A STRUCTURAL ANALYSIS OF SUBORDINATE FOLDS AT TONGBAI, HENAN PROVINCE
Cai Xuelin;Shi Shaoqing;Feng Guangzhong Chengdu College of Geology Geologcal team No. 3, Henan Geological Bureau
Through the investigation of the Heqianzhuang anticline structure,Tongbai, Henan Province,the subordinate folds and their relationship withthe major fold are described. 1, The subordinate folds are medium to Small sized secondary foldsformed simultaneously with the major one. Those formed at the limbs ofthe major fold by intra-formational shear-sliping are called drag folds.Those caused by squeezing at the core area of the major fold are calleddiapiric folds, which developed somewhat later than the drag folds. 2, Morphologically there is no obvious interdependent relationshipbetween the subordinate folds and the major fold. However, on the basisof statistical analysis, the pivot occurrences of the major fold can be pre-dicted from the occurrences of the subordinate folds.