The Lower Siluric Shales of the Mohawk Valley (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1912 Excerpt: ... fully known. The Schenectady beds may at their top reach into the upper Trenton age and this transgression into the upper Trenton is indicated by the dotted line. The Indian Ladder beds appear as a lenticular body, since their main extension is in northeastern direction, crossing the east-west sectional plane in a very limited area. Doctor Ulrich holds from his investigations that the Levis is the second trough east of the Schenectady basin and that the Chazy bay intervenes but is now covered by the overthrust Levis deposits. We have not attempted to introduce this condition on the diagram to the right of the permanent barrier because the exaggeration of the vertical scale would not permit its intelligible representation. The overthrust condition, however, which has brought the formation of the Levis basin in contact with those of the Schenectady basin in Albany and Saratoga counties, is indicated by the arrows showing the direction of the movement. We have further tentatively placed in the series of the Levis channel formations (mainly graptolite shales) a limestone outcropping about Bald mountain. From fossils collected last summer by the writer it is determined as of upper Beekmantown age. The Rysedorph Hill conglomerate, which also outcrops at various localities, belongs with the Levis channel graptolite beds and probably lies between the Normanskill shale and Snake Hill beds. Bibliography (1) 1842 Vanuxem, Lardner. Geology of New York; Report on the Third District. (2) 1843 Mather, W. W. Geology of New York; Report on the First District. Hall, James. Palaeontology of New York. v. 1.. Billings, E. On the Asteridae of the Lower Silurian Rocks of Canada. Can. Org. Remains. Dec. III, p. 75. Billings, E. Geology of Canada, Palaeozoic Fossils. v. I. Meek, F...