Sm nd isotopic dating
Even then, the scatter of the data points for the isochron is usually significant, perhaps hinting that the linear plot more closely models a mixing line than an isochron.
Rare-earth dating is plagued by the same questionable four assumptions as the K-Ar, Ar-Ar, and Rb-Sr dating methods, and the rocks they supposedly date continue to exhibit behavior that is just as consistent with a mixing line as an isochron line.
Signals of Barremian (116 Ma) or younger oceanic crust beneath the Bay of Bengal along 14N latitude between 81E and 93E, Mar.
But while the widespread realization of the importance of supercontinents in Earth history is a relatively recent development, the supercontinent cycle was first proposed thirty years ago and episodicity in tectonic processes was recognized long before plate tectonics provided a potential explanation for its occurrence. He is editor of , and his main research interests are in understanding orogenic processes, the relationship between tectonics, magmatism and mineralization, mantle plumes and mountain building, and the use of isotopic systematics as tectonic tracers.
With interest in the supercontinent cycle gaining momentum and the literature expanding rapidly, it is instructive to recall the historical context from which the concept developed. from Cambridge University in 1978 after emigrating to Canada in 1976. He has published over 250 research papers, edited several memoir volumes and journal special issues, and is co-author (with Damian Nance) of the book ‘Earth Science Today’ (Brooks-Cole/Wadsworth, 1999).
For example, , had this to say about isochron ages: The determination of accurate and precise isochron ages for igneous rocks requires that the initial isotope ratios of the analyzed minerals are identical at the time of eruption or emplacement.
Studies of young volcanic rocks at the mineral scale have shown this assumption to be invalid in many instances.