SiO2 | TiO2 | Al2O3 | Fe2O3 | FeO | MnO | MgO | CaO | Na2O | K2O | P2O5 | Total |
48.31 | 2.91 | 11.82 | 1.61 | 7.73 | 0.12 | 5.23 | 10.78 | 3.15 | 4.60 | 3.86 | 100.12 |
(After normalizing for H2O+,L.O.I,and CO2. FeO and Fe2O3 normalized to NNO Buffer.)
Rb | Sr | Ba | La | Ce | Nd | Sm | Eu | Gd | Yb | Lu | Sc | Cr | Ni | Zr | Nb | Th |
52.9 | 1380 | 2520 | 107 | 262 | 129 | 18.9 | 4.39 | 11.3 | 1.15 | 0.154 | 11.8 | 98.5 | 73.3 | 385 | 106 | 6.4 |
(PPM)
Sample | La | Ce | Nd | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu |
sp70 | 107.000 | 262.000 | 129.000 | 18.900 | 4.390 | 11.300 | 1.050 | 0.000 | 1.150 | 0.154 | |||
sp70b | 109.000 | 271.000 | 132.000 | 19.500 | 4.510 | 11.200 | 1.060 | 0.807 | 0.000 | 1.210 | 0.151 |
(Raw data values in ppm - need to correction to chondrite values)
87Rb/86Sr | error | 87Sr/86Sr | error | 87Sr/86Sri |
0.1430 | 0.0024 | 0.7046 | 0.0002 | 0.7046 |
147Sm/144Nd | error | 143Nd/144Nd | error | EpsilonNd | 0.0878 | 0.0001 | 0.5124 | 0.00002 | -4.50 |
206Pb/204Pb | error | 207Pb/206Pb | error | 208Pb/206Pb | error | 207Pb/204Pb | error | 208Pb/204Pb | error | 17.5650 | 0.0120 | 0.8793 | 0.0003 | 2.1168 | 0.0013 | 15.4450 | 0.0150 | 37.1820 | 0.0460 |
(PPM)
40Ar/39Ar age spectra for SP70
SP70. Minette. This rock is hypocrystalline, porphyritic-aphanitic with fine- to medium-grained phenocrysts in a grey-brown groundmass (36%) of mostly orthoclase and pyroxene. All crystals are subhedral except the opaque minerals (<1 mm), and analcite (<1 mm), which are subhedral to anhedral. Carbonate, chlorite, and epidote are present as anhedral masses (all < 1 mm). The following are present as phenocryst phases: biotite (.5 to 2.5 mm) are the dominant phenocryst phases; zoned titanaugite (< .5 mm), minor amounts of orthopyroxene (< .5 mm) and variolitic augite (<.1 mm); orthoclase (< 1 mm); apatite (<1 mm). Some of the medium mica grains have inclusions of orthoclase and a few others exhibit a sieve-like texture. Some of the orthoclase crystals have micro-perthite stringlets. There are some stellate clusters of titanaugite (<.5 mm). Epidote and chlorite are primarily associated with mica crystals. Amygdules (<1 mm) are scattered throughout the thin section with cores of calcite and analcite surrounded by inward pointing acicular augite (.1 mm) crystals. The overall texture is trachytic. Biotite was the phase dated.