Date File Created Name of Creator 7/18/2006 Rich Gaschnig GeoRef Data 2006-049735 DN GeoRef TI Layered mafic sill complex beneath the eastern Snake River plain;evidence from cyclic geochemical variations in basalt AU "Shervais, John W; Vetter, Scott K; Hanan, Barry B" AF "Utah State University, Department of Geology, Logan, UT, United States(USA)" AF "Centenary College, United States (USA); San Diego State University,United States (USA)" SO "Geology (Boulder), vol.34, no.5, pp.365-368, May 2006" RL [U RL http://www.gsajournals.org/] IS 0091-7613 CD GLGYBA DE alkaline earth metals; assimilation; basalts; chemical fractionation;cores; crust; crystal fractionation; cycles; electron probe data;geochemical cycle; geochemistry; granitic layer; Idaho; igneous rocks;INEEL; intrusions; isotope ratios; isotopes; lava; layered intrusions;lead; mafic composition; magmas; major elements; metals; middle crust;Pb-208/Pb-204; radioactive isotopes; rhyolites; sills; Snake Riverplain; southern Idaho; Sr-87/Sr-86; stable isotopes; strontium; traceelements; United States; volcanic rocks; volcanism AB "The eastern Snake River plain in southern Idaho, Western UnitedStates, is characterized by 1-2 km of Pleistocene to late Pliocenebasalt overlying rhyolite caldera complexes. Cyclic variations in thechemical composition of basalts from 1136 m of scientific drill coreshow that the parent magmas of these lavas evolved by crystalfractionation at shallow to intermediate crustal depths, punctuated byepisodic recharge with more primitive compositions and assimilation ofadjacent wall rock. We have identified 10 upward fractionation cyclesand four reversed cycles; assimilation of sialic crust was limited andmainly affects the oldest basalts, which directly overlie rhyolites.We infer that the crystal fractionation and/or recharge cycles tookplace in a series of sill-like intrusions at intermediate crustaldepths that now form a layered mafic intrusion that underlies theeastern Snake River plain at depth. This layered sill complex isrepresented by the approximately 10-km-thick ""basaltic sill"" that hasbeen imaged seismically at approximately 12-22 km depth. Theassociation of this mid-crustal sill complex with geochemicalfractionation cycles in basalt supports the concept that exposedlayered mafic intrusions may be linked to overlying basalt provincesthat have since been removed by erosion." LA English NT With GSA Data Repository Item 2006072 FE "References: 22; illus. incl. sects., sketch map" PY 2006 PT Serial; Analytic CP United States (USA) LL "Latitude:N432200,N440200 Longitude:W1122600,W1131000" CL 02D Isotope geochemistry; 05A Igneous and metamorphic petrology CY "GeoRef, Copyright 2006, American Geological Institute. Referenceincludes data supplied by the Geological Society of America, Boulder,CO, United States" UD 200614 DO 10.1130/G22226.1 AN 2006-049735 Sample Data Item TiO2 MgO K2O P2O5 Cr La Ce Yb Lu 87_86Sr 208_204Pb LatDD LongDD Loc_prec Location_Name Volcanic_Field Rock_Class Rock_Type Age Max_age Min_age Core_depth Material State Units wt % wt % wt % wt % ppm ppm ppm ppm ppm DD DD Ma Ma Ma meters Method 1 1 1 1 2 2 2 2 2 3 3 4 4 5 5 5 Sample Name 20 2.8 6.42 0.94 0.51 140 29.3 63.7 3.96 0.64 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 10 basalt volcanic 0.23 20 whole rock ID 77 2.61 8 0.71 0.58 193 30.9 63.4 3.82 0.6 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 10 basalt volcanic 0.78 0.23 77 whole rock ID 90 2.69 8.16 0.63 0.36 233 24.93 53.51 3.26 0.5 0.7061 38.56 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 10 basalt volcanic 0.78 0.23 90 whole rock ID 188 2.59 7.86 0.82 0.56 210 32.89 69.22 3.81 0.58 0.7062 38.55 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 9 basalt volcanic 0.78 0.23 188 whole rock ID 349 1.84 8.28 0.43 0.27 274 18.2 40.5 3.31 0.52 0.7067 38.48 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 9 basalt volcanic 1.81 0.78 349 whole rock ID 431 1.14 10.45 0.19 0.12 362 9 17.68 2.46 0.36 38.54 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 9 basalt volcanic 1.81 0.78 431 whole rock ID 626 2.19 9 0.45 0.26 276 19.4 38.4 3.25 0.59 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 8R basalt volcanic 4.45 1.81 626 whole rock ID 655 2.21 8.76 0.45 0.32 283 17.9 38.6 2.97 0.45 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 8R basalt volcanic 4.45 1.81 655 whole rock ID 705 2.11 8.86 0.66 0.33 267 21.06 44.67 2.89 0.43 0.7066 38.6 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 8R basalt volcanic 4.45 1.81 705 whole rock ID 786 2.35 8.2 0.65 0.31 209 35.1 59.2 4.46 0.7 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 8 basalt volcanic 4.45 1.81 786 whole rock ID 860 2.36 7.29 0.84 0.4 308 21.5 44.6 3.01 0.47 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 8 basalt volcanic 4.45 1.81 860 whole rock ID 927 2.39 8.63 0.62 0.43 217 21.32 46.35 3.17 0.47 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 8 basalt volcanic 4.45 1.81 927 whole rock ID 944 3.24 6.53 0.67 0.68 141 35.9 72.4 5.82 1 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 8 basalt volcanic 4.45 1.81 944 whole rock ID 998 2.33 8.75 0.54 0.34 323 23.6 49.9 3.35 0.52 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 8 basalt volcanic 4.45 1.81 998 whole rock ID 1010 2.64 7.73 0.79 0.39 158 33.3 68 3.89 0.59 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7R basalt volcanic 4.45 1.81 1010 whole rock ID 1054 2.78 7.24 0.8 0.5 154 29.17 61.56 3.4 0.51 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7R basalt volcanic 4.45 1.81 1054 whole rock ID 1074 2.93 7.24 0.79 0.45 178 32.5 67.8 3.78 0.56 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7R basalt volcanic 4.45 1.81 1074 whole rock ID 1122 2.23 6.67 1.01 0.59 170 26.77 56.6 3.25 0.48 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7 basalt volcanic 4.45 1.81 1122 whole rock ID 1136 2.08 5.41 0.9 0.22 126 39.15 78.86 3.54 0.52 0.7066 38.41 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7 basalt volcanic 4.45 1.81 1136 whole rock ID 1164 2.78 6.97 0.84 0.49 141 39.57 80.94 3.74 0.56 0.7065 38.43 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7 basalt volcanic 4.45 1.81 1164 whole rock ID 1221 2.81 7.1 0.65 0.35 140 27.82 58.89 3.39 0.5 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7 basalt volcanic 4.45 1.81 1221 whole rock ID 1239 2.93 7.35 0.74 0.59 146 30.46 64.83 3.63 0.53 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7 basalt volcanic 4.45 1.81 1239 whole rock ID 1263 1.95 8.24 0.65 0.34 301 31.14 65 2.35 0.32 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7 basalt volcanic 4.45 1.81 1263 whole rock ID 1286 2.3 9.05 0.64 0.39 343 20.58 45.47 2.4 0.35 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7 basalt volcanic 4.45 1.81 1286 whole rock ID 1290 2.31 8.32 0.55 0.41 347 22.3 47.2 3.2 0.49 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7 basalt volcanic 4.45 1.81 1290 whole rock ID 1304 2.43 7.8 0.63 0.31 201 22.52 47.4 2.85 0.42 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7 basalt volcanic 4.45 1.81 1304 whole rock ID 1316 1.98 9.08 0.53 0.21 298 20.05 42.23 2.66 0.39 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7 basalt volcanic 4.45 1.81 1316 whole rock ID 1378 2.22 9.31 0.56 0.26 258 20.46 44.16 2.94 0.44 0.7064 38.44 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 7 basalt volcanic 4.45 1.81 1378 whole rock ID 1480 2.75 8.2 0.5 0.52 191 19.6 42.3 3.3 0.51 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 6 basalt volcanic 4.45 1.81 1480 whole rock ID 1541 2.03 9.33 0.38 0.23 364 12.86 28.37 2.51 0.38 0.7071 38.3 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 6 basalt volcanic 4.45 1.81 1541 whole rock ID 1565 2.9 6.34 0.88 0.58 201 29.37 61.35 3.22 0.48 0.7071 38.49 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 6 basalt volcanic 4.45 1.81 1565 whole rock ID 1599 1.74 8.72 0.6 0.21 264 20.66 43.65 3.36 0.49 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 6 basalt volcanic 4.45 1.81 1599 whole rock ID 1632 1.94 8.94 0.62 0.36 326 23.34 50.18 3.57 0.53 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 6 basalt volcanic 4.45 1.81 1632 whole rock ID 1731 3.41 7.24 0.34 0.49 186 23.66 53.59 3.62 0.53 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 5 basalt volcanic 4.45 1.81 1731 whole rock ID 1805 3 7.47 0.54 0.39 171 22.2 48.47 3.33 0.48 0.7073 38.48 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 5 basalt volcanic 4.45 1.81 1805 whole rock ID 1863 2.42 8.13 0.52 0.47 344 21.07 44.94 3.08 0.46 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 5 basalt volcanic 4.45 1.81 1863 whole rock ID 1903 2.8 8.02 0.46 0.35 218 18.53 40.61 2.94 0.44 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 5 basalt volcanic 4.45 1.81 1903 whole rock ID 2050 2.9 7.35 0.41 0.53 202 29.64 63.76 3.83 0.55 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 4R basalt volcanic 4.45 1.81 2050 whole rock ID 2091 3.16 6.62 0.4 0.42 146 28.29 60.41 3.44 0.5 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 4R basalt volcanic 4.45 1.81 2091 whole rock ID 2190 2.78 6.07 0.39 0.59 144 26.25 56.52 3.39 0.51 0.7073 38.53 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 4 basalt volcanic 4.45 1.81 2190 whole rock ID 2198 3.16 5.86 0.65 0.21 176 47.01 95.22 5.09 0.83 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 4 basalt volcanic 4.45 1.81 2198 whole rock ID 2325 2.99 7.41 0.4 0.42 239 21.92 47.52 3.07 0.45 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 4 basalt volcanic 4.45 1.81 2325 whole rock ID 2458 2.06 8.62 0.29 0.3 242 16.12 35.32 2.81 0.43 0.7063 38.52 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 4 basalt volcanic 4.45 1.81 2458 whole rock ID 2499 3.02 7.74 0.16 0.47 165 19 43.09 3.09 0.44 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 3R basalt volcanic 4.45 1.81 2499 whole rock ID 2575 3.33 8.36 2.57 0.38 205 18.05 41.19 2.96 0.42 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 3R basalt volcanic 4.45 1.81 2575 whole rock ID 2611 3.16 7.76 0.31 0.58 210 20.75 45.98 3.31 0.49 0.707 38.54 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 3R basalt volcanic 4.45 1.81 2611 whole rock ID 2707 2.22 6.14 1.59 0.33 132 39.51 78.7 4.25 0.61 0.7067 38.54 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 3R basalt volcanic 4.45 1.81 2707 whole rock ID 2782 3.21 6.42 0.42 0.54 170 43.47 96.48 6.78 1.01 0.7075 38.46 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 3R basalt volcanic 4.45 1.81 2782 whole rock ID 2878 3.2 6.36 0.67 0.79 141 30.32 65.15 3.92 0.58 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 3 basalt volcanic 4.45 1.81 2878 whole rock ID 3000 3.06 7.66 0.24 0.34 154 22.29 48.62 3.36 0.49 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 3 basalt volcanic 4.45 1.81 3000 whole rock ID 3079 3.3 7 0.23 0.36 145 19.42 42.83 3.27 0.47 0.7073 38.58 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 3 basalt volcanic 4.45 1.81 3079 whole rock ID 3193 1.99 8.9 0.61 0.29 192 22.73 49.68 3.34 0.51 0.707 38.61 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 3 basalt volcanic 4.45 1.81 3193 whole rock ID 3242 3.36 7.1 0.68 0.57 172 29.82 62.94 3.75 0.57 0.7074 38.43 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 2 basalt volcanic 4.45 1.81 3242 whole rock ID 3341 1.43 7.9 0.36 36 6.13 14.45 1.84 0.26 0.7063 38.52 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 2 basalt volcanic 4.45 1.81 3341 whole rock ID 3409 1.65 7.74 0.35 0.06 141 12.7 26.82 2.63 0.39 37.85 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 2 basalt volcanic 4.45 1.81 3409 whole rock ID 3606 1.17 8.78 0.57 0.07 369 13.32 27.37 2.33 0.35 0.7075 37.98 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 2 basalt volcanic 4.45 1.81 3606 whole rock ID 3645 1.95 4.96 1.2 0.23 97 36.52 71.91 4.18 0.6 0.7083 37.85 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 1 basalt volcanic 4.45 1.81 3645 whole rock ID 3740 2 8.71 0.58 0.28 169 45.44 93.3 6.33 0.95 37.78 43.539 -112.8182 0.1 "Eastern Snake River Plain, Idaho National Laboratory, Core hole WO-2" Fractionation cycle 1 basalt volcanic 4.45 1.81 3740 whole rock ID Method Data 1 EMP 57 2 XRF 57 some elements were measured by ICP-MS 3 ICPMS 57 4 SCAN 2006-049735 5 STRAT 2006-049735