This rock contained chalcedonic cement before it underwent diagenesis, a process where low temperatures and low pressures alter the content of sediments before they finally lithify, or turn into rock.
在它经历成
作
之前,它含有燧石质的胶结成分。成
作

中,低温抵压改变了沉
物的成分,而后固结成
。

,斜长石的钠长石化可见于成


