ON THE DISCOVERY OF GREEN SAND IN THE 

 CAI.CAREOUS DEPOSITE OF EASTERN VIR- 

 GINIA, AND ON THE PROBABLE EXISTENCE 

 OF THIS SUBSTANCE IN EXTE?:SIVE BEDS 

 NEAR THE WESTERN LIMITS OF OUR ORDI- 

 NARY MARL. 



TVilliam and 3Iary College, June 2G, 1834. 



To the Eiiitor of the Fanners' Register. 



Since my attention was drawn to the nature and 

 properties of the New Jersey Green Sand, by 

 the specimens which yoii sent me for analysis, 

 and by our more recent conversations on the sub- 

 ject, I have made a visit to tlie rep;ion in which it 

 is found, and liave witnessed the most striking 

 evidences of its utility as a manure. Durincj this 

 excursion, I examined the marl in all its varieties, 

 and learned many interesting particulars respect- 

 ing its use, Irom intelligent farmers, long expe- 

 rienced in applying it to the soil. I have moreo- 

 ver analyzed several specimens collected on the 

 spot with the view, if possible, of throwing some 

 light upon its agency when applied to the soil. 



Since my return, I have made diligent search 

 for this substance in our marl beds and the accom- 

 panying strata, and am at present directing my in- 

 quiries to that region of Lower V^irginia in which, 

 according to geological laws, as well as fi-om some 

 indications of which I have heard, this deposife 

 may reasonably be expected to occur. As fiir as 

 relates to the marl beds of this vicinity, mv search 

 has been unexpectedly successiul. With scarce 

 a single exception, I have discovered particles of the 

 green sand, mingled with the ordinary sand, clay, 

 and shells; and in some instances, in so large a 

 proportion as no doubt greatly to enhance the use- 

 ful agency of the calcareous matter. Indeed, I 

 am inclined to believe, that in some cases, the ag- 

 ricultural efficacy of the marl is chiefly owing to 

 the green sand which it contains. In this coiiclu- 

 sion I think I shall be sustained by facts hereafter 

 to be noticed. 



The general occurrence of this substance in our 

 marl beds, is certainly a discovery of some interest; 

 and though I may perhaps exaggerate its import- 

 ance in a practical point of view, I eannot but think 

 that it is worthy of the attention of our farmers. 

 I speak of its gen eraZ occurrence, because, although 

 I have examined but few specimens fl'om a dis- 

 tance, the general resemblance of our marl depo- 

 site throughout, together with the almost invaria- 

 ble presence of the green particles in such as I 

 have inspected, would seem to justify the conclu- 

 sion that it is a usual accompaniment of our marl 

 formation, though by no means in equal propor- 

 tions in all localities. Out of more than tbrty spe- 

 cimens which I have examined, there were only 

 two in which the green particles could not be dis- 

 covered; and as tliey frequently occur in patches, 

 and not generally diffused throughout the bed, it 

 is probable that even in the beds from which these 

 two specimens Avere procured, the green sand 

 might be elsewhere found. Some of the most ef- 

 ficient marls in the neighborhood of Williams- 

 burg, contain a marked proportion of this sub- 



VoL. II.— 13 



stance. At Burwell's Mill, (three miles below 

 the city towards Yorktown) the intermixture is so 

 large, "that the sand and detritus of shells washed 

 down by the spring ireshet display a very distinct 

 greenish olive tinge, which even travellers observe 

 as they pass througli the valley in which the de- 

 posite exists. At this place, the shells, as they 

 are taken out of the extensiv^e bank recently ex- 

 |)osed by the torrent, are frequently filled with a 

 dark mass containing as much as thirty per cent, 

 of the green particles. In fact the whole bank is 

 strong!}' tinged by them and the stratum which over- 

 liesthe shells, in some places five feet in thickness, is 

 precisely similar to some of the poorer deposites in 

 New Jersey, and contains upwards ol" thirty per 

 cent, of this substance. In Judge Semple's marl 

 beds, in the same vicinity, the green particles are 

 eriually abundant — and, as in the former case, ex- 

 tend into the incumbent stratum of non-calcareouS 

 matter. In many instances, this layer of overly- 

 ing earth has been found even more efficacious on 

 the soil than the subjacent marl — a fact which 

 might naturally he interred, when the green parti- 

 cles abound chiefly in the upper stratum, fi'om the 

 extraordinary efficiency of the gi'een sand as ex- 

 perienced in' New Jersey. But by far the most 

 interesting locality of this substance iii point of 

 extent, which I have examined, occurs on the 

 shore of James river, adjacent to King's Mill and 

 Littletown. Here the banks rise pen)endicularly 

 to the height of from firty to sixty feet, and for 

 about three-fourths of this elevation are composed 

 of shells and earth mingled with a large propor- 

 tion of the green sand \vhich in some places im- 

 parts a distinct color to the surface. The sand 

 of the beach is also filled with these particles 

 which the rains have washed down, and which, 

 at first view, present the appearance of the com- 

 mon black sand of our river, though in much 

 larger quantity. At Bellefield, and other places 

 on the York river, the banks and beach are simi- 

 larly impregnated. 



The green particles may be readily recdgnised 

 by their want of histre, the ease with which they 

 may be bruised .witli the point of a penknife, and 

 the" bright green stain which they then produce. 

 In examining earth or marl in which they are 

 very sparsely scattered, the particles are sometimes 

 difficult to separate from the other matter. My 

 method is to moisten the end of the knife blade by 

 applying it to the tongue, and then to remove se- 

 veral of' the particles by adhesion. When placed 

 upon a card and bruised, they leave a brilliant 

 stain. This test may be confidently relied on. 



The occurrence of the green sand so extensively 

 through our marl region, affords strong grounds 

 for hoping that valuable beds of this substance, 

 like those of New Jerse)^, almost entirely unrain- 

 gled with other matters, may be brought to light 

 by a judicious and enterprising examination of the 

 district on the western limits of our marl. And 

 should such a discovery be made, the agiiculture 

 of Lower Virginia would become pof?sessed of a 

 new and powerful auxiliary in furthering its al- 

 ready rapid career of amelioration. Even the fact 



