转化期 meaning in English

conversion period

It could be divided into six paleogeotemperature evolution stages from early cretaceous to recent based on the result of apatite fission - tracks analysis ; subsidence - buried history analysis shows that chagan experienced fault depression stage during early cretaceous bayingebi - suhongtu period , transional stage from fault depression to sag in yingen period , and sag stage since wulansuhai stage
磷灰石裂变径迹模拟分析结果认为早白垩世至今大致可分为6个古地温演化阶段；沉降?埋藏史模拟揭示查干凹陷经历了早白垩世巴音戈壁?苏红图期的断陷期、银根期的断?坳陷转化期和晚白垩世乌兰苏海期以来的坳陷期。