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.
它经历成岩作用之前,它含有燧石质的胶结成分。成岩作用
程中,低温抵压改变了沉
物的成分,而后固结成岩。