DOI: 10.1016/j.palaeo.2013.02.020
论文题名: The lost paleosols: Masked evidence for emergence and soil formation on the Kimmeridgian Jura platform (NW Switzerland)
作者: Waite R. ; Marty D. ; Strasser A. ; Wetzel A.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2013
卷: 376 起始页码: 73
结束页码: 90
语种: 英语
英文关键词: Hardground
; Iron-hydroxide impregnation
; Karstification
; Soil erosion
; Trypanites ichnofacies
英文摘要: Lagoonal carbonates of Kimmeridgian age in NW Switzerland formed in a tropical epeiric sea and exhibit indicators of subaerial emergence such as tidal biolaminites, desiccation cracks, flat pebble conglomerates, and fenestral structures. Additionally, 30 dinosaur tracksites from at least six stratigraphic intervals indicate repeated formation of land bridges between the platform and adjacent massifs. Populations of herbivorous and carnivorous dinosaurs necessitate substantial vegetation and consequently a soil cover, but no striking evidence of paleosols have been found within the track bearing sequences. However, two stratigraphic levels exposed in nine outcrops exhibit distinctive hardgrounds that experienced early meteoric diagenesis during times of emergence. Initial induration began with the precipitation of thin micritic meniscus cements. Contemporaneously meteoric waters completely dissolved all aragonite leaving large voids. Iron-hydroxides were precipitated in the uppermost 7-10. cm where they impregnated the porous micrite and constituted a separate cement generation, which caused a penetrative dark red staining. These aspects are suggestive of the formation of Mediterranean-type red soils on the emerged platform. During transgression, the soil was eroded and wave-cut hardgrounds were superimposed on the hardgrounds formed during regression. Erosion is evidenced by micro-karst, truncated Gastrochaenolites isp. borings and the physical removal of steinkerns. The eroded material including floral remains provided surplus nutrients leading to eutrophication. This food-rich environment supported the mass-occurrence of gastropods in the nerineoid limestones and oysters (Nanogyra sp.) in the Virgula Marls.© 2013 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69771
Appears in Collections: 过去全球变化的重建
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作者单位: Départment de Géosciences, Université de Fribourg, Ch. du Musée 6, CH-1700 Fribourg, Switzerland; Paléontologie A16, Section d'archéologie et paléontologie, Office de la culture, HÔtel des Halles, P.O. Box 64, 2900 Porrentruy 2, Switzerland; Geologisches Institut, Universität Basel, Bernoullistrasse 32, CH-4056 Basel, Switzerland
Recommended Citation:
Waite R.,Marty D.,Strasser A.,et al. The lost paleosols: Masked evidence for emergence and soil formation on the Kimmeridgian Jura platform (NW Switzerland)[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2013-01-01,376