渤海湾沿岸贝壳堤对潮滩有孔虫海面变化指示意义的影响

通过对渤海湾沿岸有贝壳堤发育和无贝壳堤发育的2类现代开放潮滩有孔虫组合的对比,研究了该2类潮滩环境沉积物中有孔虫的海面指示意义。5个有孔虫组合带被MHWST(平均大潮高潮位)、MHW(平均高潮位)、MHWNT(平均大潮低潮位)和MSL(平均海面)分隔,分别对应潮滩的高盐沼、低盐沼、潮间带上部、潮间带中上部和潮间带中下部5个不同亚环境。不同亚环境沉积物因其所含的有孔虫群的独特性,均可作为高精度海面标志物,误差为各亚带高差的1/2。沿岸贝壳堤可对潮滩有孔虫的属种组成产生影响,影响程度从高潮位向低潮位逐渐降低。在MHWNT潮位之下,有孔虫组合不再受到沿岸贝壳堤的影响。     

南黄海辐射沙脊群表层沉积物中底栖有孔虫埋葬群分布特征及其环境意义

对南黄海辐射沙脊群海域123个表层沉积物样品中的有孔虫埋葬群进行了分析,发现其中浮游有孔虫含量低,平均不到7%,其分布与外海潮流有关,底栖有孔虫以浅水广盐性属种为主。通过对研究区至少在3个样品中含量大于2%的59个底栖有孔虫属种的Q型因子分析,提取了3个底栖有孔虫组合,结合沉积物粒度特征、现代海洋环境要素,将研究区划分成3个环境分区:(1)辐射沙脊群主干沙脊及大型潮流通道区,对应Ammonia beccarii vars.-Nonion akitaense-Cribrononion frigidum组合。该区可再分为两个亚区:辐射沙脊群主干沙脊及大型潮流通道北部亚区,代表受低温沿岸流和潮流影响的强水动力近岸砂质沉积环境;辐射沙脊群南部长江口偏北部亚区,反映强潮流的河口、低盐缺氧环境,兼受外海悬浮泥沙的影响。(2)海州湾及废黄河口区,对应Ammonia compressiuscula-Spiroloculina laevigata-Elphidium advenum组合,代表粉砂、黏土质底质,和水深50 m以浅的浅海环境。(3)辐射沙脊南部近岸浅水区,对应Nonion anomalinoidea-Ammonia maruhasii-Ammonia pauciloculata组合,反映了粉砂及砂质底质的近岸浅水、低盐潮间带和潮下带环境。总之,辐射沙脊群海域底栖有孔虫种群的分布,不仅受海水温盐、水深影响显著,还与此区独特的水动力条件,即外海潮波与内陆河流的共同作用有关。     

南海北部崖19-1-1井晚第三纪有孔虫动物群演替与古水深变化

依据现代海洋中有孔虫动物群的分布与环境之间的关系 ,即在一定限度内有孔虫动物群的丰度和分异度随水深增加而增加 ,有孔虫动物群的组合面貌随之发生规律性变化 ,对南海北部琼东南盆地崖 1 9-1 -1井晚第三纪有孔虫动物群进行了定量研究。通过对有孔虫动物群的丰度、分异度、辛普松指数、信息函数熵、多变度、优势度、浮游有孔虫百分含量及底栖有孔虫内生种与外生种的比值逐样计算和统计 ,讨论了陆架海区有孔虫动物群的演替与古水深变化的关系。研究认为崖 1 9-1 -1井晚第三纪以来古水深变化的总趋势为逐渐增大 ,至上新世早中期出现外浅海至半深海环境 ,为古水深最大时期 ,随后水深则逐渐减小。     

渤海莱州湾晚第四纪底栖有孔虫分布特征及古环境意义

通过对渤海莱州湾GK138、GK111及GK95孔的255个沉积物样品中的有孔虫定量统计分析,共鉴定出底栖有孔虫15属32种。根据底栖有孔虫的丰度和分异度等分布特征和AMS14 C和光释光(OSL)测年结果,揭示晚第四纪以来研究区共发育3套海相地层,分别是中更新世晚期的第三海相层、晚更新世的第二海相层和全新世的第一海相层,通过与全球海面变化曲线对比,发现其与MIS7、MIS5和MIS1阶段的高海面有良好的对应关系。样品的Q型聚类及主成分分析划分出3组代表不同沉积环境的有孔虫化石组合,第Ⅲ化石组合带为中更新世晚期海侵的产物,为河口-滨岸浅海环境。第Ⅱ化石组合为晚更新世海侵的产物,为潮间带-潮下带沉积环境,第Ⅰ化石组合带为潮上带-潮间带沉积环境。海相地层顶、底板高程和厚度的分析结果显示中更新世晚期至晚更新世期间发生过不同期次、不同强度的构造活动,而进入全新世以后构造活动相对减弱。     

东海晚更新世以来的有孔虫组合及其地质意义

<正> 有孔虫是辨认沉积相的重要标志,也是指示不同沉积环境因子(温度、盐度、水深等)之一。近年来,上海同济大学与国家海洋局第二海洋研究所共同对东海表层沉积中有孔虫的分布规律以及晚更新世低海面时期的微体化石群已作了研究,东海某些柱状样中的有孔虫群也有初步调查与研究。此外,中国科学院海洋研究所、地质部海洋地质调查局     

山东济宁煤田(东区)太原组小有孔虫生物地层

通过对山东济宁煤田 (东区 )太原组小有孔虫动物群的系统研究 ,共鉴定出小有孔虫化石 2 8属 15 5种。根据小有孔虫化石在地层中的分布和垂向的变化规律自上而下建立了 3个小有孔虫组合 : .Tetrataxis parviconi-ca- N odosaria longa- Geinitzina spandeli组合 , .Echinonodosaria echinata- Glomospira regularis组合 , .Bradyi-na sphaeroidea- Palaeotextularidae组合。通过与邻区及华北部分地区的对比 ,本区太原组小有孔虫动物群的地质时代应为早二叠世早期 ,本区石炭系 -二叠系界线应置于太原组第十一层灰岩之底     

渤海莱州湾晚第四纪底栖有孔虫分布特征及其地质意义

通过对渤海莱州湾GK138、GK111及GK95孔的255个沉积物样品中的有孔虫定量统计分析,共鉴定出底栖有孔虫15属32种。根据底栖有孔虫的丰度和分异度等分布特征和AMS14C和光释光（OSL）测年结果,揭示晚第四纪以来研究区共发育3套海相地层,分别是中更新世晚期的第三海相层、晚更新世的第二海相层和全新世的第一海相层,通过与全球海面变化曲线对比,发现其与MIS7、MIS5和MIS1阶段的高海面有良好的对应关系。样品的Q型聚类及主成分分析划分出3组代表不同沉积环境的有孔虫化石组合,第III化石组合带为中更新世晚期海侵的产物,为河口-滨岸浅海环境。第Ⅱ化石组合为晚更新世海侵的产物,为潮间带-潮下带沉积环境,第I化石组合带为潮上带-潮间带沉积环境。海相地层顶、底板高程和厚度的分析结果显示中更新世晚期至晚更新世期间发生过不同期次、不同强度的构造活动,而进入全新世以后构造活动相对减弱。     

山东淄博太原组有孔虫及石炭系与二叠系界线

通过对山东省淄博地区太原组小有孔虫类动物群的系统研究,共鉴定出小有孔虫11属22种及部分未定种。根据有孔 虫类化石在地层中的分布和垂向变化规律,建立了两个小有孔虫化石组合带：IBradyina-Plectogyra 组合与IITetrataxisNodosaria-Palaeotextularia 组合。通过与邻区及华中华北其它地区的有孔虫进行对比,并结合前人对本区 类化石的研究结 果,确定了各组合带的地质时代：太原组小有孔虫动物群第I组合带地质时代归为晚石炭世,第II组合带地质时代归为早二 叠世,其层位相当于山东地区太原组 类Pseudoschwagerina带之底。     

东海E1孔晚更新世以来的地层、生物与环境

东海E1孔水深100m，是迄今东海陆架水深最深、采样最密、研究最详细的钻孔。依据有孔虫动物群的研究和碳同位素测年，可将E1孔的地层分成3段：S1—S3(0．00～3．34m)为全新统；S4—S24(3．34～53．43m)为晚更新统；S25(53．43～55．63m)为中更新统。有孔虫以浮游种类为主，属热带至亚热带动物群。研究发现本区自晚更新世以来有3次高海面期：第一次高海面期与长江三角洲平原的镇江海进、华北平原的天津海进和华南的长乐海进相当，属全新世，为外浅海环境；第二次高海面期与长江三角洲平原的隔湖海进、华北平原的沧州海进、和华南的福州海进相当，属晚更新世晚期，为外浅海环境；第三次高海面期与长江三角洲的江阴海进、华北平原的白洋淀海进相当，属晚更新世早期，为中至外浅海环境。在最晚中更新世低海面期本区曾暴露成陆。     

河南鹤壁地区太原组有孔虫动物群及石炭-二叠系界限的探讨

通过对华北地台河南鹤壁地区太原组有孔虫动物群的系统研究,共鉴定出有孔虫化石18属33种,建立了一个区域性有孔虫动物组合带：Bradyina—Palaeotextularia组合带,根据有孔虫化石的属种类型、数量,应用数理统计方法得出组合带有孔虫化石在地层中的比例变化情况,并根据化石组合带与国内其它地区的有孔虫动物群进行对比研究,认为鹤壁剖面有孔虫动物群Bradyina—Palaeotextularia组合带归于晚石炭世晚期的早期（C2^2-）,进而对研究区石炭-二叠系界线的划分进行探讨,界限应该放在第16层（泥岩）和第15层（灰岩）之间。     

2017~2018年间青岛湾潮间带底栖有孔虫群落组成和壳体形态的季节性变化研究

2017年1月至2018年1月期间对青岛湾潮间带表层1 cm沉积物中的底栖有孔虫进行了连续13个月的调查,获得16属36种共14939个有孔虫样本。通过对活体和总体群落参数、物种组成、壳体大小与畸形的生物统计分析,发现以上参数均具有明显的季节变化特征。结果表明,该区域有孔虫活体群落与总体群落相似性高,以本地属种为主,优势种主要为Quinqueloculina seminula、Ammonia aomoriensis、Cribrononion gnythosuturatum和Ammonia beccarii。相较于2010年至2012年期间的调查结果,该区域有孔虫丰度升高、多样性降低,群落参数的变化趋势和物种组成发生了较为明显的变化：在群落参数方面,2010年至2012年期间有孔虫丰度和多样性均在冬季时最高,2017至2018年期间有孔虫丰度在春季和秋季时高、复合分异度则在夏季和冬季时高;在物种组成方面,2017年时Ammonia aomoriensis仍然保持着较高的含量,但Quinqueloculina seminula和Cribrononion gnythosuturatum的丰度和比例均有明显升高。这些变化与2017年间更高的温度和更低的盐度有关。底栖有孔虫优势种含量与壳体形态呈现明显的季节性变化,且不同优势种之间存在明显差异,表现为：A.aomoriensis最高丰度和最大壳体出现在2017年4月,春季和冬季时含量高、冬季时畸形率低,推测其更喜好中低温环境;Q.seminula最高丰度和最大壳体出现在2017年5月,夏季时含量高、畸形率低,推测其更耐受高温环境。本研究结果预示应用潮间带有孔虫群落重建古环境时,有孔虫丰度、种类组成、壳体形态都存在明显的季节性因素,需综合考虑长时间尺度下属种组成与环境变化之间的关系。

     

弱海相性有孔虫群的特征及其代表的沉积环境

本文针对我国第四纪内陆有孔虫化石群的出现及其存在问题,提出有没有非海相有孔虫以及第四纪内陆有孔虫化石群是否都与海水入侵有关等问题。作者从我国现代海岸带有孔虫群调查着手,结合国外资料,说明弱海相性有孔虫群的分布及特征,分析我国第四纪内陆有孔虫化石群的生态环境,指出弱海相性有孔虫群具有一定的指相意义,是一类非正常的海相有孔虫群,不仅存在于海岸带,也可出现在内陆环境,出现有孔虫群不一定证明有海水入侵,只要有适宜的水化学条件也可出现。推论第四纪内陆有孔虫群有的与海水有关,有的可能无关。     

Benthic foraminiferal response to changes in mining pattern: a case study from the Zuari estuary,Goa, India

Being sensitive to environmental changes, foraminifera have been extensively used to monitor pollution level in the marine environment, including the effect of mining in coastal areas. In the Goa state of India, the rejects from opencast mining on land largely find their way to the estuaries, as washout during monsoon. Additionally, the Mormugao Port at the mouth of the Zuari estuary is the hub of activities due to the transport of ore from hinterland areas by barges and its subsequent loading for export. On the directive of the Supreme Court of India, all the mining-related activities abruptly stopped throughout India, including that in Goa in 2012, and got reinstated in 2015. Therefore, it provided a fit case to test the effectiveness of benthic foraminifera as an indicator of environmental impact due to mining activities. A total of ten surface sediment samples from five locations in Zuari estuary were collected from a depth range of 4.5–8.5 m in the years of 2013 and 2016 and were analyzed for both the living (stained) and dead benthic foraminifera. The year 2013 represents a time interval immediately after the closure of extensive mining activity, and the sampling during 2016 represents minimal mining. The living benthic foraminiferal abundance was higher (19–54/g sediment) during 2013 and decreased substantially during 2016 (3–22/g sediment), suggesting an adverse effect of activities associated with mine closure on benthic foraminifera. Additionally, the relative abundance of Ammonia was also significantly low during the year 2016. The temporal variation in dead foraminifera was, however, different than that of the living foraminifera. The differential response was attributed to the terrigenous dilution as a result of change in sedimentation rate. Therefore, we conclude that living foraminifera correctly incorporate the changes in mining pattern and may be used as an effective tool to monitor the impact of mining. We further suggest that the potential counter effect of terrigenous dilution on total and living benthic foraminiferal population should be considered while interpreting temporal variations in foraminiferal abundance in marginal marine settings.     

黄海中部泥质区底栖有孔虫群落对早全新世海平面快速上升的响应

末次冰消期以来全球海平面经历了很大变动,本文通过陆架泥质区资料,对黄海中部泥质区5个沉积物柱样进行了AMS ¹⁴C年代测试,结合沉积物粒度组成与底栖有孔虫资料探讨黄海中部泥质区底栖有孔虫对早全新世海平面快速上升的响应。结果表明,约13.0 ka以来底栖有孔虫群落对海平面变化的响应呈现明显的3个阶段：早期阶段(约13.0~10.0 ka期间),底栖有孔虫以近岸浅水组合为主,与这一时期海平面相对较低对应,泥质区整体呈滨岸环境,水动力环境较强,有机质等食物供给相对丰富,底栖有孔虫丰度相对较高;中期阶段(约10.0~7.0 ka期间),底栖有孔虫群落几乎消失,可能是由于海平面快速上升,动荡的海洋环境不利于有机质沉降,造成底栖有孔虫食物供给不稳定,不利于底栖有孔虫生存所致;晚期阶段(约7.0 ka以来),底栖有孔虫群落逐渐繁盛,以黄海中部冷水团特征组合为主,反映了区域海平面相对稳定、泥质沉积的形成以及黄海冷水团核心区域的出现等海洋环境变化为底栖有孔虫带来了稳定的有机质供给,故而底栖有孔虫丰度迅速增加到与现在相当的水平。黄海中部泥质区多柱样底栖有孔虫群落变化对早全新世海平面上升有较一致的响应,为该区全新世早期海平面快速上升以及黄海现代环流体系的形成提供了更直接的证据。

     

http://www.sciencedirect.com/science/article/pii/S1674987111001356

A total of 103 surface sediment samples collected from the water depth range of 15—3300 m along Vijaydurg-Karwar stretch of central west coast of India were analyzed for foraminiferal content. Relict benthic foraminiferal assemblage was noted within 50—135 m water depth.The relict benthic foraminiferal assemblage that includes Amphistegina,Operculum and Alveolinetta in sediment samples within the water depth of 85—135 m indicates presence of coral reef at this depth during Early Holocene. The presence of barnacle fouling on Relict foraminifera at 60—90 m confirms the paleo-shoreline. The shallow depth zone is characterized by presence of agglutinated relict foraminifera.The agglutinated forms indicate freshwater influx,which eventually increased the sea level and subsequently deteriorated the paleo-coral reef.     

西北太平洋深海底栖有孔虫DNA分子多样性与群落组成特点的初步研究

深海蕴藏着丰富的自然资源,是目前世界各国争相探索的战略要地。本工作以底栖有孔虫为研究对象,研究了它在西北太平洋深海（水深4080 m至5830 m）的DNA分子多样性和群落组成特点。我们共采集了11个站位的表层沉积物,提取了样品中的总基因组DNA,利用有孔虫特异性引物扩增了其中的有孔虫DNA,应用高通量测序技术对获得的有孔虫DNA片段测序。最终,共获得1536个操作分类单元（operational taxonomic units,简称OTUs）,有1330个OTUs成功注释到有孔虫,其中721个（约54%）有孔虫OTUs属于起源最早但研究较少的软壳类单房室有孔虫。有孔虫OTUs注释结果的Identity值的平均值为92.9%,Identity值大于或等于97%的OTUs仅占20.6%,Identity值小于95%的OTUs占63.1%,说明西北太平洋深海底栖有孔虫与目前检获到的有孔虫之间存在较明显的遗传差异性,该海区极可能蕴藏着大量至今未被发现的"新物种"甚至新的高级分类阶元。在我们获得的有孔虫属中,有1/ 3呈典型的斑块性分布,且站位间的有孔虫群落结构也存在明显差异。本工作是国内利用高通量测序技术对西北太平洋深海底栖有孔虫开展调查的首次尝试,旨在为探索有孔虫的全球地理分布模式、开发和利用深海资源等工作提供分子生态和分子遗传数据支持。

     

现代浮游有孔虫对南海西南部上升流的响应

现代夏季风系统导致了南海西南部（越南岸外）上升流的发育,但浮游有孔虫对夏季上升流的响应如何尚缺乏实测资料,这不利于准确地利用有孔虫来重建古上升流的活动进而反演过去夏季风的强度变化。本研究利用2014年4月14日至11月1日布放于南海西南部夏季上升流区的时间序列沉积物捕获器材料,详细鉴定并定量统计了其所含浮游有孔虫类型。通过分析样品中浮游有孔虫各属种的通量和百分含量变化,结合区域气候环境资料,探讨南海西南部夏季上升流区浮游有孔虫对夏季风的响应,为古上升流与夏季风研究提供现代依据。研究结果表明初级生产力是控制上升流区浮游有孔虫通量变化的首要因素,喜营养种在上升流发育期增多而寡营养种含量下降。因此高表层生产力指示种,如Neogloboquadrina dutertrei可能是追溯南海西南部夏季上升流变化最可靠的指标。

     

Secondary Calcification of Planktic Foraminifera from the Indian Sector of Southern Ocean

This study focused on planktic foraminifera in plankton tows and surface sediments from the western Indian sector of Southern Ocean in order to evaluate the potential foraminiferal secondary calcification and/or dissolution in the sediment. It is found that the symbiotic foraminiferal species are abundant in the subtropical region, whereas non-symbiotic species dominate in the sub-Antarctic and polar frontal regions. The distribution of the symbiotic and non-symbiotic foraminiferal species is controlled by temperature, salinity, light, nutrients and phytoplankton biomass. There is also a lateral southern extent in abundance of planktic foraminifera from surface sediments to plankton tows. The shell weights of the planktic foraminifera N. pachyderma, G. bulloides and G. ruber within the surface sediments are on an average heavier by 27%, 34% and 40% respectively than shells of the same size within the plankton tows, indicative of secondary calcification. The planktic foraminiferal isotopes show the presence of heavier isotopes in the surface sediment foraminifera as compared to plankton tows, thus confirming secondary calcification. Secondary calcification in G. ruber occurs in the euphotic zone, whereas in case of N. pachyderma and G. bulloides it is at deeper depths. We also observed a decrease in the shell spines in surface sediment foraminifera as compared to plankton tows, indicative of the morphological changes that foraminifera underwent during gametogenesis.     

Palaeoceanographic development in Storfjorden,Svalbard, during the deglaciation and Holocene: evidence from benthic foraminiferal records

Brines can have a profound influence on the relative abundance of calcareous and agglutinated foraminiferal faunas. Here we investigated the distribution of benthic foraminiferal species in four cores from a brine‐enriched environment in Storfjorden, Svalbard. Stratigraphically, the cores comprise the last 15 000 years. The purpose of the study was to reconstruct changes in the palaeoecology and palaeoceanography of Storfjorden in relation to past climate changes, and to identify potential indicator species for brine‐affected environments. The benthic foraminifera in Storfjorden all have widespread occurrences in the Arctic realm. Calcareous species dominated Storfjorden during the deglaciation and early Holocene until c. 8200 a BP. However, agglutinated species increased in abundance whenever conditions became colder with more sea ice and stronger brine formation, such as during the Older Dryas, the Intra‐Allerød Cold Period and the Younger Dryas. Following a moderately cold period with numerous agglutinated foraminifera from c. 8200–4000 a BP, conditions became more changeable from c. 4000 a BP with repeated shifts between warmer periods dominated by calcareous species and colder periods dominated by agglutinated species. The warmer periods show a stronger influence of Atlantic Water, with reduced brine formation and less corrosive conditions at the sea bottom. Conversely, the colder periods show a stronger influence of Arctic water, with higher brine production and more corrosive bottom water. The distribution patterns of the calcareous species are basically the same whether calculated relative to the total fauna (including agglutinated specimens) or relative to calcareous specimens alone. Moreover, the patterns are similar to the patterns found elsewhere along western Svalbard in areas without the influence of brines. No particular species appear to be specifically linked to brine formation. However, the most persistent agglutinated species R. scorpiurus and A. glomerata are also the species most tolerant of the acidic bottom water that normally is associated with brine formation.     

Late Glacial–Holocene record of benthic foraminiferal morphogroups from the eastern Arabian Sea OMZ: Paleoenvironmental implications

The Arabian Sea is characterized today by a well-developed and perennial oxygen minimum zone (OMZ) at mid-water depths. The Indian margin where the OMZ impinges provides sediment records ideal to study past changes in the OMZ intensity and its vertical extent in response to the changes of monsoon-driven primary productivity and intermediate water ventilation. Benthic foraminifera, depending upon their adaptation capabilities to variation in sea floor environment and microhabitat preferences, develop various functional morphologies that can be potentially used in paleoenvironmental reconstruction. In this study, we analysed benthic foraminiferal morphogroups in assemblage records of the last 30 ka in a sediment core collected from the lower OMZ of the Indian margin (off Goa). In total, nine morphogroups within two broadly classified epifaunal and infaunal microhabitat categories are identified. The abundance of morphogroups varies significantly during the late Glacial, Deglacial and Holocene. It appears that monsoon wind driven organic matter flux, and water column ventilation governing the OMZ intensity and sea-bottom oxygen condition, have profound influence on structuring the benthic foraminiferal morphogroups. We found a few morphogroups showing major changes in their abundances during the periods corresponding to the northern hemisphere climatic events. Benthic foraminifera with planoconvex tests are abundant during the cold Heinrich events, when the sea bottom was oxygenated due to a better ventilated, weak OMZ; whereas, those having tapered/cylindrical tests dominate during the last glacial maximum and the Holocene between 5 and 8 ka BP, when the OMZ was intensified and poorly ventilated, leading to oxygen-depleted benthic environment. Characteristically, increased abundance of taxa with milioline tests during the Heinrich 1 further suggests enhanced ventilation attributed probably to the influence of oxygen-rich Antarctic Intermediate Water (AAIW).