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The least-squares line and plane and the analysis of palaeomagnetic data
Summary The classic, multivariate technique of principal component analysis can be used to find and estimate the directions of lines and planes of best least-squares fit along the demagnetizationExpand
Late Proterozoic low-latitude global glaciation: the snowball Earth
A fundamental question of earth history concerns the nature of the Late Proterozoic glaciogenic sequences that are known from almost all of the major cratonic areas, including North America, theExpand
The Paleoproterozoic snowball Earth: a climate disaster triggered by the evolution of oxygenic photosynthesis.
It is argued that oxygenic cyanobacteria evolved and radiated shortly before the Makganyene snowball, and could have destroyed a methane greenhouse and triggered a snowball event on time-scales as short as 1 million years. Expand
Low-latitude glaciation in the Palaeoproterozoic era
One of the most fundamental enigmas of the Earth's palaeoclimate concerns the temporal and spatial distributions of Precambrian glaciations. Through four billion years of Precambrian history,Expand
Paleoproterozoic snowball earth: extreme climatic and geochemical global change and its biological consequences.
Geological, geophysical, and geochemical data support a theory that Earth experienced several intervals of intense, global glaciation ("snowball Earth" conditions) during Precambrian time. ThisExpand
Age of Neoproterozoic bilatarian body and trace fossils, White Sea, Russia: implications for metazoan evolution.
A uranium-lead zircon age for a volcanic ash interstratified with fossil-bearing, shallow marine siliciclastic rocks in the Zimnie Gory section of the White Sea region indicates that a diverse assemblage of body and trace fossils occurred before 555.3 +/- 0.3 million years ago, making co-occurring trace fossils the oldest that are reliably dated. Expand
Zircon U-Pb ages for the Early Cambrian time-scale
Single zircons from two Early Cambrian volcanic horizons have been analysed using the SHRIMP ion microprobe. Full details of the analytical procedures and data reduction are given. Zircons from tuffExpand
Abrupt and Gradual Extinction Among Late Permian Land Vertebrates in the Karoo Basin, South Africa
The vertebrate fossil data show a gradual extinction in the Upper Permian punctuated by an enhanced extinction pulse at the Permians-Triassic boundary interval, particularly among the dicynodont therapsids, coinciding with negative carbon-isotope anomalies. Expand
Evidence for a Large-Scale Reorganization of Early Cambrian Continental Masses by Inertial Interchange True Polar Wander
Analysis of Vendian to Cambrian paleomagnetic data shows anomalously fast rotations and latitudinal drift for all of the major continents. These motions are consistent with an Early to MiddleExpand
Ferromagnetic resonance and low-temperature magnetic tests for biogenic magnetite
Magnetite is both a common inorganic rock-forming mineral and a biogenic product formed by a diversity of organisms. Magnetotactic bacteria produce intracellular magnetites of high purity andExpand