Pyroclastic rocks associated with the Taylor Creek Rhyolite, Scales Canyon
— Philip R. Kyle, Ted L. Eggleston, William C. McIntosh, Nelia Dunbar, Charles M. Hammond, W. David Johnson, Michael Knoper, and Judith Moore
Abstract:
Pyroclastic deposits formed during the emplacement of the 28.6 my old Taylor Creek Rhyolite are exposed in a 2 km long section in Scales Canyon. As much as 50 m of pyroclastic fall, surge, and flow deposits as well as eolian sandstone have been recognized in five measured sections. Three eruptive sequences are proposed: I — a lower, predominantly pyroclastic flow and surge sequence; II — a middle pyroclastic fall sequence; and III — an upper sequence of two coarse pyroclastic breccias. Paleomagnetic measurements on clasts from the two units within sequence III indicate the lower unit was emplaced as a hot (>500°C) pyroclastic flow, whereas the upper unit was emplaced as a mixture of hot (>500°C) and cold (<300°C) clasts. Both units apparently represent dome-collapse breccias. The lower unit contains only hot material from the interior of the dome, whereas the upper unit also contains a component of the cooler dome carapace.
The Scales Canyon pyroclastic deposits were apparently erupted over a short span of time from two or more nearby dome-related vents. Individual vents cannot be identified because the deposits are mineralogically similar.
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Recommended Citation:
- Kyle, Philip R.; Eggleston, Ted L.; McIntosh, William C.; Dunbar, Nelia; Hammond, Charles M.; Johnson, W. David; Knoper, Michael; Moore, Judith, 1986, Pyroclastic rocks associated with the Taylor Creek Rhyolite, Scales Canyon, in: Truth or Consequences region, Clemons, R. E.; King, W. E.; Mack, G. H., New Mexico Geological Society, Guidebook, 37th Field Conference, pp. 197-201. https://doi.org/10.56577/FFC-37.197