A model of rift basin evolution constrained by first‐order stratigraphic observations

Abstract

Abstract. The stratigraphy of many nonmarine rift basins records a common sedimentological history consisting of a relatively abrupt increase of water depth followed by a slower shoaling upward trend. We explore in this paper the origin of these sequences through a three-dimensional physical model that incorporates the affects of fault growth, flexure, erosion, sedimentation, and isostasy. Fault growth is assumed to occur in a self-similar manner and is treated as dislocations inducing flexure in a thin elastic plate. Topography generated by faulting and flexure is allowed to undergo diffusion to simulate erosive and sedimentary processes. Isostatic response to the redistribution of mass results in additional flexure of the thin plate. The model is tested using two models of fault growth, and we compare the numerical results with the stratigraphy observed in nonmarine rifts. Basins generated using a constant-lengthening-rate mode of fault growth fail to reproduce the stratigraphy of continental rift basins. We find that the commonly observed stratigraphic succession of lacustrine to fluvial conditions requires the displacement rate of the bounding fault to decrease with time, consistent with opening at a relatively constant areal extension rate.

Subsurface seepage of seawater across a barrier: A source of water and salt to peripheral salt basins

“…Assuming that the salt sequence was deposited in a period of 3 m.y., this equates to a post-compaction sedimentation rate of 1.33 mm/yr. In contrast, sedimentation rates of 0.10-0.15 mm/yr appear to be more typical of rifts late in their evolution (Contreras et al, 1997). This suggests that the late Aptian salts fi lled a large topographic basin with a base level substantially below sea level.…”

Finite element modeling of stress distributions and problems for multi-slice longwall mining in Bangladesh, with special reference to the Barapukuria coal mine

“…3b). This produces footwall uplift and hanging-wall subsidence, the latter, which creates the sedimentary basin (e.g., Gibson et al, 1989;Contreras et al, 1997). The structure of the Barapukuria basin is shown in Fig.…”

Subsidence and Stress Change in the Cerro Prieto Geothermal Field, B. C., Mexico

“…We estimate, from published works on compaction (CARILLO, 2003) and isostasy (CONTRERAS et al, 1997;GARCI´A ABDES-LEM, 2003) that these processes together can increase the tectonic subsidence rate by at most 40% of the estimated rate. Even if this additional rate is taken into account, the tectonic subsidence rate in CPCF is still of the order of millimeters per year.…”