地貌成因的

Some innovative results are listed below:1、According to the lithologic characters,lithofacies,genetic classification and the geomorphy,the Quaternary system is divided into piedmont-gully\'s and plain\'s. The piedmont-gully\'s Quaternary sediment,which is about 3～20 meters in thick,is in the western hills of the study area.The plain\'s Quaternary sediment is widely distributed in the study area,which is about 30～60meters thick and become thicker from southwest to northeast.2、The Quaternary sediments of plain can be divided into five sedimentary cycles.The Late Pleistocene series Quantan group,at the bottom of the Quaternary System,is constituted by a fluvial facies-river and lake facies sedimentary cycle. The Late Pleistocene series Jiashan group,at the middle of the Quaternary sediment, is constituted by two fluvial facies-neritic facies-river and lake facies sedimentary cycles.The Holocene series Binhai group,at the upper of the Quaternary sediment, is divided into three parts,the under layer and middle layer are constituted by two littoral facies-river and lake facies sedimentary cycles,the upper layer is constituted by paludal facies,which was deposited at the lower-lying land like West Lake, Jiangcun-Gu dang,Xianghu lake,and coastal-estuary facies in other area.3、Folding and fault activities were weak in Quaternary and the tectonic activity had little influence on the Quaternary sedimentation.The ancient landforms,the evolvement of the river system and transgression were the main elements which controlled the Quaternary sedimentation in Hangzhou.The ancient landforms formed the basis of the Quaternary sedimentation.The evolvement of the river system and transgression individually or jointly controlled the Quaternary sedimentation of this area.4、The alternation of the climate was the main reason for the evolvement of the river systems and transgression,and it\'s also the reason why the Quaternary system of Hangzhou has the special sedimentary structure which is called soft interbed with hard layers.

通过研究取得了以下成果：1、根据岩性、岩相、成因类型和地貌特点，将本区第四系划分为山麓沟谷区沉积和平原区沉积：山麓沟谷区第四系主要分布于西部丘陵地区，厚度较薄且变幅大，一般厚3～20m；平原区第四系广布分区，由南西向北东逐渐增厚，一般厚30～60m.2、平原区第四系自下而上大体由五个完整或不完整的沉积旋回构成：底部上更新统全塘组，由河流相—河湖相的沉积旋回构成；中部上更新统嘉善组，由河流相—浅海相—河湖相两个沉积旋回构成；上部全新统滨海组，其下中两段由滨海海湾相—河湖相的两个沉积旋回构成，上段由西湖、蒋村—古荡、湘湖等低洼处沉积的湖沼相和其他地区沉积的滨海河口相构成。3、第四纪以来，研究区内褶皱、断裂活动微弱，构造运动对第四系沉积的影响不大，古地形、古水系的发育、变迁和海侵是杭州市第四系沉积的主要控制因素：古地形构成了第四系沉积的基底，水系与海侵在其后的不同阶段或分别或联合的主导了区内的第四系沉积。4、水系的发育、变迁和海侵的共同原因是天气变化，正是由于第四纪以来"冷热交替"的天气特点形成了杭州市第四系"软硬互层"的特殊沉积结构。

Because the formers mainly used morphological methods, such as step number and elevation of terrace, canyon character, relationship of topographical units, there has no unified conclusion to origin of the Three Gorges.

Willis在1903年提及，迄今已有近100年的历史，但是由于前人主要依据阶地的级数、高程等特征，三峡峡谷特征，地貌间相互关系等地貌学方面的研究，造成三峡成因上的次成谷和先成谷之争、三峡形成时间早晚之争一直难有定论。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。