地貌学基础理论继承与创新的一部范例著作——读《华北山地地形面地文期与地貌发育史》

大学时代 ,任美锷、杨怀仁老师教我们地貌学 ,学习了台维斯、彭克等大师的地貌学理论 ,核心就是夷平面、地文期与地貌发育史原理。大学毕业后 ,到中国科学院地理研究所与吴忱同志一起 ,师从罗来兴先生。我们共同在川西滇北地区作野外考察 ,对区域地貌中的夷平面涉猎较多。去年 ,一直在河北省科学院地理研究所工作的吴忱同志 ,送我一本他毕生研究的力著———《华北山地地形面地文期与地貌发育史》一书。喜读之下 ,学到了不少东西。现略作汇总评述。1　惊喜与感慨读了吴忱研究员等人的专著《华北山地地形面地文期与地貌发育史》一书 ,惊喜之…     

华北地文期命名之新见

依据山地侵蚀与平原堆积是一个地文期的两种不同表现形式，以山地侵蚀期与平原粗(包括底部的不整合面)、细(包括表层的风化壳或古土壤)粒物质堆积期相关的原则，对华北地区新生代地文期进行重新命名。晚白垩纪地文期是北台期侵蚀一卢沟桥、无极期堆积，早第三纪地文期是甸子梁期侵蚀—孔店、沙河街期堆积，晚第三纪地文期是唐县期侵蚀—馆陶、明化镇期堆积，早更新世地文期是汾河期侵蚀一固安期堆积，中更新世地文期是湟水期侵蚀—杨柳青期堆积，晚更新世地文期是清水期侵蚀一欧庄期堆积，早、中全新世地文期是板桥期侵蚀—杨家寺、高湾期堆积，晚全新世地文期是段曲期侵蚀一岐口期堆积。     

再论华北山地甸子梁期夷平面及早第三纪地文期

华北山地海拔１０００ｍ以上的山顶面不是一个连续的面，而是两个面，由不同时期的差别侵蚀形成。其中，海拔３０００—２５００ｍ的山顶面是北台面，形成于古新世，代表中生代地文期的结束；海拔２２００—１０００ｍ的山腰面是甸子梁面，形成于渐新世，代表早第三纪地文期的结束。     

湘桂黔滇藏红色岩溶风化壳发育模式

基于对湘，桂、黔，滇，藏等地岩溶区红色风化壳的野外和室内研究，从表生地貌学，粘土矿物学和地球化学角度分析红色石灰土性质与地貌演化的关系，提出红色岩溶风化壳发育的二阶段模式；1）地貌夷平-风化物质积累阶段，在地貌演化过程中溶蚀残余物质不断积累，最后在夷平面上形成厚层连续的泥质风化壳，夷平面的地貌水文条件有利于粘粒的形成和保存，但限制了富铝化作用的有效进行，造就了岩溶风化壳粘粒含量高，富铝化程度低的特点，这与研究区23个红色岩溶风化壳剖面化学，粒度特征和粘土矿物组合特点一致。2）地貌切割-风化壳淋溶阶段，原始夷平面上的风化壳大多呈灰色，只有在构造隆升和地表微切割导致地下水位降低，淋溶条件开始改善的情况下，风化壳才有可能枞根本上转为红色。     

再论华北山地甸子梁期夷平面及早第三纪地文期

华北山地海拔１０００ｍ以上的山顶面不是一个连续的面，而是两上面，由不同时期的差别侵蚀形成。其中，海拔３０００－２５００ｍ的山顶顺是北台面，形成于古新世，代表中生代地文期的结束；海拔２２００－１０００ｍ垢山腰是甸人面，形成于渐新世，代表早第三纪地文期的结束。     

河南潭头盆地中新生代地层沉积相特征

通过对河南豫西地区潭头盆地典型剖面测量,结合古生物化石和孢粉特征及室内对比研究,认为潭头盆地中新生代含恐龙化石地层由于受构造、古气候和物质来源的影响发育了典型的冲积扇—扇三角洲—湖泊的相的粗粒—细粒沉积。     

晚新生代中国北方风尘沉积的可能物源及变化

中国北方风尘沉积是晚新生代中纬西风和冬季风输送的粉尘相互加积的结果。对北方风尘沉积物来源和搬运动力的分析表明,风尘沉积的物质来源具有多样性,物源类型和分布、传输路径随时间变化。认为亚洲中部山地古风化壳可能是中国北方早期风尘沉积,尤其是第三纪红粘土的重要物源之一;晚新生代的粉尘源区类型由山地因干旱化被风蚀的红色风化壳逐渐向盆地周边被抬升的中、新生代砂泥岩过渡,再由盆地周边过渡到盆地内部的中生代与新生代的河湖沉积物和沙漠。同时大气环流格局的变化相应地导致了粉尘源区分布和传输路径的迁移。     

玉龙雪山—苍山地区第四纪沉积与层状地貌的新构造分析

本文通过断陷盆地第四纪地层层序与沉积间断、盆地早期地层下伏红色风化壳的层位、山地古夷平面的变形、金沙江阶地与洱海湖滨阶地发育的构造分析,提出新构造期的下限为330×104aBP左右、新构造运动的波动具有明显的递进性并呈现波动周期逐渐缩短、频率增大和晚第四纪断块差异性运动增强的基本趋势,探讨了新构造运动对地貌发育的控制作用。     

华北山地夷平面研究

山地夷平面是以河流为主的各种外营力对地面的长期剥蚀、夷平作用形成并被后期地壳运动抬升到山地顶部的大范围的平坦或微波状起伏的面,是复原地貌演化的基础。20世纪90年代以来,笔者在前人研究的基础上,通过大比例尺地形图、卫片图判读以及野外考察和同位素年龄测定等方法,对华北山地夷平面进行了研究。结果表明,华北山地有3期山地夷平面和1期山麓剥蚀面,其形成条件与构造、气候、海平面有关,并有初期的地壳急剧抬升-快速下切、中晚期的逐渐减缓-侧蚀夷平与末期的相对稳定-风化壳发育3个阶段,以溯源侵蚀-谷坡后退的方式进行,夷平面形成后还会产生变形与解体。夷平面研究对于理论研究和生产实践均具有重要意义。     

哈密——一个典型的地下水补给型荒漠绿洲区

由绿洲及其所在荒漠盆地平原与周边山地共同构建的哈密盆地地域系统，是我国干旱区典型的以地下水资源为主，而发育和不断扩大的荒漠绿洲区。盆地内独具一格的水循环系统，表现出水资源在流域水循环过程中形成和转化。由于荒漠盆地平原系统不产生径流，从山地进入荒漠盆地平原的水流就成为难一的水源。在哈密盆地河水出口后，即进入透水性强，粗粒松散的冲洪积扇，成为盆地平原地下水的形成区。潜水在冲—洪积扇缘溢出地面形成泉水，进而构成泉水河。冲—洪积扇积缘地带、地表平缓，土层深厚，发育成绿洲。盆地绿洲资源沿冲—洪积扇绿呈一字线，分80多个小的个体，散布于盆地的中央，将盆地黑戈壁与灰荒漠分为两半。     

库车盆地古近纪—新近纪蒸发岩沉积演化特征及其资源效应初步探讨

库车盆地古近纪—新近纪时期具有巨厚的蒸发岩沉积,古近纪时期岩盐沉积的最大厚度达1 447.5 m,新近纪时期岩盐沉积的厚度有所减小,岩盐层最大厚度402 m。库车盆地在古近纪—新近纪时期沉积沉降中心也有所改变,从盆地西部的拜城凹陷转移到东部的康村—阳霞地区。库车盆地东西部蒸发岩岩体特征的差异,对此地区油气藏规模造成一定影响。初步判断库车盆地西部蒸发岩有可能比东部蒸发岩盐下形成的油气藏量较大。盆地中蒸发岩沉积中心的迁移对钾盐沉积也有重要影响。     

陕北丹霞地貌特征及国内外对比研究

通过野外考察,并结合地质资料和样品分析,对陕北丹霞地貌形成的地质构造背景、红层岩性、形态特征、演化过程等进行系统阐述,并与中国东南部湿润区及国外的典型丹霞地貌进行对比,总结其共性和差异。结果表明：陕北丹霞地貌形成的构造环境为大型内陆坳陷盆地——鄂尔多斯盆地,主要成景地层为洛河组紫红色中-细粒长石石英砂岩,形成于早白垩世的干旱沙漠环境,发育大型交错层理,其碎屑颗粒分选性和磨圆度较好,但结构松散,胶结程度较弱,颗粒表面有碟形撞击坑等典型风成砂岩特征。陕北丹霞地貌最显著的特征是顶部有第四纪黄土盖层,形成覆盖型丹霞,地貌发育总体上处于青年期,整体为高原-峡谷景观,发育密集的沟谷群和连续的丹霞崖壁,但孤立的单体地貌较少。陕北丹霞地貌演化过程可划分为早白垩世红层沉积-晚白垩世红层盆地构造抬升和古丹霞发育-古近纪以来间歇式抬升-第四纪黄土覆盖等4个阶段。国内外对比方面,陕北丹霞与中国东南部湿润区的丹霞地貌在构造环境,物质基础,地貌特征等方面差异较显著,但与美国西部的丹霞地貌存在许多相似性。     

Spatial coupling relationships of gas hydrate formation in the Tibetan Plateau

At present, gas hydrates are known to occur in continental high latitude permafrost regions and deep sea sediments. For middle latitude permafrost regions of the Tibetan Plateau, further research is required to ascertain its potential development of gas hydrates. This paper reviewed pertinent literature on gas hydrates in the Tibetan Plateau. Both geological and ge- ographical data are synthesized to reveal the relationship between gas hydrate formation and petroleum geological evo- lution, Plateau uplift, formation of permafrost, and glacial processes. Previous studies indicate that numerous residual basins in the Plateau have been formed by original sedimentary basins accompanied by rapid uplift of the Plateau. Ex- tensive marine Mesozoic hydrocarbon source rocks in these basins could provide rich sources of materials forming gas hydrates in permafrost. Primary hydrocarbon-generating period in the Plateau is from late Jurassic to early Cretaceous, while secondary hydrocarbon generation, regionally or locally, occurs mainly in the Paleogene. Before rapid uplift of the Plateau, oil-gas reservoirs were continuously destroyed and assembled to form new reservoirs due to structural and thermal dynamics, forcing hydrocarbon migration. Since 3.4 Ma B.P., the Plateau has undergone strong uplift and extensive gla- ciation, periglacier processes prevailed, hydrocarbon gas again migrated, and free gas beneath ice sheets within sedi- mentary materials interacted with water, generating gas hydrates which were finally preserved under a cap formed by frozen layers through rapid cooling in the Plateau. Taken as a whole, it can be safely concluded that there is great temporal and spatial coupling relationships between evolution of the Tibetan Plateau and generation of gas hydrates.     

Influence of climate and tectonic movements on granite landforms in China

Present granite landform characteristics and distribution are the integrated result of climate, tectonics and lithology. Various types of granite landforms in China signify climate zonality and differential vertical movement of earth surface, while published research results on Chinese granite landforms are very rare, especially in international journals. Based on the process analysis of chemical weathering and physical disintegration, four granite landform regions in China are classified according to the present climate regime. On the Tibetan Plateau, the cold and freezing climate induced periglacial landscapes; the northeast region is characterized by physical disintegration and low round mounds are widespread; in the northwest region controlled by arid climate, wind-carved minor landscapes are extremely prominent. The most spectacular granite landscapes in China are presented in southeast as a result of longtime chemical weathering under humid and warm conditions, as well as the differential uplift after Neogene. Correlating the weathering crust in southern China, Tibetan Plateau and India, a possible unified planation surface in Neogene is proposed. With corestones as indicators of original weathering front, the differential uplift extent of dissected planation surfaces can be estimated. At least three landforms implying uplift can be identified in southeastern China, with elevations of 300–400 m, 2000 m and 3600 m above the sea level respectively.     

Planation, bauxites and epeirogeny: One or two paleosurfaces on the West African margin?

Mapping of lateritic bauxites over the West African rifted margin and analysis of the geomorphic properties of these bauxites, combined with available geological data lead to a discussion of the presence of either two Meso-Cenozoic planation surfaces or a single Eocene surface to account for the morphotectonic and paleoclimatic evolution of the Guinean landforms. At large scale, two stepped bauxitic levels are documented. Ongoing or episodic uplift following Gondwana breakup and Meso-Cenozoic climate change are proposed to have allowed the formation and abandonment of an Early mid-Cretaceous surface today preserved as the higher bauxitic level, and the setting of an Eocene planation surface bearing a second generation of bauxites, making the lower bauxitic level. The single Eocene surface hypothesis requires that Paleogene bauxitization preserved large pre-existing relief to explain two stepped bauxitic levels of the same age. The two-surface hypothesis is favored because it would explain rebauxitization of alluvial pebbles of bauxites under the lower lateritic level.     

Catastrophic middle Pleistocene jökulhlaups in the upper Susquehanna River: Distinctive landforms from breakout floods in the central Appalachians

Widespread till and moraines record excursions of middle-Pleistocene ice that flowed up-slope into several watersheds of the Valley and Ridge Province along the West Branch of the Susquehanna River. A unique landform assemblage was created by ice-damming and jökulhlaups emanating from high gradient mountain watersheds. This combination of topography formed by multiple eastward-plunging anticlinal ridges, and the upvalley advance of glaciers resulted in an ideal geomorphic condition for the formation of temporary ice-dammed lakes. Extensive low gradient (1°–2° slope) gravel surfaces dominate the mountain front geomorphology in this region and defy simple explanation. The geomorphic circumstances that occurred in tributaries to the West Branch Susquehanna River during middle Pleistocene glaciation are extremely rare and may be unique in the world. Failure of ice dams released sediment-rich water from lakes, entraining cobbles and boulders, and depositing them in elongated debris fans extending up to 9 km downstream from their mountain-front breakout points. Poorly developed imbrication is rare, but occasionally present in matrix-supported sediments resembling debris flow deposits. Clast weathering and soils are consistent with a middle Pleistocene age for the most recent flows, circa the 880-ka paleomagnetic date for glacial lake sediments north of the region on the West Branch Susquehanna River. Post-glacial stream incision has focused along the margins of fan surfaces, resulting in topographic inversion, leaving bouldery jökulhlaup surfaces up to 15 m above Holocene channels. Because of their coarse nature and high water tables, jökulhlaup surfaces are generally forested in contrast to agricultural land use in the valleys and, thus, are readily apparent from orbital imagery.     

西南极南设得兰群岛中新生代地层特征

南设得兰群岛是晚中生代以来古太平洋板块向南极板块俯冲消减过程中形成的,目前对整个群岛的地层特征及沉积演化无统一认识。通过归纳总结国内外研究成果,认为该群岛出露的地层具明显的时空规律。群岛主体的西南部出露上侏罗统-下白垩统,发育海底扇、深海、斜坡裙、扇三角洲等沉积相,相伴随的火山作用主要为钙碱性玄武岩和玄武安山岩的喷发,记录了弧前盆地-火山岛弧的演化过程;群岛主体的东北部主要出露上白垩统-下渐新统,其中上白垩统-始新统发育一套玄武质熔岩、火山碎屑-沉积岩建造,为温暖气候下的陆相沉积,火山活动具有岛弧拉斑玄武岩与钙碱性火山岩的过渡性质。渐新统-下中新统则记录了从间冰期正常海相到冰期冰海相沉积的转变过程。     

Types and spatial combinations of Danxia landform of Fangyan in Zhejiang Province

The prominent types of Danxia landform in Fangyan include enclosed valleys, mesas, peaks, stone columns and grooves etc. Their spatial combinations have regular configurations along the northwest–southeast direction: typical grooves and caves are located in the northwestern Wufengshuyuan mainly; abundant fresh collapsed stones may be observed in central Jimingfeng and Taohuafeng; stone drums and stone columns are in the southeastern Shiguliao particularly; enclosed valleys are encircling joints of peaks and plains from three directions east, west, and south. Their spatial combinations reflect that the developments of Danxia landform have undergone stages of geomorphic cyclical erosion in the form of weathering, collapse, transportation, sedimentation and other processes, together with the “sculpture” of external forces mainly as tectonic uplift. The picturesque Danxia landform began its formation at that point. Danxia landform developed mainly in the strata of Fangyan Formation (K1f) caused by the alluvial fan-braided river phase of anterior fan in the late period of the Early Cretaceous. Regular patterns of weathering of stones and features of braided alluvial phase sediments may be verified by the analysis of three groups of experimental data. Danxia landform of Fangyan is a unique representative of the “adolescent” development type in the application of the World Natural Heritages status in China, by virtue of its outstanding universal aesthetic and scientific value.     

Geomorphic and Climatic Implications of Relict Openwork Block Accumulations Near Thabana-Ntlenyana, Lesotho

Conflicting reports appear in the literature from geomorphic studies describing the colder Late Pleistocene environmental conditions of the Lesotho Highlands in southern Africa. Evidence is given for limited glaciation and/or periglacial conditions, with or without permafrost. An investigation of the distribution, morphometric attributes and surface weathering characteristics of relict openwork block accumulations in the area around Thabana‐Ntlenyana, the highest summit in the range, supports the contention for a relatively arid periglacial environment during the Last Glacial period. A phase of enhanced block production is evident from the concentration of blocks in the upper layer of colluvium. Slope mobility on south‐facing slopes is shown in the blockfield fabrics and the increase in downslope relative age of block surfaces. Block production and slope creep are attributed to depressed temperature conditions and seasonal freeze. Colluvium, within which blocks have been incorporated and superimposed, indicates that slope mantles predate the onset of the colder period and evidence militates against either deep snow cover or localised glaciation of south‐facing slopes.     

安徽齐云山丹霞地貌成因

齐云山丹霞地貌主要发育于中白垩统小岩组K₂x¹红色砂砾岩层中, 该区地貌发育主要受景德镇-祁门断裂带、江湾-街口挤压破裂带和开化-淳安褶断带三大断裂带控制。在白垩世该区经历了地块沉降, 成为陆上的断陷湖盆, 由此接受了巨厚的白垩系红层堆积。在新构造运动中, 该区经历了隆升过程, 巨厚的白垩系沉积物变成了海拔500~600 m的山体。白垩系红色砂砾岩在经历了垂直节理发育、风化破坏阶段及剥蚀搬运阶段后, 同时受岩性本身砂岩与砾岩在组分和结构上的影响, 差异性风化剥蚀显著, 因此形成了壮观的峰林、崖、洞、方山、城堡及天生桥景观。该区585 m、400 m和150 m处的三级裂点, 大致反映了该区新构造运动中三次主要的抬升过程。