Changes

==Shale ductility vs. depth==

==Shale ductility vs. depth==

The ductility of a shale top seal ''decreases'' with progressive burial, compaction, and diagenesis within a sedimentary basin. The mechanical properties are not constant but change with progressive burial as the top seal is converted from a mud to a rock.

The ductility of a shale top seal ''decreases'' with progressive burial, compaction, and [[diagenesis]] within a sedimentary basin. The mechanical properties are not constant but change with progressive burial as the top seal is converted from a mud to a rock.

The ductility of a shale top seal also ''increases'' in response to increasing confining pressure. Thus, a shale with constant mechanical properties will have a lower ductility at shallow depths than at greater depth. Since a shale top seal does not have constant mechanical properties with progressive burial, compaction decreases ductility at the same time as confining pressure increases ductility.

The ductility of a shale top seal also ''increases'' in response to increasing confining pressure. Thus, a shale with constant mechanical properties will have a lower ductility at shallow depths than at greater depth. Since a shale top seal does not have constant mechanical properties with progressive burial, compaction decreases ductility at the same time as confining pressure increases ductility.