Title page for ETD etd-11202012-040151
|Type of Document
||Laughlin, Kenneth J.
||Interpretation of refraction and reflection stack data over the Brevard fault zone in South Carolina
||Master of Science
|Costain, John K.
|Robinson, Edwin S.
|Date of Defense
Near surface structures across the Brevard fault zone are studied using the refraction and reflection arrivals recovered from the Appalachian Ultradeep Core Hole (ADCOH) regional seismic
Line 1. In using refracted arrivals, a new processing approach is introduced that translates refracted
first arrivals from multifold seismic data into a refraction stack of two-way delay time sections.
Reprocessing of reflected arrivals has improved shallow reflectors and allowed better imaging of the
Brevard fault zone. Following processing of refraction and reflection arrivals independently, both
data sets are combined into a composite stack section. The composite stack section displays one
bright refractor interpreted as the boundary between the weathered layer and high velocity crystalline
rocks. This refractor is continuous in the Inner Piedmont with occasional vertical offsets. The
continuity of the refractor diminishes across the Brevard fault zone. In the eastern Blue Ridge, the
refractor is discontinuous with high angle truncations. On the composite stack section, the Brevard
fault zone can be traced from the surface to 6 km (2 s) where it appears to splay from the Blue
Ridge thrust. Different from previous interpretations, the Brevard fault zone is imaged as having
both an upper and a lower boundary surface as well as a group of reflectors within the zone. This
reflection package initially thickens to 2 km at 3 km depth, then thins as it reaches the Blue Ridge
master decollement. The Blue Ridge thrust is as shallow as 1.5 km (0.5 s) at the northwest end of
the Line l. A deeper decollement is interpreted below the Blue Ridge thrust. The depth of this
deeper thrust is 3 km (1 s) at the northwest end of the line, and also joins to the Blue Ridge thrust
at 6 km depth making the structures below the Brevard fault zone more complex than previously
|| Approximate Download Time
| 28.8 Modem
|| 56K Modem
|| ISDN (64 Kb)
|| ISDN (128 Kb)
|| Higher-speed Access
next to an author's name indicates that all
files or directories associated with their ETD
are accessible from the Virginia Tech campus network only.
If you have questions or technical
problems, please Contact DLA.