Probing the Mantle Past.

The article discusses the use of precision isotope analysis to reveal details about the dynamic processes involved in the formation of planet Earth's mantle. Topics include a belief among geologists that evidence of the first few hundred million years of Earth's history had been erased by mantle convection and plate tectonics, a study within the issue regarding geophysics research by M. Touboul and colleagues reporting measurements of the isotopic composition of tungsten (W) in 2.8-billion-year-old basaltic rock, called komatiite, which is known to be derived from source regions deep within Earth's mantle, and the abundance of an tungsten isotope 182W, which forms from the decay of an isotope of hafnium (182Hf).