Proterozoic Geology: Selected Papers from an International Proterozoic Symposium
A. J. Baer, 1983. "Proterozoic orogenies and crustal evolution", Proterozoic Geology: Selected Papers from an International Proterozoic Symposium, L. G. Medaris, Jr., C. W. Byers, D. M. Mickelson, W. C. Shanks
Download citation file:
A brief review of secular trends of Proterozoic sedimentation, volcanism, K20/Na20 ratio of supracrustal rocks, massive sulfide mineral deposits, isotopic Sr ratio in seawater, geochronology, and paleomagnetism clearly shows the episodic nature of orogenic activity. Brief episodes of deformation and generation of continental crust, around -1800 Ma and around -1000 Ma were separated by long (800 Ma) periods of limited continental growth. Rapid thickening of continental lithosphere and growing instability of oceanic lithosphere led to the start of subduction around -800 Ma. Subduction-controlled plate tectonics has dominated orogenic evolution ever since. A theory of unsteady mantle convection limited to the...