Multivariate analysis of Late Cretaceous Kanguk Formation (Arctic Canada) palynomorph assemblages to identify nearshore to distal marine groupings
| Autor: | W. L Strong, L. V. Hills |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Shore
geography geography.geographical_feature_category Energy Engineering and Power Technology Geology Biostratigraphy Cretaceous Detrended correspondence analysis Paleontology Arctic Geochemistry and Petrology Phanerozoic Earth and Planetary Sciences (miscellaneous) Ordination Marine transgression |
| Zdroj: | Bulletin of Canadian Petroleum Geology. 55:160-172 |
| ISSN: | 0007-4802 |
| DOI: | 10.2113/gscpgbull.55.2.160 |
| Popis: | Statistical techniques were used to differentiate palynomorph groups within two sections of the Kanguk Formation located in northern Canada. Hierarchical cluster analyses were used to classify separately 39 samples from Remus Creek (Ellesmere Island) and 115 samples from Glacier Fiord (Axel Heiberg Island). The former site is located nearest the margin of the Svendrup Basin. The two sections are separated by a distance of 180 km. A total of 437 palynomorph taxa occurred in the two sections. Compositional differentiation of the recognized cluster analysis groups was based on nonparametric Kruskal-Wallis tests, with verification of their distinctiveness based on detrended correspondence analysis ordination. These latter techniques were also used to correlate the separately compiled groups. Seven palynomorph groups were recognized which were considered to represent nearshore, offshore, and distal marine environments. The nearshore groups were dominated by Taxodiaceaepollenites hiatus (Potonie) Kremp 1949 with important secondary quantities of Psiloschizosporis cooksoniae (Pocock) Ke & Shi 1978 (Groups B and C), Trithyrodinium suspectum (Manum & Cookson) Davey 1969 (Group H), and Stereisporites antiquasporites (Wilson & Webster) Dettmann 1963 (Group I). A diverse mixture of marine palynomorphs comprised the offshore zone, with Trithyrodinium suspectum both a common and highly constant element. Kallosphaeridium ?ringnesiorum (Manum & Cookson) Helby 1987 dominated (25%) the composition of a distal marine group. Examination of individual taxa and associated attributes reveals that four primary distribution patterns occurred: an increase towards shore, an increase away from shore, a peak in the offshore zone, and those restricted to one zone. Stratigraphic profiles of the palynomorph groups suggest that the lower half of Remus Creek section was dominated by an offshore marine zone, with two major regression-transgression stages, followed by a shift toward nearshore conditions (Group C). Conditions at Glacier Fiord gradually shifted from distal marine through offshore to nearshore. The results of this study suggest that techniques such as cluster analysis and ordination in combination with comparative statistics could be useful tools for facilitating the classification, characterization, and comparison of complex multivariate paleopalynological data. |
| Databáze: | OpenAIRE |
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