I860.] 



THE SOUTHERN PLANTER. 



393 



S. E. side of the South mountain and Blue 

 Ridge, gradually contracting in breadth, and 

 ascending in level, through the States of 

 New Jersey, Pennsylvania, Maryland, and 

 Virginia, to near the centre of the latter, 

 •where it terminates. 



" Another narrow strip of the same rock 

 runs from a little north of the Roanoke 

 River south-westward almost to the Yadkin 

 in North Carolina; and between the main 

 belt and this one, there occurs a small patcli 

 on the James River, in a position which 

 indicates that originally they were all three 

 connected/^ These rocks belong to that 

 subdivision known under the name, "Tri- 

 assic." 



(6) . Oolite and Lias. — "In many of 

 the rocks of this series, small calcareous 

 globules are imbedded, which resemble the 

 roe of a fish; and, hence, such a rock is 

 called roestone, or oolite. But this structure 

 extends through only a small part of this 

 formation, and it occurs also in other rocks. 



" The oolite series consists of inter-strati- 

 fied layers of clay, sandstone, marl, and 

 limestone. The upper portion, or that which 

 is oolite proper, is divided into three systems 

 or groups, called the upper, middle, and 

 lower, separated by clay or marl deposits. 



" In this country no genuine oolite has 

 been found. But the remarkable coal-field 

 in Eastern Virginia, near Richmond, is most 

 probably of the age of the oolite and lias, 

 as has been shown by Prof, W. B. Rogers. 



''Lias is a rock usually of a blueish color, 

 like common clay; and it is, indeed, highly 

 argillaceous, but at the same time generally 

 calcareous. Bands of true argillaceous lime- 

 stone do, indeed, occur in it, as well as of cal- 

 careous sand. It has been usual to describe 

 it as a member of the oolite series. But it 

 is widely difiused, and very marked in its 

 characters, and contains peculiar and very 

 interesting organic remains.^' — Hitclicoch. 



Fossil coral and fish are abundant in this 

 formation, but its most striking peculiarity 

 consists in the number and the immense 

 size of its reptiles. 



(7) . The Cretaceous Formation takes 

 its name from the chalk (creta) in which it 

 abounds in some countries, especially in 

 Europe. In this formation the green sand, 

 so successfully employed as a fertilizer in 

 some parts of our country, is found. Green 

 sand is also found in the higher strata. 



(8) . The Tertiary Formation is the 

 highest division of the stratified rocks. The 

 strata in it are generally more nearly hori- 



zontal than in any of the lower formations. 

 It is composed of clay, limestone, marl, and 

 sand, with occasional beds of gypsum and 

 rock-salt. 



Many of the fossils of this period are the 

 remains of plants and animals closely re 

 sembling those now living upon the earth 

 But in the rocks of lower formations, th 

 fossils indicate that our earth was formerly 

 inhabited by beings diff'ering widely from 

 any now known to man. The most remark- 

 able feature of the tertiary period, is seen 

 in the number and size of its mammalia. 



The Tertiary rocks have been classed by 

 geologists into Eocene, 31eiocene, and Plei- 

 ocene ; the Eocene being the lowest in 

 position. Nearly the whole tide-water region 

 of the United States, extending from New 

 Jersey to the Rio Grande, is covered with 

 this formation. In the States lying along 

 the Gulf of Mexico, this class of rocks ex- 

 tends, in some localities, inland considerably 

 beyond the limits of tide- water. The west- 

 ern boundary of the Tertiary, in Virginia, 

 may be nearly defined by a line passing 

 through Fredericksburg, Richmond and 

 Petersburg. This line extends a little west 

 of Raleigh, N. C, to Columbia, S. C, and 

 Augusta, Ga., would mark its western limit 

 still further .South. 



(9). Alluvium and Drift. — Above all 

 the stratified rocks we discover, everywhere, 

 quantities of loose material, broken down 

 and worn ofi" from rocks of every kind, and 

 scattered over the surface. When this 

 material is carried by water, and deposited 

 along the valleys and in the bottoms of ponds 

 and lakes, it forms what is called " Alluvi- 

 um,^' and soils thus formed are alluvial. The 

 material of which they are formed, is gener- 

 ally collected from a considerable variety of 

 rocks, and hence they have all the mineral 

 elements necessary to render them fertile. 



In many places vast currents of water, 

 accompanied most probably by masses of 

 ice, have swept over extensive regions, car- 

 rying with them the abraded material from 

 the various rocks, and hills, and mountains 

 over which they have passed, and again de- 

 positing it, as a mixed mass of sand and 

 clay, full of pebbles and boulders of almost 

 every conceivable size and shape. This 

 constitutes the "Drift formation." 



The Drift forms a very important feature 

 in the geology of some of our Eastern 

 States, and also at many points in the 

 Northern and North-western States; but it 

 rarely occurs farther south than the Ohio 



