OF SOUTH CAROLINA. : 67 
no means descriptive, names: such as the “F lat-woods,” of Abbeville; the “ Meadow-woods,” of 
Union, and the “ Black-jack” lands of Chester. 
A considerable portion of the surface of the latter District is composed of trap rock, intersected 
by veins of porphyritic feldspar, quartz, and graphic granite. Wherever the feldspar abounds the 
soil is of a lighter color, so that bands of olive and chocolate-colored soils may be seen alternating. 
There is but little opportunity of observing the character of the rocks of this part of the District, 
owing to the flat nature of the surface. The usual spheroidal masses are, however, scattered on 
the surface, and the clay sub-soil is not to be mistaken. 
In Abbeville District a fine locality occurs, which is known as the “ Flat-woods:” a name that 
conveys an erroneous impression, when applied to the whole tract designated; for, unlike the 
unbroken plain, called the “Black-jack lands,” in Chester, it is undulating, and even, in some places, 
broken. Concretionary nodules of carbonate of lime often occur in washes and ravines in trap 
rocks. Such nodules are quite common in Abbeville and Chester, and sometimes lead persons to 
expect deposits of marl. 
Between Tyger and Enoree, in Union, masses of trap are strewed over the surface for miles in. 
extent. This tract is called the “ Meadow-woods”—for what reason I cannot see, as there is not a 
rood of meadow in the whole region. 
After crossing Tyger, and ascending the hill, a series of dykes of porphyritic feldspar occurs, 
with embedded specks of limpid quartz, and crystals of a bluish feldspar, almost opalescent. 
These are among the most important localities in the State. 
In Fairfield, on Dutchman’s Creek, and on Beaver-dam, they are quite numerous. In Union, 
north of the village, a dyke may be traced for miles in length. A dyke extends, almost without 
interruption, from Van Patton’s shoals, on Enoree, to Young’s P. O. a distance of six miles. Near 
Cambridge dykes are numerous; and porphyritic feldspar, much disintegrated, may be seen cross- 
ing the public road. 
Near Fellowship Meeting House, I examined, in company with my friend, Dr. Barratt, a con. 
tinuation of this dyke. It is quite hard, and contains embedded crystals of flesh-colored feldspar. 
I have received recently from the doctor, beautiful specimens of this rock, covered with dendritic 
erystalizations of oxide of manganese. 
There are other rocks which, from having ‘a similar origin, are placed here: among these the 
most important is sienite, which has been defined as a granite, with hornblende substituted for 
mica. So fur as I have observed this rock in South Carolina, it appears to be, with a few excep- 
tions, always intrusive; and in all its relations to other rocks, very similar to trap. 
In the vicinity of Abbeville Court House large masses of this rock occur above the surface, and 
are composed principally of grey feldspar, black hornblende, and quartz—bearing a striking resem- 
blance to the well known Quincy granite. Blocks of this rock are scattered along the surface, 
marking the course of the dyke to which they belonged. In the immediate vicinity other masses 
oecur, in which the hornblende predominates. ; the feldspar has a lighter color, and the quartz has 
nearly disappeared. his variety is known as hornblende rock. This rock occurs in Pickens, and 
it is only mentioned here because, from its dark color and great weight, it was taken for iron ore. 
In other localities in the State the feldspar is white, which contrasts strongly with the black 
feldspar. 
