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Details van artikel 9 van 14 gevonden artikelen
| Titel: |
Polygonal ridge patterns on the dissected Sepik piedmont plain, New Guinea |
| Auteur: |
Ruxton, B. P. |
| Verschenen in: |
Australian journal of earth sciences |
| Paginering: | Jaargang 25 (1978) nr. 5-6 pagina's 285-294 |
| Jaar: |
1978-09 |
| Inhoud: |
Polygonal ridge patterns with intervening hollows some 400 m across and with a relief of about 100 m are common as low hills on the northern dissected part of the Sepik piedmont. They are developed in Pliocene mudstone and sometimes in marl and greywacke. The crests of the highest flat-topped hills have a veneer of Pleistocene fanglomerate on them. The polygons were formed by water infiltrating through the fanglomerate on the former piedmont surface moistening and softening the sediments beneath. Swelling from centres of more intense weathering caused expansion. As the pressure centres impinged on each other a polygonal framework of rock under pressure took in less water and so remained least hydrated. On dissection the polygonal framework was exhumed and then differentially eroded to its present form. Tensional stress fields or tectonic causes do not appear to help in explaining the origin of the polygons. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 9 van 14 gevonden artikelen
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