粒度中值 meaning in English

median grain diameter
median particle size
median size

The paper divided turbidite fan in deep water from long source into braided channel microfacies , inter - braided channel microfacies , medium fan over - belt microfacies , and external fan subfacies , and divided slump turbidite which related with delta into medium fan subfacies and external fan subfacies , and summed up 15 kinds of marking of subfacies and microfacies classification . at the same time , it formed a series of effective technology of analyzing turbidite source at the base of studying region geological which combined with analyzing the content change of terrigenous debris , with the found of logging facies , and with the ancient terrestrial magnetism test and other technology means under the guidance of three - dimensional model of turbidite which has been founded already and the flat surface feature of microfacies
将远源深水浊积扇划分为辫状水道微相、辫状水道间微相、中扇过渡带微相和外扇亚相；将与三角洲有关的滑塌浊积扇划分为中扇和外扇两个亚相，并总结了浊积岩沉积划分各种亚相、微相类型的十四种标志，分别为:岩石类型、层理类型、砂岩单层厚度、粒度结构特征(粒度中值、分选性、概率曲线) 、生物化石、储层物性(孔隙度、渗透率) 、泥岩隔层特征(泥岩单层厚度、层数、颜色) 、鲍玛层序组合和自然电位曲线特征。