adj.分角的(略帶棱角的；半多角形；半多角形砂)
The middle oil-member is characterized by medium-sized sandstone and pebbled sandstone, with fair sorting and subangular sphaericity.Rock types mainly were feldspar debris sandstone. 中油組主要沉積中砂巖和含礫中砂巖，粒度整體較粗，分選性較好，磨圓度以次棱角狀為主，巖石類型為長石巖屑砂巖。
