. Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments. Geology. d. Drift, with boulders of syenite, &c. c. Yellow sand. o. Laminated clay, 25 feet thick. A. Horizontal lower Silurian strata. B. Vallev re-excavated. the valley, B, was once filled up with the beds b, c, d, e, /, which were deposited during a period of subsidence, and that subsequently the higher country (h) was submerged and overspread with drift. The partial reexcavation of B took place when this region was again uplifted above the sea to its present height. A
. Elements of geology, or, The ancient changes of the earth and its inhabitants as illustrated by geological monuments. Geology. d. Drift, with boulders of syenite, &c. c. Yellow sand. o. Laminated clay, 25 feet thick. A. Horizontal lower Silurian strata. B. Vallev re-excavated. the valley, B, was once filled up with the beds b, c, d, e, /, which were deposited during a period of subsidence, and that subsequently the higher country (h) was submerged and overspread with drift. The partial reexcavation of B took place when this region was again uplifted above the sea to its present height. Among the twenty-three species of fossil shells collected by me from these beds at Beauport, all were of recent northern species; the only supposed exception, Astarte Laurentiana, being now considered by good conchologists as a variety of the British A. compressa (see fig. 139). I also examined. b & *- Astarte compressa, Flem. = A. Laurentiana. a. Outside. o. Inside of right valve. c. Left valve. the same formation farther up the valley of the St. Lawrence, in the suburbs of Montreal, where some of the beds of loam are filled with * Geol. Trans., 2d series, vol. vi. p. 135. Mr. Smith of Jordan Hill had arrived at similar conclusions as to climate from the shells of the Scotch glacial drift, f Proceedings of Geol. Soc, No. 63, p. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Lyell, Charles, Sir, 1797-1875. New York, D. Appleton and co.
Size: 2854px × 876px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, booksubjectgeology, bookyear1868
