ELECTRON MICROSCOPY OF ANCIENT MICROFOSSILS Mentor:
نویسنده
چکیده
Prof. Xiao’s current research focuses on the biological evolution and environmental changes in the Proterozoic Eon (2500 to 543 million years ago). He has been working on some of the most important and exquisitely preserved microfossils from the ca. 600-million-year-old Doushantuo Formation in South China. These microfossils include multicellular red algae and animal embryos at successive cleaving stages. In addition, he has been working on single-celled eukaryotes from much older, about 1400-million-year-old, deposits from North China.
منابع مشابه
In situ imaging of organic sulfur in 700–800 My-old Neoproterozoic microfossils using X-ray spectromicroscopy at the S K-edge
The study of very ancient microfossils has recently raised contentious issues regarding interpretation of the biogenicity of the structures. In situ investigation of certain elements such as sulfur within potential microfossils is a powerful complement to other methods of investigation that can provide valuable information on biogenicity. We present here a first such study on Precambrian microf...
متن کاملInvestigation of the Geochemical Preservation of ca. 3.0 Ga Permineralized and Encapsulated Microfossils by Nanoscale Secondary Ion Mass Spectrometry
Observations of Archean organic-walled microfossils suggest that their fossilization took place through both encapsulation and permineralization. In this study, we investigated microfossils from the ca. 3.0 Ga Farrel Quartzite (Pilbara, Western Australia) using transmitted light microscopy, scanning electron microscopy, Raman microspectrometry, and nanoscale secondary ion mass spectrometry (Nan...
متن کاملFossil microorganisms from the approximately 2800 to 2500 million-year-old Bulawayan stromatolite: Application of ultramicrochemical analyses.
Microfossils, probably representing members of Precambrian photosynthetic communities of bacteria and blue-green algae, have been found in the approximately 2800-2500 million-year-old Bulawayan stromatolites from Rhodesia. Several populations of coccoid and elongate microfossils have been observed in the dark, carbon-rich stromatolite laminae. Some of these elongate forms are morphologically si...
متن کاملThermally-induced structural and chemical alteration of organic-walled microfossils: an experimental approach to understanding fossil preservation in metasediments.
The identification and confirmation of bona fide Archean-Paleoproterozoic microfossils can prove to be a challenging task, further compounded by diagenetic and metamorphic histories. While structures of likely biological origin are not uncommon in Precambrian rocks, the search for early fossil life has been disproportionately focused on lesser thermally altered rocks, typically greenschist or l...
متن کاملUltrastructure and morphology of Chuaria circularis (Walcott, 1899) Vidal and Ford (1985) from the Neoproterozoic Visingsö Group, Sweden
The organic-walled microfossil Chuaria circularis [Walcott, C.D., 1899. Precambrian fossiliferous formations. Geol. Soc. Am. Bull. 10, 199–244] Vidal and Ford [Vidal, G., Ford, T.D., 1985. Microbiotas from the Late Proterozoic Chuar Group (Northern Arizona) and Uinta Mountain Group (Utah) and their chronostratigraphic implications. Precambrian Res. 28, 349–389] from the Visingsö Group in Sweden...
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