成都理工大学：《环境地质学》课程PPT教学课件（双语讲稿）第六讲 地球内部健程

地球内部过程 Plate Tectonics Geologic Tectonics ° Earthquake Tsunamis海啸 and coastal Flooding 环境迪顶学 minoucntalocelogu ,率

地球内部过程 • Plate Tectonics • Geologic Tectonics • Earthquake • Tsunamis海啸 and Coastal Flooding

地球内部过程 Geologic Tectonics Folds If subjected to stresses beyond te ii those that their strength can resist, strata are permanently deformed by either buckling压弯曲or fracturing. The type of deformation depends on the mechanical properties of the rocks and the nature of the stresses. In general stresses which are applied slowly, either deep within the Earth where the confining pressure produced by overburden is high, or to rocks that are not brittle, tend to produce folds by buckling or plastic flow. The essential characteristic of a fold is a change of dip Ai/ a This occurs at the hinge枢纽、绞链 of the fold on either side of the hinge is a limbal, where the dip is comparatively steady In real folds the change of dip is seldom restricted to a line, but is concentrated in a liner zone. The plane of symmetry that bisects fs] the angle between the limbs is the axial surface(or axial plane). The intersection of the axial surface with each bedding plane is an axis of the fold 环境迪顶学 minoucntalocelogu ,率

地球内部过程 Geologic Tectonics • Folds • If subjected to stresses beyond超出 those that their strength can resist, strata are permanently deformed by either buckling压弯曲 or fracturing. The type of deformation depends on the mechanical properties of the rocks and the nature of the stresses. In general, stresses which are applied slowly, either deep within the Earth where the confining pressure produced by overburden is high, or to rocks that are not brittle, tend to produce folds by buckling or plastic flow. The essential characteristic of a fold is a change of dip倾向. This occurs at the hinge枢纽、绞链 of the fold. On either side of the hinge is a limb翼, where the dip is comparatively steady. In real folds the change of dip is seldom restricted to a line, but is concentrated in a liner zone. The plane of symmetry that bisects平分the angle between the limbs is the axial surface (or axial plane). The intersection of the axial surface with each bedding plane is an axis of the fold

地球内部过程 Geologic Tectonics Folds A fold where the limbs diverge偏斜、脱节 downwards(that is, where the dips of the limb are away from the hinge) is an anticline背斜;a fold where dips are towards the hinge is a syncline向斜. the axis is not horizonta, the fold is said to plunge, with the amount of plunge倾伏 插入 being the angle between the axis and the horizontal line vertically above it.其倾斜量以轴线 及其上方的水平线夹角表示 环境迪顶学 minoucntalocelogu ,率

地球内部过程 Geologic Tectonics • Folds • A fold where the limbs diverge偏斜、脱节 downwards (that is, where the dips of the limb are away from the hinge) is an anticline背斜; a fold where dips are towards the hinge is a syncline向斜. If the axis is not horizontal, the fold is said to plunge, with the amount of plunge倾伏、 插入 being the angle between the axis and the horizontal line vertically above it.其倾斜量以轴线 及其上方的水平线夹角表示

地球内部过程 Geologic Tectonics Folds Folds are described and classified by certain features of their geometry Which are diagnostic of how they were formed The criteria and the terms used to define folds are illustrated in Figure 4.12; they are as follows 环境迪顶学 minoucntalocelogu ,率

地球内部过程 Geologic Tectonics • Folds • Folds are described and classified by certain features of their geometry which are diagnostic of how they were formed. The criteria and the terms used to define folds are illustrated in Figure 4.12; they are as follows:

地球内部过程 Geologic Tectonics Folds 环境迪顶学 minoucntalocelogu ,率

地球内部过程 Geologic Tectonics • Folds

地球内部过程 Geologic Tectonics Folds ② Meaining Geologic M has ie U.S 环境迪顶学 minoucntalocelogu ,率

地球内部过程 Geologic Tectonics • Folds

地球内部过程 Geologic Tectonics Folds Overmoded HEp' Conce 环境迪顶学 minoucntalocelogu ,率

地球内部过程 Geologic Tectonics • Folds

地球内部过程 Geologic Tectonics Folds (a) The dip of the axial plane: where it is vertical the dip of each limb is the same in magnitude, but opposite in Overmoded direction and the width of outcrop of any bed is the same on both sides of the axis. In inc lined folds, one limb is steeper and its outcrop is correspondingly narrower than that HEp' of the other Overfolding occurs where one limb is overturned, such that both limbs dip the same way. The rotation of the axial plane, seen from left to right in the diagram, is probably produced by transport of the fold with relative drag at its base. (b The size of the angle between the limbs: this reflects the intensity of Conce compression of the fold 环境迪顶学 minoucntalocelogu ,率

地球内部过程 Geologic Tectonics • Folds (a) The dip of the axial plane: where it is vertical the dip of each limb is the same in magnitude, but opposite in direction, and the width of outcrop of any bed is the same on both sides of the axis. In inclined folds, one limb is steeper and its outcrop is correspondingly narrower than that of the other. Overfolding occurs where one limb is overturned, such that both limbs dip the same way. The rotation of the axial plane, seen from left to right in the diagram, is probably produced by transport of the fold with relative drag at its base. (b) The size of the angle between the limbs: this reflects the intensity of compression of the fold

地球内部过程 Geologic Tectonics Folds Concentric folds同心褶皱are produced by sim ple bucking, Overmoded and the beds are curved concentrically by the same amount. the beds rem ain constant in true thickness HEp' and parallel to each other after folding. Slip has taken place along the bedding planes. A concentric fold becomes progressively less open as the 'centre of the concentricity Conce 环境迪顶学 minoucntalocelogu ,率

地球内部过程 Geologic Tectonics • Folds Concentric folds同心褶皱 are produced by simple bucking, and the beds are curved concentrically by the same amount. The beds remain constant in true thickness and parallel to each other after folding. Slip has taken place along the bedding planes. A concentric fold becomes progressively less open as the 'centre' of the concentricit

地球内部过程 Geologic Tectonics Folds In similar(shear) folds all layers are deformed to a similar shape, and the bed thicknesses are constant in Overmoded a direction parallel to the axial plane. This produces an increase of true thickness at the hinges andm a decrease on the limbs similar HEp' folds are produced by differential movements along minor shear planes in a direction parallel to the axial plane. Intense folding of metamorphic变质 rocks at a time when temperature and pressure were high is usually of this type Conce 环境迪顶学 minoucntalocelogu ,率

地球内部过程 Geologic Tectonics • Folds In similar (shear) folds all layers are deformed to a similar shape, and the bed thicknesses are constant in a direction parallel to the axial plane. This produces an increase of true thickness at the hinges and a decrease on the limbs. Similar folds are produced by differential movements along minor shear planes in a direction parallel to the axial plane. Intense folding of metamorphic变质 rocks at a time when temperature and pressure were high is usually of this type