Cenozoic Stratigraphy; Paleobotany and Palynology of Cretaceous and Cenozoic; Cenozoic geological mapping
Morphological trends in the fossil pollen of Decodon and the paleobiogeographic history of the genus
2012
Fridgeir Grimsson, David K. Ferguson, Reinhard Zetter
International Journal of Plant Sciences
Multi-characteristic correlation of Upper Cretaceous volcanic ash beds from southwestern Utah to central Colorado
Kowallis, B.J., Christiansen, E.H., and Deino, A., 1989, Multi-characteristic correlation of Upper Cretaceous volcanic ash beds from southwestern Utah to central Colorado: Utah Geological and Mineral Survey Miscellaneous Publication 89-5, 22 p.
Newly recognized Cedar Mountain Formation in Salina Canyon, Sevier County, Utah
Willis, G.C., and Kowallis, B.J., 1988, Newly recognized Cedar Mountain Formation in Salina Canyon Sevier County, Utah: Brigham Young University Geology Studies, v. 35, p.57-61.
Age of the Cenomanian-Turonian boundary in the Western Interior of the United States
Kowallis, B.J., Christiansen, E.H., Deino, A.L., Kunk, M.J., Heaman, L.M., 1995, Age of the Cenomanian-Turonian boundary in the Western Interior of the United States: Cretaceous Research, v. 16, p. 109-129.
Cenozoic Glacial History of the Northern Antarctic Peninsula: A Micromorphological Investigation of Quartz Sand Grains
Co-authored with John B. Anderson
in "Tectonic, Climatic, and Cryospheric Evolution of the Antarctic Peninsula"
Doi: 10.1029/SP063, ISBN: 978-0-87590-734-5
Glacial transport, owing to its high shear-stress regime, imparts a unique suite of microtextures on quartz grains.... more
Glacial transport, owing to its high shear-stress regime, imparts a unique suite of microtextures on quartz grains. Here we examine surface textures of quartz sand grains from expedition SHALDRIL I and II and from an outcrop on Seymour Island, Antarctic Peninsula. The samples range in age from Eocene to Pleistocene and provide a record of the onset of glaciation regionally. The Eocene La Meseta Formation, Seymour Island, is void of any high-stress microtextures, supporting earlier interpretations that this unit is free of glacial influence. The inception of glacially derived high-stress microtextures and a
very low occurrence of subparallel linear fractures on quartz grains begins in the late Eocene, marking the onset of alpine glaciation. Oligocene grains exhibit a continued presence of glacially derived microtextures, with a similar style to the late Eocene sediments. The morphological character changes in the
middle Miocene. The middle Miocene microtextures are characteristic of transport from large ice sheets, displaying an increase in high-stress microtextures such as grooves, deep troughs, and crescentic gouges, an elevated degree of physical weathering, and an increased abundance of subparallel linear fractures. This is due to larger transit distances by ice rafting from the West Antarctic Ice Sheet. The Pliocene and Pleistocene samples contain abundant glacial microtextures, consistent with other evidence for the existence of the northern Antarctic Peninsula Ice Sheet at this time.
Upper Cretaceous inter-hemispheric correlation between the Southern Tethys and the Boreal: chemo-and biostratigraphy and paleoclimatic reconstructions from a new section in the Tethys Himalaya, S-Tibet
by Ines Wendler
Wendler, I., Willems, H., Gäfe, K.-U., Ding, L., Luo, H., 2011. Newsletters on Stratigraphy, 44 (2), 137-171.
A new, 430 m long and mostly continuous Upper Cretaceous section from southern hemisphere low paleolatitudes in the... more
A new, 430 m long and mostly continuous Upper Cretaceous section from southern hemisphere low paleolatitudes in the Tethys Himalaya (Guru, Tibet) is presented. The lithology, microfacies and fossil contents of the Guru section indicate a continuous shallowing trend from open oceanic conditions at the slope during the Turonian to shallow marine inner shelf environments in the Maastrichtian, interrupted by short periods of stagnation or slight deepening. Strong variations in sedimentation rates and contents of carbonate, quartz, organic carbon and sulfur appear to reflect a combination of regional and global processes. On regional scale, the patterns of varying clastic sediment supply seem to be related to the fast northward drift of the Indian plate from the temperate climate belt in the Turonian and Coniacian, crossing the arid zone during the Santonian and early Campanian, and passing into the tropical humid belt in the late Campanian. On global scale, similar sedimentary changes as in Guru with a transition from clay-rich Turonian sediments to Coniacian carbonates are found in other regions of the world, suggesting an additional influence of global oceanic and climatic factors. Intervals of omission, erosion and reworking in upper Coniacian and lower Campanian sediments of the Guru section appear to coincide with global sea-level lowstands.
Well preserved planktic foraminifera occur over most of the Guru section and provide good biostratigraphic control for correlation of stable carbon and oxygen isotopes with data from the reference section for the boreal white chalk in northern Germany at Lägerdorf-Kronsmoor and with the English Chalk reference section, showing detailed correlation of bulk sediment carbon isotopes and comparable trends in oxygen isotopes. The Campanian and Maastrichtian carbon isotope fluctuations can be related to cyclic variations in carbonate content at Lägerdorf-Kronsmoor which are thought to be driven by long eccentricity. This indicates orbital forcing of both carbonate accumulation and carbon isotope signature, most likely mediated by global sealevel changes. The possibility of detailed d13C correlation from boreal sections of the northern hemisphere to a low-latitude section of the southern hemisphere allows for global correlation with an accuracy not achieved by biostratigraphic methods so far. It further enables linking of microfossil and macrofossil biozones, facilitating precise comparison of shallow and deep water sections, which is essential for the improvement of our understanding of timing, causes and effects of climatic and oceanographic processes.
A Late Messinian Palynoflora with a Distinct Taphonomy
2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 9
A Lakeland Area in the Late Miocene
2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 8
33 views
Seen by:The Middle Late Miocene Floras - A Window into the Regional Vegetation Surrounding a Large Caldera
2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 7
The Early Late Miocene FlorasFirst Evidence of Cool Temperate and Herbaceous Taxa
2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 6
35 views
Seen by:The Classic Surtarbrandur Floras
2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 5
41 views
Seen by:The Archaic Floras
2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 4
Systematic Palaeobotany
2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 3
36 views
Seen by: and 11 moreArt Meets Science - The Unpublished Drawings by Carl Hedelin and Thérèse Ekblom
2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 14
The Biogeographic History of Iceland - The North Atlantic Land Bridge Revisited
2011
Thomas Denk, Fridgeir Grimsson, Reinhard Zetter, Leifur A Simonarson
Springer
Chapter 12
