Sediments from the Late Cretaceous Tar Heel Formation in the Atlantic Coastal Plain of North Carolina were investigated for occurrence and distribution of palynomorphs. Exposures along rivers at Elizabethtown, Goldsboro, Ivanhoe, Lock, Willis Creek and Tar River in North Carolina were systematically collected. One hundred and three sediment samples were macerated by standard techniques modified by eliminating treatments with nitric acid and potassium hydroxide, and analyzed for palynomorphs. Eighty species of palynomorphs were distributed in 4 form genera of freshwater algae, 3 of dinoflagellates, 9 of fungi, 15 of pteridophytes, 11 of gymnosperms and 24 of angiosperms. Angiosperms were the dominant components in assemblages at all localities. Representatives of the Normapolles pollen group (characteristic angiosperm pollen group of middle and high northern latitudes of eastern North America and Europe) occur throughout the Tar Heel Formation and collectively comprise 29%-54% of the angiosperm assemblages. Palynological age assessment is in concordance with earlier dating determined by other workers based on invertebrate faunas. Minimum variance clustering with squared Euclidean distances in the Q-mode (clustering of samples) indicates that stratigraphically older layers of Ivanhoe, Lock and Willis Creek are similar in palynofloral composition, and one section of the Goldsboro locality is compositionally equivalent to the Tar River locality. Minimum variance cluster analysis in the R-mode (clustering of taxa) indicates the association of Campanian taxa in the same cluster. This reconfirms that localities of the Tar Heel Formation are of Early Campanian age. Informal biostratigraphic zones of Campanian (CA2-CA4) known from other Atlantic Coastal Plain deposits do not occur in the Tar Heel Formation. Quantitative analysis is consistent with the long-standing hypothesis of diversification and dominance of angiosperm pollen groups during the Campanian. The palynological record of the Tar Heel Formation, based on some indicator taxa with modern equivalents, suggests that subtropical to warm, moist temperate conditions prevailed in the southeastern region of North America during Campanian time.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-04292002-113849 |
| Date | 30 April 2002 |
| Creators | Mitra, Madhumi |
| Contributors | James E. Mickle, Thomas Wentworth, Elisabeth Wheeler, Jenny Xiang, Marianne Feaver, James E. Mickle, Thomas Wentworth, Elisabeth Wheeler, Jenny Xiang, Marianne Feaver |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-04292002-113849/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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