676 



FARMERS' REGISTER. 



[No. 11 



Eocene. — 5. Dark green sand stratum — 

 no shells, 4 



6. Rockey sheif of cemented 



shells of the saddle-shaped 

 oyster, \ 



7. Dark green sand strata with 



small shells, 2 



17 



The highest Miocene bed is not exposed at this 

 point, but occurs a little farther up the river 

 in the character of a dark blue clay with fossil im- 

 pressions, on which there rests a thin layer of 

 ochreous clay, as brilliant in its tints as the finest 

 chrome yellow. This ochre is of the most impal- 

 pable texture when dried, and would be found very 

 valuable in coloring. 



At Mr. Washington Basset's, about A\ miles 

 higher up the river, the bank is precipitous, and 

 presents the following series of strata: 



Miocene. — Superficial gravel, 5 or 6 feet. 



Thin layer of friable sandy 



clay with casts, J? 



Olive-colored earth with shark's 

 teeth, and a few casts of 

 Miocene shells, 7 



Thin line of black pebbles. 



Eocene. — Dark greenish brown stra- 

 tum, containing a large 

 proportion of green sand, 

 and in some parts abound- 

 ing in shells. The upper 

 portion consists of a rocky 

 mass of cemented shell, 

 chiefly the saddle-oyster, 20 



At Walker Tomlin's, on the south side 

 of the river, immediately 

 below Newcastle, the beds 

 are, 



Miocene. — Friable white clay and sand 



with casts of shells, 2 



Eocene. — Olive earth with pebbles at 



bottom, 6 



A dark bluish green clay, 

 containing a great deal of 

 green sand, capped by 

 rock as at the former lo- 

 cality, 25 



At Newcastle and William H. Roane's and 

 Mrs. Ruffm's estates, a similar series of beds oc- 

 curs, rising still higher above the level of the 

 stream. About 1| miles above Newcastle, the 

 upper surface of the Eocene marl has an ele- 

 vation above the river ol more than thirty feet. 

 The lower stratum consists of the bluish green 

 clay before mentioned, containinn; only a few of 

 the more delicate shells, and richly abounding^in 

 green sand; the upper of a gray calcareous marl, 

 thickly speckled with granules of this substance. 

 Over the whole is a layer of the white friable ma- 

 terial, with Miocene impressions. 



The upper surface of the .Eocene usually pre- 

 sents an unbroken line, though at some places, as 

 at Mr. Fox's above Newcastle, this is not the 



case. The bed here consists of a light-colored 

 sand and clay, speckled with the green sand, and 

 containing vast numbers of the Eocene oyster. 

 \U outline presents numerous cavities and emi- 

 nences, exactly resembling these which occur 

 in the Miocene deposite nearer to the seaboard. 

 A narrow layer of common sand deeply tinged by 

 mixture with green sand, lies immediately upon 

 this irregular surface, and the whole is covered 

 with a bed of gravel and sand, with diagonal lines 

 of stratification, indicating the agency of currents 

 at the time of its deposition. 



At Mr. William Wickham's, the overlying stra- 

 tum consists of bands of ferruginous gravel and 

 sand, containing round concretions, like Geodes, 

 generally fiiled with sand. Thin seams of iron 

 ore run along this stratum a few feet above the 

 (ossiferous beds. These latter, in some places, 

 present a level outline, and are then always co- 

 vered by a layer of sandy clay containing much 

 green sand. On the other hand, where the out- 

 line is undulating and irregular, a stratum of gra- 

 vel rests immediately in contact with the bed of 

 marl. The size of the gravel thus deposited, as 

 well as the scooped surface of the bed on which it 

 reposes, indicating the operation of powerfid cur- 

 rents after the deposition of the strata of Eocene, 

 presents an explanation of the absence in these 

 places of the upper bed of this formation, remark- 

 ed us present in those spots where there are no 

 such indications of the action of destructive forces. 

 The matrix of the fossils is sometimes an olive- 

 colored clay, sometimes a grayish green sand and 

 clay, and sometimes a bluish black clay, contain- 

 ing a large proportion of the granules of green 

 sand. The depth of the marl is 15 feet. 



Eocene strata of the James River. 



The beds of Eocene on the James River first 

 make their appearance on its southern shore near 

 Coggin's Point, and thence continue, except when 

 interrupted by the river flats, to a small distance 

 above City Point, making a distance following the 

 flexures of the shores of about ten miles. On the 

 opposite side they have been found at Berkeley 

 and other points, but as yet this portion of the 

 deposite has been but little examined-^ 



At Coggin's Point, Tarbay and Evergreen, the 

 cliffs have a height varying from 30 to 40 feet. 

 The Miocene marl, which in some places is seen 

 overlying the Eocene, abounds in scallops and 

 other shells which make it easily recognized. Be- 

 neath this and usually separated from it by a thin 

 line of black pebbles, like those occurring on the 

 Pamunkey, there occurs a stratum of a greenish 

 red and yellow aspect, containing much green sand 

 and gypsum; the latter partly disseminated in 

 sinn!; grains, and partly grouped in large and mas- 

 sive crystals. The under stratum, rich in green 

 sand and containing a kw shells in a friable con- 

 dition, extends to some depth beneath the level of 

 the river, and appears to rest upon a bed of clay 

 of a lead color, containino; crystals of gypsum. 

 At Evergreen a stratum of pure white clay rests 

 upon the upper layer of Eocene, containing, em- 

 bedded in its lower surface, large groups of crys- 

 tals, and seems to occupy the place of the black 

 pebbles before mentioned. The whole thickness 

 of the Eocene deposite at this point, appears to be 

 about twenty feet. Below as w T ell as above thi« 



