CALCAREOUS MANURES— APPENDIX. 227 



Mr. Conrade Webb informed me that on his estate in New Kent he had 

 made very careful comparative trials of applications of this olive etirth, 

 on land with and without mariing, opposite to like pieces without the olive 

 earth ; and in neither case did its application show any elT'ect. 



Next, under this olive earth, is green-sand marl ; sometimes the upper 

 part has layers full of the saddle oyster shells, in place, whicli also occur 

 scattered throughout all this marl. Sometimes, as above Newcastle ferry, 

 there are interspersed hard lumps much richer in calcareous matter than 

 the surrounding body. The matrix in which these accidental bodies are 

 imbedded, or the whole body when they are absent, is a dark gray marl, 

 of nearly homogeneous texture, containing green-sand in large proportion, 

 and very few shells or fragments. This sometimes continues down to the 

 green-sand earth. But at and a little above the ferry, (on Mr. Carter Brax- 

 ton's farm,) there occurs between them a stratum of larger shells, mostly 

 the cardita pla7ucosta, as close together as they can lie, well preserved in 

 form, though very rotten, as all the white shells are. The shells of 

 this layer are often stained superficially of a deep and vivid green, by the 

 green-sand. This layer of shells lies on the brownish green earth before 

 mentioned, having very little calcareous matter, and of which the depth is 

 unknown, as its bottom has never been i-eached in any of the diggings. This 

 layer of whole shells was not seen elsewhere. 



Such is the succession of strata at the fine bank of Mr. Carter Braxton, 

 Hanover, a little above Newcastle ferry; and specimens of the several 

 kinds, analyzed carefully, afforded the following results of calcareous matter. 

 The proportions of green-sand were merely guessed at by the eye, but 

 by careful examination, and with the aid of a magnifying glass. 

 Upper stratum furnishing the greater proportion of all used for manure: 

 100 grains contained of carbonate of lime - - - - 37 grains. 



100 grains of lower stratum only 2 



Another specimen of upper stratum, carbonate of lime - - 10 



and green-sand moderately coarse (supposed,) - - - 40 

 At the ferry : 

 100 grains of upper stratum, carbonate of lime, - - - 15 



and (supposed) of green-sand - 35 



Lower stratum of same, carbonate of lime ... - 6 

 Masses of stony hardness, interspersed in same, contained of 



carbonate of lime 67 



and green-sand 3 



At Ml', J. W. Tomlin's land, Hanover, about a mile below the ferry, the 

 visible section of marl and green-sand earth together is 32 feet high, above 

 low tide mark, and the green-sand earth making only 7 or 8 feet of the 

 lowest part. All is eocene — as I found saddle oyster shells at the top of the 

 light colored upper layer, next to the diluvial sandy sub-soil.* Specimens 

 taken from different heights on this bank yielded the following proportions 

 of carbonate of lime : 

 From 7 feet above low tide, 100 grains contained of carbonate 



of lime 35 



At 14 feet 31 



At 29 feet - - - - ' 15 



Upper light-colored stratum — (not including in the specimen 



any of its few large saddle oyster shells) - • - - 6 

 Thin stratum of hard shelly marl, low in the section - - 45 



* This light colored upper layer is stated by the state geologist, in his report, to be 

 miocene. See first report, of l'835, and same copied at p. 670, vol. iii., Farmers' Re- 

 gister. 



