A comparison of mineral magnetic, geochemical and mineralogical techniques for compositional studies of glacial diamictons

Data from heavy mineral analysis, X-ray fluorescence spectrometry (XRF) and X-ray diffractrometry (XRD) are compared with those obtained from mineral magnetic analysis for a range of glacial diamicton samples taken from the Quaternary sequence in the Isle of Man. These data show that the mineral magnetic approach offers a useful means of characterizing glacial sediments for purposes of lithostratigraphic correlation and provenance indication and that the magnetic data are of a comparable quality to those obtained from standard applications of the more traditional techniques. The heavy mineral and XRD data indicate that little post-depositional chemical alteration of the detrital composition of the sediments has taken place. The mineral magnetic, heavy mineral and XRF analysis suggests both similar lithostratigraphic relationships between the various diamicton units and consistent indications of their likely provenance. These are consistent with published, field-based, stratigraphic relationships of the same sediments and ice-flow directions in the Irish Sea Basin during the Devensian.     

Discovery and Significance of Quaternary Glacial Vestiges in the Hexigten Area of the Southern Da Hinggan Mountains, Inner Mongolia

1 Introduction Hexigten is situated at the eastern part of the Inner Mongolian Plateau, south of the Da Hinggan Mountains and northwest of Chifeng City, Inner Mongolia, China. It is also at the junction of the Da Hinggan Mountians, Inner Mongolian Plateau and Yanshan Mountains. It is about 650 km north of Beijing. The geographic coordinates are 116?30'?118?20'E and 42?20'?44?10'N (Fig. 1). The elevation range is from 1100 m to 1700 m, and the highest peak (2029 m) of the Da Hinggan…     

A new map of glacigenic features and glacial landsystems in central mainland Nunavut,Canada

A new digital map of glacial geomorphic features and interpreted glacial landsystems was produced for an area covering ~415 000 km² in the Keewatin Sector of the Laurentide Ice Sheet (LIS) in Nunavut. The map integrates information from previous surficial geology maps and >14 000 field stations, and is significantly improved by the detailed inventory of ~152 000 glacigenic features using high-resolution ArcticDEM data and Landsat 8 imagery. From this, we identify and map coherent patterns of landform development (landsystems) between the Manitoba border and the Arctic coast, many of which are entirely new and others that are significantly modified or updated. In particular, we recognize six separate ice streams, including one probable remnant ice stream, and we delineate numerous palimpsest streamlined landscapes with associated ice-flow trends and relative ages. A continuum of relict terrains with varying basal ice thermal conditions is mapped for the first time in the ice divide migration zone between Baker Lake and Wager Bay. In addition, deglacial cold-based retreat terrains and preserved warm-based landscapes unaffected by younger glacial events have been identified. These new georeferenced, multi-scale data sets and interpreted glacial landsystems provide a comprehensive framework to strengthen reconstructions of the glacial history and dynamics of one of the largest ice domes of the LIS, identify distinct glacial sediment transport paths for applications to mineral exploration, and test numerical modelling of the LIS in support of climate change studies and long-term evolution of modern ice sheets.     

神农架地区第四纪冰川遗迹与冰期划分

神农架是中国第四纪地质环境演变的热点地区之一。本文通过对第四纪冰川地貌、冰碛残迹及二者关系研究,提供了本区第四纪古冰川发育的多方面证据。神农架地区在第四纪时期曾发生三期冰期和两期冰缘期,即松柏冰期、木鱼坪冰期、龙潭冰期、松香坪冰缘期、神农架冰缘期。本文首次系统地建立了本区第四纪气候地层系列.      

The glacial topography in the area of the middle-lower reaches of the Yangtze river

The Quaternary glacial landforms, such as cirques, glacial troughs, rockdrumlins and lateral moraines are discovered in the area of the middle-lower reaches of the Yangtze river. The isograms of gravels in the moraines reveal that the a-axes of the gravels are mostly parallel to the trends of the valleys. The inclinations of the a-axes of the gravels are 18°–23°. The tendency of the ab-pianes is varied. The inclinations of ab-planes are 15°–20°. The fine grains in the moraines are of bimodal form in the size-frequency curves. The surface of the quartz grains of the moraines possess typical characteristics of glacial sands. Based on the feature of glacial landforms and the data of analysis of the experiment in the laboratory, authors divide the climatic period of Quaternary in this area into four glacial stages.     

Ice-flow evolution of the Labrador Sector of the Laurentide Ice Sheet: a review,with new evidence from northern Quebec

Outcrops bearing stained, striated facets indicative of north–northeastward moving ice, truncated by unstained, striated facets indicative of various younger flows occur in the Caniapiscau area of north–central Quebec. This is the first report of differential staining of striated facets in the region. We propose that the staining occurred in an ice-free interval of probable interglacial age. This early ice flow probably occurred during ice retreat toward the Quebec highlands. Ice flow and glacial transport data from the southern Hudson Bay and James Bay basins indicate that the next major regional ice flow was toward the northwest and resulted from the expansion of an Early Wisconsinan glacier in the Quebec highlands. The northern part of this flow was diverted northwestward through Hudson Bay, and the southern part southwestward across James Bay, following a progressive counterclockwise rotation of flow. A zone of intersection (ZI) of two major glacier bedform systems, often referred to as the horseshoe-shaped Labrador Ice Divide, represents the head of a large northward convergent ice-flow system that extended to Ungava Bay and beyond. The Ungava flow propagated southward and captured the head of the opposing flow from an outflow centre located east of Caniaspiscau reservoir. We propose that this capture event correlates with the Gold Cove Advance in Ungava Bay and on Baffin Island at about 9900 14C yr BP. It is the largest advance of Quebec-Labrador ice yet proposed for the region. This correlation is based on the relative ice-flow chronology, accommodation of glacial lakes Naskaupi and McLean in the deglaciation sequence, the constraints placed on Last Glacial Maximum (LGM) ice configuration by the postglacial uplift pattern and events in the deep-sea record. Therefore, the Ungava ice-flow pattern is not a relict pre-Wisconsinan glacial landscape as recently proposed.     

Late Weichselian geology of southernmost Sweden

The area of study is strategically placed 250–500 km inside the border of the Weichselian glaciation. The low relief of the area, the surrounding of a shallow sea and the varying bedrock have all influenced the physical nature of the ice. Different methods, including analyses of reworked microfossils, have been used to produce a new informal lithostratigraphy for the area. The glacial striae have been studied and grouped according to orientation and relative age. Correlation is drawn between the ice-flow pattern determined by the lithostratigraphy and the pattern determined by the glacial striae. The correlation shows the general ice flow during the different glacial events in he Late Weichselian. It is possible to broadly correlate these events with the events in Denmark. The record of glacial advances between 21,000 and 13,000 B.P. starts and ends with an ice stream following the topographyy of the Baltic. The ice streams show low profile and longitudinal axial, lobatic flow. The flow pattern during the Main Weichselian advance indicates a radially flowing dome over the mainland. There is no geologic evidence of separate ice domes in the southern Baltic during the Late Weichselian.     

黄河源区第四纪地质研究的新进展

通过对黄河源区的钻孔、自然露头的研究, 建立了黄河源区的第四纪地层层序。第四纪地层可划分为下更新统、中更新统、上更新统和全新统。下更新统为河湖相沉积; 中更新统主要有湖积物、冰碛物和冰水沉积物; 上更新统主要有湖积物、冰碛物、冰水沉积物、洪积物和河流沉积物; 全新统主要由河流沉积物、洪积物和湖积物构成。黄河源区的冰期可划分为3期, 即末次冰期、倒数第二次冰期、倒数第三次冰期, 末次冰期又可分为2个冰阶。黄河源区的湖泊演化可划分为早更新世、中更新世和晚更新世—全新世3个阶段: 早更新世的湖泊范围小; 中更新世的湖泊范围明显扩大, 在位置上也较早更新世的湖泊南移; 晚更新世的湖泊经历了两次的扩张—收缩变化, 到了全新世, 除现今还发育的几个湖泊外, 大多数地区的湖水已退出, 基本上转变为河流环境。在晚更新世末期到全新世初期, 封闭黄河源区的多石峡被切开, 湖水外泄, 现今的黄河形成了, 同时发生了袭夺长江水系的水流。     

西藏札达盆地及周缘高山区第四纪冰川遗迹与冰期的初步划分和对比

札达盆地及周缘高山区的第四纪冰川遗迹分布广泛,类型齐全、发育连续.特征的冰碛及冰水堆积地貌有:冰水堆积平原或冰水堆积平台、冰碛丘陵等.挤压构造遗迹有:褶皱、断裂表皮构造、压坑、压裂构造、变形砾石等.ESR年代测定结果表明,冰碛形成的最大年龄为2.33Ma.依据冰碛、冰水堆积的特征、分布和形成年代等,区域冰川发育由老到新可划分出:7次冰期、6次间冰期、1次冰缘期、1次新冰期.该区是目前所知青藏高原第四纪冰川遗迹发现最多、保存最全和发育最连续的地区,为青藏高原地区的第四纪冰川演化研究、冰期的划分和对比、古气候古环境的研究,提供了重要的实际资料和依据.      

山西宁武吕梁山北段第四纪冰川遗迹的发现及意义

山西宁武吕梁山北段,平均海拔约2000米,相对高差数百米至千米左右,属中山区。第四纪冰川遗迹十分发育,类型多种多样,特征明显。冰川遗迹有:U形谷、刃脊、角峰、冰斗、冰窖及分布于U形谷中的大量冰川漂砾、冰碛、冰水堆积、冰臼、变形砾石、条痕石等。该区古冰川遗迹的大量发现,不仅证明了我国东部中低山区有大量第四纪冰川运动存在,而且冰川规模之大完全出乎人们意料之外。为研究该区古气候、古环境演化提供重要依据,为我国第四纪冰期划分和对比提供重要资料和证据。      

The Nordkalott-Nordqua symposium 1987

The results from a Nordic research project on Quaternary geology, entitled the Nordkalott project, were presented at a symposium in northern Sweden in 1987. Organic deposits and tills in northern Fennoscandia are interpreted as belonging to the Eemian as well as to interstadials and stades of the Weichselian. Retreat of the ice front under cold climatic conditions has been assumed for parts of northern Norway. Ice-dammed lakes formed during the deglaciation period are described from northern Finland. Boreas , Vol. 17, no. 4, consists of articles based on the symposium contributions.     

中国第四纪冰川地质遗迹调查方法综述

第四纪冰川和冰川地质遗迹的研究,是研究第四纪全球气候变化的重要课题之一。中国第四纪冰川地质遗迹分布很广,类型多。最北的大兴安岭、南部的广西大明山、东部的长白山和台湾玉山、最西的喀喇昆仑山第四纪冰川地质遗迹均有分布,是世界上低纬度地区山岳冰川发育最广泛的国家。本文在前人研究的基础上,系统阐述我国第四纪冰川地质遗迹分布概况,结合开展的全国重要地质遗迹调查,以地质遗迹调查规范为基础,系统开展第四纪冰川地质遗迹调查方法研究。根据冰川在运动过程中对地面的侵蚀、冰碛物的搬运和堆积等不同的地质作用阶段,总结我国第四纪冰川地质遗迹调查方法体系,为开展同类地质遗迹调查提供方法指导依据。     

中国第四纪冰川地质遗迹调查方法综述

第四纪冰川和冰川地质遗迹的研究,是研究第四纪全球气候变化的重要课题之一。中国第四纪冰川地质遗迹分布很广,类型多。最北的大兴安岭、南部的广西大明山、东部的长白山和台湾玉山、最西的喀喇昆仑山第四纪冰川地质遗迹均有分布,是世界上低纬度地区山岳冰川发育最广泛的国家。本文在前人研究的基础上,系统阐述我国第四纪冰川地质遗迹分布概况,结合开展的全国重要地质遗迹调查,以地质遗迹调查规范为基础,系统开展第四纪冰川地质遗迹调查方法研究。根据冰川在运动过程中对地面的侵蚀、冰碛物的搬运和堆积等不同的地质作用阶段,总结我国第四纪冰川地质遗迹调查方法体系,为开展同类地质遗迹调查提供方法指导依据。     

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）.     

博格达山北坡第四纪古冰川与新构造运动

本文以三工河为例,将该区划分为高台地冰期(Q_(p1))、洼地冰期(Q_(p2)),天池冰期(Q_(p3)~1)和力行达坂冰期(Q(_p3)~3)。对该区新构运动的性质、类型、特点作了较详细的阐述,并指出新构造运动的间歇期和波动期及其与冰期和间冰期的对应关系。最后运用深部地质资料揭示出博格达山新构造运动的源动力。     

大连红黏土形成期研究

从大连红黏土被第四系松散层所覆盖的现象出发,分析了大连地区沿海岸附近冰碛残丘的特征与形成过程。论证了大连地区陆地和海湾的红黏土都具有聚合沉积的特征,并且确定了大连红黏土形成期是在第四系冰川期之前。此外论证了大连红黏土是大连地区古地理古气候的标志性地层之一。     

北京西山潭柘寺地区第四纪冰川与环境问题

第四纪时期,北京西山潭柘寺地区没有发生过任何山地冰川作用。所渭的冰川遗迹、冰碛、冰水沉积及各种冰蚀地貌,实际上是不存在的。因此,所渭的冰期划分也都是不可靠的。在更新世冰期阶段,北京西山属冰缘环境,而非冰川环境。     

太白山古冰川地貌与地质构造

太白山分布有更新世冰川地形,其冰川槽谷在平面上呈“十”字型排列;横剖面EW向的呈宽谷形,NS向是呈U型:纵剖面EW向比较平坦,SN向呈阶梯状,其中有许多断裂陡坎。冰斗均位于断裂交汇点,面积不大而深度却相当大。这些地形的形态特征可以用构造加以解释,断裂破碎带是最有利于冰川刨蚀的地段。     

中国西南山区第四纪冰川堆积物工程地质分类探讨

中国的大陆冰川堆积物几乎都属于巨粒土或块石（漂石）土、碎石土,但因复杂的物质组成和组构特征,各地或同一地区不同成因类型（冰碛、冰水）的堆积物具有极为不同的工程地质性质,其地质体稳定性和地质灾害的易发性存在着显著的差异。我国已有的工程分类框架不能满足当代冰川堆积物甚至其他碎石土（巨粒土）的工程地质和地质灾害研究的需要。中国西南山区冰川堆积物的物质成分、细观结构等的野外调查和室内测试分析结果表明,冰川堆积物的物质成分和组构特征主要表现为:颗粒组成的不均一性和多元性、组构单元的双元性、结构的无序性和胶结性等。冰川堆积物的物质成分和组构特征与其工程性质具有密切的关系,是冰川堆积物工程地质分类的基础。本文探讨了中国西南山区冰川堆积物的工程地质分类问题,提出基于胶结程度和粒度组成的二级分类方案,对冰川堆积物及其他块（漂）石土的工程地质研究和工程实践具有一定指导意义。