Geologic Map of the western part of the Tucson 30' x 60' Quadrangle and the eastern part of the Silver Bell Mountains 30' x60' Quadrangle, southeastern Arizona
| dc.contributor.author | Pearthree, Philip A. | |
| dc.contributor.author | Richardson, Carson A. | |
| dc.contributor.author | Ferguson, Charles A. | |
| dc.date.accessioned | 2024-02-14T17:05:19Z | |
| dc.date.available | 2024-02-14T17:05:19Z | |
| dc.date.issued | 2024-02 | |
| dc.identifier.citation | Pearthree, P. A., Richardson, C. A., and Ferguson, C. A., 2022, Geologic Map of the western part of the Tucson 30’ x 60’ Quadrangle and the eastern part of the Silver Bell Mountains 30’ x 60’ Quadrangle, southeastern Arizona: Arizona Geological Survey Digital Geologic Map (DGM) 223 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10150/670961 | |
| dc.description | The composite map of the Tucson metropolitan area straddles the western ~2/3 of the Tucson 30’ x 60’ quadrangle and the eastern ~2/3 of the Silver Bell Mountains 30’ x 60’ quadrangle in eastern Pima County and western most Cochise County. The geomorphology is dominated by the watershed of the Santa Cruz River flowing northward through the center of the map area, with its tributaries of Cienega Creek and the Rillito River in the Tucson Valley and Brawley Wash in Avra Valley. The San Pedro River, east of the Rincon and Santa Catalina Mountains, constitutes a separate watershed along the eastern edge of the map area. Incision by axial streams and related basin dissection vary dramatically across the map area. In the east, the San Pedro River and tributaries have eroded deeply into basin deposits during the Quaternary. The swath of axial valley alluvium is relatively narrow and piedmonts are covered with tributary deposits ranging in age from Holocene to middle and early Pleistocene. The Santa Cruz River and its large tributaries of the Tucson basin are less incised, although piedmonts on the basin margins are moderately to deeply dissected. The broad valley floor is covered by deposits ranging in age from Holocene to early Pleistocene, with early to middle Pleistocene deposits being most extensive. Valley axes in the western part of the map drained by Brawley and Aguirre Washes are broad and minimally incised. These areas are covered by generally fine-grained Holocene floodplain deposits and low late to middle Pleistocene terraces. Holocene and late Pleistocene deposits cover most piedmont areas, with older Pleistocene remnants confined to upper piedmont areas. The oldest rocks in the Rincon, Santa Catalina, and Tortolita Mountains in the eastern third to half of the map area consist of Paleoproterozoic Pinal Schist and plutonic rocks intruded by Mesoproterozoic plutonic rocks and overlain rocks of the Apache Group. These basement rocks are overlain by Paleozoic sedimentary rocks and thin Jurassic-Triassic sedimentary rocks that underly the latest Jurassic to early Cretaceous Bisbee Group. Cretaceous and Cenozoic plutons intrude this stratigraphic framework. These rocks were exhumed along the Catalina detachment between ~26-17 Ma producing a well-developed mylonitic fabric with S/C fabrics with top-to-the-southwest sense of shear and sedimentary rocks filling hanging-wall half-grabens. The Tucson Mountains in the center of the map area represent a Cretaceous caldera that erupted the Cat Mountain Tuff, with the Amole pluton potentially constituting a resurgent ring intrusion. The Roskruge and Waterman Mountains are dominated by the Tuff of Sharp Peak (which may be correlative with the Cat Mountain Tuff) but also host several Cretaceous and Cenozoic intrusions and late Cenozoic basalt flows. The Silver Bell Mountains, in the northwestern part of the map, represent another Cretaceous caldera which erupted the Confidence Peak Tuff and were in turn intruded by a suite of late Cretaceous to early Cenozoic (“Laramide”) intrusive rocks that formed the Silver Bell porphyry copper deposit. Mid- to late Cenozoic volcanic rocks overlie the Cretaceous rocks. | en_US |
| dc.language.iso | en | en_US |
| dc.publisher | Arizona Geological Survey (Tucson, AZ) | en_US |
| dc.relation.ispartofseries | DGM - 223 | en_US |
| dc.relation.url | https://library.azgs.arizona.edu/ | en_US |
| dc.rights | Arizona Geological Survey. All rights reserved. | en_US |
| dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en_US |
| dc.subject | Silver Bell Mountains | en_US |
| dc.subject | Southeastern Arizona | en_US |
| dc.subject | Arizona | en_US |
| dc.subject | geologic map | en_US |
| dc.title | Geologic Map of the western part of the Tucson 30' x 60' Quadrangle and the eastern part of the Silver Bell Mountains 30' x60' Quadrangle, southeastern Arizona | en_US |
| csdgm.bounding.west | -111.86 | en_US |
| csdgm.bounding.east | -110.24 | en_US |
| csdgm.bounding.north | 32.5 | en_US |
| csdgm.bounding.south | 32 | en_US |
| dc.description.collectioninformation | Documents in the AZGS Documents 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. | en_US |
| refterms.dateFOA | 2024-02-14T17:05:24Z |
