Research about Southern Appalachians

USGS1987

Alleghanian deformation, metamorphism, and granite emplacement in the central Piedmont of the southern Appalachians

Evidence of late Paleozoic (Alleghanian) penetrative deformation, amphilbolite-facies, metamorphism, and syntectonic granite emplacement has been found in an area of the central Piedmont in the southern Appalachians. The High Shoals Granite batholith in the Kings Mountain belt of south-central North Carolina consists of coarse-grained, megacrystic biotite granite with a strong, nearly vertical, gneissoid, foliation, defined by parallel feldspar megacrysts and biotite. U-Ph isotopic data on zircons from the granite yield a concordant age of 317 Ma (Pennsylvanian). This pervasively deformed late Paleozoic granite in the central Piedmont is far west of those known in the Kiokee and Raleigh belts. Field relationships indicate that the High Shoals Granite was emplaced during the late stages of regional F2 folding, close in time to the thermal peak of amphibolite-facies metamorphism. Mineral assemblages typical of Barrovian metamorphism are found in zones of decreasing grade away from the High Shoals contact. These zones, delimited by a kyanite(out)-sillimanite (in) isograd which completely surrounds the batholith and by part of a regional chloritoid (out)-staurolite (in) isograd west and southwest of it, conform to the shape of the batholith and cut across F2 folds. Furthermore, hornblendes from epidoteamphibolite facies to upper amphibolite facies metamorphic rocks in the Kings Mountain belt of North Carolina and South Carolina yield 40Ar/39Ar plateau ages of 318 to 323 Ma. These dates are analytically the same as the crystallization age of High Shoals Granite as established of zireon using the U-Ph method and demonstrate the synchroneity of intrusion of the High Shoals with the dominant regional metamorphism in this part of the Kings Mountain belt.

Southern Appalachians↗

USGS1905

The southern Appalachian forests

In examining so large an area it was found that the best results could be obtained by traversing the roads and trails and making side trips wherever necessary to cover intermediate territory. Upon the topographic maps of the Geological Survey were drawn the outlines of cleared land and the several classes of forest land as they were passed. At the same time ocular estimates of the average stand and the proportion of the species composing it were made, checked occasionally by actual measurements on small representative areas. After the outlines of the several classes of land were drawn the areas were computed from the map, and the yield obtained by multiplying the number of acres of each class by the average stand. The yield is stated in feet B. M. of log timber, and cords of small wood (which includes all wood not classed as log timber). The estimates of log timber were based upon the closest cutting in practice in the United States, and include a great deal of material that is not now salable on the stump, because of the difficulty of transportation. In fact, a very small proportion of the amount estimated (probably not over 10 per cent) is merchantable under present conditions, though all would be merchantable if cheap transportation should make it accessible.

Georgia, North Carolina, South Carolina. Tennessee↗