Conodonts representing 38 species of 26 genera have been identified in samples from Upper Ordovician rocks at three central Nevada localities. Ranges of these species and associated graptolites are used graphically to determine correlation of the strata considered with an evolving composite standard that includes information from Ordovician strata at more than 100 localities in North America. R...

A low-blank, high sensitivity isotope dilution, ICP-MS analytical technique has been used to obtain REE abundance data from single conodont elements weighing as little as 5 mg. Sr isotopes can also be measured from the column eluants enabling Sr isotope ratios and REE abundance to be determined from the same dissolution. Results are comparable to published analyses comprising tens to hundreds o...