672 



FARMERS' REGISTER. 



[No. 11 



the banks of several of the streams. In the be- 

 lief then that all the extensive band of country, 

 stretching in a meridianal direction entirely across 

 the state, rests upon strata of this description, we 

 are led to regard it as furnishing an immense ad- 

 dition to the resources of the state, and as holding 

 out to our enterprising farmers situated within its 

 limits, a new motive to persevering and active re- 

 search. Let it not be supposed, however, that 

 wherever the Eocene occurs within our state, it 

 will be found to present the same materials in the 

 composition of its strata, as have been found in 

 the localities already examined. Much diversity 

 in this respect may, and probably does exist. On 

 the Mattapony, as already stated, the green sand 

 is frequently replaced by beds of clay of a dark 

 lead color; while on the Potomac, Rappahannock, 

 Pamunkey and James, variable but generally 

 large proportions of the green sand occur, and the 

 probability is, that future inquiries will develope 

 similar diversities in the materials of the beds in 

 other yet unexplored portions of the district. 

 Constancy in the character of the embedded fos- 

 sils is all that is necessary to a geological identity 

 of the formations, and this constancy may exist at 

 the same time that, there is a considerable diversi- 

 ty in the materials in which they are enclosed. It 

 is almost certain, however, that throughout a 

 large portion of the region in question, extensive 

 and valuable beds containing the preen sand do 

 exist, and that even in the highlands they might 

 be reached by excavations descending not very 

 far beneath the lower limit of the Miocene or or- 

 dinary marl. 



On the value of the Eocene green sand marl in ag- 

 riculture. 



From the descriptions already given of the 

 materials of the. various beds of Eocene, it will 

 be seen that many of them contain ingredients 

 which have long been recognized as valuable 

 when applied to land. The gypsum in some, and 

 the carbonate of lime in others, will at once be- 

 speak the favor and confidence of the agricultu- 

 rist, and no observations, either as to their useful- 

 ness or mode of application, will be necessary to 

 give them the importance they deserve. But the 

 characteristic and principal ingredient of a large 

 number of these beds, the green sand, possesses 

 claims to our attention which are equally indispu- 

 table, though not so generally appreciated or un- 

 derstood. Experiments within our own state on 

 this material, as furnished by the Eocene deposites, 

 though ihw, and on a very limited scale, have 

 been so far satisfactory. But as the marls con- 

 taining this substance, which have been employ- 

 ed, have also in most cases contained a notable 

 quantity of gypsum, or of calcareous matter, all 

 the benefits which they have produced would 

 most naturally and reasonably be ascribed to those 

 ingredients, already known for their agency in 

 ameliorating the land. On the Pamunkey the 

 Eocene marl has long been in use, but chiaflC 

 those beds have been selected for the pur 

 marling in which the largest proportion o; 

 reous matter was seen to exist. The lower lay- 

 ers, containing little or no calcareous matter, have 

 on that account, until lately, been rejected as use- 

 less, and sometimes when a bed of this description 

 of considerable extent was found immediately 



overlying a more shelly stratum, much trouble 

 and expense have been incurred in its removal, to 

 make way for the excavation of the material be- 

 neath. Appealing to the experience of the farm- 

 ers of New Jersey, by whom the green sand, in 

 an almost unmixed condition, has long been ap- 

 plied for the purposes of a manure, its unrivalled 

 efficacy, and the permanency of its ameliorating 

 effects, are to be regarded as established and un- 

 questionable facts. It is true, that at one time, 

 owing to the ignorance of those who attempted to 

 make use of it, and the application frequently of 

 a spurious material resembling it. in aspect, doubts 

 of its value have been excited in the minds of 

 some; but the extensive and uniform experience 

 of the present enterprising farmers of that stale, 

 gives an unqualified testimony to the rapidity, the 

 power, and the durability with which it acts. 



A comparatively small dressing of this marl, 

 often not exceeding ten or fifteen loads per acre, is 

 uniformly attended with beneficial results, and 

 this, whether the soil to which it is applied, be a 

 clay, or a light sferil sand. As an illustration of 

 this fertilizing property of the green sand, I will 

 subjoin the following statement quoted from the 

 report of my brother, Professor Henry D. Rogers, 

 on the geology of New Jersey, to which 

 work I beg leave to refer, for ample and satisfac- 

 tory details relating to the agricultural value of 

 this substance, as well as for practical suggestions 

 as to the most judicious modes in which it may be 

 applied: 



"When we behold a luxuriant harvest gather- 

 ed from fields where the soil originally was no- 

 thing but sand, and find it all due to the use of a 

 mineral sparsely disseminated in the sandy beach 

 of the ocean, we must look with exulting admira- 

 tion upon the benefits upon vegetation, conferred 

 by a few scattered granules of this unique and pe- 

 culiar substance. The small amount of green 

 sand dispersed through the common sand, is able, 

 as we behold, to effect immeasurable benefits in 

 spite of a great predominance of the other mate- 

 rial, which we are taught, to regard as by itself so 

 generally prejudicial to fertility. This ought to 

 exhibit an encouraging picture to those districts 

 not directly within the limits of the marl tract, 

 where some of the strata possess the green sub- 

 stance in sensible proportion. It expands most 

 materially the limits of the territory where marl- 

 ing may be introduced, and points to many beds 

 as fertilizing, which otherwise would be deemed 

 wholly inefficacious." 



If such then be the effects of this material, even 

 under circumsfanccs where comparatively little 

 advantage could have been anticipated, and if 

 such moreover be the concurrent experience of 

 those by whom it is daily and extensively employ- 

 ed, we are fully authorized in the belief, that in 

 the Eocene beds of our own state, though in gen- 

 eral less rich in the fertilizing ingredient than the 

 secondary strata of New Jersey, the agriculture 

 of eastern Virginia possesses a new and most 

 le resource. 



The chemical examination of these marls, with 

 a view to precise results, being a matter requiring 

 much time and labor, has as yet been carried on 

 only to a small extent. But a thorough analysis 

 of all the important varieties and an exact deter- 

 mination of the proportion of the various constit- 

 uents, especially the green sand, or the calcareous 



