新西兰黄土和中国黄土的对比研究

根据野外观测和实验室分析,本文详细地论述了新西兰黄土在分布、粒度组成、矿物成分、化学成分、石英砂表面微结构及古土壤等方面的特征,并通过与中国黄土的对比,指出新西兰黄土形成于比较潮湿的气候条件之下,其物源主要来自当地的河流泛滥平原、冰水平原和低海面时的大陆架平原,是风力就地吹扬堆积的产物。     

青海湖南岸全新世黄土地球化学特征及气候环境意义

位于青藏高原东北部的青海湖是我国最大的内陆湖泊，通过湖相沉积进行湖区全新世环境演变研究已取得诸多成果。作者选择青海湖南岸黑马河有绝对年代控制的全新世黄土剖面，利用CaCO2、CaO、MgO和Sr元素组分以及氧、碳同位素等较为可靠的地球化学指标，尝试进行了湖区全新世黄土的分层，探讨了黄土堆积过程中的气候环境演变。结果表明，青海湖南岸的黄土按成土作用强度的不同可分为两层：上部为成土化较弱的黄土层；下部为成土化较高的古土壤层，其仍可进一步分为两个亚层。全新世湖区气候环境的波动在地球化学分布特征中有较强表现。     

镇江地区15000年以来古植被与古气候变化

镇江位于长江下游、宁镇山脉与长江三角洲平原的过渡带上。本区西南为宁镇山脉,三角洲平原展布于本区东侧,隔江与北岸扬州遥相对望。发育在这里的众多黄土沟谷,大多独流入江,江水的涨落,直接影响沟谷发展和沉积物厚度(图1)。     

湖沼学

湖泊学P9512006032119莱州湾南岸巨淀湖沉积地层分析与沉积环境辨识=Sedi-mentary analysis and environmental evolvement of Judian lakein the south coastal plain of Laizhou Bay/韩美,张丽娜∥地理科学.—2005,25(6).—678~682湖相沉积地层中沉积物的岩性特征、粒度特征和孢粉组合特征具有良好的环境指示作用,本文对位于莱州湾南岸平原上的巨淀湖沉积地层进行了研究.通过对沉积物的岩性特征和粒度特征进行分析,划分出了湖区的垂向沉积序列.通过地层对比并结合14C测年数据,确定了湖区全新世泻湖浅海海滩相沉积层的层位和特征,并对该…     

粒度揭示的末次间冰期以来长江中游风沙-风尘体系

对长江中游地区定山-太平断面上砂山砂与下风向5个黄土剖面黄土进行了详细的粒度分析,并与其他地区黄土进行对比。结果表明:(1)粒度象和粒度参数特点显示赣北定山-太平断面砂山下风向的黄土状土为风积成土;(2)定山-太平断面的砂山砂-砂山淤泥-黄土粒度特征的渐变过渡,指示了其沉积上的渐变过渡关系。结合区域各沉积相的年代序列认为,末次间冰期以来,长江河谷、漫滩等松散碎屑物在冬季风分选下,粗颗粒物质以砂山形式在其下风向不远处沉积,而剥离出的细颗粒物质则被颠扬到较远的下风向以黄土的形式堆积,从而在区域上形成一个以砂山砂和黄土为主的风沙-风尘沉积体系。     

近2000年来内蒙后套平原黄河河道演变

通过遥感影像、地貌沉积、历史文献与地图等相关资料分析集成研究,将后套平原分为西部冲积扇平原,东部是泛滥冲积平原,并详细探讨了近2000年来本区黄河河道的演变。公元前2世纪时,后套西部平原南 (上) 冲积扇停止发育, 北(下) 冲积扇河道发育,黄河主河道的位置与现代不同,它偏于泛滥平原北部的阴山山前东流;公元6世纪后套平原西部北 冲积扇上黄河河道向东移,在东部泛滥平原上黄河明显地分为南北两汊,而黄河主流仍位于河套平原北部山前;18世纪早期至末期,黄河主河道从河套平原的北部山前南移至平原南部;19世纪中叶‘北河’淤塞,现代黄河形成。     

泥河湾盆地的水下黄土堆积及其古气候意义

本文论述了泥河湾盆地第四纪河湖相地层中水下黄土堆积的特征，认为水下黄土堆积是介于气下黄土堆积河湖相沉积之间的一种过渡类型，水下黄土和气下黄土都是干冷气候条件下的产物，而河湖相沉积则形成于相对温湿的气候环境。在沉积剖面中水下黄土和河湖相沉积交替出现，形成水下黄土－河湖相沉积系列，这个系列反映了气候的周期性变化，它可以与我国洛川剖面的黄土－古土壤系列及深海岩芯V28－239的氧同侠素气候期，很好地进行对比。这为我国华北第四纪古气候地层序列的建立，又提供了一个重要的途径。     

黄土高原南部晚更新世黄土古土壤与气候变迁

本文对黄土高原南部晚更新世黄土地层作了详细划分。根据武功、洛川黄土剖面构地层结构、地球化学和孢粉分析，确定了形成的黄土荒漠草原和平草原寒冷干旱环境，形成的古土壤落叶阔叶林或森林草原温暖湿润环境。阐明晚更新世黄土高原南部有六个土壤、植被和气候演他阶段，并将其归纳为约四万年为周期的三个暖湿—冷干气候变化旋回，与地层剖面上交替出现的三层古土壤与三层黄土相对应。通过与我国东部和北半球各地不同类型古气候记录的对比，证明黄土高原南部晚更新世黄土记录的气候变化规律在北半球具有普遍性。     

郑州地区褐土水分状况的初步分析

一、自然条件与褐土性状 郑州地区位于河南中部,处在山前冲积扇与黄河冲积平原交接地带,是丘陵地向平原过渡地段。在行政区划上包括市区、郊区和荥阳县。该区北临黄河、东连中牟,南接新、密两县,西与巩县毗连。 地势自西南向东北倾斜,西南荥阳边境海拔500余米,而东部圃田公社海拔仅80余米;以京广线为界,以西地势坡度大,以东坡度小。地势是由南、西、北三面向中部倾斜,且由西向东逐渐降低,略呈向东开口的簸箕形。南部为黄土复盖山地,特别是荥阳南部     

莱州湾南岸平原地面古河道研究

利用综合方法对莱州湾南岸平原地面古河道做了系统研究,发现并验证地面古河道２５条,按形成时代将其分为两期,其中,早一中全新世古河道６条,历史时期古河道１９条,按地貌形态将其为４种类型,包括高地古河道带,条状高地古河道,槽状洼地古河道和古河槽,其中条状高地古河道为该区主要的古河道类型。     

The paleogeographic implications of loess mounds: Laizhou Bay plain

The loess mounds are a newly discovered type of landforms on the Laizhou Bay plain south of the Bohai Sea. Research shows that they were formed in the late period of the late Pleistocene when the Bohai Sea was exposed in the period of late Wümu glacial age and changed into plain. As the exposed area is not protected by vegetation, the sediments at the sea bottom are blown and transported southward by strong north winds, and deposit on the coastal plains. As thick loess is accumulated, the loess mound landforms are formed in the direction of down wind.     

The paleogeographic implications of loess mounds: Laizhou Bay plain

Loess mounds are made of gray-yellow loess materials and the number is over 200 in the area of over 1000 km2 on the alluvial or marine-built plains south of Laizhou Bay (Figure 1). 1 The formal and distributional characteristics of loess mounds 1.1 Formal characteristics The plane forms of loess mounds are irregular oval or round. Their major axes are in north-south trending, most of them are 300 to 500 m long, with smaller ones tens m long, and individual larger ones more than 1,000 m …     

Environmental evolution in the salt-water intru-sion area south of Laizhou Bay since late Pleisto-cene

The south coastal plain of Laizhou Bay is one of the typical salt-water intrusion areas in China, the occurrence and development of which was closely related with the pa-laeoenvironment evolution. Systematic analyses of pollen, foraminifera and grain size com-position based on 14C and luminescence dating from two sediment cores were performed for the purpose of understanding the salt-water intrusion in the coastal plain of Laizhou Bay from the perspective of environmental evolution since late Pleistocene. It could be classified into seven evolution stages since 120 kaBP: 120–85 kaBP was a transition period from cold to warm; 85–76 kaBP was a period with warm and wet climate having swamp lakes developed in the lower reaches of the Weihe River, south coastal plain of Laizhou Bay; 76–50 kaBP was characterized by grassland vegetation and coarse sediments in terrestrial environment, which was the early stage of Dali Ice-Age; 50–24 kaBP was a period with alternate sea deposition in the south coastal plain of Laizhou Bay; 24–10 kaBP was the late stage of Dali Ice-Age with coldest period of Quaternary, the south coastal plain of Laizhou Bay was dry grassland and loess deposition environment; 10–4 kaBP was another warm and wet climate period, sea level was high and regressed at 4 kaBP; and has been the modern sedimentary environment since 4 kaBP. Among the three warm stages, including 85–76 kaBP, 50–24 kaBP and 10–4 kaBP, corresponded to late Yangkou, Guangrao and Kenli seawater transgression respec-tively. The duration of the latter one in south coastal plain of Laizhou Bay was longer than that in west coast of Bohai Sea and east coast of Laizhou Bay. The three periods of seawater transgression formed the foundation of salt-water intrusion in this area.     

莱洲湾南岸咸水入侵区晚更新世以来的古环境演变

The south coastal plain of Laizhou Bay is one of the typical salt-water intrusion areas in China, the occurrence and development of which was closely related with the palaeoenvironment evolution. Systematic analyses of pollen, foraminifera and grain size composition based on ^14C and luminescence dating from two sediment cores were performed for the purpose of understanding the salt-water intrusion in the coastal plain of Laizhou Bay from the perspective of environmental evolution since late Pleistocene. It could be classified into seven evolution stages since 120 kaBP： 120-85 kaBP was a transition period from cold to warm; 85-76 kaBP was a period with warm and wet climate having swamp lakes developed in the lower reaches of the Weihe River, south coastal plain of Laizhou Bay; 76-50 kaBP was characterized by grassland vegetation and coarse sediments in terrestrial environment, which was the early stage of Dali Ice-Age; 50-24 kaBP was a period with alternate sea deposition in the south coastal plain of Laizhou Bay; 24-10 kaBP was the late stage of Dali Ice-Age with coldest period of Quaternary, the south coastal plain of Laizhou Bay was dry grassland and loess deposition environment; 10-4 kaBP was another warm and wet climate period, sea level was high and regressed at 4 kaBP; and has been the modern sedimentary environment since 4 kaBP. Among the three warm stages, including 85-76 kaBP, 50-24 kaBP and 10-4 kaBP, corresponded to late Yangkou, Guangrao and Kenli seawater transgression respectively. The duration of the latter one in south coastal plain of Laizhou Bay was longer than that in west coast of Bohai Sea and east coast of Laizhou Bay. The three periods of seawater transgression formed the foundation of salt-water intrusion in this area.     

辽南滨海黄土粒度环境信息高分辨率研究

对辽南滨海黄土粒度研究证明 ,滨海黄土是在第四纪冰期寒冷气候下的产物 ,但是 ,由于滨海黄土所处靠近沿海的地理位置使得这种黄土的形成机制具有独特性。冰期时渤海湾西岸海面下降出露的冲洪积物和海底砂是滨海黄土除西北内陆地区以外的另一重要物源 ,搬运以风砂跃移方式进行。滨海黄土的粒度中包涵了丰富的有关渤海湾海面变化的信息。辽南滨海黄土剖面中的粒度拟合值、 2 - 3Ф粒级百分含量反映了渤海的海退、海侵过程和末次冰期蒙古高压的强弱 ,这种变化与滨海黄土 3个孢粉组合带所反映的古气候环境相吻合 ,同邻近地区的海面升降变化和深海岩芯氧同位素阶段也存在良好的对应关系 ,滨海黄土粒度的拟合度是本区古环境变化的重要的替代指标。     

黄土丘陵地貌形成模式与地貌演变

通过对陕西北部典型黄土丘陵区地貌调查,提出了黄土丘陵地貌形成模式,并对地貌演变进行了探讨。黄土高原原生黄土丘陵分布广泛,主要在下伏古丘陵基础上由黄土加积而成;次生黄土丘陵是黄土塬、黄土台塬等经沟谷侵蚀、改造而成。黄土丘陵区河流阶地和沟谷层状地貌反映了河流、沟谷的形成与演变。黄河一级支流形成于早更新世末;早中更新世末、晚中更新世初黄河一级支流和较大的二级支流形成了较完整的水系;中更新世末如韭园沟等较大的沟谷形成;晚更新世末河网、沟谷格局与现在已基本一致;尚未切入基岩的冲沟多形成于全新世;长度百米至数十米的切沟多是历史时期或近几十年来形成的。     

陇东合水县塬梁峁地貌分类及演化

黄土地貌是按独特的演化模式形成当今复杂多样且有序分异的地貌形态组合。基于数学形态法将合水县地区黄土地貌分类并计算得出塬梁峁地貌单元的分类指标,再通过黄土地貌单元的形态特征及分类指标,对黄土塬梁峁地貌演化模式作出定量化和可视化表达,并预测塬即将消失的区域。研究发现：① 似圆度是界定黄土地貌单元演化进程的重要指标,黄土地貌单元在演化过程中,其形状规律程度逐渐增加;可用周长面积比和平均坡度界定塬梁的分界,可用边界临接指数界定梁峁的分界。② 塬向梁演化实质就是残塬向树杈梁演化。残塬是人类赖以生存的地貌单元,是固沟保塬工程的重点实施对象。     

全新世以来苏南地区的古地理演变

本文以全新世以来古气候演变的影响为主,论述海面升降变化,引起苏南地区全新世早、中、晚期的古地理演变。文中综合前人研究成果,笔者野外考察资料,重点阐明全新世中期的两大泻湖及其以后的发展演变。     

基于DEM的黄土塬形态特征分析及发育阶段划分

基于DEM的地形分析方法已被广泛应用于地貌学研究中,但当前研究以定性或半定量居多,利用各类参数对大面积区域的量化分析研究较少。本文以黄土高原为研究区,利用GIS 及DEM地形分析方法,将坡度小于15°的正地貌提取出来,然后利用坡度与起伏度结合分析得到黄土塬顶面,两者相减得到黄土塬坡面,最终提取黄土塬1106 个;选取黄土塬核心区的106 个样本,分别计算坡面平均坡度、顶面长短轴比、沟壑密度、顶面与底面比、地面裂度5 个指标,然后对其分别进行等级划分,计算5 个指标的几何平均值,作为评价研究区黄土塬相对年龄的指标;对组合指标（I）进行分析后,将其划分为3 级,分别为早期（I<1.74）、中期（1.74≤I<2.12）和晚期（I≥2.12）。研究结果显示,在黄土塬的不同发育阶段,各个形态指标整体上存在差异,各子类型内部也存在发育先后不一致的情况。在对黄土塬各子类型计算发育阶段指数之后发现,从黄土塬、黄土残塬到黄土梁塬,I值逐渐增大。形态指标的有序变化与前人研究所得的黄土地貌发育过程十分一致。     

Earth surface processes and their effects on human behavior in monsoonal China during the Pleistocene-Holocene epochs

There is a wide diversity of landforms in China. The topography of three major terraces, decreasing in height stepwise from west to east, was formed by the early Miocene. With the commencement of the Great Northern Hemisphere Glaciations (GHGs) and the glacial-interglacial cycles in the Pleistocene, thick loess deposits accumulated in north China, and fluvial terraces were formed and lakes expanded and contracted in eastern and central China. The earliest evidence of hominins in China is dated to ～1.7 Ma; they occupied the monsoon-dominated region for a long interval, until the late Pleistocene, ～50 ka. In this study, we investigated a large area rich in the relics and artifacts of early man. The results indicate that the early humans occupied riverine areas, especially medium-sized fluvial basins, and lake shores. Even in the relatively recent geological past, the occupation and abandonment of settlements were directly forced by the shifting of sand dune fields in the desert-loess transitional zone, which in turn was closely associated with variations in the monsoon climate and vegetation patterns. Our observations indicate that landforms were one of the main determinants of early human behavior, in that loess tableland, large alluvial plains, desert-Gobi areas, and the Tibetan Plateau, were not suitable environments for early human settlement. We infer that the early humans in China adapted their behavior to specific landforms and landform processes. The monsoon climate, which shapes the large-scale step-like pattern of fluvial landforms, promotes vegetation coverage and dominates soil formation, provides a crucial context for early human adaptation. The adaptation of early humans to earth surface processes in East Asia is investigated for the first time in this study. Future investigations will provide further information that will increase our understanding of the linkage between early human behavior and landform processes in East Asia.