628 



F A R M E R S ' REGISTER. 



[No. 10 



a yellow and sometimes of a reddish color, in 

 which are occasionally found at or near the sun 

 liice, pebbles and small boulders of sandstone, 

 rarely as much as six inches in diameter. The 

 nature of these boulders would indicate that they 

 were most probably derived from the sandstone 

 formation, which ranges along the eastern boun- 

 dary of the primary ridge. In some places this 

 stratum consists of little else than a white silicious 

 sand; in others, the admixture of ochrcous clay is 

 so considerable as to furnish a suitable material for 

 the manufacture of bricks. 



Beneath this superficial layer, beds of a very ar- 

 gillaceous clay occasionally occur, sometimes of 

 considerable depth and extent, and of a texture to 

 be useful in puddling. Its color is various, being 

 in some places a dark blue or irreen, in others a 

 bright red, or dingy yellow. Wherever found its 

 upper boundary is remarkably even and horizon- 

 tal; but where it rests upon beds of fossil shells, its 

 lower limit conforms to all the irregularities of 

 surface which those beds usually present. Its ap- 

 pearance, in some places, is that of a steep, almost 

 perpendicular wall of smooth surface, and di- 

 vided by very narrow lines running horizontally. 

 These narrow lines, at a distance of from five 

 inches to a foot asunder, are formed by a more fer- 

 ruginous and silicious clay. At Bellefield on the 

 York river, seven miles from Williamsburg, this 

 deposite may be seen overlying the stratum con- 

 taining shells, in some places, having a thickness 

 of from twelve to fifteen feet, and then gradually 

 fining out and passing into a light colored and 

 coarser mass. The upper surface is horizontal, 

 and the lines of division above alluded to are per- 

 fectly parallel and regular. The lower surface of 

 the clay conforms to that of the shell stratum upon 

 which it rests. In many places these argillaceous 

 beds consist of a yellowish clay, beautifully varie- 

 gated by streaks of red and blue. In some places 

 there exists a slight impregnation of alum and 

 copperas in these beds of clay. This is particu- 

 larly the case in some localities on the Rappahan- 

 nock and the. York and Chickahominy rivers. 

 The proportion of these ingredients is however 

 not sufficiently great to entitle these strata to at- 

 tention in an economical point of view, althouo-h 

 it is fully sufficient to impart a very ungrateful fla- 

 vor, and perhaps some useful medicinal proper- 

 ties to the springs and wells of the neighbor- 

 hood. 



A thin stralum of red ferruginous stone, con- 

 taining a large portion of oxide of iron, is found in 

 this region running horizontally below, and some- 

 times in the beds of clay before described, and 

 generally separated by only a few feet from the 

 underlying masses of shells. This stratum, which 

 is very generally present, varies in thickness 

 from an inch lo a foot. Its texture is sometimes 

 cellular, sometimes compact and fibrous, like that 

 of certain varieties of hematite. In the more 

 eastern portions of the Miocene district, the pecu- 

 liar structure of which will be hereafter described, 

 much ore of this description lies loosely scattered 

 on the surface; while in the more elevated 

 parts of the country, its invariable position is such 

 as above described. The character of the ore in 

 many localities is such as to promise great facility 

 in reducing ii to the metallic state, together with a 

 large per centage of resulting metal. A speci- 

 men obtained from above the marl on the cliff at 



Mount Pleasant, Surry county, yielded by analy- 

 sis in the 100 grs. 



per oxide of iron, 

 ulliiiiiina, 

 silica, 

 water, 



Loss 



98.36 

 1.64 



100.00 



With a sufficient supply of ore like this, accompa- 

 nied with the advantage of a shell limestone some- 

 times beautifully crystalline, in its immediate vi- 

 cinity, the manufacture of iron would promise a 

 high degree of productiveness; and it is by no 

 means improbable that in some parts of this region 

 the supply of the ore may be found sufficient to 

 make such an enterprise not only safe but profita- 

 ble. The subject, is at all events worthy of some 

 attention. Indeed it appears not a little surprising 

 that this rich mineral seems hitherto to have es- 

 caped observation, or at least to have been regard- 

 ed as undeserving of an especial notice. 



In some places, as for example, in Essex coun- 

 ty, chiefly upon the ridge land, beds of a ferrugi- 

 nous sandstone are found of sufficient extent to be 

 used as a building material. This rock is not to be 

 confounded with the sandstones which occur some 

 distance to the west of this, on the borders of the 

 primary region; but it is to be looked upon as in 

 the case of a very similar material, recently made 

 ihe subject of minute inquiry by my brother in 

 New Jersey, as a remnant or outlying portion of 

 a once somewhat extensive deposite of ferrugi- 

 nous gravel and conglomerate, which by subse- 

 quent denuding action has been almost entirely re- 

 moved. 



The matter which in most cases rests immedi- 

 ately upon the shells, is a yellowish brown sand, fre- 

 quently containing a large proportion of clay. 

 Throughout this mass, and often extending to the 

 distance of five or six feet from the shells, parti- 

 cles of green sand, or the silicate of iron and pot- 

 ash, are more or less abundantly disseminated; and 

 in the immediate vicinity of the shells, these par- 

 ticles are generally condensed into narrow stripes 

 conforming in flexure to the irregularities of the 

 bed beneath. Even where a deep hole exists in 

 the layer of shells, the stripes of green sand are 

 seen still following the depression and rise of the 

 surface, and preserving a uniform distance from it. 

 Sometimes these thin layers are so much indurated 

 as to have almost the appearance of stone. In 

 none of the strata above described have fossils of 

 any description ever been discovered. 



The materials with which the shells are inter- 

 mixed, or in which they are embedded, have va- 

 rious characters. In some cases they consist prin- 

 cipally of a nearly white sand; in others the ar- 

 gillaceous matter greatly predominates, and the 

 mass is a somewhat tenacious clay. Frequently 

 much oxide of iron is mingled with the earthy 

 matter, and giving it more or less of a yellow or 

 brown appearance, and this is the aspect which the 

 upper beds containing shells most usually present. 

 Very generally the lowest visible fossililerous stra- 

 tum is composed of a green silicious sand, and a 

 bluish clay, which being always very moist, is 

 soft and tenacious, and presents a dark blue or 



