Holbrook Anticline, Arizona: An Exposed Analog for Fractured Reservoirs Over Salt-Dissolution Fronts

摘要

Fractured late Paleozoic and Mesozoic strate at the southern edge of the Holbrook basin in east-central Arizona overlie an active salt-dissolution front. Where the evaporites have been dissolved, the overlyig strata have been offset by approximately 100m, creating a draped monocline called the Holbrook Anticline. This dissolution-front monolcine extends along a northwesterly trend for more than 100km. Strata immediately over the dissolution front have been streteched by bending during migration of the front. The regional fractures that were present in these strata have been reactivated in extension, and some of the fractures at the crest of the anticline now have"apertures" up to several meters wide. Large wedges of rock between fractures are locally displaced downward as much as 15m, forming small grabens.