Eolian event stratigraphy - A conceptual framework
- Univ. of Texas, Austin (United States)
A basis for eolian event stratigraphy is to distill the impact of events into fundamental processes and products. For accumulation (net deposit through time) to occur, the sediment budget must be positive. If the sediment budget becomes neutral or negative, accumulation ceases and a bypass or erosional super bounding surface, respectively, forms capping the genetic unit. Within the three types of eolian systems (dry, wet, stabilized), the mechanisms of accumulation and super-surface formation differ. In the dry system, accumulation occurs because of areal deceleration of sand-carrying winds. Because of dune-interdune flow conditions, accumulation begins when interdune flats are closed, requiring sand supply, time, and conditions for dune growth at the expense of interdune flats. In the wet system, accumulation of dune and interdune deposits occurs by trapping with a rising water table. Accumulations vary with the nature of the water table rise, proportion of dunes and interdune flats, and interdune topography. In the stabilized system, accumulation occurs with rapid stabilization of elements of active eolian systems; super surfaces form when the causes of stabilization cease. The eolian rock record consists of preserved accumulations and super surfaces. Accumulation space is distinct from preservation space. Preservation space is made by subsidence and water table rise. Without preservation space, an unconformity results. The dominance of subsidence versus water table rise is reflected in dry and wet accumulations respectively, such as the Jurassic Navajo and Entrada sandstones.
- OSTI ID:
- 5739027
- Report Number(s):
- CONF-910403--
- Journal Information:
- AAPG Bulletin (American Association of Petroleum Geologists); (United States), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Vol. 75:3; ISSN AABUD; ISSN 0149-1423
- Country of Publication:
- United States
- Language:
- English
Similar Records
Controls on eolian facies architecture, Middle Jurassic Page Sandstone, Colorado plateau
Eolian paleotopographic highs as stratigraphic traps: origin and distinction