Geologic Map of the Prescott Valley South 7 ½' Quadrangle, Yavapai County, Arizona v.2

Johnson, B.J.; Cook, J.P.; Pearthree, P.A.

dc.contributor.author	Johnson, B.J.
dc.contributor.author	Cook, J.P.
dc.contributor.author	Pearthree, P.A.
dc.date.accessioned	2018-09-29T00:31:46Z
dc.date.available	2018-09-29T00:31:46Z
dc.date.issued	2021-09-01
dc.identifier.citation	Johnson, B.J., Cook, J.P. and Pearthree, P.A., 2021, Geologic Map of the Prescott Valley South 7 ½' Quadrangle, Yavapai County, Arizona. Arizona Geological Survey Digital Geological Map, DGM-103 v.2, 1:24,000 map scale, 1 map sheet.
dc.identifier.uri	http://hdl.handle.net/10150/629463
dc.description	The Prescott Valley South 7 ½' Quadrangle is located east of Prescott in Yavapai County in central Arizona. New geologic mapping and map compilation for the entire quadrangle, presented here, were done under the joint State-Federal STATEMAP program, as specified by the National Geologic Mapping Act of 1992. Mapping was jointly funded by the Arizona Geological Survey and the U.S. Geological Survey under STATEMAP assistance award G11AC20455. This map was compiled digitally using ESRI ArcGIS software. The Prescott Valley South 7 ½' Quadrangle coincides with the southeast quarter of the Prescott 15’ Quadrangle, which was mapped by Krieger (1965) at 1:48,000 scale. To prepare this new quadrangle map, new mapping was done at 1:24,000 scale to field check and improve upon the previous mapping. Previous mapping did not significantly differentiate Quaternary map units. For this mapping investigation, Quaternary units were differentiated in detail for the entire map area. Georeferenced aerial-photograph imagery was used extensively for mapping Quaternary deposits. The Prescott Valley South 7 ½' Quadrangle is at the north end of the Bradshaw Mountains, which are underlain by bedrock of mainly Paleoproterozoic age. The rocks include gabbro, granodiorite, and granite plutons with intervening supracrustal belts of metavolcanic and metasedimentary schist. For the most part the belts and plutons define a northerly striking structural grain. Tectonic foliation in the supracrustal rocks and in deformed parts of the plutons strikes northerly and dips steeply west throughout most of the map area. A notable exception is the Chaparral shear zone (Bergh and Karlstrom, 1992), a northeast-striking dextral shear zone 1 km wide of mylonitic and phyllonitic rocks that transects the northerly trending structures in the southeast corner of the quadrangle. Within this zone, foliation is nearly vertical and a lineation defined by mineral streaks is gently plunging. Metamorphic grade in the Chaparral shear zone is lower greenschist facies (chlorite zone). Outside of the shear zone, rocks in more northerly exposures were metamorphosed in middle greenschist (biotite zone) to possibly amphibolite facies. Deformation and metamorphism in the northern Bradshaw Mountains mainly occurred from 1710 to 1690 Ma (Anderson, 1989). Gently tilted Miocene volcanic rocks that unconformably overlie the Proterozoic rocks are exposed on Glassford Hill, along the western margin of the quadrangle (Krieger, 1965).
dc.language.iso	en
dc.relation.ispartofseries	DGM-103
dc.relation.url	https://library.azgs.arizona.edu/item/ADGM-1631829438819-69
dc.rights	Arizona Geological Survey. All rights reserved.
dc.subject	Arizona Geological Survey Digital Geologic Maps
dc.subject	Miocene
dc.subject	Tertiary
dc.subject	Quaternary
dc.subject	Paleoproterozoic
dc.subject	Glassford Hill
dc.subject	Basin and Range Province
dc.subject	Bradshaw Mountains
dc.subject	Yavapai County
dc.subject	amphibolite facies
dc.subject	mylonite
dc.subject	Chaparral shear zone
dc.subject	metasedimentary rocks
dc.subject	metavolcanic rocks
dc.subject	granodiorite
dc.subject	granite
dc.subject	gabbro
dc.title	Geologic Map of the Prescott Valley South 7 ½' Quadrangle, Yavapai County, Arizona v.2
csdgm.bounding.west	-112.375
csdgm.bounding.east	-112.25
csdgm.bounding.north	34.625
csdgm.bounding.south	34.5
dc.description.collectioninformation	Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact azgs-info@email.arizona.edu.
refterms.dateFOA	2018-09-29T00:31:46Z