Earliest part of Earth's stratigraphic record: A reappraisal of the >3.7 Ga Isua (Greenland) supracrustal sequence

摘要: Investigations of the Isua supracrustal rocks in West Greenland allow us to identify protoliths and alteration history for most rocks. The consisted alternating basalt banded iron formation. This sequence was invaded by dunitic sills, metamorphosed, later intruded felsic gneisses. Pervasive carbonation K metasomatism produced a lithologies, mimicking those found modern platform deposits. However, could have originated purely oceanic environment with no sialic detrital components. probably consists several tectonic panels, some which are cut >3810 Ma intrusive