closed fold meaning in English

闭合褶皱

Several propositions about the area of plane close folding
平面闭折线的几个面积定理
Nw compressive structures are developed in indosinian epoch in which folds are predominant and companied with some small thrusts . nearly ns or nnw compressive structures are developed at the end of yanshan epoch in which it is mainly overthrusted structures and closed folded structures . large gentle anticlines and synclines are developed from the end of mesozoic to early tertiary , and antithetic sagging structures are developed in mesozoic
研究发现，本区印支期发育了以褶皱为主、局部伴有小型逆断层的北西向压性构造，燕山末期(中生代末期)发育了以逆掩构造和紧闭的褶皱构造为主的近南北向或北北西向压性构造，中生代末到第三纪早期发育了以宽缓为特征的大型背斜向斜构造，以及中生界内部的逆牵引构造。