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dc.contributor.advisor Dunbar, Robert B.
dc.creatorFrantz, Erika Lee
dc.date.accessioned 2009-06-04T00:17:07Z
dc.date.available 2009-06-04T00:17:07Z
dc.date.issued 1993
dc.identifier.urihttps://hdl.handle.net/1911/13724
dc.description.abstract Yumaque formation biosiliceous sediments resemble modern and Neogene sediments deposited under coastal upwelling conditions. High biogenic silica accumulation rates (up to 69 g$\cdot$cm$\sp{-2}\cdot$yr$\sp{-3}$), preservation of fine sedimentary features, and high original organic carbon, resulted from favorable basin geometries and upwelling of nutrient-rich water. Light biosiliceous-rich and dark detrital-rich alternations occur at scales ranging from millimeters to meters. Mm-scale laminae couplets are interpreted as varves. Spectral analysis of laminae thickness using a varve-calibrated time scale reveals significant variance at periods of 5-6 and 8 years, within the El Nino (ENSO) frequency band, and at 11 years, possibly linked to the 10-12 year solar cycle. Centimeter to meter-scale cyclicity representing between a few hundred to a few thousand years correlates to solar and geomagnetic phenomenon. The Yumaque formation and similar biosiliceous deposits along the eastern Pacific margin may be indicative of widespread late Eocene biosiliceous sedimentation around the Pacific.
dc.format.extent 231 p.
dc.format.mimetype application/pdf
dc.language.iso eng
dc.subjectGeology
dc.title Sedimentological and geochemical study of the late Eocene to early Oligocene Yumaque formation, east Pisco Basin, Peru
dc.type.genre Thesis
dc.type.material Text
thesis.degree.department Earth Science
thesis.degree.discipline Natural Sciences
thesis.degree.grantor Rice University
thesis.degree.level Masters
thesis.degree.name Master of Arts
dc.identifier.citation Frantz, Erika Lee. "Sedimentological and geochemical study of the late Eocene to early Oligocene Yumaque formation, east Pisco Basin, Peru." (1993) Master’s Thesis, Rice University. https://hdl.handle.net/1911/13724.


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