Date File Created Name of Creator 4/27/2011 Josh Rosera (UNC) GeoRef Data 2011-012663 DN GeoRef TI Shrinking of the Colorado Plateau via lithospheric mantle erosion; evidence from Nd and Sr isotopes and geochronology of Neogene basalts AU "Crow, Ryan; Karlstrom, Karl; Asmerom, Yemane; Schmandt, Brandon; Polyak, Victor; DuFrane, Andrew" AF "Department of Earth and Planetary Sciences, University of New Mexico, Alburquerque, New Mexico 87131, USA" AF "Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403, USA" SO "Geology (Boulder), vol. 39, pp. 27-30" IS 0091-7613 CD GLGYBA DE "absolute age, alkali basalts, alkaline earth metals, Ar/Ar, Arizona, asthenosphere, basalts, basanite, body waves, Cenozoic, Colorado Plateau, continental lithosphere, cosmogenic elements, dates, elastic waves, erosion, geochemistry, geochronology, Grand Canyon, He-3, helium, igneous rocks, isotope ratios, isotopes, lithosphere, low-velocity zones, magmatism, mantle, metals, Mohave County Arizona, neodymium, Neogene, noble gases, plateaus, rare earths, seismic waves, Sr-87/Sr-86, stable isotopes, strontium, teleseismic signals, Tertiary, tomography, Uinkaret volcanic field, United States, upper mantle, upwelling, velocity structure, volcanic fields, volcanic rocks, volcanism" AB "Geochronologic data from the southern margins of the Colorado Plateau (western United States) show an inboard radial migration of Neogene basaltic magmatism. Nd and Sr isotopic data show that as basaltic volcanism migrates inboard it also becomes increasingly more asthenospheric. Strongly asthenospheric alkali basalt (epsilon (sub Nd) >4) appeared on the western plateau margin ca. 5 Ma, on the southeastern margin at 7 Ma, and is lacking from the plateau's other margins. Tomographic data suggest that low-velocity mantle underlies almost all recent (younger than 1 Ma) basaltic volcanism in a ring around much of the Colorado Plateau at a depth of 80 km. The combined isotopic and tomographic data indicate that the low-velocity mantle is asthenosphere along the western and southeastern margins of the plateau, but modified lithosphere around the remaining margins. Temporal and spatial patterns suggest a process by which upwelling asthenosphere is progressively infiltrating and replacing lithospheric mantle, especially where Proterozoic boundaries exist. This model explains (1) the dramatic velocity contrast seen well inboard of the physiographic edge of the plateau, (2) the inboard sweep of Neogene magmatism, and (3) isotopic evidence that much (but not all) of the low-velocity mantle is asthenospheric. These data support models that ongoing uplift of the edges of the Colorado Plateau is driven by mantle processes." LA English FE "References: 28, illus. incl. sect., sketch map" PY 2011 PT Serial; Analytic CP United States (USA) CL "18 Solid-earth geophysics, 03 Geochronology" CY "GeoRef, Copyright 2011, American Geological Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States | Reference includes data supplied by the Geological Society of America, Boulder, CO, USA, United States" AN 2011-012663 Sample Data Item LatDD LongDD Loc_prec Age Max_age Min_age 143_144Nd 87_86Sr SiO2 TiO2 Al2O3 FeO MnO MgO CaO Na2O K2O P2O5 Ni Cr Sc V Ba Rb Sr Zr Y Nb Ga Cu Zn Pb La Ce Th Nd U Material Rock_Type Rock_Class State Units dd dd ma ma ma wt% wt% wt% wt% wt% wt% wt% wt% wt% wt% ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm Method 1 1 2 2 2 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Sample Name WOO-190-2 36.1239 -113.1966 0.0001 0.318 0.398 0.238 0.512563 0.705217 50.88 1.38 14.82 10.57 0.16 8.6 8.44 3.2 0.73 0.19 187 341 24 178 234 12 282 96 20 11 18 72 98 2 12 26 2 15 1 Whole Rock Volcanic THOLEIITE AZ RC06-187.7-1 36.1527 -113.2088 0.0001 0.209 0.232 0.186 0.51257 0.705409 51.34 1.38 14.95 10.54 0.16 8.82 8.55 3.26 0.72 0.19 187 361 24 181 261 12 294 96 19 10 19 65 97 4 15 28 2 17 1 Whole Rock Volcanic THOLEIITE AZ LP01-179-04 36.2004 -113.0797 0.0001 0.487 0.535 0.439 0.512658 0.703978 49.22 1.64 16.62 9.38 0.16 7.62 10.19 3.41 1.04 0.45 79 225 30 230 748 13 583 141 23 29 18 68 83 7 36 61 7 28 3 Whole Rock Volcanic ALKALI Basalt AZ WOO-195-1 36.0923 -113.2649 0.0001 0.298 0.355 0.241 0.512663 0.704583 48.46 1.74 14.29 11.65 0.18 10.07 9.03 3.09 0.89 0.36 235 386 26 192 411 12 466 130 20 23 20 49 111 4 26 46 4 22 2 Whole Rock Volcanic ALKALI Basalt AZ K07-SHIV-1 36.2904 -113.4773 0.0001 5.41 5.49 5.33 0.512696 0.704591 46.2 2.24 13.37 10.94 0.17 12.19 10.77 2.99 1.18 0.58 283 473 29 248 894 16 691 168 22 44 18 73 92 5 45 87 6 38 2 Whole Rock Volcanic Basalt AZ LP01-189-01 36.1295 -113.2036 0.0001 0.127 0.154 0.1 0.512696 0.704174 Whole Rock Volcanic ALKALI basalt AZ LP01-184-01 36.1499 -113.1998 0.0001 0.2 0.272 0.128 0.512746 0.704086 45.57 2.32 12.8 11.09 0.17 12.53 10.47 2.79 1.13 0.55 314 467 26 242 838 15 671 169 20 43 16 77 98 4 42 76 5 36 2 Whole Rock Volcanic ALKALI basalt AZ RC08-188.1R-1 36.1448 -113.2039 0.0001 0.611 0.634 0.588 0.51279 0.703854 46.3 2.29 13.54 10.5 0.17 10.42 9.76 3.03 1.44 0.6 222 343 23 207 682 20 716 214 22 48 20 65 103 6 46 76 6 35 3 Whole Rock Volcanic ALKALI basalt AZ RC07-246-1C 35.824 -113.6464 0.0001 0.567 0.582 0.552 0.512902 0.703581 43.16 2.84 13.51 11.44 0.18 10.55 10.71 3.38 1.69 0.83 177 290 24 244 672 19 913 281 25 71 20 56 106 5 54 103 7 49 2 Whole Rock Volcanic TEPHRITEBASANITE AZ RC06-178-1 36.2076 -113.0596 0.0001 0.593 0.614 0.572 0.512931 0.706378 44.08 2.76 13.35 11.55 0.17 10.69 10.01 3.46 1.35 0.66 204 377 23 244 447 23 843 235 20 54 20 56 107 3 41 76 4 39 3 Whole Rock Volcanic TEPHRITEBASANITE AZ RC08-LS-CHEM 36.3443 -113.1371 0.0001 0.001 0.513035 0.70289 45.88 2.74 15.35 12.46 0.16 7.94 8.33 4.35 2.04 0.59 135 141 13 205 341 20 681 217 19 41 24 48 130 4 25 61 4 28 1 Whole Rock Volcanic TEPHRITEBASANITE AZ Method Data 1 TABLE 2011-012663 2 AR-AR 2007-128477 3 MC-ICP-MS:WR 147 4 XRF 299 Normalization Data Item 143Nd/144Nd 87Sr/86Sr Method Number 3 3 Standard Name La Jolla 0.511845 Unknown 0.710238 Fractionation Data Method Number 3 3 Item 143Nd/144Nd 87Sr/86Sr Reference Data 2 Georef# 2007-128477 TI (super 40) Ar/ (super 39) Ar and field studies of Quaternary basalts in Grand Canyon and model for carving Grand Canyon; quantifying the interaction of river incision and normal faulting across the western edge of the Colorado Plateau AU "Karlstrom, Karl E; Crow, Ryan S; Peters, Lisa; McIntosh, William; Raucci, Jason; Crossey, Laura J; Umhoefer, Paul; Dunbar, Nelia W" PB "Geological Society of America Bulletin, vol. 119, no. 11-12, pp.1283-1312, Dec 2007 " PY 2007 CY "GeoRef, Copyright 2007, American Geological Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States | Reference includes data supplied by the Geological Society of America, Boulder, CO, USA, United States" AN 2007-128477