云南东川地区层状地貌面的成因

在东川地区的山地及小江河谷的两侧山麓上部，分布着不同高度和不同规模的层状地貌面，对其成因仍有不同的认识。分歧主要表现在两个方面：一是高原隆升之前的初始地貌面是否是准平原型夷平面；二是山顶面之下的梯级层状地貌面的成因。本文从以下几个方面对上述问题进行讨论：(1)层状地貌面的地貌特征及其与侵蚀河谷体系的关系；(2)层状地貌面上堆积物的性质；(3)层状地貌面与断裂构造水平展布的关系；(4)相邻层状地貌面的空间过渡关系；(5)区域构造演化背景。作者认为在云贵高原抬升过程中，东川地区以挤压穹起隆升变形为主。不同海拔高度的层状地貌面具有多成因特性。山顶面及局部高原面是高原隆升之前古夷平面的残留。并遭到后期强烈的侵蚀改造。目前，尚缺乏足够证据证明高原隆升之前的古夷平面为准平原型夷平面。小江河谷两侧的梯级层状地貌面是侵蚀或剥蚀面，它们形成于高原隆升及初始地貌面解体之后，其梯级空间分布特征与区域性的阶段隆升有关。     

祁连山北麓地貌信息熵与山体演化阶段分析

利用定量化的手段分析地貌演化的阶段和趋势,是地貌学研究领域的一个重大的理论课题。在地理信息系统软件ArcGIS和ArcView的支持下,利用数字高程模型提取祁连山北麓的河网和流域。利用Strahler积分计算了各个流域的地貌信息熵,按照主夷平面的高度将祁连山北麓的各个流域分为不同的部分,它们具有不同的地貌信息熵值。结果显示,祁连山地区正在进入戴维斯侵蚀旋回的幼年期阶段。     

论地貌的平衡与演化

地貌的平衡与演化牵涉到地貌学的理论核心,是其他地貌问题研究的前提和基础。但长期以来对此缺乏共识,认识混乱文呈讨论了地貌平衡的基本含义,认为根据剥蚀速率和堆积速率的大小,可把地貌平衡分为稳定平衡、不稳定平衡及动力平衡等３类,除稳定平衡外,其他两类平衡连同不平衡和非平衡都是与时间相关的,因而都是地貌演化的表现形式。即平衡可以伴随地貌演化而存在,把平衡与演化对立起来的错误观点引起了不少混乱。真实地貌作为     

地貌面、地文期与地貌演化——从华北地貌演化研究看地貌学的一些基本理论

华北地貌的形成演化研究以传统地貌学理论戴维斯等的"地貌面"和"侵蚀旋回"理论为指导。研究表明,它基本适用于华北地貌的形成与演化;同时也发现了传统地貌学理论的不足。该文用华北地貌形成演化的实际资料弥补了这个不足,并进一步探讨了地貌形成演化理论的某些新观点。     

夷平面的三维显示与定量分析方法初探

夷平面是当代地貌学研究的一个重要课题之一,对于重建一个地区的地貌演化的历史具有重要的意义,中利用遥感与地理信息系统建立了位兰州以南、青藏高原东北部边缘的美武高 程工与陆地卫星影像结合起来集成分析,论述了美武高原三维地貌影像图的信息特点,提取了若干区段的地形剖面,进而在分析了高原夷平面地貌参数体系的基础上运用遥感图像监督分类技术自动提出高原夷平面的具体分布区域,揭示了此项对于夷平面分析的巨大潜力。     

地貌发育演化研究的空代时理论与方法

地貌的发育在特定的条件下往往呈现空间分布上由“新”至“老”的过渡,据此,对地貌类型与特征在空间上的序列采样,即可为研究某种地貌的个体发育提供基本依据。该方法即为地貌学研究中的空代时。本文首先介绍了空代时方法产生的背景与基本概念。分析了近年来空代时方法应用于河流地貌、构造地貌、河口海岸地貌等不同地貌类型演化过程的研究进展。在此基础上,明确了空代时方法在地貌学研究中的适用条件、影响因素及分类体系,并提出了地貌学空代时的研究范式。本文认为今后的研究工作一方面应充分利用海量的地理空间数据,运用空代时方法研究多种空间尺度下的地貌演化的问题;另一方面,应结合现有的物理机制和统计规律,构建集形、数、理一体化的地貌演化模型。     

河南伊洛河流域更新世地貌演变及驱动评述

根据野外调查,结合相关文献,利用GIS制图与空间分析功能对伊洛河流域更新世地貌特征与演化进行了分析,在原有地貌类型基础上划分若干地貌单元,对各类地貌单元的海拔高度、坡度、面积及比例进行量算,并对地貌演变的气候与构造驱动进行评述,为区域早期人地关系研究奠定基础.结果显示,晚第三纪以来发生的新构造运动,在区域主要表现为间歇性的抬升,其对区域宏观地貌特征的形成起到决定作用.新近纪以来的气候冷、暖、干、湿的交替波动,在地貌发育过程中起到较小尺度下的修塑作用,主要表现为堆积、侵蚀等不同特征.伊洛河流域现代地貌特征的形成是构造、气候等因素共同作用的结果.尽管燕山运动奠定了伊洛河流域的地貌轮廓,但在内外力共同作用下,区域地貌不断演变,现代地貌特征逐步形成且仍在不断演化之中.     

中国夷平面研究的新进展—吴忱等著，华北山地地形面、地文期与地貌发育史》评介

夷平面的研究是地貌学理论、古环境学和地球动力学研究中的一个重要方面,对于寻找某些矿藏也很有意义.在我国,夷平面在华北山地广泛发育,是研究的发祥地.20世纪初就有中外地学家不断发表论著,并且将研究逐步扩及到西北和西南地区.50至60年代,关于夷平面研究逐渐稀少.70至90年代中期,夷平面的研究几乎成为空白,只在其它研究项目中捎带涉及.夷平面研究长期停滞不前的原因,笔者认为主要有三:一是未能找到确切的断代证据以定出夷平面的形成时代;二是未能开展大范围的连续追溯、调查和制图,进行夷平面的分级、对比和查明区域变化;三是对夷平面研究的理论和实际意义缺乏深刻理解.其中,难度最大的是夷平面的形成时代鉴定、分级与对比.     

王乃樑先生对中国地貌学发展的主要贡献

王乃樑先生是中国著名的地貌学家。20世纪40年代至90年代初期,先后在清华大学和北京大学任教。他对中国黄土高原、华北、东北、西北、四川、湖北和广西等广大地区进行了地貌和新生代沉积研究,在新生代沉积与地貌演化历史、新构造活动与构造地貌学、地貌学与沉积学基本理论与方法等诸多领域取得了一系列创新性的成果。在地貌学学科建设、人才培养、科学研究和国内外学术交流诸方面,为中国地貌学的发展做出了卓越贡献。     

试论地貌学的新进展和趋势

地貌变化有内在的规律,对环境保育、资源利用和自然灾害防治有重要影响。作为交叉学科和地理学的重要分支学科,地貌学具有重要理论价值和实际意义。过去10多年来,随着遥感、地理信息技术和沉积物定年、地球物理和地球化学探测以及数值模拟等新技术和新方法的应用,地貌学家的研究视野和深度不断扩大与加深,在构造地貌、气候地貌和人类活动与地貌过程等传统领域有很多新进展,揭示了不同地貌单元的变化规律和机理,极大地推动了地貌学的发展。在新时代,除了继续加强传统地貌单元的深入研究外,地貌学的发展应与全球环境变化和未来地球等重大科学问题(计划)紧密结合;地貌学家要关心人类活动对地貌过程的影响及适应,并利用新技术开展地貌过程的定量重建和数值模拟。同时加强地理学专业学生的地质学基础学习、发展定量地貌学和行星地貌学、系统开展人类活动对地貌过程的影响和适应研究,是提升中国地貌学水平的途径,也可为推动国际地貌学发展做出贡献。     

夷平面研究综述

夷平面100多年的研究已经取得了一定的进展。文章从定义、识别、分类、形成和测年等方面论述了夷平面的研究情况,完善了夷平面的定义,加强了对影响夷平面形成和保存的自然因素的探讨,提出了未来夷平面研究的方向。     

青藏高原东北缘马衔山夷平面特征指标的提取与分析

夷平面研究在地貌演化和新构造运动,特别是青藏高原隆升过程研究中占有极其重要的地位,准确界定夷平面分布范围是开展夷平面定量--半定量研究的重要基础.截至目前,前人已利用计算机图像处理技术和目视解译等方法开展了相关工作,并取得重要研究进展.然而,以往利用坡度高程指标提取夷平面时存在一定的随意性和主观性.青藏高原内部及其周边地区发育系列夷平面,其中高原东北缘马衔山地区较好的保存了两级夷平面.被夷平的地层为前寒武系马衔山群混合岩,山顶面上发育冰缘地貌,主夷平面波状起伏,上有岛山和晚新生代沉积,局部覆盖有40 m左右红粘土和30 m以上更新世黄土,并在局地残留3 m以上风化壳,是开展夷平面研究的理想地区.为探讨如何确定提取夷平面的最佳坡度高程指标,本文基于夷平面的特殊地貌几何形态,利用均值变点分析法和最小误差法确定了提取夷平面的最佳高程和坡度指标,并据此对马衔山地区的两级夷平面的分布范围进行提取和统计分析.最后结合剖面线,坡向分布图和区域地质资料探讨了夷平面的构造变形特征.研究发现马衔山地区两级夷平面最佳坡度指标均为12°,山顶面和主夷平面高程主要分布在3470~3640 m和2670~2870 m;统计分析表明山顶面面积约为6.4 km²,平均高程为3559 m,主夷平面面积约为15.5 km²,平均高程为2771 m;而夷平面的变形特征主要受控于区域断层.     

A peak-cluster assessment method for the identification of upland planation surfaces

Residual upland planation surfaces serve as strong evidence of peneplains during long intervals of base-level stability in the peneplanation process. Multi-stage planation surfaces could aid the calculation of uplift rates and the reconstruction of upland plateau evolution. However, most planation surfaces have been damaged by crustal uplift, tectonic deformation, and surface erosion, thus increasing the difficulty in automatically identifying residual planation surfaces. This study proposes a peak-cluster assessment method for the automatic identification of potential upland planation surfaces. It consists of two steps: peak extraction and peak-cluster characterization. Three critical parameters, namely, landform planation index (LPI), peak elevation standard deviation, and peak density, are employed to assess peak clusters. The proposed method is applied and validated in five case areas in the Tibetan Plateau using a Shuttle Radar Topography Mission digital elevation model (SRTM DEM) with 3 arc-second resolution. Results show that the proposed method can effectively extract potential planation surfaces, which are found to be stable with different resolutions of DEM data. A significant planation characteristic can be obtained in the relatively flat areas of the Gangdise–Nyainqentanglha Mountains and Qaidam Basin. Several vestiges of potential former planation areas are also extracted in the hilly-gully areas of the western part of the Himalaya Mountains, the northern part of the Tangula–Hengduan Mountains, and the northeastern part of the Kunlun–Qinling Mountains despite the absence of significant topographical features characterized by low slope angles or low terrain reliefs. Vestiges of planation surfaces are also identified in these hilly-gully upland areas. Hence, the proposed method can be effectively used to extract potential upland planation surfaces not only in flat areas but also in hilly-gully areas.     

中国气候和构造运动对花岗岩地貌的影响

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.     

分形理论及其在地貌学中的应用──分形地貌学研究综述及展望

本文简介了分形的有关基本概念,回顾了分形理论在海岸、流水、喀斯特地貌等多种地貌类型和流域地貌发育的形态研究中,以及在地貌过程研究中的应用的新近成果,并提出了今后分形地貌学研究的五个主要方面.     

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.     

渭河三阳川盆地最高级阶地的年代厘定及其对河谷发育的指示意义

青藏高原东缘水系的演化历史长期存在着重大争议,鉴于任一水系的形成演化都是通过主要河谷的发育及其不断延展与整合完成的,因此确定河谷发育的起始时代是研究水系演化的关键。本文针对渭河上游三阳川盆地最高级阶地形成时代的研究,发现李家小湾河流阶地砾石层的ESR年代为1.26±0.15 Ma和1.32±0.19 Ma,26Al/10Be埋藏年代为1.45±0.70 Ma和1.04±0.43 Ma,说明该段河谷形成于早更新世晚期。综合青藏高原东缘夷平面、剥蚀面与河流阶地的研究成果,推断该区现代河谷系列主要形成于1.2 Ma以后,河流平均下切速率较高,为0.1~0.32 m/ka,指示了中更新世以来该区快速的地表抬升与河谷发育过程;而其前少数地段的先成河谷下切速率介于0.04~0.29 m/ka之间,说明区域地势总体低平,地表过程以剥蚀夷平为主,即高原东缘的现今水系格局主要是第四纪期间构造和气候共同作用下河流侵蚀的产物。     

ESSAY PAPER The interaction between geological structure and global tectonics in multistoreyed landscape development: a denudation chronology of the South Indian shield

This study constitutes a comprehensive attempt to interpret the multistoreyed benchland scenery of the South Indian shield. In South India, two rifted margins (and now competing base levels), a low-elevation margin facing the Bay of Bengal, in existence since ≈130  Ma, and a younger (65  Ma) high-elevation margin facing the Arabian Sea, together with a high-standing backbone of extremely resistant granulitic rocks known as charnockites, have influenced the long-term erosional response to rock uplift and to the eustatic shift of shorelines in a complex way.
Several tiers of flat-lying, denudational topographic surfaces, which are indifferent to stratification, schistosity or foliation and highlighted by a characteristic weathering mantle, are identified and the conditions of their genesis discussed. General definitions and assumptions concerning the evolution of planation surfaces are presented. A major key issue is the nature of crustal uplift in cratonic regions: its relation to global tectonics, its role in the redistribution in time and space of available relief and in the deformation of pre-existing planation surfaces, and its bearing on denudational signals which may be recorded both by isotopic measurement techniques and offshore sedimentary sequences. The proposed denudation chronology considers all these aspects, and the analysis sets out to establish a thread of geodynamic events that can account for the observed morphology. Drainage, weathering and crustal uplift patterns, geological structures and chronostratigraphic data are examined in relation to their possible connections with the migration of drainage divides and surface lowering patterns. The high number of degrees of freedom involved when considering the long-term interplay between gravity-driven and radiation-driven denudation systems is one of the many problems facing this analysis, and is extensively addressed in the discussion.