. Maryland geological survey . on the mineralogical composition of thedeposits has been found to hold in Maryland and the same is true inPennsylvania and Few Jersey. STAGE OP DECOMPOSITION. Another method of correlating the surficial deposits is by comparingthe stage of decomposition exhibited in each. The value of this methodrests on the assumption that the oldest formation- or the one first de-posited, has been exposed longest to the chemical action of surface watersand has consequently reached a further stage of decomposition than anyof the other terrace deposits, each one of which should s
. Maryland geological survey . on the mineralogical composition of thedeposits has been found to hold in Maryland and the same is true inPennsylvania and Few Jersey. STAGE OP DECOMPOSITION. Another method of correlating the surficial deposits is by comparingthe stage of decomposition exhibited in each. The value of this methodrests on the assumption that the oldest formation- or the one first de-posited, has been exposed longest to the chemical action of surface watersand has consequently reached a further stage of decomposition than anyof the other terrace deposits, each one of which should show a more ad-vanced stage of decay than the one immediately succeeding it. In sub-jecting this method to a practical lest in the field, it appears that theassumption on which it is founded is too sweeping. There are no doubtcertain classes of deposits where discriminations by the stage of decom-position can be applied with confidence. In many glacial deposits for MARYLAND GEOLOGICAL SURVEY. PLIOCENE AND PLEISTOCENE, PLATE Fig. i.—view of st. jerome creek, showing drowned valleys, near ridge, st. marys county.
Size: 1919px × 1302px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectpaleont, bookyear1901
