--> Normal Fault Control on Accommodation and Sediment Flux in Rift Basins: Examples from Neotectonic Extensional Basins, by R. L. Gawthorpe, A. J. Fraser, and R. E. LL. Collier; #90986 (1994).

Datapages, Inc.Print this page

Abstract: Normal Fault Control on Accommodation and Sediment Flux in Rift Basins: Examples from Neotectonic Extensional Basins

Robert L. Gawthorpe, Alastair J. Fraser, Richard E. LL. Collier

Analysis of active normal fault zones and syn-rift sequences from the Basin and Range Province and the Aegean allows the quantification of slip rates and the spatial variation in sediment flux around rift basins. These factors have a major impact on sequence development in extensional basins and can be related to the large-scale (20-50 km) segmentation of normal fault zones.

Of particular importance is the observation that high rates of hanging-wall subsidence close to the centre of normal fault segments may cancel out the effects of glacio-eustatic sea level fall. Thus, in the centre of fault segments, accommodation development is normally characterized by continual addition of new space. As a result, adjacent to normal faults, sequences lack Type I sequence boundaries and lowstand systems tracts, and stack into aggradational sequence sets. In contrast, away from the fault zone and near segment boundaries, slip rates are much lower and hence relative sea level change is dominated by glacio-eustacy. Relative sea level falls are an important element of accommodation curves resulting in Type I sequence boundaries and lowstand deposits. Sequence stacking pat erns reflect not only glacio-eustatic and local fault-controlled subsidence, but also the interaction of these with adjacent uplifting footwalls and/or regional uplift controls. In addition to tectonically influenced accommodation development, areas of high sediment flux, namely major segment boundaries, and antecedent drainage networks have a strong influence on sequence architecture.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994