澧阳平原晚更新世晚期至全新世早中期环境演变及其对人类活动的影响

通过对澧阳平原野外调查,多剖面地层对比分析及岩板垱（YBD）剖面样品的粒度、地球化学元素分析和年代测定,揭示该区晚更新世晚期至全新世早中期环境演变,并探讨其对人类活动的影响。研究结果表明,30~6 ka B.P.间,澧阳平原由冲沟发育的黄土台地向河湖发育的平原丘岗地貌过渡;气候环境经历了弱暖湿-气候变差-凉湿-波动回暖-暖湿的变化;更新世末至全新世早期稻作农业的出现与该区的环境条件和文化基础密切相关;环境演变也推动了古人类活动范围和聚落特征的变化。     

Late Devensian and Holocene landscape change in the uplands of the Isle of Man

The Late Glacial and Holocene geomorphology of the Manx uplands has received scant attention in previous researches. Solifluction deposits and terraces provide the earliest evidence for geomorphic activity after deglaciation. Fluvial incision into drift-choked valleys is correlated with the formation of the large mountain front alluvial fans that flank the Manx uplands. Formation of these alluvial fans is constrained to 15,000–10,500 cal. years BP by ¹⁴C dates on organic deposits beneath and above the alluvial fan gravels. Alluvial fan and river terraces along four valleys postdate this incision. Optically Stimulated Luminescence (OSL) and ¹⁴C dating provide a tentative chronology for these landforms. The higher terraces are Late Glacial fluvial surfaces that were probably occupied by rivers into the Holocene. Incision during the Late Holocene led to the abandonment of the higher surfaces, producing a suite of younger river terraces and alluvial fan surfaces. Independent dating constrains this fluvial activity to post-Bronze Age (3500–2800 cal. years BP). Increased human activity and climatic change during the Late Holocene are possible causes for this increased geomorphic activity.     

伶仃洋ZK19孔晚第四纪沉积地球化学特征 及其古环境意义

依据对珠江口伶仃洋海域ZK19孔岩芯材料的沉积学、年代学和沉积地球化学研究,探讨了该海域古环境演变特征。该孔以末次盛冰期风化层为界,存在2个沉积旋回和2次海侵事件。微量元素质量分数、主量元素（Al2O3/Na2O值、MgO/Al2O3值、Sr/Ba值及V/Cr值等）,化学蚀变指数（CIA）和化学风化指数（CIW）的变化特征,反映了MIS4晚期至MIS3初期,该地由陆相向滨海相过渡,气候从偏冷逐渐升温,海平面逐渐上升,但速度较慢;MIS3该地为河口湾相,气候进一步转暖,海平面以较大幅度上升;MIS2阶段（末次盛冰期）海平面大幅下降,气候变冷;MIS1的8―12 cal. ka B.P.气候逐渐转暖,海平面快速上升,为河流相―滨海潮滩相―河口湾浅滩相―河口湾相;中全新世大暖期,受水下滩槽地貌侧向迁移影响,该孔地层遭剥蚀;晚全新世3 cal. ka B.P.以来,气候整体相对稳定,较早全新世温暖,沉积环境依次为河口湾相―三角洲前缘斜坡相―三角洲前缘浅滩相。     

Late Quaternary aggradation rates and stratigraphic architecture of the southern Po Plain,Italy

The Po River Basin, where accumulation and preservation of thick sedimentary packages are enhanced by high rates of tectonic subsidence, represents an ideal site to assess the relations between vertical changes in stratigraphic architecture and sediment accumulation rates. Based on a large stratigraphic database, a markedly contrasting stratigraphy of Late Pleistocene and Holocene deposits is reconstructed from the subsurface of the modern alluvial and coastal plains. Laterally extensive fluvial channel bodies and related pedogenically modified muds of latest Pleistocene age are unconformably overlain by Holocene overbank fines, grading seaward into paralic and nearshore facies associations. In the interfluvial areas, a stiff paleosol, dating at about 12.5–10 cal ky BP, marks the Pleistocene–Holocene boundary. Across this paleosol, aggradation rates (ARs) from 16 radiocarbon‐dated cores invariably show a sharp increase, from 0.1–0.9 mm year^?1 to 0.9–2.9 mm year^?1. Comparatively lower Pleistocene values are inferred to reflect fluvial activity under a low‐accommodation (lowstand and early transgressive) regime, whereas higher ARs during the Holocene are related to increasing accommodation under late transgressive and highstand conditions. Holocene sediment accumulation patterns vary significantly from site to site, and do not exhibit common trends. Very high accumulation rates (20–60 mm year^?1) are indicated by fluvial channel or progradational delta facies, suggesting that extremely variable spatial distribution of Holocene ARs was primarily controlled by autogenic processes, such as fluvial channel avulsion or delta lobe switching. Contrasting AR between uppermost Pleistocene and Holocene deposits also are reported from the interfluves of several coeval, alluvial‐coastal plain systems worldwide, suggesting a key control by allogenic processes. Sediment accumulation curves from adjacent incised valley fills show, instead, variable shapes as a function of the complex mechanisms of valley formation and filling.     

The role of neotectonics and glaciation on terrace formation along the Nysa K odzka River in the Sudeten Mountains (southwestern Poland)

The Nysa K odzka river drainage basin in the Sudeten Mts., SW Poland, preserves a complex late Cainozoic succession that includes eight fluvial series or terraces and deposits from two glacial episodes as well as local volcanic rocks, slope deposits and loess. Fluvial sedimentation took place during the Late Pliocene and from the early Middle Pleistocene (Cromerian), with a long erosion phase (gap) during the Early Pleistocene. Fluvial series are dated to the Late Pliocene, Cromerian, Holsteinian, late Saalian/Eemian, Weichselian, and the Holocene. Glacial deposits represent the early Elsterian and early Saalian stages. Almost all these stratigraphic units have been observed in all geomorphic zones of the river: the mountainous K odzko Basin, the Bardo Mts. (Bardo gorge) and in the mountain foreland. The main phase of tectonic uplift and strong erosion was during the Early Pleistocene. Minor uplift is documented also during the post-early Saalian and probably the post-Elsterian. The post-early Saalian and post-Elstrian uplift phases are probably due to glacio-isostatic rebound. The Quaternary terrace sequence was formed due to base-level changes, epigenetic erosion after glaciations and neotectonic movements. The Cromerian fluvial deposits/terraces do not indicate tectonic influence at all. All other Quaternary terraces indicate clear divergence, and the post-early Saalian terraces also show fault scarps. The fluvial pattern remained stable, once formed during the Pliocene, with only minor changes along the uplifted block along the Bardo gorge, inferring an antecedent origin for the Bardo gorge. Only during the post-glacial times, have epigenetic incisions slightly modified the valley.     

贝加尔地区萨彦山东部Jom-Bolok火山谷湖泊古环境研究（英文）

This article describes the lake basins of the Jom-Bolok volcanic region in the East Sayan(the largest manifestation of the Holocene eruptions in Central Asia). The geomorphological position, origins, aspects of the structure and development are reviewed considering its sedimentary filling. The limnic morphogenesis here develops under the conditions of contrasting relief, high energy of neotectonic and exogenous processes. We established that Lake Khara-Nur, formed as a result of lava-damming of the Jom-Bolok river valley, emerged in its present form approximately 6500 years ago. A complex record on the environment and climatic changes, acquired from its sediments, made it possible to determine for the first time in this region the long-term trends in the development of the Middle and Late Holocene mountain geosystems and also the distinction of several paleogeographic stages of the formation of the natural environment. An average geochemical record resolution for the bottom sediments of the lake was made uniquely for the East Siberian lake records and is equal to 35 years, while the palynological record approximates 110 years.     

旧石器时代至商周时期贵州遗址空间分布及其自然环境背景

根据对贵州230 处遗址的时空变化分析发现, 贵州旧石器时代遗址集中分布在中部、西北部和黔西南等喀斯特发育的高海拔区域。至新石器时代, 遗址仍集中分布在中部、西北部和黔西南地区, 但南部、东部等沿河地带和中西部的山间坝子开始有遗址分布。到商周时期, 遗址主要分布在沿河地带和山间坝子里。其中, 东部和南部海拔低于1000 m的地区遗址多分布在沿河地带, 而西部和北部海拔高于1000 m的地区遗址则分布在山间坝子。贵州位于亚热带湿润气候区, 气候环境的冷暖干湿波动对从事渔猎、采集及原始农业生产的古人类影响不大, 人类居住空间变化更多的与贵州特殊的自然地理背景有关, 特别是喀斯特地貌发育及适宜农业生产地方的空间差异, 对贵州旧石器至商周时期的遗址分布影响显著。旧石器时代人类以采集和渔猎为生, 临近水源的天然溶洞是人类居住的首选。随农业的出现和发展, 便于农耕的沿河地带和山间坝子成为人类的生活居住地。故新石器时代, 贵州先民居住呈现洞穴和河流阶地或山间坝子并存;至商周时期, 农业成为人类的主要经济生产方式, 人类主要居住在沿河地带和山间坝子里。     

"冰臼"是古地貌面上的流水侵蚀遗迹——壶穴——就韩同林《发现冰臼》一书中的资料谈华北北部的"冰臼"

分布在华北北部山顶面上的“冰臼”,无论从地理环境、地貌演化,还是从海拔高度方面分析,都不是第四纪大冰盖的证据,而是古地貌面上流水侵蚀的遗迹。它分布在3个海拔高度不同的山地夷平面上和现代河流谷地内,与当时的地理环境和山地的地貌演化密切相关。未构成山地夷平面前准平原上的河流以河网密集的曲流河为主。随着准平原的抬升,河流也开始下切,下切的河流以溯源侵蚀为主。在源头地区的顺直型谷地中,一是河流流速较急,且挟有数量不多、颗粒较粗的砂砾石;二是源头地区大块石较多,容易形成涡流;三是河水不深,丰水期刚刚没过块石,枯水期块石露出水面。在质地不均的岩体(特别是花岗岩)中,挟带砂砾石的涡流在岩面上形成了壶穴。准平原及壶穴最后被抬升到山地的顶部,构成了山地夷平面。     

黄淮海平原地貌结构特征及其演化

本文对黄淮海平原地貌从地表到地下随时间变化进行了四维空间的研究，着重探讨了平原地貌结构和它的发育、演化规律，为本区地下水资源评价、国土整治和环境保护提供了一定的理论依据。     

一万年来白洋淀的扩张与收缩

本文探讨了一万年来的全新世期间,白洋淀兴起、扩张和收缩的变迁过程,恢复了各个发展阶段的古湖淀范围,论述了相应时期的古环境特征,指出了白洋淀令后的演变趋势。     

巢湖凌家滩遗址古人类活动的地理环境特征

通过对巢湖凌家滩文化遗址的野外勘查、采样和室内磁化率、烧失量、化学元素及光释光年代分析,结合巢湖湖泊岩芯记录的中全新世环境特征、研究区较高分辨率遥感影像和文物考古成果,综合研究表明:古凌家滩人生活于中全新世气候适宜期,其文化的发展和繁荣处在气候由温暖湿润向温和略干转换的过渡阶段;晚更新世末期堆积形成的地面(OSL年代11.6 ±1.0 ka B.P.)是古凌家滩人生活的地貌面,本区古地貌面海拔以及拔河高度与现今不同,这与该区新构造运动沉降和气候-水文因素作用有关;中全新世温暖湿润的气候条件下,太湖山南麓台地被进一步切割为山前长条形岗地与河流相间的地貌形态,遗址所在的长岗岗地是东、西、南三面临水的"半岛"环境,河川相连,便于水运交通、渔猎和水稻种植。     

The late Quaternary evolution of the Negro River, Amazon, Brazil: Implications for island and floodplain formation in large anabranching tropical systems

The Rio Negro has responded significantly in the Late Pleistocene and Holocene to lagged environmental changes largely associated with activity during the last glacial in the Amazon basin. On the basis of geological structure, the Rio Negro can be divided into six distinct reaches that each reflects very marked differential processes and geomorphological styles. No deposits of the Upper Pleniglacial were recognized in the field. The oldest recognizable Late Pleistocene alluvial unit is the Upper Terrace of Middle Pleniglacial age (ca. 65–25 ka) (reach I), tentatively correlated with the oldest terrace identified on the left bank of reach III. At that time, the river was mainly an aggradational bed load system carrying abundant quartz sand, a product of more seasonal conditions in the upper catchment. The late glacial (14–10 ka) is represented by a lower finer-grained terrace along the upper basin (reach I), which was recognized in the Tiquié, Curicuriarí, and Vaupes rivers. At that time, the river carried abundant suspended load as a response to climatic changes associated with deglaciation.Since about 14 ka, the river has behaved as a progradational system, infilling in downstream series a sequence of structurally controlled sedimentary basins or ‘compartments,’ creating alluvial floodplains and associated anabranching channel systems. Reach II was the first to be filled, then reach III, both accumulating mainly sand. Fine deposits increase downstream in reach III and become predominant in some anabranch islands of the distal reach. The lowermost reaches of the Negro (V and VI) have been greatly affected by a rising base level and associated backwater effect from aggradation of the Amazon during late glacial and recent times. Reach V has acted almost entirely as a fine sediment trap. The remarkable Anavilhanas archipelago is the product of Holocene deposition in the upper part of this sedimentary basin; however, suspended sediment load declined about 1.5 ka, prior to the lower part of this basin becoming infilled.The progradational behavior of the Rio Negro, filling tectonic basins as successive sediment traps with sand in the upper basins and fines in the downstream ones, illustrates how a large river system responses to profound changes in Late Quaternary base level and sediment supply. The most stable equilibrium conditions have been achieved in the Holocene in reaches IIb and IIIa, where an anabranching channel and erosional–relictual island system relatively efficiently convey water and sediment downstream. Reaches IIIb and V never achieved equilibrium conditions during the Holocene, characterised as they are today with incomplete floodplains and open water.     

华北平原中部晚上新世以来沉积物碳氧同位素特征及其古环境意义

利用华北平原中部衡水水文地质科研深孔的岩芯,对平原区古土壤钙结核层碳氧同位素组分的古气候环境意义及相关气候指标的定量转换进行探讨,发现碳氧同位素对古气候变化具有较好的响应关系:3.5MaB.P.以来华北平原古气候逐渐由湿润转向干旱,早更新世由多个干湿冷暖旋回组成,晚期气候由暖迅速转凉;中更新世气候略温和,由3个冷干-暖湿旋回组成;晚更新世气候变化趋势为湿润-干燥-湿润,总体上呈现增温趋势。进入全新世后,δ13C平均值(-5)较低,属于相对湿润期;δ18 O平均值(-9.5)较低,属于相对寒冷期。应用相关公式可以定量恢复古温度变化,但平原区古土壤层受后期地下水作用的影响较大,如何消除这一影响还需更多数据支持。     

中国热带第四纪动物群与气候波动

中国热带第四纪动物群的70多个实例约有40%出现在冷期,反映气候波动幅度较小.动物群的时空分布可以佐证早更新世气候波动的2个主旋回、中更新世的3个主旋回、晚更新世的2个主旋回和全新世大暖期.末次冰期和新冰期未曾危及热带动物群的生存.历史时期的冷波动使动物逐步南迁,但其绝迹主要是受人为因素影响.     

Holocene geomorphology,tectonics, and archaeology in Barrancas,arid Central Andes piedmont (33°S)

Archaeology and geomorphology are closely linked in Barrancas, Argentina, where both disciplines are necessary to understand human–environment interactions during the Holocene. The geomorphology suggests that the area was located in a distal alluvial environment of the Zonda paleo-river that drained to the east. Active tectonics during the Pliocene-Early Pleistocene caused the gradual uplift of the Lunlunta Sierras to the southwest, which led to the bifurcation of the paleo-river. For most of the Holocene, the area was seasonally flooded, suggesting a lacustrine microenvironment. A long record of human occupation beginning in the Early Holocene suggests an extended period of intimate human–environment interactions. Recently, the environment has shifted dramatically. Erosion has created a badlands and significantly impacted the archaeological record. Understanding geomorphological processes is central for archaeological research in general, and especially in Barrancas. This research is an integral part of the ongoing community archaeology program in the area, and for the planned creation of an archaeological reserve.     

Non-synchronous response of adjacent floodplain systems to Holocene environmental change

Two adjacent upland floodplains are compared to establish the local response of floodplains to environmental change. Radiocarbon dating, the analysis of sedimentary exposures, terrace mapping, aerial photography and archaeological evidence are used to examine Late Quaternary valley fill sediments on the Afon Tanat and the Afon Vymwy in the Upper Severn Basin, Wales, UK.The alluvial stratigraphy of the two floodplain systems consists of Late Devensian (last glacial) fluvio-glacial sediments at the valley margins deposited under a braided outwash river regime. Holocene age terraces, with floodplain and palaeochannel deposits composed of gravels overlain by silty-sands, are inset into this older unit and were formed by meandering fluvial channel systems. A combination of field and laboratory data demonstrates that from the mid-late Holocene the two floodplain systems had divergent development. The Afon Vyrnwy has remained vertically stable for the last ca. 4000 yrs. whereas the adjacent Afon Tanat continued to be vertically and laterally active.Both floodplain systems have been affected by Late Quaternary climatic fluctuations and anthropogenic activity from the Bronze Age to the Roman period, but local geomorphic gradient controls, combined with a possibly greater focus of anthropogenic activity in the Tanat catchment, may explain the differential evolution of the two systems. The data demonstrate that multiple reach-scale studies are essential for revealing significant stages in the chronology and historical development of fluvial systems.     

Soil-stratigraphic techniques in the study of soil and landform evolution across the Southern Alps, New Zealand

The Southern Alps lie along the convergent Pacific-Indian plate boundary. Geomorphically distinct eastern, axial and western regions reflect the east-west gradient in tectonic uplift (1 to 10 mm a⁻¹) and precipitation (600 to 10,000 mm a⁻¹). The eastern region is divided into front-ange and basin-and-range subregions. Soil-sequence studies on terraces established temporal contrasts in pedogenesis within and between eastern and western regions encompassing Entisols, Inceptisols and Spodosols. On Late Pleistocene and early Holocene terraces Dystrochrepts are persistent soils in the eastern region and Aquods in the western region. These soil sequences are used in the interpretation of relative soil age, stratigraphy and erosion history in hill and mountain drainage basins of the eastern and western regions. In the subhumid to humid eastern front-range subregion, simple soil forms occur as catenary sequences, and there is little evidence of erosion following the destruction of forests in the last millenium. Mollisols are dominant in the subhumid, and Dystrochrepts in humid areas, respectively. Soil-debris mantle regoliths date from the early Holocene and are still developing on slopes. The soil pattern on mountain slopes in the humid, eastern basin-and-range subregion is a complex array of simple, eroded, composite and compound soils. This pattern has resulted from erosion following forest destruction within the last millenium. The oldest surface or buried forest soils are Dystrochrepts dating from the Late Pleistocene to early Holocene. Wind erosion of these low-fertility soils contributes to the loessial sediments in which younger soils have formed. In the western region, soil patterns and soil stratigraphy indicate continous instability with a complex pattern of highly leached, shallow Orthents and bedrock outcrops on slopes. The soils are eroded from slopes within 2 ka. These contrasts in soil development and erosion periodicity in the eastern and western regions of the Southern Alps parallel the east-west contrasts in erosion rates of ca. 1–10 mm a⁻¹.     

白洋淀地区晚冰期以来的气候和环境演变

华北平原晚冰期以来气候环境演变研究对该地区社会发展、灾害风险评估和科学应对未来全球增温背景下极端降水和洪涝事件具有重要意义。本文以华北平原中部白洋淀地区高阳剖面（BG-2019）为研究对象,通过高精度AMS¹⁴C、OSL定年技术和高分辨率孢粉组合、粒度组分分析,恢复和重建了白洋淀地区晚冰期以来（距今13710 a—今）区域植被演替和气候环境变化历史。结果显示：BG-2019剖面在距今10270~13710 a和距今4630~5400 a发育湖相沉积,距今3470~3700 a发育沼泽相沉积;距今7130~8000 a发育河流—入湖三角洲相沉积,距今3700~4630 a和距今3230~3470 a发育河流相沉积;距今8000~10270 a和距今5400~7130 a存在明显的沉积间断/地层缺失;表明采样剖面所在位置缺乏连续的湖相地层。晚冰期白洋淀为局地小湖沼;中全新世湖沼较发育、范围广,但也不是连续广袤的湖相沉积;晚全新世湖泊范围收缩。晚冰期和全新世白洋淀流域植被景观存在显著差异;晚冰期气候寒冷干燥,平原发育以蒿属、藜亚科、禾本科和菊科等为主的草地,周围山地森林覆盖度低;中全新世气候温暖湿润,平原大部仍发育以蒿属、藜亚科和禾本科为主的草地,湖区水蕨和水生植物繁盛,周围山地生长松属、栎属为主的针阔混交林,森林覆盖度增高;晚全新世气候温和偏干,平原仍是以蒿属、藜亚科和禾本科等为主的草地,西部山地生长以松属为主的针阔混交林,森林覆盖度较高。     

GEOMORPHOLOGICAL EVIDENCE OF INTENSE PREHISTORIC SOIL EROSION IN THE HIGHLANDS OF CENTRAL JORDAN

Soils and alluvial sediments in two wadi systems provide preliminary evidence of intense prehistoric soil erosion in the Plateau of Central Jordan. Magnetic susceptibility, color, secondary carbonate morphology, and soil structure suggest that, at the end of the Pleistocene, red Mediterranean soils (terra rossa soils) extended into areas that today are dry steppes on desert fringes. The chronological correlation between alluvial depositional events and cultural phases in the context of climatic change in the Levant suggests that climatic fluctuations at the end of the Pleistocene, which were characterized by gradual drying and warming, triggered several consecutive cycles of soil erosion. There is also evidence to suggest that the advent of early farming in the early Holocene played an important role in the continuation of soil erosion processes. The results of this preliminary research suggest that studies of ancient soil erosion in this region, red Mediterranean soils are a useful chronological and pedological datum to be correlated with alluvial and colluvial deposits. [Key words: soil erosion, alluvial sequences, red Mediterranean soils, Levant, Jordan, Middle East, soil properties.]     

Pre-farming environment and OSL chronology in the Negev Highlands,Israel

The ancient agriculture in the southern Levant is very much dependant on the interaction between the geological and geomorphological characteristics of the desert environment and the arid climatic conditions. Field observations and luminescence dating in the Negev Highlands, southern Israel, indicate that deposition of fluvio-loess sediments occurred mainly during the late Pleistocene glacial period. These sediments, which were transformed into loessy soil, support a high natural biomass and have an agricultural potential. Major soil erosion started after 27 ka, exposing bedrock, increasing runoff and erosion. These feedback processes were intensified during the Holocene. Since the mid Holocene, the co-existence of soil and runoff created a unique setup which enabled the establishment of desert agriculture in the southern Levant, based on runoff-harvesting techniques. Extensive construction of stone terrace walls on top of diachronous middle–late Holocene alluvial units in the less degraded valleys led to the deposition of the anthropogenic unit, consisting of fine grained re-deposited loess as a by-product of the flood irrigation. This process contributed to soil conservation and counteracted the continuous natural soil erosion and desertification. The ability to practice desert agriculture is still preserved in the southern Levant, and historic climate changes are not required to explain the rise and fall of the great farming cultures.