气候变化领域集成服务门户(CCPortal): Abundant trace fossil Polykampton in Palaeogene deep-sea flysch deposits of the Lesser Caucasus in Georgia: Palaeoecological and palaeoenvironmental implications

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DOI	10.1016/j.palaeo.2020.109958
	Abundant trace fossil Polykampton in Palaeogene deep-sea flysch deposits of the Lesser Caucasus in Georgia: Palaeoecological and palaeoenvironmental implications
	Uchman A.; Lebanidze Z.; Beridze T.; Kobakhidze N.; Lobzhanidze K.; Khutsishvili S.; Chagelishvili R.; Makadze D.; Koiava K.; Khundadze N.
发表日期	2020
ISSN	0031-0182
卷号	558
英文摘要	The new ichnospecies of Polykampton georgianum occurs abundantly in a part of the Borjomi Flysch (Upper Paleocene – Lower Eocene) in Georgia, in particular in the 45.3 m thick Ardagani-1 section that is dominated by grey silt- and mudstones having sandstones intercalated. The trace fossil occurs in the middle and upper part of the section. The trace fossil is composed of a median tunnel and side lobes that are filled with material differing from the host sediment. It is interpreted as a sequestrichnion, wherein the tracemaker stored organic-rich mud in the lobes as a food resource for times of food deficiency. The today ferruginization of the median tunnel resulting from the former presence of pyrite suggests strong chemical gradient between its lumen and the surrounding. Chemichnial behaviour is not excluded as nutritional strategy of the worm-like tracemaker (a polychaete?). It occupies a middle tier and is commonly crosscut by Trichichnus, Chondrites and Scolicia. Rare or absent other trace fossils typical of deep-sea fine-grained deposits suggest slight dysoxia. Significant impoverishment of the tiering pattern (only Trichichnus present) and absence of trace fossils in the lower part of the section point to strong dysoxia or episodic anoxia. The trace fossil assemblage is atypical, but in general it resembles the Nereites ichnosubfacies of the Nereites ichnofacies, which characterizes distal parts of the turbiditic depositional systems. The contrast between the dark grey to grey silt- and mudstones deposited during the waning phase of gravitational flows and greenish pelagic mud suggests that the former originated from an organic-rich depositional setting, presumably within the oxygen minimum zone in the upper-slope to outer-shelf domain. Sequestration of the organic-rich mud was a successful adaptation of the Polykampton georgianum producers in this specific environmental setting. © 2020 Elsevier B.V.
英文关键词	Flysch; Ichnofabrics; Ichnology; Ichnotaxonomy; Palaeoecology; Transcaucasus region
语种	英语
scopus关键词	chondrite; deep-sea organism; fossil assemblage; morphology; mudstone; new species; Paleocene-Eocene boundary; paleoecology; paleoenvironment; trace fossil; Georgia; United States; Nereites; Polychaeta; Scolicia
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150341
作者单位	Jagiellonian University, Faculty of Geography and Geology, Institute of Geological Sciences, Gronostajowa 3a, Kraków, PL-30-387, Poland; Department of Geology, Faculty of Exact and Natural Sciences, Iv. Javakhishvili Tbilisi State University, University str. 13, Tbilisi, 0186, Georgia; Alexander Janelidze Institute of Geology, Iv. Javakhishvili Tbilisi State University, Politkovskaia 31, Tbilisi, 0186, Georgia; Department of Geology and Paleontology, Georgian National Museum, Purtseladze str. 3, Tbilisi, 0105, Georgia; Alexander Tvalchrelidze Caucasian Institute of Mineral Resources, Tbilisi State University, Mindeli str. 12, Tbilisi, 0186, Georgia
推荐引用方式 GB/T 7714	Uchman A.,Lebanidze Z.,Beridze T.,et al. Abundant trace fossil Polykampton in Palaeogene deep-sea flysch deposits of the Lesser Caucasus in Georgia: Palaeoecological and palaeoenvironmental implications[J],2020,558.
APA	Uchman A..,Lebanidze Z..,Beridze T..,Kobakhidze N..,Lobzhanidze K..,...&Khundadze N..(2020).Abundant trace fossil Polykampton in Palaeogene deep-sea flysch deposits of the Lesser Caucasus in Georgia: Palaeoecological and palaeoenvironmental implications.Palaeogeography, Palaeoclimatology, Palaeoecology,558.
MLA	Uchman A.,et al."Abundant trace fossil Polykampton in Palaeogene deep-sea flysch deposits of the Lesser Caucasus in Georgia: Palaeoecological and palaeoenvironmental implications".Palaeogeography, Palaeoclimatology, Palaeoecology 558(2020).