Changes

==Identifying unconformities==

==Identifying unconformities==

Unconformities are [[Hierarchy of sequences|third-order]] sequence boundaries. They are generally regional onlap surfaces. In ''basinal settings'', they are characterized by onlap of allochthonous deposits (i.e., debris flows, slump deposits, turbidites), prograding deltas, carbonate platform deposits, or evaporites. In ''shallow-water or nonmarine settings'', they are characterized by onlap of strata deposited in fluvial, deltaic, or nearshore marine or peritidal environments.<ref name=ch21r48>Weber, L., J., Sarg, J., F., Wright, F., M., 1995, Sequence stratigraphy and reservoir delineation of the middle Pennsylvanian (Desmoinesian), Paradox basin and Aneth field, southwestern U., S., A., in Read, J., F., Weber, L., J., Sarg, J., F., Wright, F., M., eds., Milankovitch Sea-Level Changes, Cycles, and Reservoirs on Carbonate Platforms in Greenhouse and Ice-House Worlds: SEPM Short Course No. 35, 79 p.</ref> We can identify unconformities using stratigraphic evidence and individual well evidence.

Unconformities are [[Hierarchy of sequences|third-order]] sequence boundaries. They are generally regional onlap surfaces. In ''basinal settings'', they are characterized by onlap of allochthonous deposits (i.e., debris flows, slump deposits, turbidites), [[Well_log_sequence_analysis#Parasequence_stacking_patterns|prograding]] deltas, carbonate platform deposits, or evaporites. In ''shallow-water or nonmarine settings'', they are characterized by onlap of strata deposited in fluvial, deltaic, or nearshore marine or peritidal environments.<ref name=ch21r48>Weber, L., J., Sarg, J., F., Wright, F., M., 1995, Sequence stratigraphy and reservoir delineation of the middle Pennsylvanian (Desmoinesian), Paradox basin and Aneth field, southwestern U., S., A., in Read, J., F., Weber, L., J., Sarg, J., F., Wright, F., M., eds., Milankovitch Sea-Level Changes, Cycles, and Reservoirs on Carbonate Platforms in Greenhouse and Ice-House Worlds: SEPM Short Course No. 35, 79 p.</ref> We can identify unconformities using stratigraphic evidence and individual well evidence.

===Stratigraphic evidence===

===Stratigraphic evidence===