. Collected reprints / Atlantic Oceanographic and Meteorological Laboratories [and] Pacific Oceanographic Laboratories. Oceanography 39° 00 NX 38° 45'NN. 7^T 74°00 W FIRST ORDER HIGHS CRESTLINES. SECOND ORDER HIGHS FIGURE 20. Great Egg shelf valley and shoal retreat massif. Large-scale ridges in inset may date from a period when the ancestral Great Egg estuary was active. Nearshore large-scale ridges were probably formed by shoreface de- tachment during erosional retreat of the shoreface, after capture of the ancestral Schuylkill River by the Delaware River, and consequent reduct
. Collected reprints / Atlantic Oceanographic and Meteorological Laboratories [and] Pacific Oceanographic Laboratories. Oceanography 39° 00 NX 38° 45'NN. 7^T 74°00 W FIRST ORDER HIGHS CRESTLINES. SECOND ORDER HIGHS FIGURE 20. Great Egg shelf valley and shoal retreat massif. Large-scale ridges in inset may date from a period when the ancestral Great Egg estuary was active. Nearshore large-scale ridges were probably formed by shoreface de- tachment during erosional retreat of the shoreface, after capture of the ancestral Schuylkill River by the Delaware River, and consequent reduction in discharge of the Great Egg estuary. See Fig. 6 for relationships of Schuylkill, Delaware, and Great Egg rivers. From Stubblefield and Swift (in press). presumably converge with the shoreline, tend to be floored with primarily medium- and coarse-grained sands, molded into a well-defined ridge topography. On the southern halves of the coastal compartment, where the shoreline tends to curve to the west, storm flows might be expected to expand and decelerate. Here the fine sand blanket of the shoreface extends across the inner shelf floor, as though nourished by material swept out of the ridge topography to the north. The schematic flow pattern in the lowest panel of Fig. 24 is not basic on detailed observations. It is intended to indicate that current flowing generally southwest parallel to the long dimension of the shelf will tend to converge with the northeastern portion of the shoreline and diverge from the southwestern portion of the shoreline. A somewhat closer relationship appears to exist between flow geometry and sediment distribution in the vicinity of the shoal retreat massifs (Fig. 25). The ridge topography attains its maximum relief where it has been molded onto the crests of the massifs. The massifs do not exhibit bilateral symmetry; troughs are deepest and widest on the northern sides. As a trough axis is traced across the massif, erosional windows exposing
Size: 1980px × 1262px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1900, bookcollectionamericana, bookleafnumber563
