褶皱轴

通过对各期构造的褶皱轴迹和共轭节理的统计分析，恢复了印支期、燕山期、喜山期构造的古应力场。

By statistics and analysis of fold axis 、 lines and conjugate joints in structures of every stages , the paleotectonic stress fields in Indo-chinese stage , Yanshan stage and Himalayan stage were resumed .

结果显示，唐山矿推覆构造的走向与煤田内褶皱轴大致平行，沿地层走向呈NE向；

The result shows that the trend of nappe structure is approximately parallel with axis of folds in the coal field , trending NE along the formation strike .

地质构造中任意类型褶皱轴面的位置、产状及其变化的测定

Measurement of position and occurrence of axis plane of all folded types and their changes in geological structure

金矿体呈透镜状、脉状，产状受北东向褶皱轴及层间破碎带控制；中生代脉岩与矿体相互穿切。

The attitude of orebody accords with the strata , and is controlled by the axis of folding and interlamination broken belt .

认为区内褶曲发育，褶皱轴部地带为裂隙发育带，煤层裂隙发育，连通性好，具备储层渗透性好的优势；

Considered that well-developed folds in the area , thus the axial zones of folds must be well-developed fissure zones , good connectivity make the reservoir provided with good permeability ;

第二期形成北东向中常褶皱及轴面折劈理；

The second by north east-trend neutral folds and axial crenulation cleavage ;

片理（劈理）为早世代挤压-剪切褶皱的轴面片理，又成为晚世代弯滑褶皱的滑动面；

The cleavage and schistosity acted as an axial plane role in the early generation of compressed shear fold , and changed into a slip plane in the later generation of flexural slip fold .

根据断层性质与大小主应力的方向关系、褶皱构造的轴面方向等得出区域最大主应力的方向为NE-NW向。

According to the relationship between fault properties and directions of principle stresses , the directions of the axial planes of the folds , the direction of maximum principal stress in this area is NE-NW trending .

晚期为直立褶皱，褶皱轴主要为北东&北北西向。

The late stage of superposed folding structures are upright folds with the northeastern and north-northwestern fold axial trend .

本文介绍了求解褶皱枢纽及轴面，确定π组构类型和褶皱位态分类的计算机方法原理，程序使用方法（资料收集、程序操作步骤等）和效果。

The principles of computer methods in determination of fold hinge , axial plane , type of π fabric and in classification of fold orientation are discussed .

第一期北西向褶皱构造为轴向北西的断层转折褶皱，形成于中寒武世&泥盆纪，它们当时都是一些水下隆起，在全区均有分布。

The first generational northwest folds were fault band folds , formed during Middle Cambrian to Devonian , which were under water uplift , distributed over the whole studied area .

晚中新世-上新世初的冲绳海槽运动一幕使东亚大陆边缘的古岛弧褶皱隆起，在褶皱轴部形成张裂地堑，形成冲绳海槽的雏形，琉球弧地块从东亚大陆裂离；

The first phase of the OT movement occurred from the late Miocene to the early Pliocene , which caused the former island arc at the margin of the east Asia mainland folded and upwarped .

晚期褶皱表现为不同时代、不同方向、不同类型的叠加褶皱，轴面近直立，有时伴有轴面劈理。

The later folding is characterized by the superposition of folds of different ages and orientations , nearly-vertical axial-plane and rare cleavages .