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The snowball Earth hypothesis: testing the limits of global change
The gradual discovery that late Neoproterozoic ice sheets extended to sea level near the equator poses a palaeoenvironmental conundrum. Was the Earth’s orbital obliquity > 60� (making the tropicsExpand
Did the Breakout of Laurentia Turn Gondwanaland Inside-Out?
Comparative geology suggests that the continents adjacent to northern, western, southern, and eastern Laurentia in the Late Proterozoic were Siberia, Australia-Antarctica, southern Africa, andExpand
Toward a Neoproterozoic composite carbon-isotope record
Glacial deposits of Sturtian and Marinoan age occur in the well-studied Neoproterozoic successions of northern Namibia, South Australia, and northwestern Canada. In all three regions, the MarinoanExpand
Anatomy of North America: thematic geologic portrayals of the continent
Abstract Six thematic tectonic maps are used to analyse the makeup of the North American continent. Themes are: 1. (1) major tectonic elements of the continent 2. (2) time of last major deformationExpand
Speculations on Laurentia's first gigayear (2.0 to 1.0 Ga)
It is postulated that a mantle superswell (convective upwelling thousands of kilometres in diameter) developed beneath a stationary supercontinent aggregated in the late Early Proterozoic, givingExpand
On the initiation of a snowball Earth
[1] The Snowball Earth hypothesis explains the development of glaciation at low latitudes in the Neoproterozoic, as well as the associated iron formations and cap carbonates, in terms of a runawayExpand
A palaeogeographic context for Neoproterozoic glaciation
The distributions of 77 Neoproterozoic glacigenic formations are shown on global palaeogeographic maps for 715 Ma (Sturtian), 635 Ma (Marinoan) and 580 Ma (Ediacaran), constructed on groundsExpand
Tectono-magmatic evolution of the 1.9-Ga great bear magmatic zone, Wopmay orogen, northwestern Canada☆
Hildebrand, R.S., Hoffman, P.F. and Bowring, S.A., 1987. Tectono-magmatic evolution of the 1.9-Ga Great Bear magmatic zone, Wopmay orogen, northwestern Canada. In: S.D. Weaver and R.W. JohnsonExpand