Physical Sciences and Mathematics Commons^™

The Timing Of Deformation In The Four Peaks Area, Central Arizona, And Relevance For The Mazatzal Orogeny, Calvin A. Mako

Masters Theses

The Mazatzal orogeny (1.66-1.60 Ga) is a key element of the tectonic evolution of the North American continent during the Proterozoic (Whitmeyer and Karlstrom, 2007). Recently, Mesoproterozoic detrital zircon grains (1.55-1.45 Ga) have been found in metasedimentary rocks that were thought to have been deformed during the Paleoproterozoic Mazatzal orogeny (Jones et al. 2011; Doe et al. 2012, 2013; Daniel et al. 2013). Some type examples Mazatzal deformation now seem to be too young to have been deformed in the accepted time of that orogeny (1.66-1.60 Ga) and may have been deformed in the younger, newly defined, Picuris orogeny. This …

From ~1.5 Ma To Today: Insights Into The Southern San Andreas Fault System From 3d Mechanical Models, Laura Fattaruso

Masters Theses

Three-dimensional mechanical simulations of the San Andreas fault (SAF) within the Coachella Valley in California produce deformation that match geologic observations and demonstrate the impact of fault geometry on uplift patterns. Most models that include the Coachella Valley segment of the SAF have assumed a vertical orientation, but recent studies suggest that this segment dips 60-70° northeast. We compare models with varied fault geometry and evaluate how well they reproduce observed uplift patterns. Our model with a dipping SAF matches geologic observations, while models containing a vertical fault do not. This suggests that the active Coachella Valley segment of the …

Characterizing The Relationship Of Part Of The Inner Piedmont And Pine Mountain Window, Georgia, From Detailed Geologic Mapping, Geochemistry, Geochronology, And Structural Analysis At The Southwestern End Of The Cat Square Terrane, Justin Randolph Rehrer

Masters Theses

Geologic investigations at the southwestern end of the Cat Square terrane (CSt) in central Georgia provided new insight into the complex tectonic history of the Pine Mountain window (PMw) and neighboring Inner Piedmont terranes. Detailed 1:24,000-scale geologic mapping of an approximately 180 km2 area near Barnesville, Georgia has provided the foundation for further geochemical, geochronologic, and structural analyses refining models for tectonic development and emplacement of the CSt and PMw.

Whole-rock geochemical analyses of several CSt amphibolites yielded data suggesting a continental back-arc setting for genesis of the Cat Square basin (CSb). Major element data confirm derivation from a basaltic …

Structural Analysis Of The Tablerock Thrust Sheet, Grandfather Mountain Window, Northwestern North Carolina: Emplacement Kinematics Of A Large Horse In A Major Thrust System, Ann Elizabeth Walker

Masters Theses

The Tablerock thrust sheet is exposed along the southwestern margin of Grandfather Mountain window in northwestern North Carolina, where it separates basement and cover rocks inside the window from basement thrust sheets of the overriding Blue Ridge-Piedmont megathrust sheet. It is a complex of footwall-derived horses of rifted-margin metasedimentary rocks, including Neoproterozoic to Early Cambrian Chilhowee Group quartzite and phyllite, and Shady Dolomite. Penetrative deformation throughout the Tablerock thrust sheet is defined by an extensively transposed foliation, and strong colinearity between well developed transport lineations and SE/NW-trending tight, isoclinal, and sheath folds. Centimeter- to meter-scale sheath folds are common throughout …