Bulletin Volume 27-28 (English, French, Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1917 edition. Excerpt: ...County, may consist almost entirely of shells and shell fragments and analyze between 80 per cent and 90 per cent of calcium carbonate, or the shells may represent such an inconsiderable element as shown in adjoining bluffs along Cape Fear River that the material is practically a pure sand of no agricultural value. The shell marls of the Yorktown formation which are exposed in a narrow belt extending from Gates to western Beaufort County are similarly made up of shells and shell fragments in a usually sandy matrix. Shell marls, where the percentage of lime falls below 75 per cent and in which the matrix is sand, are of slight value on the lighter soils of the state that are already too sandy and non-retentive of soil moisture, but may be used advantageously on heavy "black land" where they not only correct the acidity of the soil but greatly improve its texture and physical condition. Similar comment applies to the marls of the Duplin formation which have been utilized for agricultural purposes in Duplin, Sampson, Robeson, Bladen, and Columbus counties. The marls of the St. Marys formation, on the other hand, while frequently similar to those just mentioned and of admirable quality, more often have the shells and shell fragments embedded in a clayey matrix, as in numerous outcrops in Bertie, Edgecombe, Pitt, and Greene counties. These clayey shell marls, frequently termed blue marls, are not suitable for use on heavy soils since they disintegrate slowly and do not improve the physical character or workability of the soil. On the other hand, they may prove of benefit when applied to light sandy soils naturally deficient in loamy constituents. See Plate XV, B. The green sand marls found along Tar River, Contentnea Creek, Northeast...