Identifier

etd-11102011-090846

Degree

Master of Science (MS)

Department

Geology and Geophysics

Document Type

Thesis

Abstract

This manuscript presents a biostratigraphic and sequence stratigraphic interpretation of palynological data from two outcrop sections on the NE flank of the Upper Magdalena Valley (UMV) basin comprising the Santonian to Lower Maastrichtian interval. The objectives of this study where: a) to characterize the lithologically similar Lower Lidita, Upper Lidita, and El Cobre, Buscavidas formations and b) to provide a better understanding of important correlation horizons in the northeastern part of the UMV basin and to confirm the age assignment of stratal units. A cyclic pattern of palynomorph distribution was recognized in both sections and tied to the different stages of the sequence stratigraphic cycle. Spikes of spore abundances accompanied by pollen characterized the lowstand systems tracts, which were followed by the occurrence of euryhaline dinoflagellate cysts such as ceratioids and/or gymnodinioids during the transgressive systems tract. Maximum flooding surfaces (MFS) were recognized by a sudden increase in open marine palynomorphs such as peridinioids and/or gonyaulacoids and the scarcity of terrestrial representatives. Highstand systems tracts were identified by a gradual decrease in open marine dinoflagellates along with the occurrence of euryhaline dinoflagellate cysts and terrestrial representatives. The end of the eustatic cycle was inferred by a subsequent spike in the abundance of spores and minor pollen components, indicating onset of deposition. The sequence stratigraphic interpretation from palynological analysis was correlated to the global sea level curve allowing the identification of the Santonian-Campanian and Campanian-Maastrichtian boundaries. Some systems tracts from supercycles ZC-3, ZC-4 and TA-1 were recognized from the palynological data at the two study areas.

Date

2011

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Warny, Sophie

DOI

10.31390/gradschool_theses.1326

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