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Earth's air pressure 2.7 billion years ago constrained to less than half of modern levels
The composition of the Earth’s early atmosphere is uncertain. The morphology of vesicles in basalts suggests that the air pressure 2.7 billion years ago was less than half of modern levels.
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The developmental cycles of early Cambrian Olivooidae fam. nov. (?Cycloneuralia) from the Yangtze Platform (China)
Abstract Eggs, embryos, and hatchlings of olivooids are common and distinctive components of the earliest Cambrian small shelly fossil assemblage ( Anabarites trisulcatus–Protohertzina anabaricaExpand
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Microbial influence on erosion, grain transport and bedform genesis in sandy substrates under unidirectional flow
Interpreting the physical dynamics of ancient environments requires an understanding of how current-generated sedimentary structures, such as ripples and dunes, are created. TraditionalExpand
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Exceptional continental record of biotic recovery after the Cretaceous–Paleogene mass extinction
Terrestrial record of recovery The extinction that occurred at the end of the Cretaceous period is best known as the end of the nonavian dinosaurs. In theory, this paved the way for the expansion ofExpand
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Hypothesized Cambrian medusae from Saint John, New Brunswick, reinterpreted as sedimentary structures
More than a hundred radial and discoidal structures occur on bed tops of shales and very fine sandstones of the Cambrian (Series 3) King Square Formation in New Brunswick, Canada. These structuresExpand
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Sustained low marine sulfate concentrations from the Neoproterozoic to the Cambrian: Insights from carbonates of northwestern Mexico and eastern California
Abstract Stratigraphic carbonate-carbon isotope trends are similar for correlative Ediacaran and Cambrian carbonates of Sonora, Mexico, and Death Valley, California. In contrast, the sulfur isotopeExpand
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Evolution of Neoproterozoic Wonoka–Shuram Anomaly-aged carbonates: Evidence from clumped isotope paleothermometry
The Wonoka–Shuram Anomaly represents the largest negative carbon isotope excursion recognized in the geologic record and is associated with the emergence and diversification of metazoan life ca. 580Expand
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Cambrian Sauk transgression in the Grand Canyon region redefined by detrital zircons
The Sauk transgression was one of the most dramatic global marine transgressions in Earth history. It is recorded by deposition of predominantly Cambrian non-marine to shallow marine sheet sandstonesExpand
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EOLIAN-AQUATIC DEPOSITS AND FAUNAS OF THE MIDDLE CAMBRIAN POTSDAM GROUP
Abstract Exposures of the middle Cambrian Potsdam Group of northern New York, including the type section, represent a suite of interfingering eolian dune and aquatic deposits that record theExpand
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DEAD IN THEIR TRACKS—CAMBRIAN ARTHROPODS AND THEIR TRACES FROM INTERTIDAL SANDSTONES OF QUEBEC AND WISCONSIN
Abstract The large euthycarcinoid arthropod Mictomerus melochevillensis from the middle Cambrian-Furongian Potsdam Group of Quebec occurs as three-dimensional casts at the end of Cruziana- andExpand
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