descensional

from The Century Dictionary.

• Specifically, in geology, noting the disaggregation of the antecedent rock, the separation of unlike particles, and their final aggregation in beds; noting the breaking down of complex silicates, the solution of certain original components, and a gathering of the modified and assorted product into stratified deposits.
• Of or pertaining to descension or descent.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Pertaining to descension.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Relating to descension.