3.46 Ga Apex chert ‘microfossils’ reinterpreted as mineral artefacts produced during phyllosilicate exfoliation
نویسندگان
چکیده
منابع مشابه
Multiple generations of carbon in the apex chert and implications for preservation of microfossils.
While the Apex chert is one of the most well-studied Archean deposits on Earth, its formation history is still not fully understood. Here, we present Raman spectroscopic data collected on the carbonaceous material (CM) present within the matrix of the Apex chert. These data, collected within a paragenetic framework, reveal two different phases of CM deposited within separate phases of quartz ma...
متن کاملDetermining the Biogenicity of Microfossils in the Apex Chert, Western Australia, Using Transmission Electron Microscopy
Introduction: For over a decade, the oldest evidence for life on this planet has been microfossils in the 3.5 Ga Apex Chert in Western Australia [1]. Recently, the biogenicity of these carbon-rich structures has been called into question through reanalysis of the local geology and reinterpretation of the original thin sections. Although initially described as a stratiform, bedded chert of silic...
متن کاملMicrofossils of the Early Archean Apex chert: new evidence of the antiquity of life.
Eleven taxa (including eight heretofore undescribed species) of cellularly preserved filamentous microbes, among the oldest fossils known, have been discovered in a bedded chert unit of the Early Archean Apex Basalt of northwestern Western Australia. This prokaryotic assemblage establishes that trichomic cyanobacterium-like microorganisms were extant and morphologically diverse at least as earl...
متن کاملRaman Imaging Spectroscopy of a Putative Microfossil from the ∼3.46 Ga Apex Chert: Insights from Quartz Grain Orientation
The utility of nondestructive laser Raman for testing the biogenicity of microfossil-like structures in ancient rocks is promising, yet results from deposits like the ∼3.46 Ga Apex chert remain contentious. The essence of the debate is that associated microstructures, which are not purported to be microfossils, also contain reduced carbon that displays Raman D- and G-band peaks similar to those...
متن کاملSiliceous microfossils from the lower cambrian of northwest Canada: possible source for biogenic chert.
Round to oval, scalelike siliceous microstructures from cherts in Cambrian limestones of the western Yukon Territory suggest affinity with chrysophycean algae. At least six morphotypes present include porous forms with single branching processes and nonporous oval, ringlike forms. Partially dissolved specimens may indicate a contribution to contemporaneous or early diagenetic chert formation.
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ژورنال
عنوان ژورنال: Gondwana Research
سال: 2016
ISSN: 1342-937X
DOI: 10.1016/j.gr.2015.07.010