Comment on "Zircon thermometer reveals minimum melting conditions on earliest Earth" II.
- Citation data:
Science (New York, N.Y.), ISSN: 1095-9203, Vol: 311, Issue: 5762, Page: 779; author reply 779
- Publication Year:
- melting; minimum; reveals; thermometer; ii; zircon; earth; comment; earliest; conditions; GeoQUEST; Life Sciences; Physical Sciences and Mathematics; Social and Behavioral Sciences
Watson and Harrison (Reports, 6 May 2005, p. 841) interpreted low temperatures (approximately 700 degrees C) for Hadean zircons as evidence of the existence of wet, minimum-melting conditions within 200 million years of solar system formation. However, high-temperature melts (approximately 900 degrees C) are zircon-undersaturated and crystallize zircon only after substantial temperature drop during fractional crystallization. Zircon thermometry cannot distinguish between low- and high-temperature Hadean igneous sources.