STRUCTURAL AND KINEMATIC INVESTIGATION OF THE DADEVILLE COMPLEX-BREVARD ZONE CONTACT (SOUTHERN APPALACHIANS): POLYPHASE EMPLACEMENT OF AN ALLOCHTHONOUS TERRANE ON THE LAURENTIAN MARGIN

<p>The Dadeville Complex (DC) lies in the Inner Piedmont of eastern Alabama and western Georgia. The DC formed as a volcanic island arc during the Taconic orogeny (Ordovician Period) and was accreted onto Laurentia during the Acadian orogeny (Devonian-Mississippian Periods); however, the mechanism and role of accretion during the Acadian orogeny is not well constrained. Three proposed emplacement mechanisms for the DC include: (1) orogen-perpendicular translation; (2) orogen-parallel translation; (3) orogenic channel flow.</p> <p>Today, the DC is a major (over 100 kilometers long) allochthonous terrane composed mostly of meta-igneous rocks. This study investigated structural fabrics and kinematic indicators in the Ponders quadrangle in eastern Alabama, which includes the DC and Brevard Zone, one of the largest shear zones in the southern Appalachians, to assess the emplacement models.</p> <p>Map patterns in the study area indicate two distinct sets of folds in the DC. F1 folds are north or south trending and were created by east-west oriented shortening (D1). F2 folds are east or west trending and were formed by north-south directed shortening (D2). D2 created the shallowly east or west plunging mineral lineations and also refolded F1 to create doubly-plunging hinges. Both deformational events occurred during the Acadian/Neoacadian orogeny at peak amphibolite-facies metamorphism. The DC was accreted onto Laurentia in two stages with distinct shortening directions, potentially due to rotation along the Alabama promontory.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Year dc:date.available

2023

Author dc:creator

• Williams, Andrew

Contributors dc:contributor

• Dr. Jeremy Deans
• Dr. Alyson Brink
• Dr. Franklin Heitmuller

• Dadeville Complex
• Brevard Zone
• Island Arc
• Appalachian Mountains
• Structural Geology
• Alabama
• Geology
• Tectonics and Structure

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/998

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-2054