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