为探究东海扬子浅滩晚更新世沉积物的来源,对该区域的YZ05钻孔MIS6阶段沉积物中的石英流体包裹体进行了岩相学分析,并与长江干流表层沉积物中的流体包裹体进行对比研究.结果显示,YZ05钻孔晚更新世沉积物中单位体积(0.001 mm3)石英颗粒的包裹体数量在17～47个之间,个体大小多为2～5 μm,以孤立分布为主.其中次生包裹体数量较多,约占包裹体总数的88％～96％,原生包裹体以椭圆或四边形居多,室温下多为富液相,气液比大多为10％～30％.研究区及现代长江干流表层沉积物中的流体包裹体形态较为一致.此外,研究还发现了颈缩形态的包裹体及气液比大于80％的富气相原生包裹体,此类包裹体在长江上游石鼓地区较为常见.因此,可以推测晚更新世时(至少在47 ka BP),长江上游物质已经到达扬子浅滩西南海域.

南黄海陆架地区物源研究备受关注,到底是长江还是黄河源至今尚未有定论.通过对长江和黄河流域锆石U-Pb测年数据集混合模拟分析以及结合YZ08孔沉积相和锆石U-Pb的年龄图谱分析,结果表明:晚更新世以来,南黄海陆架地区存在长江古河道,MIS5时期长江可能在苏北弶港入海;在物源方面,MIS5时期弶港地区主要受长江物源影响,MIS1～MIS2时期则为长江主导的混合源,随着黄河夺淮人海带来泥沙物质,近代以来转为黄河主导的混合源.基于Bootstrap随机抽样方法抓取了长江和黄河的锆石U-Pb测年数据集,并结合统计学原理模拟出长江和黄河不同比例混合物源的锆石年龄图谱,对锆石物源判别方法做出了改进,弥补了传统锆石U-Pb年龄图谱在混合源判别分析上的不足,对南黄海物源研究具有一定的意义.

作为国土空间规划的三大战略格局之一,生态安全格局是海岸带地区生态安全的重要保障.本研究遵循"陆海统筹、生态优先"的理念,基于"本底分析-要素识别-格局构建"的总体思路,采用陆海生态敏感性评价、最小累积阻力模型、"源地-廊道-节点"模型等分析方法,规划构建了茂名市海岸带的生态安全格局.结果表明:(1)研究区的海岸侵蚀和特殊生境以不敏感为主,一般生境以轻度敏感为主,水土流失、风暴潮、赤潮、海岸带利用以中度敏感为主,社会经济以高度敏感为主;(2)研究区生态敏感性总体较高,陆海复合系统的综合敏感性指数由陆地向海洋呈现"减小-增加-减小"的空间变化规律;(3)本研究共提取出生态源地21块,面积116.78 km2;识别出生态廊道35条、生态节点24个,分别呈"一横五纵三环""陆多海少、南多北少"的空间分布格局;(4)本研究构建出"一带、三湾、五廊、多点"的区域生态安全格局,在此基础上提出规划指引,以期为茂名市海岸带的生态文明建设提供科学指导.

碎屑锆石U-Pb年代学是探寻沉积物物源的重要手段,在沉积学、大地构造学和地貌学等领域应用广泛.从数据获取、分析和比较3个方面综述了碎屑锆石U-Pb年代学研究的最新进展.在数据获取方面,从基本原理出发阐述了样品制备方法、同位素年龄数据选取和测试数量问题;在数据分析方面,对比了概率密度图、核密度估计图和累积年龄分布图的数据可视化方法;在数据比较方面,结合实例分析了定量比较的基本算法和应用优势,包括基于非参数性假设检验(K-S检验)、年龄谱对比(互相关系数)和多维定标法的相似(差异)性量化分析等.最后介绍了3款常用软件,并在数据获取、分析与比较方面分别给出了建议,供以后的研究者参考.

2014年在东海陆架扬子浅滩水深41.5 m处钻获进尺80 m的YZ05孔,该孔沉积相方面的研究成果虽然已经发表过,但略显简单,结合新获得的有孔虫鉴定结果和指示海陆环境变化的Sr/Ba比值,仍有必要对沉积相进行更为精细的研究.根据沉积物颜色、粒度、沉积结构和构造、接触关系和所含化石,共识别出河道-边滩相(F1)、河漫滩相(F2)、泥质潮滩相(F3)、河口湾前缘相(F4)、潮流沙脊相(F5)、脊间潮道相(F6)、分流河道沙坝相(F7)、分流河道相(F8)、远端三角洲前缘相(F9)以及前三角洲相(F10)十种类型.通过相组合与相序列分析,并辅以选择性提取方法获得的可交换态Sr/Ba比值,识别出退积型的河口湾序列和进积型的三角洲序列,它们与冰后期长江三角洲具有相似的沉积层序.AMS14C测年和光释光测年数据指示YZ05孔属于晚更新世以来的沉积.扬子浅滩的物质基础是晚更新世的三角洲堆积体,在全新世早期海面快速上升背景下,堆积成潮流沙脊,改造后形成潮流沙席.

基于RS、GIS、Matlab等技术与平台提取遥感影像岸线是当前实现海岸动态监测和分析各类型海岸动力地貌演化的重要技术方法.本文选取江苏南通江海岸带为研究区,对多期预处理后的MSS、TM和OLI影像进行卷积滤波、图像分割等处理;然后使用Matlab,基于Canny算子检测图像边缘,提取了多期影像的瞬时水边线.与此同时,结合不同类型海岸目视解译标志和吕四港近5 a潮汐数据矫正提取瞬时水边线,最后提取南通市4期江海岸线并分析了近45 a来南通江海岸线演变特性.

The persistence and prevalence of microplastics in the environment have raised concerns among scientists, the general public, and environmental regulatory agencies, and a large number of studies on microplastics in sediments have been published. We reviewed those studies and focused on understanding the spatial and temporal variations, biological effects, and analytic methods of microplastics in sediments. Microplastics are widely distributed in marine and freshwater sediments. The distribution of microplastics is mainly influenced by anthropogenic input and environmental processes that determine the transportation, transformation and accumulation. The appearance of microplastics in sedimentary records has been proposed as a stratigraphic marker for the onset of the Anthropocene Epoch. Our current understanding of biological effects of microplastics is based mainly on field research and laboratory-scale experiments using unrealistic concentration and limited forms of microplastics. Future studies should consider environmentally relevant concentration, the diverse composition and form of microplastics presenting in the natural environment. Density separation method for separation of microplastics in sediments is the most commonly used, and component identification by optical analysis (Fourier-transform infrared spectroscopy spectra, Raman spectra etc.) are important analytic methods. Yet the separation method remains to be standardized across laboratories. Other separation methods include electrostatics separation, organic solvent extraction and magnet separation. We recommend the combination of density separation, electrostatic separation and organic solvent separation to improve the separation efficiency of microplastics and to standardize the analytic process for sediment microplastics in future studies.

近年来,利用遥感技术对湖泊、河流、海岸等水体信息的监测和评估成为时代发展趋势.本研究选取连云港市1988年、1998年、2008年和2018年四个时期同一月份的TM、ETM和OLI影像,基于RS和GIS平台,研究连云港市近30年水体信息变化.对多期遥感影像进行预处理和增强处理后,区别于以往普遍使用的单波段阈值分析法、比值法、差值法、水体指数法等水体信息提取方法,本研究尝试使用“马氏距离”法分类提取研究区水体信息,并使用决策树法分类统计连云港市近30年水体变化.研究发现:近三十年来,研究区水域面积整体呈下降趋势.其中,以最近十年水域面积减少更为突出,这一特征与该地区近年来社会经济建设和自然因素变化密切相关.

The South China Sea(SCS)is one of the largest marginal seas in the Western Pacific and sensitive to climate changes.Emilimia Huxley and Gephyrocapsa Oceanica can produce a compound with 37~39 carbon atoms which we call long chain alkenones in the process of growth and metabolism.The unsaturation of this alkenones is UK37 .The sea surface temperature (SST)variation process of the Beibu Gulf during the last 10 thousand years has been reconstructed based on the sediment core SO-31(location 18°36′46.45″N,107°22′43.20″E,core length 7.34 m)by using the organic thermometer UK37 .Overall,the SST of the Beibu Gulf has been increasing gradually for the last 10 thousand years.The highest temperature is 28.0 ℃ at 255 a BP and the lowest is about 22.0 ℃ at 2658 a BP with an average of 25.4 ℃.The SST has an overall increasing trend during the Holocene,but increasing obviously during the last 1 .3 ka.The fluctuation amplitude is low between 10.0 ka BP and 5.3 ka BP,but becoming large since 5.3 ka BP. For the last 5300 years,SST has a one hundred scale periodic time,which might be related to the double century cycle of total solar irradiance.In addition,the core has recorded 8 temperature events with regional significance including 6 cold events at 9.2 ka BP,5.3 ka BP,4.3 ka BP,2.7 ka BP,1 .3 ka BP,0.6~0.2 ka BP and 2 warm events at 6.9 ka BP,0.9 ka BP.The Beibu Gulf SST fluctuation during the last 10 ka is mainly controlled total solar irradiance,East Asia Winter Monsoon and even high latitudinal ice melting events.Meanwhile,volcanic eruptions and reducing cosmic rays are also important to SST changes during the last 1 ka.

Coastlines of sand-barrier lagoons have provided significant locations for coastal economic development as has frequently occurred along the eastern coast of Hainan Island in southern China. Here, increased levels of human activity have greatly destabilized this ecosystem, subjecting it to major damage. The present study used innovative technology to classify and evaluate six phases of overlapping coastlines in Li’an and Xincun Lagoons in Lingshui County in southeastern Hainan Island between 1987 and 2013. This included the retrieval and integrated analysis of remote sensing images that was combined with data related to ocean dynamics and bathymetric surveys. Average historic high-tide lines were acquired by extracting humidity parameters from images using the Kauth-Thomas Transformation. Variations in the position and length of multiple coastlines were analyzed using GIS with a mathematical and statistical approach. The lengths of anthropogenic coastlines increased by 50% and moved seawards by 94.04 m in Li’an and 102.56 m in Xincun. Meanwhile, the areas in the Xincun and Li’an Lagoons decreased from 21.17 km2 to 19.43 km2 (−8.2%) and 9.94 km2 to 7.92 km2 (20.3%), respectively. Extensive human activity along the coastlines, such as saltwater aquaculture and farming, salt plant, and land reclamation, have profoundly altered the sedimentary geomorphology, local hydrodynamics, and the ecosystem itself. Consequently, the coastlines in Xincun and Li’an Lagoons in this newly designated pilot tourism city became vulnerable to modification. This research fills a critical gap related to the evolution of historical coastlines and provides an inventory of coastlines in support of coastal management.

Based on comprehensive analysis of lithology,sedimentary structure and micro-fossils assemblage of core YZ05 from the Yangtze Shoal,five sedimentary units were identified.At the same time,combined with several sediment dating results and stratigraphic correlation of some cores in the adjacent region,we divided the environmental evolution of the Yangtze Shoal into five stages since MIS6.River(MIS6),shallow sea to nearshore to shallow sea(MIS5),estuary front to estuary(MIS3)and shallow sea(tidal sand sheet,MIS1)have been developed successively in the study area.Research also reveals that the river highland formed during the low sea-level period in MIS6 is the ancient topographic foundation of the Yangtze Shoal.Estuarine deposits formed during MIS3 provided a large amount of sediment sources,and this contributed to the quickly topographic rise of the shoal.The convergent and divergent tidal current field established from 10ka to 6 ka BP and transformation of strong tidal current provided the dynamic conditions for the formation of the Yangtze Shoal.The sandy sediments formed by tidal current had probablity accumulation curves as three-segments type with a high quantity of rolling component,and their frequency curves were bimodal type.This is related to the accumulation of coarse particles in the tidal period and the accumulation of fine particles in the intermittent period.

In the radial tidal ridge field, northern Jiangsu coast of the South Yellow Sea, Late Pleistocene-Holocene glacial-eustatic sea-level fluctuations have formed a set of particular tidal genetic strata. Sedimentary facies associations are attributed to tidal flat, tidal ridge, tidal channel and creek infilling, flood plain environments as well as tidal ravinement and channel base lag. Five sedimentary units were delineated according to facies assemblages and major facies change boundaries. The facies assemblages indicate that two stacked aggradational tide-dominated units (U1 and U2), were formed during MIS 3 (Late Pleistocene). The sand source from the palaeo-Yangtze River mainly contributed to the formation of thick aggradational sequences in these units. The unit U2 features tidal channels characterized by extensive lateral migration. The tidal environment during the Late Pleistocene was similar to the present littoral tidal flat. During the Last Glacial Maximum when sea-level fell to -150 m on the South Yellow Sea shelf, the study area became terrestrial exposed and flood plain deposits accumulated (unit U3). A prominent transgressive surface occurs at the boundary between the Late Pleistocene deposits and the Holocene succession. A tidal ravinement surface separates the Holocene strata into a transgressive unit (U4, mainly composed of tidal flat facies) and a tidal sand ridge unit (U5). The formation of tidal sand ridges corresponds to the sand input from the abandoned Yellow River Delta after AD 1128. Glacio-eustatic sea-level changes and tidal erosion controlled the evolution of the Late Pleistocene-Holocene succession, while tidal current fields and sand supply from nearby deltas have played a key role in the RTR system formation.

The coastal sediments of the South Yellow Sea (SYS) provide a record of regional land– sea interactions. This study investigated the applicability of optical dating, using coarse-grained quartz, to provide a chronology of these sediments. A 150-m-long drilling core (YZ07) was retrieved from the southwest coast of the SYS on the northern flank of the Yangtze River delta. Overall, 28 samples extracted from the upper 50 m of core YZ07 were investigated. Preheat plateau and dose recovery tests were conducted. The optically stimulated luminescence (OSL) signals were typical of quartz and they were dominated by fast components. The spread in measured equivalent doses (Des) for each sample was generally consistent with the OSL signals being fully reset before deposition. The OSL ages generally increased with depth and indicated a 24-ka sedimentary record for the upper 50 m of the core. The age–depth relationship revealed two distinct sedimentary periods: (1) very slow sedimentation or even a depositional hiatus from the last glacial maximum (LGM) to the early Holocene (~24 to 8 ka); (2) very fast sedimentation at a rate of ~6 m/ka during the middle to late Holocene (since ~8 ka). It is speculated that sedimentation within the study area since the LGM might have been related to sea level change, delta initiation, and incised-valley fill processes.

The Pearl River is the largest river in southern China; it has eight outlets flowing into the South China Sea, four of which (Humen, Jiaomen, Hongqili and Hengmen) empty via Lingdingyang Bay. Tides, discharge strength and the presence of islands control sediments within these four outlets. Sediments are deposited, and form three shoals and two channels. The shoreline and its seabed topography have changed dramatically with increasing human impact.In order to understand the geomorphological evolution of Lingdingyang Bay and its hydrodynamics, we integrated data obtained from two marine environment investigations conducted by the Guangzhou Marine Geological Survey (GMGS) in 2003 and in 2012, together with remote sensing multi-temporal images and historical materials, and analysed them using a geographical information system (GIS).The results obtained show that the outlets are becoming narrower; the surface water area of Lingdingyang Bay is diminishing. Meanwhile, the sediment flux is reducing and becoming finer grained because the currents are being blocked by shoals and islands. Some parts of the bay are becoming deeper (27-37 m in the Chuanbi Channel). Correspondingly, the hydrodynamics in the bay are becoming weaker and sediments easier to deposit. Water exchange between the inner and outer sea is decreasing under the influence of unrestricted anthropogenic activities.Lingdingyang Bay should be managed and protected continuously based on a scientific framework: otherwise, it will become narrower and, perhaps, even evolving eventually into a river, which may result in serious futures disasters through flooding and tides.

利用陵水沙坝-潟湖获得的钻孔,通过沉积相分析,共划分出5个沉积单元,从上到下为U1、U2-1、U2-2、U3和U4,它们分别对应海岸沙丘相、浅海海湾相、滨岸相、冲积平原相和潟湖相.结合钻孔对比和AMS-14C测年,恢复了研究区晚更新世以来的沉积环境演化.末次冰期间冰期海平面上升,研究区部分被淹,发育海陆过渡潟湖环境;末次冰期极盛期,气候变冷、海平面下降,研究区暴露,发育下切河谷,洪水泛滥在河谷间形成冲积平原;冰后期海水初次淹没,研究区成为滨岸环境;全新世高海面阶段,研究区成为浅海海湾,珊瑚一度繁盛.波浪携带泥沙于湾口岛屿背后的波影区形成水下沙坝,于湾顶区形成沙嘴,两者相向生长,最后联结成为统一的连岛沙坝,分割黎安和新村潟湖.3000年后,随海平面波动上升,连岛沙坝露出水面,被海岸沙丘覆盖,最终形成现代沙坝-潟湖地貌形态.

In this paper, the type, vertical evolution, and distribution pattern of sedimentary facies of the Paleogene Dainan Formation in the Gaoyou Depression of the North Jiangsu Basin are studied in detail. Results show that fan delta, delta, nearshore subaqueous fan, and lacustrine facies developed during the Dainan Formation period and their distribution pattern was mainly controlled by tectonics and paleogeography. The fan delta and nearshore subaqueous fan facies predominantly occur in the southern steep slope region where fault-induced subsidence is thought to have created substantial accommodation, whereas the delta facies are distributed on the northern gentle slope which is thought to have experienced less subsidence. Finally, the lacustrine facies is shown to have developed in the center of the depression, as well as on the flanks of the fan delta, delta, and nearshore subaqueous fan facies. Vertically, the Dainan Formation represents an integrated transgressive–regressive cycle, with the E2 d 1 being the transgressive sequence and the E2 d 2 being the regressive sequence. This distribution model of sedimentary facies plays an important role in predicting favorable reservoir belts for the Dainan Formation in the Gaoyou Depression and similar areas. In the Gaoyou Depression, sandstones of the subaqueous distributary channels in the fan delta and the subaqueous branch channels in the delta are characterized by physical properties favorable for reservoir formation.

在岩心观察和沉积相研究基础上,对长江河口区H1孔末次冰期以来沉积物样品进行了粒度分析,讨论了沉积物粒度特征与水动力条件演化关系.分析表明,研究区末次冰期以来先后经历了河床、河漫滩、河口湾、浅海和三角洲等5种沉积环境.其中,河床相砂含量很高,平均粒径和环境敏感粒级最粗,分选变化较大,概率累积曲线主要为跳跃总体为主的两段式,频率分布曲线为单峰式且主峰粒径大;河漫滩沉积物整体粒度较细,以粉砂为主,分选较稳定,累积曲线仍以两段式为主,但悬浮总体比例较河床相高,环境敏感粒级更细;河口湾沉积物明显分异为粗细两类,分选波动较大,累积曲线主要为具过渡段的跳跃总体为主的两段式,双峰式粒度频率分布;浅海相平均粒径最细,分选性差但稳定,具悬浮一段式的累积曲线,粒度频率分布为单峰式且主峰粒径很小,环境敏感细粒组分分布宽泛;三角洲沉积物主要为砂和粉砂,分选性相对较好,累积曲线为跳跃总体为主的两段式,单峰式粒度频率分布但主峰粒径变化较大.总体上,H1孔沉积物的粒度特征能较好地反映研究区末次冰期以来沉积环境水动力条件“强—较弱—较强—弱—较强”的变化过程.