Pleistocene Ventifacts and Ice-Marginal Conditions, New Jersey, USA
| Autor: | Mark Demitroff |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
010506 paleontology
geography Pine barrens Katabatic wind geography.geographical_feature_category 010504 meteorology & atmospheric sciences Pleistocene Ventifact Weathering Permafrost 01 natural sciences Aeolian processes Physical geography Ice sheet Geomorphology Geology 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Permafrost and Periglacial Processes. 27:123-137 |
| ISSN: | 1045-6740 |
| DOI: | 10.1002/ppp.1860 |
| Popis: | The Pleistocene environment of the New Jersey Pine Barrens has been interpreted as either cool and moist, with boreal forest, or cold and dry, with semi-desert conditions. The presence of ventifacts is often cited as perfunctory evidence for strong Pleistocene wind action and sparse vegetation. This study examines sites where ventifacts had been reported and identifies abundant pebble- to boulder-sized samples with a wide suite of erosional forms. Faceting occurred when the land was sparsely vegetated, allowing abundant wind-entrained abradants to etch gravel and rocks as a consequence of katabatic winds blowing off the nearby Laurentide Ice Sheet. Most ventifacts occur on upland surfaces and attest to geomorphic stability in this part of the region's otherwise low-relief landscape. Ventifacts were reworked and incorporated within deposits attributed to periglacial mass movement, particularly during climatic amelioration. Aeolian features such as pavement einkante, scallops and weathering pits can evolve only where sustained wind velocities are very high, sand sources are abundant and vegetation is absent. The Pine Barrens' ventifacts provide evidence of cold, dry and windy conditions and aid in the interpretation of landscape evolution. Copyright © 2015 John Wiley & Sons, Ltd. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text