DOI: 10.1007/s00531-012-0799-7
Scopus记录号: 2-s2.0-84872345112
论文题名: Seasonal to sub-seasonal palaeoenvironmental changes in Lake Sihetun (Lower Cretaceous Yixian Formation, NE China)
作者: Hethke M. ; Fürsich F.T. ; Jiang B. ; Pan Y.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2013
卷: 102, 期: 1 起始页码: 351
结束页码: 378
语种: 英语
英文关键词: Fossil preservation
; Lower Cretaceous
; Microfacies
; Palaeoenvironment
; Varves
; Yixian Formation
Scopus关键词: allochthon
; biostratigraphy
; Cretaceous
; deposition
; fossil assemblage
; lithostratigraphy
; microfacies
; paleoclimate
; paleoenvironment
; seasonal variation
; sediment yield
; siliciclastic deposit
; varve
; China
; Chrysophyceae
; Conchostraca
; Hexapoda
; Invertebrata
英文摘要: Sedimentary properties of the fossil-bearing deposits of Lake Sihetun (Yixian Formation, Lower Cretaceous) were investigated on a high-resolution, sub-millimetric scale. Data were obtained from three excavations and 50 thin-sections. Lake evolution is subdivided into four phases, of which Phases 2 and 3 provided suitable conditions for excellent fossil preservation. Six microfacies are recognized within these two phases: (1) allochthonous, siliciclastic laminae (26. 1 μm thick on average), (2) chrysophycean cyst accumulations, (3) tuffaceous silt, (4) lacustrine chemical precipitates, (5) tuff and (6) normal-graded, sandy to silty siliciclastics. Phase 2 is characterized by Microfacies 1-5 and Phase 3 by Microfacies 6. Biofilms are common, and mass occurrences of framboids (pyrite pseudomorphs) are occurring in sediments of Phase 2. Varves can be verified for Microfacies 2 and 4 (179 μm thick). Thicknesses of Microfacies 2 highly fluctuate depending on the occurrence of seasonal heavier rains, which led to deposition of tuffaceous silt layers (Microfacies 3). Meromictic conditions dominated Phase 2, but recurrent mixing is demonstrated by short-lived colonization events by a benthic invertebrate fauna. The transition of Phase 2 to holomictic Phase 3 is marked by a dramatic increase in sediment yield associated with a change from dry to humid climates. Fossil preservation differs according to the diverse physical and chemical conditions during lake evolution. Phase 2 yields framboid replacement of organic tissue and excellent preservation of growth increments of clam-shrimp carapaces, which are poorly preserved in Phase 3. Conversely, though exhibiting a different mode of preservation, insect fossils are superbly preserved as dark stains sealed by silica coatings during Phase 3. © 2012 Springer-Verlag. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84872345112&doi=10.1007%2fs00531-012-0799-7&partnerID=40&md5=c135d71cfd9bd7250b8dc26de6ddf1b4
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70580
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: GeoZentrum Nordbayern, FG Paläoumwelt, Universität Erlangen-Nürnberg, Loewenichstraße 28, 91054 Erlangen, Germany; State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, 22nd Hankou Road, Nanjing, 210093, China; State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39th East Beijing Road, Nanjing, 210008, China
Recommended Citation:
Hethke M.,Fürsich F.T.,Jiang B.,et al. Seasonal to sub-seasonal palaeoenvironmental changes in Lake Sihetun (Lower Cretaceous Yixian Formation, NE China)[J]. International Journal of Earth Sciences,2013-01-01,102(1)