1. Institute of Earth Sciences, Academia Sinica, 128, Section 2, Academia Road, Nangang, Taipei 11529, Taiwan, prjian@earth.sinica.edu.tw
2. Also at Department of Geosciences, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan.
3. Department of Geosciences, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan, shung@ntu.edu.tw, hueihung@gmail.com
4. Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, California 90095 U.S.A., meng@ess.ucla.edu