激光象山爵溪镇下沙中全新世海滩岩中热带贝类初步研究

本文本文报道了浙江象山县爵溪镇下沙中全新世海滩岩中的部分热带贝类，计有８属９种。这一动物群的现生物均生活于热带海域的潮间带及潮下带，研究结果表明该区海滩岩是迄今发现的拥大量热带生物的最北面的海滩岩，进一步证实了海滩岩是热带海洋的产物。以及浙江浙江沿海地区中全新世的时的气候与现代气候有很大差别，这对古气候变迁的研究具有重要意义。     

浙江沿海中全新世古气候、古环境初步分析

首次通过对浙江象山爵溪镇下沙、大岙和岱山大长涂岛小沙河3个中全新世海滩岩剖面进行以动物群分析为基础,应用δ¹⁸O和¹⁴C等手段相结合的综合研究,初步分析了浙江沿海中全新世的古气候、古环境。认为海滩岩中热带贝类的出现是中全新世时气候变暖的结果。当时热带向北扩展到了浙江中北部地区,可分为3个暖期：6 040 aBP前、5 860～3 218 aBP和2 875～2 770 aBP,其中5 860～3 210 aBP较暖,它又可分为：5 860～5 490 aBP,5 490～4 110 aBP和3 765～3 210 aBP3个阶段,以5 490～4 110 aBP为最暖期,由δ¹⁸O计算的古气温约比现今当地高5～6℃。还由微量元素等特征推测了当时的古环境。     

浙江沿海中合新世古气候,古环境初步分析

首次通过对浙江象山爵溪镇下沙、大岙和岱山大长涂岛小沙河３个中全新世海滩岩剖面进行以动物群分析为基础，应用δ＾１８Ｏ和＾１４Ｃ等手段相结合的综合研究，初步分析了浙江沿海中全新世的古气候、古环境。     

福建全新世海滩岩及其地质意义

福建已发现全新世海滩岩１０余处，主要分布于平潭岛以南，笔者选择了具有＾１４Ｃ年龄和海拔高程的海滩岩共２６组数据，建立了全新世海平面变化曲线，讨论了海平面升降特点、新的构造差异运行和古气温的变化。     

华南海岸风沙研究中若干问题探讨

根据野外调查和室内实验分析以及测年数据，本文讨论了华南热带海岸特有的两种风成沉积沙体；海岸沙丘岩的沉积特征，成岩机制及其与海滩岩的区分；老红砂成因，年龄与发育模式。     

秦安大地湾高分辨率全新世植被演变与气候变迁初步研究

主要根据孢粉分析结果,并结合磁化率,碳酸钙恢复了陇西黄土高原地区全新世期间植被气候的变化过程。结果表明全新世气候存在３个大的阶段,全新世早期气候以寒冷为主要特点,中全新世气候温暖湿润,晚全新世气候以干旱为主要特征。     

广西近岸西部中全新世显著海侵及气候特征

【目的】北部湾北部是冷暖空气的交汇带,气候复杂多变,而断裂活动导致的沉降差异又是海岸变迁的重要驱动因素,为了探究该区域环境变迁的规律,研究其中全新世显著海侵和气候特征。【方法】以广西西部近岸为典型,于防城港湾口外水下斜坡进行沉积物岩芯取样和粒度、元素、矿物、微体古生物、~(14)C年龄等地质地球化学要素综合测试,分析对比要素的变化特征及其气候联系。【结果】孢粉组合反映植被以山地热带、亚热带种属居优。沉积物组分为粘土质粉砂、砂质粉砂和粉砂质砂。体现出元素分段变化,碎屑矿物含量变异性较高的分布规律;化学元素等基本以3.00~2.80m深度为界,前后分布有明显环境差异,显示气候变干变冷之特征。该转折点亦是大规模海侵的起始阶段,主要表现为绿石明显富集,Sr/Ba显著增高,有孔虫、硅藻、钙质和硅质生物碎屑随之快速增加;该转折点在时间和要素变化特征方面与邻区相近,揭示这并非偶然现象,与中全新世6.00ka B.P.前后夏季风减弱、冬季风加强的大尺度气候变化相联系。【结论】中全新世广西西北部近岸出现了大规模海侵,可能与区域乃至全球气候变化有关。     

黄土高原不同地貌类型区全新世植被变化研究

总结了24个具有年代控制的全新世剖面的孢粉记录后,得出以下主要认识:一是孢粉资料揭示出黄土高原不同地貌类型的全新世植被类型存在差异,在基岩山地和河谷地带全新世曾发育有森林植被,而黄土塬面上和黄土/沙漠过渡地带全新世植被以草原为主,未见森林植被.二是考虑到年代误差范围,尽管黄土高原不同地貌单元的全新世植被类型不同,但植被变化反映的环境演化格局基本一致,即早全新世黄土高原气候较干燥,中全新世气候温暖湿润,晚全新世气候又开始变干.     

根据孢粉分析对黑龙港地区全新世地层及其植被演变的认识

根据孢粉分析资料和C~(14)测年数据,本区的全新世地层以三分为宜,即早全新世(距今10000—7500年),中全新世(距今7500—2500年)和晚全新世(距今2500年至今)。黑龙港地区全新世以来的自然环境也曾发生过较明显的演变。中全新世时,有过比现在高2—4℃的温暖气候,随后又变凉了。黑龙港地区的盐碱灾害,在早全新世时期可能就已存在,后来由于气候的变凉变干,加上人类活动的影响,又加重了这一灾害的程度。     

临汾凹陷一万年来环境演化研究

黄土状岩石在环境条件适宜情况下,可以发育多层古土壤,这些黄土状岩—古土壤系列是研究全新世环境变化的主要依据之一.本文研究了两个有代表性的实例剖面,揭示了临汾凹陷1万年的环境演化过程,为今后气候环境预测提供了新的参量.     

Paleoenvironmental information recorded by pollen in B-3GC gravity core in Okinawa Trough

Based on pollen records in B-3GC gravity core, environmental change since 9500 aBP of Okinawa Trough and its adjacent islands was derived. The result showed that the most time during this period was in a warm temperate climate except in middle Holocene (6800-4400 aBP) that was under subtropical climate control. During 9500–8300 aBP and 3100–2000 aBP periods, it appeared colder and drier than the rest time. The original area of pollen sources surrounding Okinawa Trough was covered by evergreen and deciduous broadleaf forest alternatively with mixed broad-leaf-conifer forest distributed in high mountainous areas. Usually, these three kinds of forests existed at the same time with difference in altitude. Pollen from subtropical and tropical plants increased obviously in about 5000–6000 aBP, reflecting a great lifting of vegetation zone and expansion of evergreen broad-leaf forest in the study area. However, there was a slight descending of plant zone and shrinking of evergreen broadleaf forest during 9500-8300 aBP and 3000-2000 aBP. During the remaining periods vegetation zone was higher than the present but in a limited range.     

High—resolution records of Holocene from the Shuangchi Maar Lake in Hainan Island

The results of sedimentary characteristics,grain-size,clay mineral,C/N and pollen analysis reveal the evolution history of the Shuangchi Maar Lake of Hainan Island as well as the short-term climate variations in tropical areas.It is testified that the Maar sediment system was sensitive in recording the rapid climate changes in the Holocene.These multidisciplinary results demonstrate that the thermal maximum in the Holocene climate lasted from 7200 to 2700 aBP,with serveral abrupt ephemeral vibrations occurring between 7250-6120aBP and at around 4460,3850 and 2700 aBP.In the late Holocent,particularly at -2700 aBP,a distinct environmental change indicating an important climate transition in the tropical eastern Asia was recorded,probably responding to the enhancement of ENSO phenomena in the Pacific Ocean.In addition,the high-resolution algae record clearly indicates periodical climate fluctuations at 500 a cyclicity during the last 2500 years.     

Mid-Holocene climate change in North China, and the effect on cultural development

In this study, to reconstruct the paleoclimatic history, pollen and oxygen isotope were analyzed on the 160 samples of a 2.7 m peat core from Taishizhuang, Huailai County, Hebei Province. Combining our data with other information of climate history and archaeology from this area, we found that there is a close linkage between cultural development and the mid-Holocene (6000-3000 cal. aBP) environment changes. The main results and conclusions are presented as the following: The climate during 5678-5400 cal. aBP was unstable and in general colder and drier than today. From 5400 to 4800 cal. aBP the climate was much warmer and wetter than before. The climate during 4800-4300 cal. aBP was persistently cold, with an exceptional cold event occurring at 4600-4300 cal. aBP. This cold event was recorded at several other localities in Northern China even the Northern Hemisphere and played an important role in the cultural development. After the cold event, there was a return to warmer conditions between 4200 and 3300 cal.aBP.     

河南洛阳寺河南剖面中全新世以来的孢粉分析及环境变化

对河南洛阳寺河南剖面进行的高分辨率的孢粉分析表明,该地区中全新世以来的孢粉组合以草本植物占绝对优势。其中以蒿属（Artemisia）最为丰富,其次为禾本科（Gramineae）和藜科（Chinopodiaceae）。乔木花粉含量较少,以松属（Pinus）为主。根据孢粉组合的变化,将剖面划分为5个孢粉组合带。早期（7.235～7.380 aBP）气候较为寒冷干燥,缺少乔木花粉。随着全新世大暖期的到来,在Ⅱ孢粉带上乔木花粉大量出现,种类丰富。尤其5.625～6.120 aBP期间出现了很多喜暖树种,是中全新世以来气候最好的时期。在4.580～5.625 aBP期间,乔木花粉急剧减少,表明气候发生恶化。随着气候的逐渐好转,乔木花粉在Ⅳ孢粉带（3.090～4.580 aBP）上重新出现,但喜暖树种较少。3.090 aBP以后出现较多的禾本科花粉,可能和该地区人类活动的增强相关。     

东北地区苔蛾亚科（鳞翅目：灯蛾科）2新记录种及1新记录属

记述了东北地区2新记录种：泥土苔蛾Eilema lutarella（Linnaeus,1758）和点艳苔蛾北米亚种Asuraunipuncta megala Hampson,1900,以及东北地区1新记录属：艳苔蛾属Asura Walker,1854.对2新记录种成虫外部形态和外生殖器特征进行了简要描述.     

盐城海涂生物资源及开发利用现状的调查

调查发现盐城海涂生物资源丰富,种类繁多,蕴藏量大。其中潮间带底栖动物就有100余种,泥螺、文蛤、四角哈蜊、青蛤的生物总量均在万吨以上,托氏(虫昌)螺、海豆芽、沙蚕、大竹蛏等的资源量也非常丰富;高等植物10余种,芦苇、大米草、互花米草等资源量丰富。生物资源的开发利用主要为滩涂采捕、滩涂养殖和产品加工等方面。     

河南孟津地区中全新世环境变化及其对人类活动的影响

在河南孟津地区发现全新世古土壤－黄土沉积剖面和湖沼相沉积剖面。作者对这2个剖面之间进行了野外调查,绘制了其间的地层图,并在古土壤-黄土沉积剖面采样,对样品做了粒度、磁化率以及CaCO₃含量分析。通过古土壤－黄土沉积剖面与湖沼相沉积剖面的对比,研究了中全新世孟津地区环境变化及其对人类活动的影响。结果表明孟津地区在7020～5660aBP和4610～3755aBP是古湖泊形成和古土壤发育的时期,气候温暖湿润;在5660～4610aBP孟津地区经历了一次气候波动,湖泊缩小为零星湖沼, 古土壤发育中断;3755～3055aBP湖泊萎缩干涸,黄土开始沉积,气候转向冷干。河南龙山文化时代晚期,湖面水位较高,人类在古土壤上活动;二里头文化时期湖泊萎缩,人类活动向低处转移,湖泊完全干涸时人类开始在干涸的湖相沉积层上活动。     

Palynological records of environmental changes in the middle part of Inner Mongolia,China

Today, the central part of Inner Mongolia has a continental climate, with cold winters, hot summers, and approximately 70% of the precipitation falling in the summer months. Vegetation is dominated by steppe vegetation with Stipa bungeana and Stipa breviflora. Scattered individuals of Quercus liaotungensis, Populus davidiana, Betula platyplylla are distributed in the mountains, with some Pinus tabluaoformis, near Miaoyu, and with fragmentary Picea above 1700—1800 m a.s.l. The Huitenglian…     

青海湖全新世短尺度水体环境演变的初步研究

青海湖是闻名世界的高原内陆咸水湖，在湖滨岩线附近发育的特殊岩石－青海湖湖滩岩是研究第四幻气候事件与古湖面变化的标志岩石。湖滩岩的主要成岩期为全新世，其成岩序列发现有５１４０、４７００－４４００、３８８０－３６００、２８２０－２７２０、２５３０－２４６０、１９７０－１９００、１５３０－１４５０ａ等七个阶段。