An overview of the Proterozoic geology in the Thompson Peak--Glorieta Baldy area, Sante Fe County, New Mexico
Christopher G. Daniel

Abstract:

The Thompson Peak-Glorieta Baldy area of the southern Santa Fe Mountains, New Mexico, exposes a variety of Proterozoic metasedimentary, mafic and felsic metavolcanic, and granitic rocks. The supracrustal rocks have been referred to as the Dalton Canyon succession or the McClure septum. However, this paper proposes that the supracrustal rocks be designated the Thompson Peak metamorphic suite. A reevaluation of metamorphic mineral assemblages (Grt+Bt+St, Bt+St+Sill) and new thermobarometry data from these rocks shows that peak metamorphic temperatures and pressures are significantly higher than previously estimated. Temperatures ranged from 600 to 680 °C depending on location, and the pressure is estimated at 5-6 kbar. This relatively high-temperature metamorphism appears to be related to heat from ~1650 Ma granitic plutons that bound the supracrustal rocks. The relative timing of metamorphism and deformation is bracketed by a strongly deformed quartz porphyry that intrudes the supracrustal rocks and a crosscutting, weakly deformed to undeformed two-mica granite. The quartz porphyry yields an age of ~1655 Ma (U/Pb zircon) giving an upper limit to the absolute timing of this tectonism; the age of the two-mica granite is unknown. The rocks of the Thompson Peak metamorphic suite are interpreted to be the northernmost exposure of the Mazatzal (1660-1640 Ma) crustal province, and represent sedimentary, volcaniclastic and volcanic rocks deposited near the margin of the older ( 1700 Ma) Yavapai crustal province and subsequently metamorphosed and deformed during the 1650-1600 Ma Mazatzal orogeny.


Citation:

  1. Daniel, Christopher G., 1995, An overview of the Proterozoic geology in the Thompson Peak--Glorieta Baldy area, Sante Fe County, New Mexico, in: Geology of the Sante Fe Region, Bauer, Paul W.; Kues, Barry S.; Dunbar, Nelia W.; Karlstrom, K. E.; Harrison, Bruce, New Mexico Geological Society, Guidebook, 46th Field Conference, pp. 209-218.

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