Geological Evidence for the Operation of Plate Tectonics throughout the Archean: Records from Archean Paleo-Plate Boundaries

Iron and carbon isotope evidence for microbial iron respiration throughout the Archean

Mass-independent fractionation of sulfur isotopes in Archean sediments: strong evidence for an anoxic Archean atmosphere.

Mass-independent fractionation (MIF) of sulfur isotopes has been reported in sediments of Archean and Early Proterozoic Age (> 2.3 Ga) but not in younger rocks. The only fractionation mechanism that is consistent with the data on all four sulfur isotopes involves atmospheric photochemical reactions such as SO2 photolysis. We have used a one-dimensional photochemical model to investigate how the...

Plate tectonics on early Earth? Weighing the paleomagnetic evidence

Paleomagnetism is the only quantitative method available to test for lateral motions by tectonic plates across the surface of ancient Earth. Here, we present several analyses of such motions using strict quality criteria from the global paleomagnetic database of pre–800 Ma rocks. Extensive surface motion of cratons can be documented confi dently to older than ca. 2775 Ma, but considering only t...

Evidence of Archean life: Stromatolites and microfossils

Evidence of Archean life: Stromatolites and microfossils J. William Schopf a,∗, Anatoliy B. Kudryavtsev b, Andrew D. Czaja c, Abhishek B. Tripathi c a Department of Earth and Space Sciences, Center for the Study of Evolution and the Origin of Life (Institute of Geophysics and Planetary Physics), Molecular Biology Institute, and NASA Astrobiology Institute, University of California, Los Angeles,...

From Continental Drift to Plate Tectonics

SINCE THE l6TH CENTURY, CARTOGRAPHERS HAVE NOTICED THE jigsaw-puzzle fit of the continental edges. Since the 19th century, geologists have known that some fossil plants and animals are extraordinarily similar across the globe, and some sequences of rock formations in distant continents are also strikingly alike. At the turn of the 20th century, Austrian geologist Eduard Suess proposed the theor...