The Upper Mississippian Bluefield Formation in the Central Appalachian Basin: a Hierarchical Sequence Stratigraphic Record of a Greenhouse to Icehouse Transition

The Upper Mississippian (Chesterian) Bluefield Formation of southeastern West Virginia and southwestern Virginia is the basal unit of the Mauch Chunk Group, a succession of predominantly siliciclastic strata sourced from actively rising tectonic highlands east of the Appalachian Basin. The Bluefield Formation conformably overlies shallow-marine carbonate units of the Greenbrier Group, and is unconformably overlain by incised fluvio-estuarine facies of the Stony Gap sandstone member (Hinton Formation). Outcrops along the Allegheny Front were investigated sedimentologically and structurally, and subjected to gamma ray analysis. Composite outcrop sections from deformed rocks of the Allegheny Front were correlated with the relatively undeformed rocks in the subsurface of the Appalachian Basin to the west using over 100 commercial oil and gas test wells. Regional subsurface cross-sections and isopachs define a depocenter in the southeastern part of the study area. Measured outcrop sections reveal that the stratigraphic record in the depocenter consists predominantly of meter-scale, upward-shallowing parasequences, each capped by a flooding surface. These parasequences are stacked into four regionally correlatable depositional sequences. On the basin margin to the southwest and northwest, incised valleys, and fewer meter-scale parasequences characterize depositional sequences. Stacking of parasequences into sequences reflects a hierarchy of greenhouse-type 5th order, and icehouse-type 4th order eustatic changes superimposed on differential subsidence. Due to early Alleghenian thrust loading, the depocenter experienced greater total accommodation, which prevented incision during lowstands. Instead, in the depocenter, lowstands are typified by preservation of 5th order coal-bearing parasequences. Basin-margin areas experienced less total accommodation resulting in development of 4th order lowstand incised valleys and erosive removal of parasequences. This study demonstrates that both tectonic and eustatic forcing mechanisms controlled stratigraphic evolution of the Bluefield Formation.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Geological Sciences

Department dc:contributor.department

Geological Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1999

Author dc:creator

• Maynard, Joel Phillip

Chairs dc:contributor.committeechair

• Law, Richard D.
• Eriksson, Kenneth A.

Committee member dc:contributor.committeemember

• Henika, William S.

• sequence stratigraphy
• Bluefield Formation
• Appalachian basin

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-0105100-144522

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/40533