Problems for Future Consideration
Although the subsurface information provided by the COCORP reflection data place strong constraints on the crustal structure and evolution of the southern Appalachians, numerous questions remain. It is the purpose of this section to outline some of the fundamental problems which may help to further enhance the understanding of the structural development in the Appalachians. Some examples include:
What is the nature of the reflecting boundaries in the middle crust east of the Inner Piedmont? Are they basinal facies (meta-) sediments which stratigraphically correlate with the layers beneath the Inner Piedmont, or are they unrelated? This question is critical to determining whether the thrusts extend east of the Inner Piedmont, and thus to beneath the present Atlantic shelf.
How do the reflectors beneath the Blue Ridge, Inner Piedmont, Eastern Piedmont, and Coastal Plain vary along strike? Do they vary in thickness and metamorphic grade significantly? Do the faults such as the Brevard and Augusta faults vary in dip along strike?
Are the Precambrian (Grenville) units in the Blue Ridge and Piedmont all underlain by layered reflectors (presumably sediments), and thus allochthonous; or, are some of them autochthonous and thus true fensters through an overlying thrust sheet? Seismic data across the Grandfather Mountain window (Harris and Bayer, 1979a; Harris et al, 1981) and the Green Mountains (Ando et al, in press) can be interpreted to indicate emplacement of the Precambrian (Grenville) rocks along thrust faults, and thus imply they are allochthonous. A particularly important area is the Pine Mountain belt
Figures & Tables
The Cocorp Seismic Reflection Traverse Across the Southern Appalachians
This publication consists of 5 chapters and resulted from the need to incorporate most of the COCORP southern Appalachian seismic reflection data and interpretations into a single work. Presented are ideas and models which are not only internally consistent, but also are consistent with what is known about the major geological and geophysical features.