中国全新世大暖期哺乳动物与气候波动

中国全新世哺乳动物群有众多地点，并已作了详细研究，绝大多数地点有＾１４Ｃ的年代测定，全新世一更新世的界线，作者根据哺乳动物及＾１４Ｃ年代测定，在１２－１０ｋａＢ．Ｐ之间，可作为二者之间的过渡层位，在１０ｋａＢ．Ｐ。可作为全新世的开始，中国的全新世大暖期出现于８．５－３．０ｋａＢ．Ｐ。在此期间内的哺乳动物偏南种类似为明显，如亚洲象，苏门犀及爪哇犀等，在５．６－３．０ｋａＢ．Ｐ。这一时期内的气候波动剧     

中国全新世高温期中的气候突变事件及其对人类的影响

本文通过孢粉、闪芯和古湖泊等研究，确定了高温期起迄时间为８．５－３ＫｂＢ．Ｐ．，恢复了高温期的气候与环境的基本特征，作者发现在高温期仍在有７．８，５．３和４ｋａＢ．Ｐ．等三次具有普遍意义的气候突变事件，其降温幅度甚至可达３－４℃。这些突变事件对人类文明和环境变化起很重要的作用，尤其是与它位伴随出现的各种严重自然灾害阻碍和限制了古文明的发展，有时甚至是毁灭性的打击。     

福建沿海全新世高温期的气候与海面变化

本文综合分析了福建沿海全新世高温期的孢粉资料和海平面变化资料,建立了气温和海平面变化曲线.结果表明,8ka,B.P.前为气温和海平面上升期,8ka,B.P.以来为高温期和高海平面期,海平面升降与气温升降几乎同步.     

全新世气候系统的突变及周期性

高纬冰心、海洋沉积物及陆相古气候沉积记录揭示了全新世冰后期(最近1万年以来)存在系列气候突变事件及百年—千年尺度的气候周期韵律,证实了在冰期-间冰期旋回大尺度气候背景下全球气候存在较大不稳定特征这一基本事实。全新世作为与人类文明衔接的最新地质时段,各国科学家针对全新世气候系统变化特征及驱动机制的研究不断取得新的进展,这些成果将为未来气候演化趋势预测提供重要的历史相似性。总结了近年来关于全新世气候系统的突变及周期性研究的一些成果,并进行了概略的评述和展望。     

全新世高温期气候不稳定性记录

对黄土高原黄土剖面中的黑垆进行了植物孢粉植物硅酸体,碳同位素和化学分析测试,结果表明,黑垆土良好地记录了全新世高温期气候不稳定性,在大致９－６ｋａＢ．Ｐ．期间,曾发生数次强度不等的快速变化。     

晋南地区全新世中期遗址时空分布与气候演化的关系

基于ArcGIS10.8平台结合最邻近指数、核密度分析叠加标准差椭圆等方法,研究晋南地区全新世中期1 415处遗址的时空演变。结果表明：晋南地区全新世中期遗址空间分布从集聚到逐渐离散;遗址重心向高纬度地区、逆时针方向位移,方向呈现先东北后西北的变化。核密度分析表明,空间布局从仰韶期的团状到龙山期的以陶寺文化为中心的带状分布。与仰韶时期相比,龙山时期处于过渡时期的弱暖湿气候阶段,干燥更为明显,遗址沿着盆地和河流分布。由于此时农业技术水平高,人类适应能力增强,人口迅速增加,从而推动了龙山文化发展;后期气候逐渐恶化,人类生存面临严峻挑战,导致龙山文化被迫中断。随后进入了夏商时期,遗址数目较少,分布与山地联系密切。这种龙山文化到夏商文化的演变可能与4 kaBP前后降温事件有关。因此,研究全新世中期晋南地区遗址时空分布与环境演化,对于理解不同环境下人类响应与适应具有重要意义。     

全新世大暖期云南洱海环境演化的湖泊沉积记录

根据高分辨率湖泊沉积的有机碳稳定同位素记录、硅藻等环境指标分析结果,将洱海全新世大暖期（８．１－３．０ＫaＢ．Ｐ）的环境演化为７个阶段,环境变化序列以温（暖）湿 －暖（温）干为主,其中存在的明显冷干（湿）事件,冷事件出现在７．２ＫaＢ．Ｐ、５．３ＫaＢ．Ｐ和３．７ＫaＢ．Ｐ。全新世大暖期洱海湖面波动与气候变化具有明显的一致性。洱海湖泊沉积记录的环境演化主要受亚洲季风强弱转换和时空迁移的影响,冷事件与亚     

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     

中国西北地区中晚全新世火历史集成重建与气候演化

为了探讨西北地区古火演化及其驱动机制,基于28个样点的炭屑和黑碳记录,集成重建该区8 kaBP的古火变化序列;同时结合古植被、古气候、历史文献等记录,分析了古火活动与气候变化和人类活动之间的关系。结果表明：西北地区中晚全新世火历史可以划分为4个阶段;① 火活动波动阶段（8～6 kaBP）,古火事件发生频繁,主要受气候变化的影响;② 火活动平稳阶段（6～4 kaBP）,气候趋于暖湿化,植被有所发展,贮藏了一定的燃烧质;③ 火活动快速上升阶段（4～2 kaBP）,人类活动成为火事件的主要影响因素,古火活动频率呈现不断上升的趋势;④ 火活动大范围发生阶段（2～0 kaBP）,气候由湿冷向干冷转化,生物质干燥易燃,农业快速发展,朝代更替和战争频繁,火活动异常剧烈。     

典型气候事件对北极渔业资源的影响

随着北极海冰融化加剧,越来越多的渔船涌入北极海域,促使北极渔业资源得到了更好的开发。在这种情况下,研究气候事件对北极海域的影响变得至关重要。本文选取了北大西洋多年代际涛动（Atlantic Multidecadal Oscillation,AMO）、北极涛动（Arctic Oscillation,AO）和北大西洋涛动（North Atlantic Oscillation,NAO） 这三种典型气候事件,通过超前滞后相关、回归分析等统计方法,探究它们与北极渔区 （以27渔区为代表） 渔业总捕捞量以及4种主要经济鱼种 （大西洋鳕、大西洋鲱、格陵兰大比目鱼和大西洋鲑） 捕捞量之间的联系。研究结果表明：1950－2020年,27渔区的海洋渔业总捕捞量总体呈现出两次上升与两次下降过程;在AMO及AO两种气候事件中,AMO对27渔区的捕捞量影响最为显著,同时海冰范围变化对捕捞资源同期影响很强;其中的1980－2020年,4种主要经济鱼种捕捞量与AO相关性均较低,而与AMO呈现明显正或负相关性;4种主要经济鱼种捕捞量与大西洋海表温度存在显著相关性,尤其是类AMO型的海温变化对这4种鱼种捕捞量波动可能存在显著影响。本研究不仅揭示了气候变化对北极渔业资源的显著影响,还根据研究结果提出相应的对策建议,为进一步研究提供了方向和参考,以期实现北极渔业资源可持续发展。     

东海陆架盆地南部中生代构造-沉积演化与油气勘探方向

东海陆架盆地位于欧亚板块东南缘,中生代以来盆地形成和演化过程受到古太平洋板块多期洋壳俯冲及其多构造体系叠加改造,其盆地原型、构造-沉积演化与油气成藏关系一直是研究的热点。本文综合应用东海陆架盆地南部最新地震调查、钻井和临近陆域资料,通过海陆对比、中生界层序地层建立、构造-沉积演化过程重塑,探讨中生界油气成藏的关键问题和勘探方向。研究结果认为东海陆架盆地南部中生界存在2个超层序7个层序,中生代以来演化表现为晚三叠世前的被动大陆边缘基底、晚三叠世—中侏罗世活动大陆边缘拗陷、白垩纪活动陆缘断陷盆地;早期基底NE向格架控制中生代盆地结构与宏观含油气性,中生代两期构造演化造就了两套生储盖组合,基隆运动、渔山运动和雁荡运动控制早期油气的生成、聚集,龙井运动主要控制早期油气藏调整与改造、再成藏;继承性隆起（斜坡）闽江斜坡和“凹中凸”台北转折带是中生界油气主要勘探方向。     

东海北部陆缘地区全新世孢粉组合及其古环境演变

对东海北部陆缘地区NH 0504孔和东海Dh1井全新世地层的孢粉进行了研究,划分出5个孢粉组合带和2个亚带,恢复了该地区植被演替、气候波动和古环境演变的5个阶段,为该区的地层年代划分和对比提供了科学的证据,为全新世古植被、古气候和古环境的重建提供了重要的孢粉学资料。划分的5个阶段为:第1阶段为针阔叶混交林-草地,反映出当时的气候以温凉略湿为特征(前北方期);第2阶段为含常绿阔叶树的针阔叶混交林,反映出当时的气候以温和略干为特征(北方期);第3阶段为以常绿栎类和栲属等为主的常绿阔叶林,反映出当时气候以热暖潮湿为特征(大西洋期);第4阶段是以栎、松和禾本科为主的针阔叶混交林,反映出当时的气候以温暖略干为特征(亚北方期);第5阶段是以落叶栎类、常绿栎类、松为主的落叶阔叶、常绿阔叶、针叶混交林-草地,反映出当时的气候以温暖湿润为特征(亚大西洋期)。     

岁差驱动与中国黄土高原的次级气候旋回

以黄土高原普遍存在的次级古土壤为基础,结合粒度资料和磁化率资料,对黄土高原的次级气候阶段进行了划分与对比,初步建立了黄土高原L21以来的次级气候旋回序列。以北半球夏至日在近日点和远日点为界,将岁差旋回转变为北半球"理想岁差气候旋回",并与黄土高原次级气候旋回逐一对比,发现L21以来的72个岁差旋回中,共发育了122个次级气候阶段,合61个次级气候旋回。除去岁差变化微弱的时段,黄土高原次级气候旋回与理想岁差旋回间几乎是一一对应的关系。从而认为,黄土高原的次级气候旋回主要由岁差旋回驱动。与反映全球变化的一级气候旋回相比,黄土高原的次级气候旋回凸显了具有半球效应的岁差旋回在黄土高原气候变化中的作用。黄土高原的次级气候旋回一定程度上受到冰期旋回的遮掩,需要在高原各地往复追索才能清楚揭示。黄土高原的次级气候旋回不仅可以作为地层划分与对比的基本单元,也由于岁差的约束而在一定程度上具有了绝对年代的意义,在地层划分和古气候研究中应引起足够的重视。     

Phases of compression during the evolution of the Pannonian Basin and its bearing on hydrocarbon exploration

Progress in understanding the structural evolution of the Pannonian Basin is reported. This has been driven by the application of seismic stratigraphy constrained by magnetostratigraphic data and the recent release of a great amount of hydrocarbon exploration data. This has led to a redefinition and better understanding of the syn-rift period and style of rifting. In addition, a complex structural evolution history during the post-rift phase has been recognized. Two compressive events are defined: one in the early stage and another in the late stage of evolution. The importance of these findings for hydrocarbon exploration includes an improved knowledge of the timing of trap formations and a possible explanation for remarkably variable reservoir pressures in pools of the Great Hungarian Plain.     

全新世大暖气广西钦州湾红树林衰退的红树林源有机质贡献示踪及其对亚洲季风的响应

The response of mangrove ecosystems to the Asian monsoon in the future global warming can be understood by reconstructing the development of mangrove forests during the Holocene climatic optimum(HCO), using proxies preserved in coastal sediments. The total organic matter in sediments of a segmented core, with calibrated age ranges between 5.6 and 7.7 cal. ka BP and corresponding to the HCO, from the Qinzhou Bay in Guangxi, China, is quantitatively partitioned into three end-members according to their sources: mangrove-derived, terrigenous,and marine phytoplanktonic, using a three-end-member model depicted by organic carbon isotope(δ13Corg) and the molar ratio of total organic carbon to total nitrogen(C/N). The percentage of mangrove-derived organic matter(MOM) contribution is used as a proxy for mangrove development. Three visible drops in MOM contribution occurred at ca. 7.3, ca. 6.9, and ca. 6.2 cal. ka BP, respectively, are recognized against a relatively stable and higher MOM contribution level, indicating that three distinct mangrove forest degradations occurred in the Qinzhou Bay during the HCO. The three mangrove forest degradations approximately correspond to the time of the strengthened/weakened Asian winter/summer monsoon. This indicates that even during a period favorable for the mangrove development, such as the HCO, climatic extremes, such as cold and dry events driven by the strengthened/weakened Asian winter/summer monsoon, can trigger the degradation of mangrove forests.     

The gradual subduction-collision evolution model of Proto-South China Sea and its control on oil and gas

This study involved outcrop, drilling, seismic, gravity, and magnetic data to systematically document the geological records of the subduction process of Proto-South China Sea (PSCS) and establish its evolution model. The results indicate that a series of arc-shaped ophiolite belts and calcalkaline magmatic rocks are developed in northern Borneo, both of which have the characteristics of gradually changing younger from west to east, and are direct signs of subduction and collision of PSCS. At the same time, the subduction of PSCS led to the formation of three accretion zones from the south to the north in Borneo, the Kuching belt, Sibu belt, and Miri belt. The sedimentary formation of northern Borneo is characterized by a three-layer structure, with the oceanic basement at the bottom, overlying the deep-sea flysch deposits of the Rajang–Crocker group, and the molasse sedimentary sequence that is dominated by river-delta and shallow marine facies at the top, recording the whole subduction–collision–orogeny process of PSCS. Further, seismic reflection and tomography also confirmed the subduction and collision of PSCS. Based on the geological records of the subduction and collision of PSCS, combined with the comprehensive analysis of segmented expansion and key tectonic events in the South China Sea, we establish the “gradual” subduction-collision evolution model of PSCS. During the late Eocene to middle Miocene, the Zengmu, Nansha, and Liyue–Palawan blocks were separated by West Baram Line and Balabac Fault, which collided with the Borneo block and Kagayan Ridge successively from the west to the east, forming several foreland basin systems, and PSCS subducted and closed from the west to the east. The subduction and extinction of PSCS controlled the oil and gas distribution pattern of southern South China Sea (SSCS) mainly in three aspects. First, the “gradual” closure process of PSCS led to the continuous development of many large deltas in SSCS. Second, the deltas formed during the subduction–collision of PSCS controlled the development of source rocks in the basins of SSCS. Macroscopically, the distribution and scale of deltas controlled the distribution and scale of source rocks, forming two types of source rocks, namely, coal measures and terrestrial marine facies. Microscopically, the difference of terrestrial higher plants carried by the delta controlled the proportion of macerals of source rocks. Third, the difference of source rocks mainly controlled the distribution pattern of oil and gas in SSCS. Meanwhile, the difference in the scale of source rocks mainly controlled the difference in the amount of oil and gas discoveries, resulting in a huge amount of oil and gas discoveries in the basin of SSCS. Meanwhile, the difference of macerals of source rocks mainly controlled the difference of oil and gas generation, forming the oil and gas distribution pattern of “nearshore oil and far-shore gas”.     

从海南岛全新世孢粉研究看海滨红树林的演化

海南岛是我国第二大岛,位于18°09'～21°10'N,108°03'～110°03'E北隔琼州海峡与雷州半岛相望.海岸线长达1500km,全岛面积为33900km2,四周地形低,中南部山地耸立,海拔100m以下的台地、平原占全岛面积的近2/3.     

Unusual diatoms linked to climatic events in the northeastern English Channel

The composition of the micro-phytoplankton was investigated at two fixed stations in the northeastern English Channel from November 1997 to December 2005. In late summer-autumn 2005, proliferations of the centric diatoms Proboscia indica and Rhizosolenia hebetata f. semispina were recorded for the first time in this area. The weather in 2005 was abnormal: a cold winter and early arrival of summer conditions that extended to late autumn. This resulted in an unusually long, sustained calm and warm period. We suggest that the reduction in mixing may have allowed diatoms of more-stratified waters to be competitive in the normally highly mixed northeastern English Channel in summer-autumn 2005. In 2003 and in 2005, two warm-water diatom species were recorded for the first time. A colony of Eucampia cornuta was observed after an exceptional heat wave in September of 2003, and again in September 2005. Simultaneously at both fixed stations, Chaetoceros peruvianus was recorded in the warm October of 2005. The climatic events are associated with the northward spreading of thermophilic diatoms such as E. cornuta and Ch. peruvianus in the European Atlantic waters, and the proliferation of diatoms of stratified environments such as P. indica and R. hebetata f. semispina in the usually highly turbulent waters of the northeastern English Channel.