--> ABSTRACT: Signatures of Climate vs. Sea-Level Change in Quaternary Incised Valley-Fill Successions: Examples from the Texas Gulf Coast, by Blum, Mike; #90026 (2004)
[First Hit]

Datapages, Inc.Print this page

Blum, Mike1
(1) Louisiana State University, Baton Rouge, LA

ABSTRACT: Signatures of Climate vs. Previous HitSeaNext Hit-Previous HitLevelNext Hit Change in Quaternary Incised Valley-Fill Successions: Examples from the Texas Gulf Coast

Recognizing the signatures of climate vs. Previous HitseaNext Hit-Previous HitlevelNext Hit change within incised valley fills has become increasingly important. For Quaternary analog Previous HitsystemsNext Hit, reconstructions of changes through time in long profiles, as geometric representations of former floodplain surfaces, play key roles in understanding the relative importance of climatic vs. Previous HitseaNext Hit-Previous HitlevelNext Hit controls.
Based on data from river Previous HitsystemsNext Hit of the passive margin Texas Coast, the fundamental signature of climatically-modulated changes in discharge and sediment load is illustrated by downstream continuity of long profiles, stratigraphic units, and component facies. This continuity extends from upstream, where Previous HitseaNext Hit Previous HitlevelNext Hit is not an issue, downstream to where Previous HitseaNext Hit-Previous HitlevelNext Hit change becomes increasingly important. Conversely, the influence of Previous HitseaNext Hit-Previous HitlevelNext Hit change is shown by downstream crossovers in long profiles and systematic changes in stacking patterns for stratigraphic units that represent different periods within a eustatic Previous HitcycleNext Hit.
Previous HitSeaNext Hit-Previous HitlevelNext Hit change is a necessary condition for large-scale incision and partitioning of incised valleys as channels extend basinward, or large-scale valley filling as channels shorten during Previous HitseaNext Hit-Previous HitlevelNext Hit rise, but climate changes in the hinterland trigger such events. Interactions between climate and Previous HitseaNext Hit-Previous HitlevelNext Hit change therefore control changes in accumulation space and resultant valley-fill stratigraphic architecture. However, preservation in the stratigraphic record reflects controls that operate over different time scales. Upstream from a passive margin flexural hinge, preservation space is zero, and the record will be eroded away. Preservation space increases downstream and preservation of the signatures of climate vs. Previous HitseaNext Hit-Previous HitlevelTop change depends on how rapidly the record subsides below the maximum lowstand depth of incision.

 

AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.