Magnetic stripes and isotopic clocks Magnetic Stripes and Isotopic Clocks http://pubs.usgs.gov/gip/dynamic/stripes.html Magnetic stripes and isotopic clocks http://pubs.usgs.gov/gip/dynamic/stripes.html Magnetic Stripes and Isotopic Clocks http://pubs.usgs.gov/gip/dynamic/stripes.html Magnetic stripes and isotopic clocks Magnetic Stripes and Isotopic Clocks http://pubs.usgs.gov/gip/dynamic/stripes.html http://pubs.usgs.gov/gip/dynamic/stripes.html http://pubs.usgs.gov/gip/dynamic/stripes.html Magnetic Stripes and Isotopic Clocks http://pubs.usgs.gov/gip/dynamic/stripes.html