Effects of Relative Sea-Level Changes and Local Tectonics on a Lower Cretaceous Fluvial to Transitional Marine Sequence, Bighorn Basin, Wyoming, USA

  1. M. Marzo and
  2. C. Puigdefábregas
  1. E. P. Kvale1 and
  2. C. F. Vondra2

Published Online: 14 APR 2009

DOI: 10.1002/9781444303995.ch25

Alluvial Sedimentation

Alluvial Sedimentation

How to Cite

Kvale, E. P. and Vondra, C. F. (1993) Effects of Relative Sea-Level Changes and Local Tectonics on a Lower Cretaceous Fluvial to Transitional Marine Sequence, Bighorn Basin, Wyoming, USA, in Alluvial Sedimentation (eds M. Marzo and C. Puigdefábregas), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303995.ch25

Editor Information

  1. Barcelona, Spain

Author Information

  1. 1

    Indiana Geological Survey, 611 N. Walnut Grove, Bloomington, IN 47405, USA

  2. 2

    Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA 50011, USA

Publication History

  1. Published Online: 14 APR 2009
  2. Published Print: 16 SEP 1993

ISBN Information

Print ISBN: 9780632035458

Online ISBN: 9781444303995

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Keywords:

  • Effects of relative sea-level changes;
  • a large, fluvially dominated straight channel (upper estuary);
  • a mud-dominated mixed fluvial-tidal channel (middle estuary);
  • a small, high sinuosity fluvial channel (small tributary);
  • sub-Greybull interval unconformity;
  • Sykes Mountain Formation overlies Greybull interval ,consists of dark siltstones,interbedded

Summary

The upper part of the Himes Member (‘Greybull interval’) of the Lower Cretaceous Cloverly Formation, in the Bighorn Basin of northern Wyoming is non-marine to transitional marine in origin and formed during an Early Cretaceous marine transgression. Three distinct channel-fill types are recognized in the upper Himes sequence and can be interpreted to represent deposition in: (i) a large, fluvially dominated straight channel (upper estuary), (ii) a mud-dominated mixed fluvial–tidal channel (middle estuary), and (iii) a small, high sinuosity fluvial channel (small tributary). The dominant sediment source for sands in the upper Himes was to the east, possibly the craton. The Sykes Mountain Formation conformably overlies the upper Himes and records a change from transitional marine to fully marine conditions upwards. In the lower part, the Sykes Mountain Formation is characterized by sheet sandstones, interpreted to be storm deposits, that are interbedded with mudstones. Locally, the sheet sandstones are cut by shoreward-directed (easterly directed) tidal channel bodies deposited in a lower estuary. The ‘Greybull interval’ overlies a regional unconformity that formed during an Early Cretaceous (late Aptian to early Albian) relative sea-level drop. Relief on the unconformity is as much as 23 m. Sea-level rise initiated the formation of estuaries with local tectonic effects influencing the placement of some of these.