水煮地球

在漫长的地史长河中,气候一直处于冷(冰期)、暖(间冰期)交替之中。冰期地球平均气温比现代低7～9℃,间冰期则比现代高8～12℃。地球的最后一次冰期时代为第四纪,约始于200万年前,并延续到今天。根据来自南极大陆东部腹地的东方站取出的冰芯,以及取自北极格陵兰冰盖中央顶部的冰芯记录,在过去的100年中,全球气温平均上升了0．3～0．6℃。由于温度升高,使得极地沉睡了千百万年的冰川已开始出现部分的融化,从而导致全球海平面升高,海面温度上升,飓风发生的强度与频率也明显增加。     

第四纪大冰期或晚新生代大冰期已经在11,000年前结束了——“天地生人”系列讲座(十一)

在第１０讲 ,我们提出“第三个宏冬（或晚新生代大冰期 ,或第四纪大冰期）已经在１１,０００年前结束了。”严格地讲 ,这一认识并不完全是新的。因为在中国和外国的许多教科书中 ,对第四纪（指过去的１６０或２６０万年内）的气候变迁史已有共识。大家普遍承认 ,在第四纪 ,世界上曾发生过四次冰期。其中末次冰期 ,或玉木冰期 ,相当于深海氧同位素的第２～４阶段 ,发生在距今１ １～７万年 ;倒数第二次冰期 ,或里斯冰期 ,相当于氧同位素的第６阶段 ,则出现在距今１２ ７～１８万年 ;倒数第三次冰期 ,或明德冰期 ,相当于氧同位素的第１４～１…     

南海西沙海槽111PC孔的硅藻与古环境记录

对南海西沙海槽111PC孔沉积物中的硅藻化石研究表明,硅藻以热带、亚热带浮游性种类和近岸性种类为主,可划分出6个硅藻组合带,大体对应于浮游有孔虫氧同位素6个期次。结合有地层对比意义的属种及组合,建立了里斯冰期以来本孔的硅藻生物地层框架。硅藻丰度、属种组合变化指示海区气候经历了冰期-间冰期气候旋回及不稳定性波动。晚玉木冰期硅藻丰度高,冰后期、中玉木冰期次之,里斯冰期至早玉木冰期丰度较低,这与南海西南部不同,与南海东北相似但也不尽相同。里斯冰期至里斯玉木间冰期转换阶段,硅藻属种对气候变暖的反应较快。硅藻属种特征显示中玉木冰期气候为弱暖期,且有早晚两个暖湿阶段。硅藻属种的不连续分布也表明沉积环境在部分时段极不稳定。     

福建沿岸晚第四纪孢粉,硅藻组合及其古环境意义

通过对福建沿岸８个钻孔的孢粉、硅藻的综合分析,发现晚第四纪地层中有８个综合孢粉组合带与７个硅藻阶段。结合古地磁和１４Ｃ测年资料认为,该地区晚第四纪地层划分为晚更新世中、晚期（早大理冰期、大理亚间冰期、晚大理冰期）和全新世（早期、早中期、晚中期、晚期）。气候变迁序列为冷而干燥→暖而湿→冷而干燥→温暖稍干→暖而湿→热暖潮湿→温暖略干→温暖湿润。据古环境分析认为有七次海侵（或海进）,且各次海侵（或海进）的影响范围差异较大     

苏州草鞋山遗址新石器时代以来的植硅石研究

本文首次对苏州草鞋山遗址新石器时代以来的植硅石进行分析。结果表明：马家浜文化时期气候发展经历了三个阶段。第一阶段（距今约６２７５ａ以前）气候温暖湿润,禾本科植物以芦竹亚科、竹亚科和水稻为主;第二阶段（距今约６２７５－６２００ａ间）气候温凉略干,黍亚科大量出现;第三阶段（距今约６２００－５９８５ａ间）气温回升。菘泽文化至宋代,气温继续变暖,此阶段,禾本科各亚科植物均有生长。本遗址马家浜文化时期发现典型水稻扇型及亚铃型硅酸体,反映该地自马家浜文化时期以来,水稻栽培已有一定规模     

南海北部0.36-1.02Ma高分辨率碳屑记录及天然火

依据南海ODP1144站下段（225．7－501．3m,ca.0.36-1.02Ma)碳屑、孢粉记录,将1144站下段225.7-501.3m划分19个碳屑、孢粉组合带（11－29）,并分别与氧同位素11－29期（MIS11－29）相对应。冰期时,草本植物花粉和碳屑总沉积率增加,气候干燥,天然火的强度较大;冰期MIS24,大陆内部及冰期出露的大陆架上的天然火灾强度相对最弱;而冰期MIS12,大陆内部及冰期出露的大陆架上的天然火灾强度相对最强;间冰期气候湿润,草本花粉和碳屑总沉积率降低。一方面由于间冰期海平面上升,大陆架被淹没,导致碳屑来源减少;另一方面亦反应天然火灾强度减低。间冰期MIS17,25和27碳屑沉积率分别较冰期MIS18,24及26略高,推测间冰期MIS17,25和27冬季风强度仍相对较强,大陆内部天然火灾强度亦相对较强。     

拟裸蝗属昆虫生物地理研究

采用支序生物地理学的方法对拟裸蝗属昆虫生物地理进行了研究。研究表明各地区明显地分为两个类群,同时地区分化分4次完成,保山、个旧和昭通为较早分化地区。并推测拟裸蝗属的形成可能在第1次冰期,其起源地在云南、四川两省交界的横断山东部地区,种的分化在第3次冰期之后,主要集中在新仙女木降温事件前后。冰期和间冰期的交互出现所导致的气温剧烈变化是促使其分化成种的主要原因。并认为拟裸蝗属昆虫今后的分布区域将进一步缩小,并向更高海拔的山地迁移。     

冰川·生物·人类

近年来,世界各地气候波动的幅度和频率都有所增大,出现了所谓“气候异常”。气候变迁问题涉及的面很广,这里仅从第四纪气候变迁与动植物进化、人类发展的关系方面,谈谈我们对这个问题的一些看法。地球上不断变化着的气候毛主席在《矛盾论》中指出:“整个地球及地球各部分的地理和气候也是变化着的”。地球上的地质、地理、气候和生物等等,都不是一成不变的,它们都有着自己发生、发展的过程。自从地球在大约50亿年前生成以来,大规模的气候变迁有过好几次,达到象大冰期那样寒冷的时期至少有3次。距今6亿年以前的震旦纪冰期,我国大约发生在距今7一7.5亿年左右(有人     

鹤的趣闻

鹤类的变迁 鹤类在地球上的出现距今约有6000万年的历史。今天除南美洲和南极洲外,在世界各地均有鹤类分布。古鸟类学家经过对化石的研究证明,世界上最早的鹤与现在生活在非洲的冠鹤相似。当时,鹤类约有30多种,它们主要西息在赤道以北的大陆。那里不仅有温暖的气候,还有大面积的湿地和草原,十分适宜鹤类生存繁衍。 从第三纪晚期上新世到第四纪初期,全球气温有过明显的降低趋向,这是世界性气候变化,导致全世界冰川期的到来。整个第四纪自然界的最大特点是冰期和间冰期、海浸和海退、地壳的上升和下降等交替现象。由于气候和地壳的剧变,新的山脉把大陆分开,湿地被冰川和山脉所取代。     

末次冰期南海巽他陆架上的植被和气候——17962孔孢粉记录

提供了南海大陆坡上17962孔深海沉积物的孢粉记录.该孔长8 m,底部14C年龄为30 000 a BP,跨越了深海氧同位素3期、末次冰期、冰消期和全新世几个地质历史阶段.孢粉记录显示末次冰期低海面时南海南部出露的陆架上覆盖了低地雨林.同时,在邻近的岛屿上山地雨林扩张,表明气候比现在凉,但是没有变干的迹象.冰消期植被和气候都经历了快速变暖和变凉的波动.全新世时,红树林和低地雨林的扩张以及孢粉沉积率的明显降低均表明气候变暖,海面上升,大陆架被淹没.     

Palaeoclimate and Palaeoenvironment of the Last Glacial Stage in Salawusu Area of Nei Monggol,China

Salawusu area of Nei Monggol, is the famous ruins of “Hetao man” and their culture. It is also the native haunt of Salawusu Fauna and the typical site of the late Pleistocene in northern China. By densely sampling and carefully analysing, the authors worked out a beautiful and complete pollen-spore diagram of the Salawusu section, which records in detail the proccess of the vegetational development and the climatic changes of this region since Last Glacial periode, about 60 ka B.P. Accordingly, the last glacial period may be divided into three substages: Early, middle and late substage, corresponding to the pollen-spore zones: Ⅰ,Ⅱ, and Ⅲ. Substages are divided into cold stadials and relative warmmer tnterstadials, corresponding to subzones of pollenspore zones. This scheme can be well correlated with that of other regions in China, in Europe, in America and the results of the oxygen isotopic research in deep sea, all over the world.     

乌尔吉晚更新世动物群和古生态环境

乌尔吉地区晚更新世地层出露广泛,哺乳动物化石常有发现.乌尔吉动物群属于猛犸象—披毛犀动物群,其时代为晚更新世晚期.动物群的生态性质明显反映了当时应为寒温带湿冷草原为主间有疏林和少量灌丛的自然景观.     

广西百色第三纪哺乳动物群与气候变迁

在广西百色共发现了三个层位:晚始新世早期的洞均组,晚始新世晚期的那读组和早渐新世的公康组。它们的哺乳动物的种类数目分别为14,27和ll,而其南方类型的百分含量则分别为50,77.8和54.5。故在晚始新世早期或早渐新世,气候较凉;而在晚始新世晚期,气候较暖。这是与北美的情况相类似的。     

阿坝藏族自治州若尔盖晚更新世地层及哺乳类化石

文中记述阿坝藏族自治州若尔盖县境内黄河阶地堆积及其所产哺乳动物化石,并经 C~(14) 测定,化石距今约22650±300年,地质时代为晚更新世晚期.     

Paleovegetation and Paleoclimate in the Past 20,000 Years in Jiaozhou Bay,Qingdao District

The spore-pollen assemblages collected from drilling cores in Jiaozhou Bay, Qingdao district, are analyzed in this paper. We have ascertained paleovegetation and paleodimate since last 20000 years in the studied district. It is concluded that development process can be devided into six stages, each stage has its corresponding characteristics on paleovegetation and paleoclimate. These stages are listed as follows: ( 1 ) Vegetation was mainly herbaceous plants and climate was cold and dry during 20000–13000 years B P (2) During 13000– 11000 years B P, there was a little conifer forest and herbaceous plants, in which aquatic and weter plants were relatively richer in quantities, climate was mild and wet. (3) During 11000–8500 years B P there was a little conifer and broadleaved forest and herbaceous plants, climate was mild and slightly dry. (4)During 8500–5000 years B P broadleaved trees were predominant but mixed with conifer forest, climate was warm and wet. (5) During 5000–2500 years B P conifer trees were predominant but mixed with broadleaved trees and herbaceous plants, climate was mild and slightly dry. (6) From 2300 years B P to present, we can further divide this stage into two periods, the preceding period and the late period. In the preceding period, vegetation was composed by conifer and broadleaved trees and herbaceous plants, climate was warm and wet; while conifer trees (including a little broadleaved trees) were prevailed in the late period, climate was mild and wet. As a result, we have concluded that the general tendency of climate variation for the studied district is consistent with North China and East China one, but there still exists a little differences. The authors suggest that the time limit between Pleistocene and Holocene should be demarcated at 11000 years B P owing to sharply increasing temperature for the studied district.     

关于萨拉乌苏遗址地层及人类化石年代的问题

本文回顾了与人类化石相关的萨拉乌苏河晚更新世地层及文化层的年代学研究,经过14C测年和相关证据认为,采集的萨拉乌苏PA.62号股骨不属于萨拉乌苏遗址的原生地层。     

华北晚新生代哺乳动物的进化事件及其与欧美的对比

本文记述了过去300万年内在华北地区所发生的9次哺乳动物的进化事件:1.真象最低层位(距今约300万年);2.真马最低层位(距今约250万年);3.狼的最低层位(距今185—190万年);4.葛氏斑鹿最低层位(距今约140万年);5.丽牛最高层位(距今约90万年);6.丁氏鼢鼠最高层位(距今约62万年);7.中国鬣狗最高层位(距今约24万年);8.原始牛最低层位(距今约12.7万年);9.更新世末绝灭事件(距今约1.1万年)。本文将它们与欧美的进化事件进行了初步的对比。     

中更新世以来兽类地理分布的变化及其天文气候学的解释

中更新世以来,兽类的地理分布曾发生过重大的变化,如西伯利亚的兽类曾三次大举西迁,入侵西欧.它们分别发生在氧同位素的第16、6、2-4阶段.如果考察过去73万年以来全球所获得的、北半球冬半年平均的太阳辐射量的变化,那么第16、6、2-4阶段乃是太阳辐射量比较低的时期.故中更新世以来兽类地理分布的变化是受气候变迁的制约的.而后者则是受天文因素的自然变化所控制的.     

Late Quaternary history of atmospheric and oceanic circulation in the eastern equatorial Pacific

Four radiolarian assemblages have been defined in recent seafloor sediments of the equatorial Pacific Ocean. The distribution of these assemblages corresponds to the modern pattern of oceanic circulation and water mass structure in this region: the eastern Pacific shallow permanent thermocline and the Equatorial Undercurrent; Peru Current upwelling and the oxygen minimum; the subtropical water mass; warm western tropical water and the North Equatorial Countercurrent. In twelve cores chosen to transect the region both longitudinally and latitudinally, the distribution of these four assemblages has been reconstructed for six time-intervals during the last 127,000 years: 18,000 B.P. (glacial Stage 2); 36,000 B.P. and 52,000 B.P. (interstadial Stage 3); 65,000 B.P. (glacial Stage 4); 82,000 B.P. and 120,000 B.P. (interglacial Stage 5). Atmospheric and oceanic circulation changes through time have been inferred from the reconstructed microfossil assemblage distributions. Changes in assemblage distributions indicate that variations in intensity, direction and mean position of the tradewinds caused marked changes in the oceanic circulation patterns through the last glacial cycle.Near the end of interglacial Stage 5, the disappearance of the North Equatorial Countercurrent from the eastern Pacific suggests that the mean position of the tradewinds was shifted to the south approximately 5° of latitude relative to the modern position, so that the Northeast trades prevented the flow of the North Equatorial Countercurrent into the eastern Pacific. Near the end of interstadial Stage 3, a change in wind direction occurred from predominantly zonal winds, which enhance equatorial divergence and surfacing of the Equatorial Undercurrent, to more meridional winds, which enhance coastal upwelling associated with the Peru Current.In the tropical Pacific Ocean, late Quaternary changes in atmospheric and oceanic circulation are linked with times of continental ice sheet growth in the Northern Hemisphere (i.e., the interglacial-to-glacial transitions across oxygen isotope stage boundaries $\text{5}\text{4}$ and $\text{3}\text{2}$). The major changes in circulation seem to occur a few thousand years in advance of the glacial episodes, at or near periods of ice sheet growth. This relationship indicates that changes in atmospheric circulation in the tropics led and influenced the development of conditions suitable for polar and continental ice sheet growth in the Northern Hemisphere.     

吉林乾安大布苏晚更新世动物群

描述比较了在吉林省乾安县大布苏泡子新发现的鬣狗科化石Crocutaultima。依据到目前为止所发现的 6目 1 2科 1 8属 1 9种脊椎动物化石组合 ,结合含化石地层的孢粉分析和1 4 C测年数据推测 ,大布苏一带在晚更新世晚期曾经以草原景观为主 ,兼有森林及荒漠 ,而且经历了从干凉草地向较潮湿凉爽的疏林或森林草原 ,直至干凉半荒漠草原环境变迁的历程。