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Thesis (Ph. D.)--University of Wisconsin, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Iowa, 2005. / Includes bibliographical references (leaves 86-87).

Thesis (M.S.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: David W. Bowen. Includes bibliographical references (leaves 149-162).

The objectives of this study were to quantitatively analyze calcareous nannofossil assemblages across the Cretaceous/Tertiary (K/T) boundary of several sections to determine the nature of nannoplankton extinctions and to compare the results with recent hypotheses of step-wise or sequential extinctions of planktonic foraminifer. Objectives were also to compare uppermost Maastrichtian and lowermost Danian nannofossil assemblages across latitude in the Indian, Tethys, and Atlantic Ocean to determine biogeographic gradients indicative of the latitudinal thermal gradients. The results of these investigations are summarized as follows. (1) No step-wise or gradual extinctions are noted. Nannoplankton extinctions are synchronous and correlate with shifts in carbon isotopes, carbonate sedimentation decline, and anomalous iridium abundance. (2) No unequivocal evidence exists for survivorship of Cretaceous species in Danian sediments. Associations with iridium in particular, suggests that Cretaceous specimens in Danian sediments are reworked by processes of bioturbation and/or current activity. (3) There is no evidence of significant changes in latest Maastrichtian nannofossil assemblages. This indicates stable conditions preceding the K/T boundary event. (4) The lowermost Danian is characterized by sequential blooms of surviving and new species. No two localities are the same in terms of the species composition of these blooms. This reflects the unstable conditions around the globe following the K/T boundary crisis. (5) Latitudinal thermal gradients were established in the Southern Hemisphere by latest Maastrichtian time and continued into the early Danian as indicated by the biogeographic provinces defined by Prediscosphaera stoveri and Hornibrookina. / Source: Dissertation Abstracts International, Volume: 54-07, Section: B, page: 3530. / Major Professor: Sherwood W. Wise, Jr. / Thesis (Ph.D.)--The Florida State University, 1993.

Four Eocene to Oligocene calcareous nannofossil species groups were analyzed biometrically from DSDP and ODP Sites 366, 549, 558, 563, 628, 647, and 748. Integrated biostratigraphic and magnetostratigraphic data established the age of each sample in order to compare biometrically established events between sites. / Principal Component Analysis (PCA) and Discriminant Function Analysis (DFA) of Cyclicargolithus shows that no significant differences in shape occur with changes in size, age, or latitude. Size increases are asynchronous between sites, and are not biostratigraphically useful within the Oligocene. All species of Cyclicargolithus are synonymized with C. pseudogammation n. comb. / Development of a large sized (mean $>$11 um) population of the Reticulofenestra umbilica/R. hillae group occurred between 45.0 and 42.8 Ma in three sites. The first occurrence of specimens $>$14 um in size is highly asynchronous and not biostratigraphically useful. A continuum between large and small holed forms indicates that R. hillae should be considered as a forma of R. umbilica. This forma is more abundant in the uppermost Eocene to lower Oligocene. / Principal Components Analysis of the Reticulofenestra bisecta complex revealed an overall gradual size increase from middle Eocene to Oligocene, and a rapid increase in hole size beginning in early Oligocene in high latitudes. R. bisecta subsp. filewiczii is synonymized with R. bisecta subsp. lockeri n. stat., and R. scrippsae is synonymized with R. bisecta. / Principal Components Analysis of the Chiasmolithus expansus/C. oamaruensis/C. altus lineage revealed large fluctuations in the width of the central 'X' structure from upper middle Eocene to Oligocene, possibly related to changes in water masses. The narrowing of the 'X' is due mainly to narrowing of the central bar connecting the cross bars of the 'X'. A trend towards smaller relative hole sizes occurred from the Eocene to Oligocene. Both C. oamaruensis and C. altus may have evolved from C. expansus in the upper middle to lower upper Eocene. End-member forms were geographically separated, with transitional forms occurring between them through the lower Oligocene. C. altus may be a colder water form than C. oamaruensis. / Source: Dissertation Abstracts International, Volume: 50-05, Section: B, page: 1823. / Major Professor: Sherwood W. Wise, Jr. / Thesis (Ph.D.)--The Florida State University, 1989.

The detailed study of an expanded Paleogene section with abundant, moderate to well preserved calcareous nannofossils from South Atlantic DSDP Site 516 has resulted in a precise correlation of most traditional and nontraditional calcareous nannofossil datums with the magnetostratigraphy. Comparison of results from Site 516 with those of previous studies for other areas enables a critical evaluation of the accuracy, synchroneity or diachroneity of the species events over geographically long distances. / ODP Leg 113 recovered the highest latitude (up to 65$\sp\circ$S) calcareous sequences in the Southern Hemisphere deep oceans. Calcareous nannofossil biostratigraphy has been established for the middle Eocene to Pleistocene sections. Correlation of the calcareous nannofossil datums with the magnetostratigraphy indicates that the last occurrences (LO's) of Isthmolithus recurvus and Chiasmolithus solitus are synchronous in the middle and high latitudes, and that the LO's Reticulofenestra bisecta, R. umbilica, R. reticulata, and the range of Chiasmolithus oamaruensis are diachronous through latitude. Bicolumnus ovatus n. gen., n. sp., is described. / Late Paleogene calcareous nannoplankton have been analyzed quantitatively for eight DSDP and ODP sites ranging from the equatorial zone to 65$\sp\circ$S latitude in the South Atlantic Ocean. This study reveals that large latitudinal biogeographic gradients had been established at least by the middle Eocene. The biogeographic gradient data conflict with the widely accepted inference from the oxygen isotopic data that the thermal gradients between mid latitudes and high latitudes are low or nearly flat for the Paleogene oceans. Lower surface water salinities in the high latitudes may have lowered the $\delta\sp{18}$O values of the planktonic microfossils, but apparently did not affect the distribution of the calcareous nannoplankton, which offers an independent means for estimating latitudinal thermal gradients. / Source: Dissertation Abstracts International, Volume: 51-01, Section: B, page: 0123. / Major Professor: Sherwood W. Wise, Jr. / Thesis (Ph.D.)--The Florida State University, 1989.

Thesis (M.S.)--Ohio State University. / Includes bibliographical references (leaves 210-226). Available online via OhioLINK's ETD Center

Thesis (M.S.)--University of Wisconsin--Madison, 1969. / Title from title screen (viewed Mar. 21, 2007). Includes bibliographical references. Online version of the print original.

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