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THE JOURNAL OF GEOLOGY.

more complete and definite recognition of the several members of the coastal series in which both the Cretaceous and Tertiary formations were described in some detail.

With the establishment of the official geological survey of New Jersey under the direction of Professor H. D. Rogers[1] the first attempt was made at a detailed differentiation of the local deposits. The formations, beginning at the bottom, were designated as follows: Clays and Sands, Greensand, Limestone, Ferruginous Sand, and Brown Sandstone. Although the various members were not clearly defined and widely different materials were included under the same division, yet the easterly dip of the strata was observed and the broader distinctions in the stratigraphy of the area were recognized.

Dr. T. A. Conrad,[2] in 1848, first suggested that the upper portion of the greensand series was of later age than the Cretaceous, a conclusion which he more fully elaborated at a later date.

The second geological survey of New Jersey, organized in 1854, under the direction of Wm. Kitchell, had as assistant geologist, George H. Cook, who a few years later became himself State Geologist, a position he held for over twenty-five years, until his death in 1889. He devoted from the first much attention to the greensands, and his classification of the strata has met with wide acceptance. It is elaborated in much detail in the Geology of New Jersey, published in 1868. The series of formations as recognized by Professor Cook is as follows, beginning with the oldest: Plastic Clay, Clay Marls, Lower Marl Bed, Red Sand, Middle Marl Bed, Yellow Sand, and Upper Marl Bed. Subsequently, Professor Cook[3] considered that an unconformity existed between the Eocene and Cretaceous members of the Upper Marl Bed.

There is no area in this country where the several formations have been studied more with reference to their own characteristics

  1. ↑ Philadelphia Acad. Nat. Sci. Jour. Vol. 6, 1828, pp. 59-71.
  2. ↑ Philadelphia Acad. Nat. Sci. Jour. new ser. Vol. 1, 1848, p. 129.Philadelphia Acad. Nat. Sci. Proc. Vol. 17, 1865, pp. 71, 72.
  3. ↑ Report of the State Geologist for 1883, pp. 13-19.
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