Abstract

Depositional systems recorded in cratonic successions are formed by fluvial, eolian, deltaic, wave, storm, and tidal processes. Their spatial and temporal distribution is controlled by tectonic uplift, the areal width over which marine processes inundate cratons, and climate.

The craton width of marine sedimentation appears to control the lateral and vertical distribution of sediment depositional systems. For transgressive clastic sequences, craton widths are narrow and are dominated by subtidal and coastal storm-generated and wave-dominated barrier depositional systems, during early phases of transgression. As the craton becomes submerged over a wider area, tidal depositional systems become dominant and include subtidal sand bodies and coastal tidal flats. During regression, fluvial and eolian depositional systems become dominant.

Tectonism controls the facies patterns in two ways. If tectonism is active during deposition, cratonic sequences of narrower shelves, dominated by wave and storm depositional systems, seem to be characteristic. If tectonism consists of uplifts confined to the margins of the craton, sediment yield increases onto the craton, favoring regressive fluvial and deltaic depositional systems.

Although the climatic variable is more difficult to evaluate, it tends to control the occurrence of clastic sediments (more humid) and carbonate sediments (arid, tropical). In tropical and subtropical latitudes, a carbonate facies distribution is favored, and the stratigraphic development of depositional systems controlled by increasing width of cratonic inundation by marine processes occurs in much the same way as suggested for clastic sediments. If tectonic uplift is active in areas adjoining carbonate cratonic sedimentation, a regressive deltaic clastic wedge occurs, instead of nonmarine eolian sediments, which appear to be normative regressive sediments in carbonate terrains.

First Page Preview

First page PDF preview
You do not currently have access to this article.