ABSTRACT STANDARD, ISSAC DANIEL, Kinematics and timing of the Gold Hill fault zone in the vicinity of High Rock Lake, south-central North Carolina. James P. Hibbard, Ph.D., committee chair. The Gold Hill fault zone is a first-order structure in the Carolina Zone of the southern Appalachians that separates medium grade ductiley deformed rocks of the Charlotte terrane from low grade, mildly deformed rocks of the Carolina terrane. Based on circumstantial evidence, the Gold Hill fault zone has traditionally been viewed as a Devonian dextral shear zone. However, at the western boundary of the Carolina terrane, Late Ordovician, northeast trending, en echelon regional folds are truncated by the north-northeast-trending Gold Hill fault zone. The orientation of these folds relative to the trace of the Gold Hill fault zone suggests previously undocumented early sinistral shear along this major structure. In this vein, new work involving structural mapping and modern kinematic analysis has been undertaken near High Rock Lake, North Carolina in order to investigate the early history of the Gold Hill fault zone. At the western boundary of the Carolina terrane in the vicinity of High Rock Lake, lower to middle greenschist facies rocks of the Albemarle Group are folded about the southwest plunging axis of the Silver Valley syncline and imprinted by a steep northeast- striking axial planar cleavage. In this area, the Gold Hill fault truncates structures associated with the Silver Valley syncline and separates two distinct structural domains. The southwestern domain is characterized by lower to middle greenschist facies unseparated Albemarle Group units deformed by upright, southwest-trending, outcrop-scale folds that contain a steep, north-northeast to northeast striking axial planar cleavage. The folds and cleavage in this domain are similar in geometry and style to the Silver Valley syncline and are interpreted to be genetically related to regional folds in the Carolina terrane. The northwestern domain consists of upper greenschist facies phyllitic volcaniclastic rocks of the western belt. Foliation surfaces in this domain, which strike north-northeast and dip steeply, contain a consistent sub-vertical stretching lineation, as well as a heterogeneously distributed sub-horizontal stretching lineation. Kinematic indicators suggest that motion on the Gold Hill fault zone involved thrusting of the western belt (hanging wall) over the Carolina terrane (foot wall) coupled with a component of sinistral strike-slip motion. These new structural and kinematic relationships suggest Late Ordovician or younger sinistral transpression that may be related to the accretion of the Carolina Zone to Laurentia. KINEMATICS AND TIMING OF THE GOLD HILL FAULT ZONE IN THE VICINITY OF HIGH ROCK LAKE, SOUTH-CENTRAL NORTH CAROLINA by ISSAC DANIEL STANDARD A thesis submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirements for the Degree of Master of Science MARINE, EARTH, AND ATMOSPHERIC SCIENCE Raleigh 2003 BIOGRAPHY The author was born in Covington, Georgia on September 2, 1976. Living in Covington, Georgia, he began a long and distinguished career as a student at institutions including Palmer Stone Elementary, George Walton Academy, and Athens Christian School. Finally, he acquired a diploma from Newton County High School in the summer of 1995. Deciding to exceed the expectations of his community, the author attended Abraham Baldwin Agricultural College in Tifton, Georgia in the fall of 1995. However, romantic interests led him to Statesboro, Georgia the following year. In Statesboro, the author enrolled at Georgia Southern University as a business major and proceeded to live the good life at the expense of his parents, occasionally working as contractor, rain station operator, and cotton scout during the summer. In 1998, he was introduced to Dr. Charles H. Trupe, a surly but respectable man who fostered a passion for geology in the author. In the spring of 2000, the author received a Bachelor of Science degree in geology after the completion of his senior research on the Burnsville fault, a Paleozoic shear zone in the North Carolina Blue Ridge (Standard and Trupe, 2000). Intent on avoiding the “straight life”, the author left his home state to become a graduate student under the direction of Dr. James P. Hibbard at North Carolina State University in the fall of 2000. At NCSU, the author underwent rigorous training in Appalachian geology, structural geology, isotopic geology, and metamorphic geology. Using the alias “Si′ mon Dumas”, he escaped the taxing nature of course work and research through deviant behavior in the company of various reprobate individuals. Realizing the error of his ways, the author began attending church in an attempt to reform his life. With a new, positive outlook on the future, he completed his research and received his Master of Science degree in geology from NCSU in the fall of 2003 for the work presented in this thesis. ii ACKNOWLEDGMENTS My greatest thanks go to Dr. James P. Hibbard, Dr. Edward F. Stoddard, and Dr. Brent V. Miller for being the members of my advisory committee and furthering my knowledge of geology in the classroom. I especially thank Dr. Hibbard for the motivation, advisement, criticism, and funding that made it possible for me to contribute to his research. I also thank my fellow graduate student and friend, Brad Carter, for providing academic insight into both this project and my course work. I thank Dr. Charles H. Trupe for being a mentor to my career and for the strong background in structural and field geology that I received as an undergraduate. I am forever grateful to my parents for the emotional and financial support that has allowed me to succeed beyond my own expectations. Finally, above all, I thank God for His obvious and undeserved hand in my life. The primary funding for this project was provided by the National Science Foundation, NSF grant number EAR 0106112 to James Hibbard. Partial funding was provided by the North Carolina Geological Survey. iii TABLE OF CONTENTS LIST OF FIGURES.................................................................................................................vii LIST OF MINERAL ABBREVIATIONS...............................................................................ix INTRODUCTION....................................................................................................................1 Focus of Study...............................................................................................................1 Regional Setting..............................................................................................................5 Previous Work ...............................................................................................................9 Location of Study Area................................................................................................12 Research Methodology................................................................................................13 Revision of Nomenclature............................................................................................14 LITHOLOGIC UNITS............................................................................................................15 General Statement.......................................................................................................15 Albemarle Group..............................................................................................16 Cid Formation......................................................................................16 Distribution..............................................................................16 Rock Types..............................................................................17 Contacts...................................................................................19 Age...........................................................................................19 Floyd Church Formation......................................................................20 Distribution..............................................................................20 Rock Types..............................................................................20 Sedimentary Rocks.......................................................20 Volcanic Rocks.............................................................23 Contacts...................................................................................24 Age...........................................................................................24 Unseparated Albemarle Group........................................................................25 Distribution..........................................................................................25 Rock Types..........................................................................................25 Sedimentary Rocks...................................................................25 Volcanic Rocks.........................................................................27 Phyllite.....................................................................................27 Contacts...............................................................................................28 Age and Correlation..............................................................................28 Western Belt.....................................................................................................29