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Witte Hi Pt S P Geology

Boulder fields formed at the base of slopes where

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Unformatted text preview: led alluvium, consist of sand and gravel laid down in channels, and finer sediment laid down on narrow flood plains. Many modern streams in High Point flow along channels originally cut by glacial meltwater. In a few places, such as the ravine northwest of Steeny Kill Lake (Plate 1), these channels are as much as 60 feet deep. Alluvial fans formed where tributaries entered larger valleys and deposited their heavier loads. Their composition is highly variable, chiefly derived from local surficial materials laid down by intermittent and perennial streams. Most are entrenched by modern streams. This suggests they are probably of late Wisconsinan and early Holocene age and formed when rigorous climate, sparse vegetation, and abundant sediment favored their formation. Swamps and bogs contain sediment and organic material that can be used to reconstruct past climates. Because their materials were laid down layer upon layer, they may preserve a record from the end of the Ice Age to the present. Pollen and other plant material retrieved from swamps may be identified and provide dates used to interpret past climate. Several studies of bogs and swamps in northwestern New Jersey and northeastern Pennsylvania have established a dated pollen stratigraphy that nearly goes back to the onset of deglaciation. The pollen records the transition from tundra with sparse vegetation, to an open parkland of sedge and grass with scattered stands of spruce and fir. From about 14,000 22 to 11,000 years ago a dense closed boreal forest developed that consisted largely of spruce and fir blanketing the uplands. This was followed by a period (11, 000 to 9,700 years ago) when pine became dominant. About 9,400 years ago oak became dominant and displaced the conifers, signaling the change from a boreal to a temperate climate. Mastodon remains, excavated from Shotwell Pond in Stokes State Forest show the presence of these large mammals on Kittatinny Mountain during the close of the Ice Age. They disappeared from this area about 12,000 years ago, presum...
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