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Full-Text Articles in Physical Sciences and Mathematics
Neogene Dinoflagellate Cysts From The Tropical Americas, Damian Cardenas
Neogene Dinoflagellate Cysts From The Tropical Americas, Damian Cardenas
Doctoral Dissertations
"Marine palynomorphs, mainly dinoflagellate cysts and acritarchs, constitute excellent proxies for biostratigraphic and paleoceanographic studies in neritic sequences. Neogene marine palynological studies have mostly focused on the Northern Hemisphere, resulting in the scarcity of dinoflagellate cysts and acritarchs from tropical latitudes. Forty samples encompassing the late Chattian-late Burgidalian time interval (~24.1- 17.3 Ma) in the Southern Caribbean were analyzed for their marine palynological contents. A biostratigraphic scheme for the region is proposed and includes the upper Chattian-lower Aquitanian Minisphaeridium latirictum Interval Zone (~23.9-22.0 Ma), the upper Aquitanian Achomosphaera alcicornu Interval Zone (~22.0-20.3 Ma), and the Burdigalian Cribroperidinium tenuitabulatum Interval Zone …
The Consequences Of Plan Colombia: Domestic Drug Policies In Colombia, Brittany T. Reid
The Consequences Of Plan Colombia: Domestic Drug Policies In Colombia, Brittany T. Reid
Standard Theses
None
Palynostratigraphy Of The Umir Formation, Middle Magdalena Valley Basin (Mmvb) Colombia, Carlos Enrique Santos
Palynostratigraphy Of The Umir Formation, Middle Magdalena Valley Basin (Mmvb) Colombia, Carlos Enrique Santos
LSU Master's Theses
The Late Cretaceous Umir Formation in Middle Magdalena Valley Basin (MMVB) was recently acknowledged as a new target. However, there is little known about the regional distribution of the Umir Formation since it is affected by structural complexity and a major regional unconformity. To improve biosteering of the Umir Formation and reduce exploratory risks, a detailed biostratigraphic analysis of the Umir Formation in the MMVB is presented. Eighty samples from four cores drilled in the Central Eastern MMVB were analyzed for palynological content. These cores represent 976.6 meters of the Middle to Upper Umir Formation. The sediment yielded a good …
Eruption Dynamics And Petrology Of The Most Recent Eruptions Of Nevado Del Ruiz Volcano, Colombia, South America, Richard Henry Young
Eruption Dynamics And Petrology Of The Most Recent Eruptions Of Nevado Del Ruiz Volcano, Colombia, South America, Richard Henry Young
LSU Historical Dissertations and Theses
Field measurements and petrographic analyses of pumices from the most recent tephra deposits of Nevado del Ruiz volcano provide a context in which to view the disastrous eruption of 13 November, 1985 (R0). The pumices are all crystal-rich, two-pyroxene andesites to dacites with whole rock SiO2 contents of 62 - 66 wt.%, and magma water contents estimated to be between 1 - 4 wt.%. The 1985 tephra has greater petrologic diversity than earlier deposits which may be related to an input of a hotter, more basic magma into the Ruiz system, as suggested by xenocrystic olivine which is most …