TBM mammals, pmag, geochron: Tables

TABLE 1. CA-TIMS U-Pb zircon data. Zircon dissolution and chemistry were adapted from methods developed by Krogh (1973), Parrish et al. (1987) and Mattinson (2005). All zircons were chemically abraded (CATIMS). Final dissolutions were spiked with a mixed ²⁰⁵Pb/ ²³U/ ²³⁵U tracer (ET535). Pb and UO₂ from zircons were loaded onto single rhenium filaments with silica gel without any ion exchange cleanup; isotopic compositions were measured in single Daly-photomultiplier mode on a Micromass Sector 54 thermal ionization mass spectrometer at the University of Wyoming. Mass discrimination for Pb was 0.245 ± 0.10 %/amu for Daly analyses based on replicate analyses of NIST SRM 981. U fractionation was determined internally during each run. Procedural blanks ranged from 0.55 to 4 picograms Pb during the course of the study. U blanks were consistently less than 0.1 pg. Isotopic composition of the Pb blank was measured as 18.419 ± 1.37, 15.369 ± 0.63 and 37.228 ± 2.59 for ²⁰⁶Pb/ ²⁰⁴Pb, ²⁰⁷Pb/ ²⁰⁴Pb, and ²⁰⁸Pb/ ²⁰⁴Pb, respectively. Concordia coordinates, intercepts, uncertainties and Concordia Ages were calculated using PbMacDat and ISOPLOT programs (based on Ludwig 1988, 1991, 1998); initial Pb isotopic compositions for zircon were estimated by Stacey and Kramers (1975) model. The decay constants used by PbMacDat are those recommended by the I.U.G.S. Subcommission on Geochronology (Steiger and Jäger, 1977): 0.155125 x 10 ^-9/yr for ²³⁸U, 0.98485 x 10-9/yr for ²³⁵U and present-day ²³⁸U/ ²³⁵U = 137.88.

Abbreviations and notes
Sample: euh = euhedral; ash = ash-fall zircon morphology; s = single grain; *excluded from age calculations.
Weight: represents estimated weight after first step of CATIMS zircon dissolution and is only approximate. U and Pb concentrations are based on this weight and are useful for internal comparisons only. Picograms (pg) sample and common Pb from the second dissolution step are measured directly, however, and are accurate.
Sample Pb: sample Pb (radiogenic + initial) corrected for laboratory blank.
cPb: total common Pb. All was assigned to laboratory blank.
Pb*/Pbc: radiogenic Pb to total common Pb (blank + initial).
Corrected atomic ratios: 206Pb/204Pb corrected for mass discrimination and tracer, all others corrected for blank, mass discrimination, tracer and initial Pb, values in parentheses are 2 sigma errors in percent. 206Pb/238Pb ratios and dates corrected for Th disequilibrium assuming Th/U magma of 2.2.
Rho: ²⁰⁶ Pb/238U versus 207Pb/235U error correlation coefficient.

TABLE 2. Paleomagnetic data for samples from two stratigraphic levels in uppermost Bridger Formation. PCM6Sept15-02 and PCM6Sept15-03 are from the base of white tuffaceous sandstone in the TBM type section on the southwest flank of Cedar Mountain (Figure 1). PCM7Sept15-01 is from the Basal E tuff in the uppermost Twin Buttes Member (Bridger D) on west flank of Sage Creek Mountain. Latitude and Longitude are relative to WGS84 datum. Stratigraphic level (in meters) of site relative to the base of the TBM (= Basal E limestone, Figure 1). Decstrat and Incstrat are declination and inclination of Characteristic Remanent Magnetization in stratigraphic coordinates, α95 is 95% cone of confidence, K is value of precision parameter, R is length of resultant vector, VGP long/lat are longitude and latitude of virtual geomagnetic pole.

TABLE 3. Measurements (in mm) of Didelphimorphia from TBM (a = approximate; b = broken dimension; p. = partial).

TABLE 4. Faunal characterization of Ui1a faunas (revised after Murphey and Kelly, 2017, table 5). Taxonomic lists of mammals of Uintan biochron Ui1a from TBM and the basal Tertiary Conglomerate Local Fauna (BTC) of lower member of the Devil's Graveyard Formation, Texas, along with taxa from lower in Bridger Formation (Br2 or Br3) that are hold overs in the TBM and BTC, and taxa that range-through to Ui1b or later. References: Leidy, 1872 ¹; Marsh, 1872b ²; Matthew, 1909 ³; Troxell, 1923b ⁴; Wilson, 1937 ⁵; McKenna and Simpson, 1959 ⁶; Wood, 1959 ⁷, 1973 ⁸; Robinson, 1968 ⁹; Szalay, 1969 ¹⁰, 1976 ¹¹; West, 1974 ¹²; Gazin, 1976 ¹³; Krishtalka, 1976 ¹⁴; Lillegraven et al., 1981 ¹⁵; West and Hutchinson, 1981 ¹⁶; Wilson and Schiebout, 1984 ¹⁷; West, 1982 ¹⁸; Wilson, 1984 ¹⁹, 1986 ²⁰; Krishtalka, personal communication in Wilson, 1986 ²¹; McCarroll et al., 1996a ²²; Walsh, 1996b ²³; Asher et al., 2002 ²⁴; Turnbull, 2002 ²⁵; Williams and Kirk, 2008 ²⁶; Gunnell et al., 2008 ²⁷, 2009 ²⁸; Mihlbachler, 2008 ²⁹; Murphey and Dunn, 2009 ³⁰; Campisano et al., 2014 ³¹; Kelly and Murphey, 2016a ³²; Murphey and Kelly, 2017 ³³; this paper ³⁴. LRD, lowest range datum (= first appearance). Index species, taxa restricted to Ui1a. N, number of taxa.

TABLE 5. Faunal Characterization of the Ui1b (revised after Gunnell et al., 2009, table 7). Sand Wash Basin taxa records were removed because the relative stratigraphic positions of localities are undetermined and the taxa need to be reevaluated with a detailed systematic analysis, except for the Bridgerian locality 20 of West and Dawson (1975) from below Robin's Blue Egg Marker bed. HRD, highest range datum (= last occurrence). LRD, lowest range datum (= first appearance). Index species, taxa restricted to Ui1b. AT, Adobe Town middle member, Washakie Formation. BB, Blacks Fork Member, Bridger Formation. FS, Friars Formation. FTT, "Foggy Day beds," Tepee Trail Formation. HTT, "Holy City beds," Tepee Trail Formation. TB, Twin Buttes Member, Bridger Formation.