Middle Ordovician (Chazyan) conodont biostratigraphy and structural geology of the McMullin Syncline, Smyth County, Virginia

The McMullin syncline is located in Smyth County within the Valley and Ridge Province of southwestern Virginia. The syncline lies in a recess along the northern periphery of the Seven Springs-Pulaski thrust and consists of seven small fault blocks which are complicated by three generations of folding, the the F2 and F3 folds trending oblique to nearly perpendicular to regional Appalachian trends. Two components of stress operated on the local area, a major one directed from the southeast and a lesser one from the southwest. The latter component resulted from rotation of the Seven Springs-Pulaski thrust. The Marion, Virginia area where the McMullin syncline occurs developed up-plunge from the Tennessee basin depocenter. The McMullin syncline includes the Middle Ordovician cartonate onlap package which was deposited over the lower Ordovician upper Knox Group during a major transgression. Altogether, 3519 conodonts representing 48 monoelement or multielement apparatuses and 19 form species were recovered. Biostratigraphically important conodonts recovered from this ramp to basin sequence include: Polyplacognathus friendsvillensis, Polyplacognathus sweeti, Eoplacognatus lindstroemi, Pygodus serrus, and Pygodus anserinus. The Polyplacognathus friendsvillensis-P. Sweeti evolutionary lineage is a valuable datum on which to base correlations in the Southern Appalachians. The datum in this study confirms that the transgression moved northwestward. The Lenoir and Arline Formations correlate with the Pygodus serrus Zone of Eergström’s (1971a) North Atlantic zonation and the Effna Formation with the lowermost Pygodus anserinus Zone.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Geology

Department dc:contributor.department

Geology

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1981

Author dc:creator

• Sautter, Nancy J.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/80321

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/80321