New Mexico Geological Society Annual Spring Meeting — Abstracts

Crustal growth along the southern margin of Laurentia is typically viewed in three major stages: the 1.7 Ga Yavapai orogeny, the 1.65 Mazatzal orogeny, and intracratonic deformation and magmatism at 1.45 Ga. Historically, the Jemez lineament has been viewed as the potential suture zone between the Yavapai and Mazatzal provinces. New data indicates that this feature is not entirely consistent with a boundary of this nature, and may be more accurately described as a backarc transition zone between the provinces. Support of this are metasedimentary successions consisting of only Yavapai-aged detritus on either side of the Clear Creek shear zone—an expression of the lineament in the northern Sierra Nacimiento Mountains—constrained by 1.7 Ga intrusions into the sediment.
The relationship between these basins, intrusions, and growth along southern Laurentia present a complex process involving rapid erosion of granitic rocks into basins producing first cycle, ultramature quartzite successions, and rapid basin submergence to allow pluton emplacement as early as 1698 Ma. The characteristics of these metasediments, in composition and detrital zircon age, allow their inclusion in similar quartzite basins along the southern margin of Laurentia. The complexity of the relationships between rock units spanning the Nacimiento uplift makes interpretation of the transition from the Yavapai province to the Mazatzal province ambiguous, raising questions about the nature of this boundary.
Considering this, we will continue to examine tectonic and stratigraphic relationships between rock units in the Sierra Nacimiento Mountains and similar successions in the Picuris Mountains, while analyzing Hf-Yb-Lu isotopic character of plutons in the Nacimientos in an attempt to understand crustal origin and evolution across the Yavapai-Mazatzal boundary. This study will allow us to further define the nature of this provincial transition and Proterozoic continental evolution in southwestern Laurentia.

References:

1. Jones, J.V., III, Connelly, J.N., Karlstrom, K.E., Williams, M.L., Doe, M.F., 2009, Age, provenance, and tectonic setting of Paleoproterozoic quartzite successions in the southwestern United States, GSA Bulletin, January/February 2009, vol. 121, p. 247-264.
2. Jones, J.V., III, Daniel, C.G., Frei, D., Thrane, K., 2011, Revised regional correlations and tectonic implications of Paleoproterozoic and Mesoproterozoic metasedimentary rocks in northern New Mexico, USA: New findings from detrital zircon studies of the Hondo Group, Vadito Group, and Marqueñas Formation, GSA Geosphere, August 2011, vol. 7, no. 4, p. 974-991.
3. Karlstrom, K.E., Amato, J.M., Williams, M.L., Heizler, M., Shaw, C.A., Read, A.S., Bauer, P., 2004, Proterozoic Tectonic Evolution of the New Mexico Region: A Synthesis, The Geology of New Mexico, A Geologic History, New Mexico Geological Society, p. 1-34.
4. Magnani, M.B., Miller, K.C., Levander, A., Karlstrom, K.E., 2004, The Yavapai-Mazatzal boundary: A long-lived tectonic element in the lithosphere of southwestern North America, GSA Bulletin, September/October 2004, vol. 116, no. 7/8, p. 1137-1142. 
5. Premo, W.R., Kellogg, K.S., Budahn, J., in review, U-Pb Zircon Geochronology, Major and Trace Element Geochemisty, and ND Isotopes on Proterozoic Rocks in the Sierra Nacimiento Region, North-Central New Mexico—Are These Rocks the Leading Edge of the Mazatzal Arc? U.S. Geological Society Professional Paper, in review.