福建省中部沿海地区十二万年来的古气候

根据福建中部沿海地区有关钻孔或露头第四系孢粉样的研究,将该区距今12万年以来的古气候划分为七个气候期:(1)温暖湿润的琅岐期,距今12.0—7.0万年;(2)冷干的前福州期,距今7.0—4.1万年;(3)前期凉爽,后期温湿的福州期,距今4.1—2.0万年;(4)冷干的后福州期,距今2.0—1.2万年;(5)稍温干的前长乐期,距今1.2—0.8万年;(6)暖热湿润的长乐期,距今0.8—0.3万年;(7)稍温湿的后长乐期,距今0.3万年至现在。福建省中部沿海地区晚更新世下限距今约12万年,全新世下限距今约1.2万年。     

渭河宝鸡段阶地形成时代及地层对比

渭河宝鸡段阶地共分为5级,第四纪地层自下更新统至全新统均有出露。五级阶地形成于早更新世中晚期,距今约130万年;四级阶地形成于早更新世晚期,距今约85万年;三级阶地形成于早更新世中期,距今约55万年;二级阶地形成于中更新世晚期—晚更新世早期,距今约15～11万年;一级阶地形成于全新世早期,距今约0.8万年。     

滇西北第四系的划分

本文通过野外实测剖面研究,室内古生物化石鉴定,~(14)C年代测定,古地磁极性变化测试等手段,对滇西北第四系进行了较详细的划分。确定本区第四纪下限为距今248万年,中更新世、晚更新世和全新世三者的下限,分别为距今73万年、3万—4万年和1.35万年;滇西北第四纪重要冰期(大理冰期)则距今1.8—2.0万年。     

华北山地多成因壶穴初步研究——对华北山地“冰臼”等“冰川地貌”的讨论

华北山地"距今二、三百万年"的"冰臼"绝大部分位于第四纪河谷内,"距今1～2万年"的"冰川壶穴"位于全新世河谷内,与华北山地地貌演化相矛盾;所谓的"冰川地貌"组合不是真正的地貌组合,而是不同时代、不同成因地貌的混合,因此,华北山地不存在冰臼。所谓的"冰臼"是不同时代、多种成因的壶穴——距今2.50Ma前后的河蚀壶穴,距今10～20ka的雪蚀壶穴,距今10ka以来的溶蚀穴、溶蚀—河蚀壶穴、风化—风蚀壶穴、现代壶穴和水潭。     

A Study on Multi-original Potholes in North China Mountain Regions——A Discussion on “Glacial Potholes” and Other “Glacial Landforms” in North China Mountain Regions

华北山地“距今二、三百万年”的“冰臼”绝大部分位于第四纪河谷内,“距今1～2万年”的“冰川壶穴”位于全新世河谷内,与华北山地地貌演化相矛盾;所谓的“冰川地貌”组合不是真正的地貌组合,而是不同时代、不同成因地貌的混合,因此,华北山地不存在冰臼.所谓的“冰臼”是不同时代、多种成因的壶穴——距今2.50Ma前后的河蚀壶穴,距今10～ 20 ka的雪蚀壶穴,距今10ka以来的溶蚀穴、溶蚀—河蚀壶穴、风化—风蚀壶穴、现代壶穴和水潭.     

中国东部喀斯特洞穴沉积物铀系年代

本文报导采自中国东部喀斯特地区128个洞穴沉积物的230Th/234U年代测定结果。最年轻年龄为4300年,最老年龄大于35万年。中国东部洞穴沉积物有三个发育时期,它们是距今4000—13,000年,35,000—60,000年和75,000—12万年;也有两个不发育期,是距今15,000—35,000年和65,000—75,000年。这五个时期分别与V28-239深海岩心同位素记录的第一、第三、第五暖期和第二、第四冷期相对应.      

莱州湾地区10万年以来沉积环境变化

本文用热释光测年和地球化学标志法研究了莱州湾地区沉积环境的变化。石英的375℃热释光峰作为测年基础。岩芯样品的测定结果、反映了自全新世(1.2万年)至晚更新世(11万年)地层的年代特点。实验中来用了Sr/Ba、Rb、Mn/Fe和CaO作为地球化学标志,所得数据经Sheppard方程和Fisher判别处理。在得到的沉积环境变化曲线和大洋δ~(18)O曲线对比中可以看出,本区在十万年以来出现过三次海陆相地层变化序列,其中在距今11—7万年和深度为43.5—60m处,在距今4.6—2.1万年和深度为23—35m处,以及在距今1.1—0.6万年和深度为8—11m处出现过三次海相地层,分别与沧州、献县和黄骅海侵事件相应,并同时受到全球气候变化的控制。     

贵州威宁15000年来的古环境：南屯泥炭层剖面研究

本文系贵州威宁草海东南缘喀斯特谷地的南屯泥炭层剖面孢粉研究。剖面深8m,达基岩,采样112块,分析后获孢粉22446粒,有77个科属。根据孢粉组合及~(14)C年龄,该剖面为15000多年来的沉积物。其古植被、古气候可分四个阶段:(1)距今15700—10780年左右,为稀树草丛与以松为主的针阔叶混交林交替出现,反映为3个冷期2个温暖期(莎草多)。(Ⅱ)距今10780—5400年左右,植被由疏树草丛—阔叶树繁茂(莎草由少到多)—阔叶树逐渐减退(莎草很多)—疏林草地.气候相应由开始转暖到温暖湿润及温暖转凉再转寒冷。(Ⅲ)距今5400—700年左右是以针叶树松属为主阔叶树为次的混交林(莎草多)与松林(莎草少)交替出现,气候相应由温湿—温凉干燥……温湿……温凉干燥—温湿—温凉干燥—温湿。(Ⅳ)距今700年左右以来,则以松、栎为主的针阔叶混交林(莎草少)气候温暖较干。根据上述情况,笔者认为以气候开始转暖作为划分更新世与全新世的分界标志,南屯剖面应划在7.15M处,距今10780年左右。其气候期的划分:(Ⅰ)代表晚冰期,(Ⅱ)代表前北方期——大西洋期,(Ⅲ)代表亚北方期——亚大西洋期,(Ⅳ)代表太平洋期。本剖面是贵州晚冰期来比较典型而完整的代表。     

云南中部杞麓湖地区晚更新世——全新世植被研究

根据植被及C~14资料,本文将杞麓湖水下沉积物分为6个花粉带,其沉积年代及气候如下: 1.11.00--9.40m(水下沉积物深度,下同)松—油杉、冷杉、云杉、铁杉—栎针阔叶混交林带。气候冷湿。距今约3000—15000年,晚更新世(大理冰期最盛期)。 2.9.40—7.OOm 稀疏松-栎林带。气候干凉。距今约15000-12350年,晚更新世晚期(大理冰期冰后期)。 3.7.00-4.80m 松-油杉-栎、榆针阔叶林繁盛带。气候温暖。距今约12350-9500年,早全新世(前北方期-北方期)。 4.4.80-3.OOm 松-柏-栋、桦针阔叶林继续繁盛带。气候暖湿。距今约9500-5500年,中全新世(大西洋期-亚北方期) 5.3.00--0.84m 松-油杉-栎,以针叶树为主的针阔叶林带。气候温凉略干。距今约5000-1600年,晚全新世(亚大西洋期)。 6.0.84--O.OOm 稀疏松林。约1600年至今。本带森林面积迅速减小,可能由于人类的生产和生活活动所致,尚有待进一步研究。     

天山天格尔第二峰地区全新世中后期冰川变化的初步研究

本区冰川在全新世总的后退过程中有四次前进,发生在距今5700年、4100年、2800年前及403—74年之间,以第一次规模最大和时间最长。小冰期包括了距今403年、208年和74年前的三个冰进阶段,以第二次冰进最盛。温度变幅为2.5℃。地衣测量是一种适宜的测年手段。     

贡嘎山第四纪冰川遗迹及冰期划分

在对贡嘎山现代冰川和古冰川考察研究的基础上，结合定位观测分析，对该区第四纪冰川遗迹进行了深入讨论，划分出三次冰期，即中更新世早期的倒数第三次冰期，中更新世晚期的倒数第二次冰期和晚更新世的末次冰期，以及全新世的新冰期和小冰期。提出在早更新世时，由于山体未达到当时冰川发育的雪线高度，所以未发育冰川；中更新世早期的冰期冰川为半覆盖式冰川类型，规模不大；中更新世晚期的冰期冰川是本区最大冰川作用时期，形成网状山麓冰川，东坡冰川曾达磨西台地；晚更新世冰期冰川以山谷冰川为主，以后规模逐次缩小。     

Latest Pleistocene and Holocene glacier fluctuations in the Himalaya and Tibet

The timing and extent of latest Pleistocene and Holocene alpine glacier fluctuations in the Himalaya and Tibet are poorly defined due to the logistical and political inaccessibility of the region, and the general lack of modern studies of the glacial successions. Nevertheless, renewed interest in the region and the aid of newly developing numerical dating techniques have provided new insights into the nature of latest Pleistocene and Holocene glacier oscillations. These studies provide abundant evidence for significant glacial advances throughout the Last Glacial cycle. In most high Himalayan and Tibetan regions glaciers reached their maximum extent early in the Last Glacial cycle. However, true Last Glacial Maximum glacier advances were significantly less extensive. Notable glacier advances occurred during the Lateglacial and the early Holocene, with minor advances in some regions during the mid-Holocene. There is abundant evidence for multiple glacial advances throughout the latter part of the Holocene, although these are generally very poorly defined, and were less extensive than the early Holocene glacier advances. The poor chronological control on latest Pleistocene and Holocene glacial successions makes it difficult to construct correlations across the region, and with other glaciated regions in the world, which in turn makes it hard to assess the relative importance of the different climatic mechanisms that force glaciation in this region. The Lateglacial and Holocene glacial record, however, is particularly well preserved in several regions, notably in Muztag Ata and Kongur, and the Khumbu Himal. These successions have the potential to be examined in detail using newly developing numerical dating methods to derive a high-resolution record of glaciation to help in paleoclimatic reconstruction and understanding the dynamics of climate and glaciation in the Himalaya and Tibet.     

青藏高原唐古拉山口第四纪冰碛层划分及其地质环境意义

在对唐古拉山口现代冰川和古冰川考察研究的基础上，结合定位观测资料和TL、^10B-^26Al-^21Ne及^14C测年数据，对区内第四纪冰川遗迹进行了深入讨论，划分出二次冰期(即中更新世晚期的倒数第二次冰期、晚更新世中一晚期的末次冰期)和二次全新世冰进(即新冰期和小冰期)。提出在早更新世时，由于山体未达到当时冰川发育的雪线高度，所以未发育冰川。但在唐古拉山口地区，截止目前还未找到中更新世早期的倒数第三次冰期的冰川遗迹，由于高原隆升的滞后性和冰川发育的延滞效应及“亚洲干极”的耦合，推测仍只发育局部冰川作用。进一步研究表明，古今雪线由高原边缘向腹地升高，唐古拉山地区高出边缘1500m左右，生动表现了“亚洲干极”的作用；广泛分布的湖群说明羌塘地区是一个大江大河尚未伸入的内流地区，意味着青藏高原是个年青的高原。由于青藏高原的隆升，对高原腹地引起的干旱化过程和水分严重不足，使唐古拉山地区的冰川自倒数第二次冰期以来，冰川规模一次比一次明显地减小。     

Glacial history of southernmost South America

In southernmost South America, an incomplete radiometrically dated glacial chronology has been obtained by KAr dating for the interval 3.5-1 MY ago, and a more detailed chronology by C-14 dating for the last 25,000 years, with some older minimal ages. The first major glaciation was about 3.5 MY ago during the middle Pliocene. Little is yet known about glacial fluctuations during the interval 3.5-2.1 MY ago. Between 2.1 and 1 MY ago many glaciations occurred, probably including the greatest of late Cenozoic time which took place after 1.2 MY and, according to inconclusive evidence, before 1 MY ago. The Patagonian Gravel in its type area is mid-Pliocene to early Pleistocene glacial outwash that accumulated from the first to the greatest glaciations. During the late Pleistocene several glaciations occurred, but only the most recent has been radiometrically dated. During the last glaciation the glaciers were most extensive before 56,000 BP. Successively smaller advances that culminated about 19,500 BP and, probably, about 13,000 BP were separated by an interstade when glaciers shrank by more than half. The glaciers receded rapidly after 13,000 BP and were within their present borders by 11,000 BP; they remained so during the European Younger Dryas Stade 11,000-10,000 BP. Neoglacial regional readvances culminated 4600-4200 BP, probably 2700-2000 BP, and during the last three centuries; most glaciers reached their Neoglacial maxima during the first episode. Between readvances, the glaciers shrank within their present borders.     

东天山黑沟流域冰川沉积序列及OSL测年研究

黑沟源于东天山最大现代冰川作用中心博格达峰的南坡. 在第四纪冰期与间冰期旋回中,该流域的冰川均发生过多次规模较大的进退,在谷中留下了较为完整的冰川沉积序列. 这些冰川地形包含有重要的古气候变化信息,对其研究可重建黑沟流域的冰川演化史. 应用OSL对该流域的冰川沉积物进行定年,测定结果表明冰水沉积物（沙质透镜体）比冰碛物更适宜应用单片再生剂量（SAR）测年技术进行测定. 基于测得的年龄并结合地貌地层学原理可初步得出：晚第四纪期间,黑沟流域共发生了5次规模较大的冰川作用,分别为全新世期间的小冰期（16世纪以来冷期的冰进）与新冰期（距今3~4 ka的冰进）,末次冰期晚冰阶（MIS 2）与早冰阶（MIS 4）以及倒数第二次冰期（MIS 6）.     

Quaternary glaciation of Mt. Qomolangma-Xixabangma region

The uplift of the Himalaya and Qinghai-Xizang plateau began at the end of Pliocene to the beginning of Early Pleistocene, changing the atmospheric circulation in Asia, enhancing the South Asian monsoon and enormously effecting the climatic conditions and glacial development.According to the evidence of glacial deposits, geomorphology, paleobiology, paleopedology, etc., at least four glaciations can be recognized. The uplift of the Himalayas was earlier than that of other mountains, so that the glaciation occurred in Early Pleistocene, forming small piedmont glaciers on the N slope, whilst at the same time there were wide short valley glaciers on the S slope. During the Middle Pleistocene, the height of Himalaya was about 4000 m a s l, the monsoon was strong, and much water vapour reached the interior of the plateau, the most favourable period for glacial development. Great piedmont glaciers and small ice caps formed on the mountains N of Himalayas and great valley glaciers occurred on the S slope, but no great ice sheet covered the plateau.During the early Late Pleistocene, the Himalayas had risen to over 5000 m asl, forming a barrier against the incursion of the Indian monsoon, so that the precipitation decreased sharply on the plateau N of Himalayas, thus diminishing the extent of the glaciation. But on the high mountains of the S part of Xizang and on several high mountains of the S slope of the Great Himalaya, the precipitation increased and the extent of glaciation reached a maximum. Since Last Glaciation, the precipitation of the alpine zone has decreased more sharply, the climate has become drier and colder, becoming unfavourable for glacial development.During the Holocene, three stages may be distinguished, i.e. the recession in Early Holocene (10,000-8000 BP); the disappearance of most glaciers in the Hypsithermal period in Middle Holocene, (8000-3000 BP); and the neoglacial fluctuations in Late Holocene (3000 BP up to present). The glaciers of the Neoglaciation advanced several hundred meters or even 3–5 km farther than existing glaciers.     

希夏邦马峰东南富曲河谷的冰川沉积和冰川构造

在希夏邦马峰（海拔８０１２ｍ）东南富曲河谷，中更新世以来有三次冰期；即聂拉木、富曲和普罗冰期。它们均可再分为两个亚阶段。聂拉木南的高冰碛平台长３.５ｍ，宽１.５ｋｍ，厚２００ｍ。属于中更新世聂拉木冰期（聂聂雄拉冰期）的巨大山谷冰川沉积，中尼公路从高冰碛平台尾端通过，形成数公里长的冰碛剖面，呈现出美丽多姿的冰川成因类型沉积和冰川构造现象，包括冰下，冰上融出碛，冰内.冰下河道沉积，冰湖沉积，坠碛，流磺等。冰川运动时造成的冰川构造，如断层、滑动面-…等也很清楚，代表了海洋型（暖冰川）冰川沉积和冰川构造特征，是中国目前研究冰川构造最理想的场所。     

Late Quaternary glaciation and equilibrium line altitude variations of the McKinley River region,central Alaska Range

Dortch, J. M., Owen, L. A., Caffee, M. W. & Brease, P. 2009: Late Quaternary glaciation and equilibrium line altitude variations of the McKinley River region, central Alaska Range. Boreas, 10.1111/j.1502‐3885.2009.00121.x. ISSN 0300‐9483 Glacial deposits and landforms produced by the Muldrow and Peters glaciers in the McKinley River region of Alaska were examined using geomorphic and ¹⁰Be terrestrial cosmogenic nuclide (TCN) surface exposure dating (SED) methods to assess the timing and nature of late Quaternary glaciation and moraine stabilization. In addition to the oldest glacial deposits (McLeod Creek Drift), a group of four late Pleistocene moraines (MP‐I, II, III and IV) and three late Holocene till deposits (‘X’, ‘Y’ and ‘Z’ drifts) are present in the region, representing at least eight glacial advances. The ¹⁰Be TCN ages for the MP‐I moraine ranged from 2.5 kyr to 146 kyr, which highlights the problems of defining the ages of late Quaternary moraines using SED methods in central Alaska. The Muldrow ‘X’ drift has a ¹⁰Be TCN age of ～0.54 kyr, which is ～1.3 kyr younger than the independent minimum lichen age of ～1.8 kyr. This age difference probably represents the minimum time between formation and early stabilization of the moraine. Contemporary and former equilibrium line altitudes (ELAs) were determined. The ELA depressions for the Muldrow glacial system were 560, 400, 350 and 190 m and for the Peters glacial system 560, 360, 150 and 10 m, based on MP‐I through MP‐IV moraines, respectively. The difference between ELA depressions for the Muldrow and Peters glaciers likely reflects differences in supraglacial debris‐cover, glacier hypsometry and topographic controls on glacier mass balance.     

他念他翁山中段第四纪冰川作用ESR定年初步研究

他念他翁山中段地处青藏高原东南部和云贵高原过渡地带,海拔4 200 m以上保存着确切的第四纪冰川遗迹.对其进行深入研究,不仅可以重建横断山脉冰川作用的演化历史,还能够为青藏高原的隆升机制提供重要依据.采用野外地貌调查与电子自旋共振测年（ESR）相结合的方法,查明他念他翁山第四纪冰川发育的地貌特点,并初步对研究区的冰期系列进行划分.结果显示,他念他翁山中段古冰川类型主要为山麓冰川、山谷冰川和冰斗冰川.晚第四纪以来至少经历了4次冰川作用,分别为倒数第二次冰期（MIS 6）,年代为（192±51）~（207±45）ka;末次冰期中期（MIS 3）,年代为（55±8）~（54±9）ka;末次冰盛期（MIS 2）,年代为（25±1）~（38±6）ka,以及全新世新冰期/小冰期（MIS 1）.     

Holocene glacier fluctuations in the middle Canadian Rocky Mountains

Holocene glacial advances in the Banff-Jasper-Yoho area of the Canadian Rocky Mountains have been extremely limited in extent. Limiting ¹⁴C dates from two sites within 1 km of contemporary glaciers of fresh terminal moraines indicate that the late Wisconsin Ice Sheet and valley glaciers disappeared prior to 9660 yr B.P. Two subsequent glacial advances are recognized. The earlier Crowfoot Advance is represented by moraines and rock-glacier deposits overlain by Mazama ash (6600 yr B.P.) and is therefore early Holocene or possibly late Wisconsin in age. The late Neoglacial Cavell Advance of the last few centuries is dated by dendrochronology and lichenometry. In addition, there is fragmentary, undated evidence of intermediate-age advance(s), mainly from rock-glacier deposits. All these advances were of limited extent (1–2 km beyond present ice margins) and the Cavell Advance was usually the most extensive. Major exceptions to this pattern occur only where rock glaciers or extensive ice-cored moraines developed during the earlier advance(s?). These deposits were not overrun by glaciers during the Cavell Advance because of their relatively greater downvalley extent and the physical barrier they presented to subsequent glacial advances. Earlier work which postulated more extensive early Holocene advances in the Canadian Rocky Mountains is shown to have inadequate dating control: Many of the features previously attributed to older Holocene events are late Wisconsin in age.