Stratigraphy of loessic cover beds at the Lamplough, West Coast, South Island, New Zealand
| Autor: | R. F. Thomas, D. N. Eden, G. Mew |
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| Rok vydání: | 1988 |
| Předmět: | |
| Zdroj: | Journal of the Royal Society of New Zealand. 18:325-332 |
| ISSN: | 1175-8899 0303-6758 |
| DOI: | 10.1080/03036758.1988.10426473 |
| Popis: | Eighteen cores of cover beds from the two lowermost terraces (here called lower and upper) at the Lamplough road south of Greymouth, were sampled at regular vertical intervals. Samples from representative cores were analysed for particle size distribution and volcanic glass content Particle size distribution confirmed that the cover beds are loess, and changes in the slope of trend lines drawn through plots of sand/silt ratio against depth suggest a similar depositional pattern in uppermost materials on both terraces. The mean thickness of loess on the upper terrace is two to three times thicker than that on the lower terrace, and includes more brown layers. The source direction for the loess was investigated but not determined. Volcanic glass, from the Kawakawa Tephra dated at approximately 20,000 years B.P., is found over a similar range of depths (above 40 cm) on both terraces. Assuming a uniform rate of loess deposition up to the present day, the base of the loess on the lower terrace is like... |
| Databáze: | OpenAIRE |
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