Loess in China

ISBN-13: 9783642828348 / Angielski / Miękka / 2011 / 224 str.

Tungsheng Liu

Opis

The distribution, deposition, composition and texture of loess in China is studied. Based on on-the-spot investigations, Loess and the Environment supplies information on: the loess-paleosol time sequence, loess fabric, and geological events derived from studying biological relics. Proceeding from the loess environmental system, the climatic fluctuation sequence of different scales has been reconstructed, and the whole process of eolian loess accumulation and its relationship with modern silt dust, water and soil conservation, engineering geology, agricultural soil as well as local diseases are discussed.

Spis treści

1. A Brief History of Loess Studies in China.- 1.1 The Significance of the Study of Loess.- 1.2 The Terminology and Concept of Loess.- 1.3 The Process of Loess Formation.- 1.3.1 The Source of Loess Material.- 1.3.2 Transportation and Sedimentation of Loess.- 1.3.3 The Biogeochemical Stage of Loess-Forming and Loess Evolution.- 1.4 A Brief History of Loess Studies.- 2. Regional Distribution of the Aeolian Products (Loess).- 2.1 Loess Distribution.- 2.1.1 Area of Loess Cover.- 2.1.2 Loess Deposit Subregions.- 2.1.3 Some Aspects of the Loess Distribution in China.- 2.2 Geological Structure of Basins with Loess Sediments.- 2.2.1 Basins with Loess Sediments and Their Strata.- 2.2.2 Division of Ages for Luochuan Loess-Paleosol.- 3. Time Sequence of Loess Deposits.- 3.1 Luochuan Loess-Paleosol Sequence.- 3.1.1 Geological Events Recorded by Loess-Paleosol Sequence.- 3.1.2 Luochuan Loess Section.- 3.1.3 Geological-Climatic Events and Loess Sequences.- 3.1.4 Polycyclic Geological-Climatic Events and Brunhes Chronostratigraphy in Northern China.- 3.2 Magnetostratigraphy of Loess and the Lower Boundary of the Pleistocene.- 3.2.1 Magnetostratigraphy of Luochuan Loess.- 3.2.2 Geological Significance of the Magnetic Boundary.- 3.3 14C Dating of Loess.- 3.3.1 Loess 14C Dating Methods.- 3.3.2 Results of Loess 14C Dates.- 3.3.3 Discussion.- 3.4 Loess Sedimentation Sequence in the Last 10000 Years.- 3.4.1 Distribution of Holocene Loess.- 3.4.2 Age of Black Loam and Stratigraphic Division of Holocene Loess in the Middle Reaches of the Huanghe River.- 3.4.3 Particle Size and Mineral Composition of Holocene Loess.- 3.5 Discussion of Loess-Paleosol Sequence and of Geological Events in the Past 2.4 Million Years.- 3.5.1 Time Sequence of Luochuan Loess-Paleosols.- 3.5.2 Geological Events over the Past 2.4 Million Years.- 3.5.3 Discussion on the Age of Early Human Fossils in Northern China.- 4. Fossils in Loess and Its Ecological Environment.- 4.1 Fossil Mammals with Special Evidence of the Evolution of Myospalax.- 4.1.1 Description of New Species and Its Importance to the Age of Loess.- 4.2 Fossil Snails and Their Environment.- 4.3 Spores, Pollen and Paleovegetation.- 4.3.1 Pollen Analysis of Loess.- 4.3.2 Spores and Pollen Assemblage, Paleovegetation and Paleoenvironment of the Luochuan Region.- 5. Composition of Loess.- 5.1 Grain-Size Distribution.- 5.1.1 A General Description of the Features of Grain-Size Distribution.- 5.1.2 “Silt to Clay” Ratio Kd and Its Geological Implication.- 5.1.3 Grain-Size Cycles and the Lithologic-Stratigraphic Association.- 5.1.4 Formation of Loess in Light of the Grain-Size Distribution.- 5.2 Heavy Minerals.- 5.2.1 The Main Compositional Characteristics of Heavy Minerals in Loess and Paleosol.- 5.2.2 Differences in Composition of Heavy Minerals in Loesses of Different Periods.- 5.2.3 Characteristics of Heavy Mineral Assemblage in Cinnamonic Paleosol.- 5.2.4 Discussion.- 5.3 Clay Mineral.- 5.3.1 Clay Mineral Composition of Loess.- 5.3.2 The Structural Variation of Illite in Loess.- 5.3.3 A Discussion on the Geological Environments of Formation of Loess and Paleosol with a Special Emphasis on Clay Mineral Analyses.- 5.3.4 Source of the Clay Minerals in Loess.- 5.3.5 Influence of Diagenesis on Clay Minerals in Loess.- 5.4 Geochemical Characteristics.- 5.4.1 The Main Chemical Components of Loess.- 5.4.2 Carbonates in Loess.- 5.4.3 Trace Elements in Loess.- 5.4.4 Geochemical Features of Paleosol.- 5.4.5 The Relationship Between Element Geochemistry and Paleoclimatology.- 5.4.6 Medium Conditions of Loess Accumulation.- 5.5 Rare Earth Elements.- 5.5.1 Content and Distribution of Rare Earth Elements in Loess.- 5.5.2 REE Distribution Patterns and Characteristics of Luochuan Loess.- 5.5.3 Geochemical Implications of Some REE Ratios in Loess.- 5.5.4 Correlations Between REE and Elements of Fe, Al and Ca in Loess.- 5.6 Amino Acids.- 5.6.1 Sampling and Analytical Preparation.- 5.6.2 Results and Discussion.- 5.7 Paleosol.- 5.7.1 Micromorphology of Paleosol and Loess.- 5.7.2 The Classification of Paleosols.- 5.7.3 Weathered Types of Loess.- 5.7.4 Paleoenvironmental Significance of Paleosol and Loess.- 6. Loess and the Environment.- 6.1 Dust Deposition and the Modern Dust Storm.- 6.1.1 General Characteristics of Dust Storms and Their Bearing on Loess.- 6.1.2 Analyses of Several Dust Storm Events.- 6.1.3 Dust Storms and Atmospheric Motion in Various Scales.- 6.1.4 Dust Storms and the Source Region of Loess.- 6.2 Amount and Rate of Loess Deposition.- 6.2.1 Depositional Amount of Loess.- 6.2.2 Depositional Rate and Stratigraphical Ages of Loess.- 6.2.3 Discussion.- 6.3 Long-Term Climatic Changes in the Loess Plateau of China.- 6.3.1 Variational Sequence of Climatic Elements (Annual Mean Temperature and Annual Mean Precipitation) of Luochuan for the Past 1.1 Million Years.- 6.3.2 Paleoclimatic Curves Over the Last 2.4 Million Years.- 6.3.3 Comparison Between Pleistocene Land/Sea Climatic Records.- 6.4 Spectral Analysis of Luochuan Loess-Paleosol Sequence.- 6.4.1 Time Models of the Loess-Paleosol Sequence.- 6.4.2 Approach to Multispectral Analysis.- 6.4.3 Dominant Oscillations of Luochuan Climatic Series.- 6.4.4 Discussion.- 6.5 Composition of Loess and Loessial Soil and Agricultural Production.- 6.5.1 Composition and Texture of Loess and Agricultural Production.- 6.5.2 Trace Elements in Loess and Loessial Soil and Agricultural Production.- 6.6 Geochemical Environment of Loess and Endemic Diseases.- 6.6.1 Keshan Disease.- 6.6.2 Kaschin-Beck Disease.- 6.6.3 Disease by Local Fluorine Poisoning.- 6.6.4 Other Local Disease in Loess Region.- 6.6.5 Local Cancer of the Esophagus.- 6.6.6 Local Diseases in Loess Region and Geological Investigation.- 6.7 Property of Engineering Geology of Loess Deposits and Evaluation of Regional Stability.- 6.7.1 Characteristics of Regional Distribution of Physico-Mechanical Properties of Loess.- 6.7.2 Collapsing Loess and Its Regional Distribution.- 6.7.3 Engineering-Geological Division and Regional Stability.- 6.8 Environment and Erosion of Loesses.- 6.8.1 Circumstance of the Erosion of Loesses on the Loess Plateau.- 6.8.2 Geological Environment and Erosion of Loess.- 6.8.3 The Gully System and the Mosaic Environment of Loess.- 6.8.4 Geological Environment and Some Problems of Water and Soil Conservation.- 7. Methods in Loess Research.- 7.1 The Principles of Stratigraphic Classification and Nomenclature of Loess Sequence.- 7.1.1 The Codes for Quaternary Stratigraphy.- 7.1.2 The Status Quo of Loess Stratigraphic Classification in China.- 7.1.3 Loess Stratigraphic Classification and Nomenclature.- 7.2 Thermoluminescent Dating of Loess.- 7.2.1 Methods for Determining the Age of Loess.- 7.2.2 The Formative Age of Luochuan Loess.- References.