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At least 865 records · Page 48Linked to original sources
USGS1919

Some American Jurassic ammonites of the genera Quenstedticeras, Cardioceras, and Amoeboceras, family Cardioceratida

The species cordiforme Meek and Hayden, distans Whitfield, canadense Whiteaves, and dubium Hyatt (probably including whitneyi J. P. Smith), variously assigned to the genera Amaltheus, Quenstediceras, Amoeboceras, and Cardioceras, and subtumidum Whitfield and Hovey, assigned to Aegoceras, include all the previously described species of Jurassic ammonites that are considered in this paper. Material accumulated in the National Museum at Washington, mainly through the efforts of field parties of the United States Geological Survey, has shown, however, the presence of a number of undescribed forms of considerable scientific interest. These new species were obtained mainly from the Sundance formation of Wyoming. One comes from the Ellis formation of Montana, one from Jurassic beds near Lillooet, British Columbia, and three from the Cardioceras-bearing beds near the base of the Naknek formation of Alaska.

Wyoming↗
USGS1985

An approach for appraising the accuracy of suspended-sediment data

Procedures are presented for appraising the accuracy of suspended-sediment data. Types of errors involved are sampling error, spatial error, temporal error, and sediment-discharge error. The standard error of estimate is used to represent errors. Suspended-sediment data for 17 U.S. Geological Survey gaging stations in Arizona, California, Nebraska, New Mexico, Pennsylvania, and Washington are used in applications of the procedures. For the study sites, the magnitudes of the different types of error apparently vary directly with percentage of sediment-water mixture that is sand; when the percentage sand is relatively high, magnitudes of the different types of error have a relatively wide range. For seven sites of the Sacramento River , Calif., and its tributaries, the standard sampling error apparently can range from 2.5 percent when percentage sand is relatively low to 20 percent when percentage sand is relatively high. For 16 sites in Arizona, California, Nebraska, New Mexico, and Pennsylvania, the coefficient of variation for concentrations of suspended sediment across streams apparently can range from 2.5 percent (low percentage sand) to 70 percent (high percentage sand). (USGS)

Professional Paper↗