This report presents new fission-track ages for Tertiary volcanic rocks in the Mogollon plateau, southwestern NM. John Kerr Peak Quartz Latite forms a dome complex and is interbedded with Bearwallow Mountain Formation; it lies above Railroad Canyon Rhyolite. Two samples of John Kerr Peak taken: 1) SE1/4 sec 10, T6S, R16W, Catron Co, NM, Basin-and-Range province, producing a fission-track date on sphene and zircon of 20.2 +/-0.9 m.y.; and 2) SW1/4 sec 18, T6S, R15W, Catron Co, producing a fission-track date on sphene and apatite of 22.1 +-0.9 m.y. Average age of unit is 21.4 +/-1.1 m.y.
Source: GNU records (USGS DDS-6; Denver GNULEX).
Has yielded ages of 13.6 +/-0.5 m.y. (biotite), 12.0 +/-1.6 m.y. (zircon), 22.7 +/-4.8 and 20.6 +/-4.8 m.y. (sphene), 22.7 +/-5.2 m.y. (apatite), 21.4 +/-2.2 and 19.9 +/-2.2 m.y. (zircon) from samples collected in Catron Co, NM in Basin-and-Range province. [These ages are regarded as Miocene.]
Source: GNU records (USGS DDS-6; Denver GNULEX).
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