DOI: 10.1016/j.palaeo.2014.05.005
论文题名: Integrated paleoenvironmental analysis of the Niobrara Formation: Cretaceous Western Interior Seaway, northern Colorado
作者: Da Gama R.O.B.P. ; Lutz B. ; Desjardins P. ; Thompson M. ; Prince I. ; Espejo I.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2014
卷: 413 起始页码: 66
结束页码: 80
语种: 英语
英文关键词: Biostratigraphy
; Coniacian
; Niobrara
; Paleoenvironments
; Santonian
; Western interior seaway
英文摘要: This study presents a regional chronostratigraphic framework and paleoenvironmental reconstruction of the Niobrara Formation in northern Colorado based upon multidisciplinary biostratigraphic and lithostratigraphic data. A local biostratigraphic zonation is described for the Coniacian to earliest Campanian of this region of the Western Interior Seaway based primarily upon the distribution of calcareous nannofossils. Three key paleoenvironmental packages are also identified and linked to the evolution of regional sedimentary facies. During the Early to Late Coniacian, Tethyan water masses interacted with Boreal surface currents to produce regional upwelling along tectonically-controlled bathymetric highs. A well mixed, relatively well oxygenated water column with warm surface water temperatures and high fertility sustained a rich microflora/fauna and promoted higher carbonate production.Enhanced fluvial input and a weakening of Tethyan influence during the Early Santonian mark the onset of a regional environmental shift. This period of transition extends through the Middle Santonian and is characterized by pulses of transported material and relatively frequent turnover of faunal associations. Increased terrigenous runoff likely produced eutrophic surface waters and intensified water column stratification, leading to a general deterioration of the bottom water environment in a progressively dysoxic setting.Continued strengthening of fluvial input during the Late Santonian to Early Campanian resulted in surface water freshening and sustained primary productivity. This surface water environment-in conjunction with stifled vertical mixing-promoted the development of a stagnant and intensely stratified water column. The basin was therefore severely dysoxic (possibly anoxic) and corrosive with chemically reducing bottom waters and an expanded oxygen minimum zone, thereby limiting biotic development and causing the deposition of finely laminated, mud-rich (carbonate poor) seciments. © 2014 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69216
Appears in Collections: 过去全球变化的重建
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作者单位: Applied Stratigraphy and Paleontology, Shell International Exploration and Production Inc., 200 N. Dairy Ashford, Houston, TX, United States; Technology Excellence and Deployment, Upstream Americas Unconventionals, Shell Exploration and Production Co., 200 N. Dairy Ashford, Houston, TX, United States; Sedimentary Petrology and Reservoir Quality, Shell International Exploration and Production Inc., 200 N. Dairy Ashford, Houston, TX, United States
Recommended Citation:
Da Gama R.O.B.P.,Lutz B.,Desjardins P.,et al. Integrated paleoenvironmental analysis of the Niobrara Formation: Cretaceous Western Interior Seaway, northern Colorado[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2014-01-01,413