• DOI:10.1086/607150
• Corpus ID: 129629329

Sedimentary Measurement of Cretaceous Time

@article{GilbertSedimentaryMO,
  title={Sedimentary Measurement of Cretaceous Time},
  author={Grove Karl Gilbert},
  journal={The Journal of Geology},
  volume={3},
  pages={121 - 127}
}

• G. K. Gilbert
• Published 1 February 1895
• Geology
• The Journal of Geology

Along the base of the Rocky Mountains, and eastward for many miles, the basin of the Arkansas river is occupied by Cretaceous rocks. At bottom are the Dakota sandstones, several hundred feet in thickness; and above these a great body of shales, constituting the Benton, Niobrara and Pierre groups and having a total thickness of 3900 feet. In the main these shales are argillaceous; but at a few horizons they are calcareous, and at one level a sandstone appears, accompanied by a few feet of arenaceous shale. The sandy passage is best developed near the mountains, and disappears altogether toward the east. The calcareous passages are more persistent and have been recognized throughout the district. At least two of them occur many miles farther to the north. As the shales and the associated limestones approach the mountains they do not assume the character of littoral deposits, but remain practically unchanged; and it is thence inferred that the sea in which they were deposited extended to a remote western shore.