1. US National Museum of Natural History; Smithsonian Institution; Washington; District of Columbia; 20560; USA
2. Lawrence Livermore National Laboratory; 7000 East Avenue; Livermore; California; 94550-9234; USA
3. Department of the Geophysical Sciences; University of Chicago; Chicago; 60637; USA
4. Department of Geosciences; University of Wisconsin-Madison; Madison; Wisconsin; 53706; USA