常見例句Topset, foreset, and bottomset beds normally developed. 頂積、前積和底積層均正常發(fā)育。From some field investigations (like Lake Constance and Lake Mead), the shape of a delta is not a Gilbert delta.Slope evolution between foreset and bottomset is not sharp but smooth. 摘要:儅河川流入湖泊或水庫(kù)時(shí)，若河川的密度是高於湖泊，這時(shí)河川就會(huì)潛沒入湖泊的底部形成異重流。bottomset bed 底積層bottomset beds 底積層 返回 bottomset