Geochronologic and Hf-isotope framework of Proterozoic rocks from central New Mexico, USA: Formation of the Mazatzal crustal province in an extended continental margin arc

Autor: Karl E. Karlstrom, Christopher G. Daniel, Mark E. Holland, James V. Jones, Tyler A. Grambling, Kimberly N. Nagotko
Rok vydání: 2020
Předmět:
Zdroj: Precambrian Research. 347:105820
ISSN: 0301-9268
DOI: 10.1016/j.precamres.2020.105820
Popis: The growth of southern Laurentia has been attributed to the accretion of juvenile arc terranes during the successive 1.74–1.68 Ga Yavapai and 1.65–1.60 Ga Mazatzal orogenies. However, in light of the increasing importance of the ca. 1.49–1.40 Ga Mesoproterozoic Picuris orogeny, the tectonic setting in which the Mazatzal crustal province and its distinctive quartzite-rhyolite successions were generated needs additional examination. The Sandia-Manzano-Los Pinos uplift in central New Mexico is an ideal place to characterize the tectonic history of the Mazatzal crustal province. A comprehensive geochronologic and Hf-isotopic dataset for Proterozoic rocks of the Sandia-Manzano-Los Pinos uplift is presented. Plutonic and metavolcanic rocks in the Sandia-Manzano-Los Pinos uplift were emplaced in three pulses at 1668–1655 Ma, 1587 Ma, and 1459–1453 Ma. Hf-isotope data from the Paleoproterozoic plutonic rocks are juvenile, with both leucogranite and arc-related granodiorite yielding eHf(t) values ranging from +6 to +12, compared to the coeval depleted mantle value of +10 at ca. 1.65 Ga. Inherited zircon in Paleoproterozoic rocks suggest that crust older than 1.7 Ga was involved in their genesis. Hf-isotope data from Mesoproterozoic plutonic rocks in the Sandia-Manzano-Los Pinos uplift are consistent with derivation from 1.7 to 1.6 Ga lithosphere. Detrital zircon indicate that metasedimentary rocks of the lower Manzano group were derived primarily from local sources that have U-Pb-Hf isotope compositions similar to the plutonic rocks which intrude and volcanic rocks that underlie the Manzano group. The detrital zircon provenance of the Manzano group broadens up-section from unimodal populations with age peaks at ca. 1.65 Ga to include 1.7–3.0 Ga detrital zircon derived from older Laurentian sources like the Yavapai and Mojave provinces. We offer a new model for the formation of the Mazatzal crustal province of New Mexico as a continental margin arc built on top of the previously assembled Yavapai province. The Manzano group quartzite-rhyolite succession was formed by lithospheric extension above a north-dipping, southward retreating subduction zone. The Manzano group was then subjected to ca. 1.65 Ga syn-magmatic tectonism and later intracratonic contractional tectonism, likely during the 1.46–1.40 Ga Picuris orogeny.
Databáze: OpenAIRE
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