燧石质

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.

在成岩作用之前，含有燧石质的胶结成。成岩作用过程中，低温抵压改变了沉物的成，而后固结成岩。