is used to build age models based on the idea that periodic astronomical forcing of sea‐level controls the layering. Reliable age models are crucial to any interpretation of rates and durations of environmental change, but the physical processes that actually control this stratal architecture in shallow water carbonates are controversial. In particular, are upward‐shallowing stacks of carbonate beds bounded by flooding surfaces (‘parasequences’) truly a record of relative sea‐level change? The purpose of this study is to examine a tidal flat that is actively accumulating carbonate stratigraphy, and to determine the relative importance of tidal channel migration (poorly known, but investigated here) and Holocene sea‐level rise (well‐known) in controlling post‐glacial parasequence architecture. This work represents a field study of peritidal carbonate accumulation at Triple Goose Creek, north‐west Andros Island. By integrating surface facies maps with differential global positioning system topographic surveys, a quantitative relationship between facies and elevation is derived. Sedimentary facies are sensitive to elevation changes as small as 5 cm, and are responding to both internal (distance to nearest tidal channel) and external (sea‐level rise) controls. The surface maps also are integrated with 187 sediment cores that each span the entire Holocene succession. While flooding of the Triple Goose Creek area should have occurred by ca 4500 years ago, preservation of Holocene sediment did not begin until 1200 years ago. The tidal channels are shown to be stationary, or to migrate sluggishly at up to 6 cm per year. Therefore, while the location of tidal channels is responsible for the modern mosaic of surface facies, these facies and the channels that control them have not migrated substantially during the ca 1200 years of sediment accumulation at Triple Goose Creek. Once the region was channellized, vertical and lateral shifts in facies, such as the landward retreating shoreline, expanding mangrove ponds and seaward advancing inland algal marsh, are driven by changes in relative sea‐level and sediment supply, not migrating channels. While stratigraphic columns look different depending on the distance to the nearest tidal channel, the overall parasequence architecture everywhere at Triple Goose Creek records an upward‐shallowing trend controlled by the infilling of accommodation space generated by post‐glacial sea‐level rise.     

Mangrove development and its response to environmental change in Yingluo Bay (SW China) during the last 150 years: Stable carbon isotopes and mangrove pollen

Located at the interface of terrestrial and marine ecosystems, mangroves are particularly sensitive to environmental change. They provide a sedimentary sink for organic carbon, whereby cores can provide detailed records of mangrove species. We aimed to trace the history of mangrove development over the past 150 years in Yingluo Bay, SW China. Sedimentation rates (avg. 0.32 and 0.37 cm/year) were calculated on the basis of ln(²¹⁰Pb_ex) vs. mass depth, and offset the rate of relative sea level rise (0.22–0.24 cm/year), leading to a seaward expansion of new mangrove habitats. Chemical tracers (δ¹³C_org and C:N) and an isotope mixing model were utilized to trace the contribution of mangrove-derived organic matter (MOM). Changes in the relative abundance of pollen from mangrove plants was used to compensate for diagenetic alteration of the stable isotope values and potential overlaps in isotope values for different sources of organic matter. The result of Pearson correlation analysis showed that the MOM was moderately positive correlated with total mangrove pollen, indicating that stable carbon isotopes and mangrove pollen provide similar information for tracing mangrove ecosystems. Based on results from this study, compositional changes in mangrove communities could be divided into two main stages: a degradation period (1870–1930 AD) and a flourishing period (1930–2011 AD), corresponding to colder temperature and warmer temperature, respectively. Owing to the location being far away from any industrial area and human activity, temperature may be a key factor for mangrove development.     

Clay mineralogy as a tool for integrated sequence stratigraphic and palaeogeographic reconstructions: Late Oligocene–Early Aquitanian western internal South Iberian Margin,Spain

The different hydrodynamic behaviour of detrital clay minerals in the marine depositional environment allows assessment of relative sea‐level variations in the sedimentary record. Comparison of smectite and kaolinite:illite (S+K:I) changes with the global sea‐level curves and with the third‐order cycles of the eustatic curve for European basins allows assessment of the influence of global eustasy and local tectonics on sequence stratigraphy. In the South Iberian Margin, sedimentation took place both on open‐marine platforms and in deeper water areas. On this margin during the Late Oligocene to Early Aquitanian, the variations in sedimentation were caused not only by global eustasy but also by compressive tectonics. Correlations were made between the S+K:I cycles and the third‐order cycles for European basins, enabling the definition of four third‐order sedimentary sequences (here called C1, C2, C3, and A1) and two lower‐order sequences within C3 and A1 (here called C3a, C3b, A1a, and A1b) related to tectonic movements. High S+K:I values were observed during episodes of maximum flooding in each sequence and lower‐order sequence and in each succession, enabling changes in palaeocoastal morphology to be considered. Copyright © 2012 John Wiley & Sons, Ltd.     

Palynoflora of the Gil’chin and Dim dinosaur localities (the Zeya-Bureya Basin,Russian Far East)

The analysis of the palynological spectra from the Gil’chin and Dim dinosaur localities of the Zeya-Bureya Basin revealed that the first of them is characterized by the high abundance of Filicales spores accompanied (in descending order) by tricolpate, bisaccate conifer pollen, Ginkgocycadophytus, Taxodiaceae, Cupressaceae, Taxaceae (TCT), Ulmoideipites, and “unica”-type pollen. The spectra from the second site are dominated by Filicales spores and (second in significance) pollen of plants characteristic of river valley communities (Platanaceae and Ulmaceae) accompanied by common bisaccate conifer pollen and subordinate TCT and Ginkgocycadophytus pollen. The middle Maastrichtian bone-bearing taphocoenoses of the Gil’chin and Dim localities were formed in spacious swamped river valleys covered by ferns and taxodialeans. The Platanaceae and Ulmaceae pollen implies the development of light forests in river valleys. The Ulmaceae pollen is indicative of highly variable environments in the mid-Maastrichtian, probably, with an intermittent water influx. The low share of bissacate pollen in the palynospectra from these two localities is presumably determined by their remoteness from the slopes of the depression.     

Sedimentological sequence and depositional evolutionary model of Lower Triassic carbonate rocks in the South Yellow Sea Basin

Based on well logging and seismic data, combined with a comparative analysis of drilling data in the Lower Yangtze region, the sequence stratigraphic framework of the Qinglong Formation was established and divided into four third-order sequences. Each sequence is mainly composed of the transgress system tract (TST) and the high-stand system tract (HST). According to the lithology, logging curve and seismic reflection structure, the sedimentary filling characteristics and evolution law for the sequence are analyzed. The results show that each sequence is dominated by a half-cycle decline of sea level, and the rise-fall of sea level controls the distribution and evolution of sedimentary systems within the sequence. During the relative sea-level rise, sedimentation rates slow down and muddy sediments are developed. The characteristics of condensing intervals on the flooding surface are very obvious, and continental shelf and open platform deposition are mainly developed. During the relative decline of sea level, the thickness of sediments increased. The main developments were restricted platform and platform shoal environment, and locally developed evaporation platform environment.     

青海共和盆地达连海湖泊流域表土花粉-气候响应面分析

孢粉分析是研究过去全球变化的一种重要方法,而研究花粉与现代气候之间的相互关系是古气候定量重建研究中的前沿课题。要预测未来气候的中长期变化,必须从花粉记录中定量提取古气候信息,建立的多种孢粉-气候数学模型必须经过不同边界条件下的古气候数据检验校正才能应用到实际当中。花粉-气候响应面方法是考虑了花粉与气候间的非线形关系上,提出的将现代花粉丰度在地理空间的分布转换为气候空间的分布,并以提供定量的古气候数据,已被广泛应用于COHMAP等各种重要古气候研究项目。本文就是利用该方法,以青藏高原东北部共和盆地达连海湖泊流域54个表土样品中的花粉丰度及采样点的气候参数为基础数据,通过主成分分析选择了特征值高且指示意义明显的4种花粉类型,对其丰度与7月平均温度及年平均降水量两个气候参数进行多项式回归分析,其结果显示模型对数据拟合较好,为定量重建该区古气候变化提出了较为准确的数量指标。