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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 69 (1985)

Issue: 2. (February)

First Page: 269

Last Page: 269

Title: Mechanical Analysis of Salt Dome Growth in East Texas Basin: ABSTRACT

Author(s): Frank Irwin, Raymond C. Fletcher

Article Type: Meeting abstract


Analysis of the early pillow phase of salt dome growth is used to interpret observations of salt dome growth in the East Texas basin. Two limiting models are those of "redistribution" (R), in which erosion and sedimentation keep the overburden surface planar, and "no redistribution" (NR), in which the topography induced by dome growth is not modified. Spacing between nearest neighbor domes, (13 ± 4 km) and initial salt thickness (h = 1.8 ± 0.3 km) yields a spacing/thickness ratio of 7, with range from 4 to 11. If salt viscosity (^eegr) is less than overburden viscosity (^eegr1), and overburden thickness is h1 >= h, this implies 0.01 < ^eegr/^eegr1 < 1 for both (R) and (NR). Growth rate is proportional to amplitude (dA/dt = A/t*), where A is half the relief between the pillow top and the lowest point of the peripheral sink, and t* is a characteristic time. For a salt viscosity of 1018 poise, and a density contrast of 0.2 g/cm3 , t* ranges from 0.1 to 1 m.y. for (R), with values 2-5 times larger for (NR). For the former, a dome with 100-m amplitude grows at rates ranging from 1,000 to 100 m/m.y.; maximum reported rates of 40-100 m/m.y. are in fair agreement. Both facies patterns around domes and slower growth rates can be explained by the presence of substantial dome-induced topography. Spatial patterns and growth histories of groups of domes are investigated by following the development of a variety of local perturbations.

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