Protolith age of the Altar and Carnero complexes and latest Cretaceous–Miocene deformation in the Caborca–Altar region of northwestern Sonora, Mexico

In the Caborca–Altar area of northwest Sonora, variably deformed and metamorphosed sedimentary and volcanic rocks crop out in a northwest-southeast–trending belt (El Batamote belt) at least 70 km long. We obtained detrital zircon U-Pb ages from two distinctive components of the belt near Altar, her...

Full description

Saved in:
Bibliographic Details
Main Authors: Carl E. Jacobson, César Jacques-Ayala, Andrew P. Barth, Juan Carlos García y Barragán, Jane N. Pedrick, Joseph L. Wooden
Format: Article
Language:English
Published: Universidad Nacional Autónoma de México 2019-03-01
Series:Revista Mexicana de Ciencias Geológicas
Subjects:
Online Access:https://rmcg.unam.mx/index.php/rmcg/article/view/784
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850161402686210048
author Carl E. Jacobson
César Jacques-Ayala
Andrew P. Barth
Juan Carlos García y Barragán
Jane N. Pedrick
Joseph L. Wooden
author_facet Carl E. Jacobson
César Jacques-Ayala
Andrew P. Barth
Juan Carlos García y Barragán
Jane N. Pedrick
Joseph L. Wooden
author_sort Carl E. Jacobson
collection DOAJ
description In the Caborca–Altar area of northwest Sonora, variably deformed and metamorphosed sedimentary and volcanic rocks crop out in a northwest-southeast–trending belt (El Batamote belt) at least 70 km long. We obtained detrital zircon U-Pb ages from two distinctive components of the belt near Altar, here termed the Altar complex and Carnero complex. Zircon ages for metasandstone and metaconglomerate matrix from the Altar complex indicate a Late Cretaceous maximum age of sedimentation, with at least part of the complex no older than 77.5 ± 2.5 (2σ). Pre-Cretaceous detrital zircons in the complex were derived largely from local sources, including Proterozoic basement, the Neoproterozoic–Cambrian miogeocline and the Jurassic arc. The detrital zircon ages and lithologic character of the Altar complex suggest correlation with the Escalante Formation, the uppermost unit of the Upper Cretaceous El Chanate Group. In contrast, one sample from the Carnero complex yielded a Middle Jurassic maximum depositional age and a detrital zircon age distribution like that of the Jurassic eolianites of the North American Cordillera. The Carnero complex may correlate with the Middle Jurassic Rancho San Martín Formation but could also be a metamorphosed equivalent of the Upper Jurassic Cucurpe Formation, Upper Jurassic to Lower Cretaceous Bisbee Group, or El Chanate Group derived by recycling of Jurassic erg sandstones. The Late Cretaceous age for the Altar complex protolith contradicts models that relate deposition of the entire El Batamote protolith to a basin formed by oblique slip along the Late Jurassic Mojave-Sonora megashear. Instead, the belt is best explained as an assemblage of Middle Jurassic to Upper Cretaceous formations deformed and locally metamorphosed beneath a northeast-directed Laramide thrust complex. Potassium-argon and 40Ar/39Ar ages confirm previous inferences that deformation of El Batamote belt occurred between the Late Cretaceous and late Eocene. A second phase of deformation, involving low-angle normal faults, occurred during and/or after intrusion of the ~22-21 Ma Rancho Herradura granodiorite.
format Article
id doaj-art-5152c91ee01e48b8aa3ba8e7b047c9b1
institution OA Journals
issn 1026-8774
2007-2902
language English
publishDate 2019-03-01
publisher Universidad Nacional Autónoma de México
record_format Article
series Revista Mexicana de Ciencias Geológicas
spelling doaj-art-5152c91ee01e48b8aa3ba8e7b047c9b12025-08-20T02:22:50ZengUniversidad Nacional Autónoma de MéxicoRevista Mexicana de Ciencias Geológicas1026-87742007-29022019-03-0136110.22201/cgeo.20072902e.2019.1.784Protolith age of the Altar and Carnero complexes and latest Cretaceous–Miocene deformation in the Caborca–Altar region of northwestern Sonora, MexicoCarl E. Jacobson0César Jacques-Ayala1Andrew P. Barth2Juan Carlos García y Barragán3Jane N. Pedrick4Joseph L. Wooden5Department of Geological and Atmospheric Sciences, Iowa State University, 253 Science Hall, 2237 Osborn Drive, Ames, IA 50011, USA. Department of Earth and Space Sciences, 207 Merion Science Center, 720 S. Church Street, West Chester University of Pennsylvania, West Chester, PA 19355, USA.Instituto de Geología, Universidad Nacional Autónoma de México, Blvd. Colosio s/n y Madrid, Apartado Postal 1039, Hermosillo, Son. 83000, Mexico.Department of Earth Sciences, Indiana University-Purdue University Indianapolis, 723 W. Michigan Street, SL118, Indianapolis, IN 46202, USA.Instituto de Geología, Universidad Nacional Autónoma de México, Blvd. Colosio s/n y Madrid, Apartado Postal 1039, Hermosillo, Son. 83000, Mexico.Department of Geological and Atmospheric Sciences, Iowa State University, 253 Science Hall, 2237 Osborn Drive, Ames, IA 50011, USA.U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025, USA. In the Caborca–Altar area of northwest Sonora, variably deformed and metamorphosed sedimentary and volcanic rocks crop out in a northwest-southeast–trending belt (El Batamote belt) at least 70 km long. We obtained detrital zircon U-Pb ages from two distinctive components of the belt near Altar, here termed the Altar complex and Carnero complex. Zircon ages for metasandstone and metaconglomerate matrix from the Altar complex indicate a Late Cretaceous maximum age of sedimentation, with at least part of the complex no older than 77.5 ± 2.5 (2σ). Pre-Cretaceous detrital zircons in the complex were derived largely from local sources, including Proterozoic basement, the Neoproterozoic–Cambrian miogeocline and the Jurassic arc. The detrital zircon ages and lithologic character of the Altar complex suggest correlation with the Escalante Formation, the uppermost unit of the Upper Cretaceous El Chanate Group. In contrast, one sample from the Carnero complex yielded a Middle Jurassic maximum depositional age and a detrital zircon age distribution like that of the Jurassic eolianites of the North American Cordillera. The Carnero complex may correlate with the Middle Jurassic Rancho San Martín Formation but could also be a metamorphosed equivalent of the Upper Jurassic Cucurpe Formation, Upper Jurassic to Lower Cretaceous Bisbee Group, or El Chanate Group derived by recycling of Jurassic erg sandstones. The Late Cretaceous age for the Altar complex protolith contradicts models that relate deposition of the entire El Batamote protolith to a basin formed by oblique slip along the Late Jurassic Mojave-Sonora megashear. Instead, the belt is best explained as an assemblage of Middle Jurassic to Upper Cretaceous formations deformed and locally metamorphosed beneath a northeast-directed Laramide thrust complex. Potassium-argon and 40Ar/39Ar ages confirm previous inferences that deformation of El Batamote belt occurred between the Late Cretaceous and late Eocene. A second phase of deformation, involving low-angle normal faults, occurred during and/or after intrusion of the ~22-21 Ma Rancho Herradura granodiorite. https://rmcg.unam.mx/index.php/rmcg/article/view/784Altar complexCarnero complexEl Batamote beltEl Chanate GroupMojave-Sonora megashearLaramide orogeny
spellingShingle Carl E. Jacobson
César Jacques-Ayala
Andrew P. Barth
Juan Carlos García y Barragán
Jane N. Pedrick
Joseph L. Wooden
Protolith age of the Altar and Carnero complexes and latest Cretaceous–Miocene deformation in the Caborca–Altar region of northwestern Sonora, Mexico
Revista Mexicana de Ciencias Geológicas
Altar complex
Carnero complex
El Batamote belt
El Chanate Group
Mojave-Sonora megashear
Laramide orogeny
title Protolith age of the Altar and Carnero complexes and latest Cretaceous–Miocene deformation in the Caborca–Altar region of northwestern Sonora, Mexico
title_full Protolith age of the Altar and Carnero complexes and latest Cretaceous–Miocene deformation in the Caborca–Altar region of northwestern Sonora, Mexico
title_fullStr Protolith age of the Altar and Carnero complexes and latest Cretaceous–Miocene deformation in the Caborca–Altar region of northwestern Sonora, Mexico
title_full_unstemmed Protolith age of the Altar and Carnero complexes and latest Cretaceous–Miocene deformation in the Caborca–Altar region of northwestern Sonora, Mexico
title_short Protolith age of the Altar and Carnero complexes and latest Cretaceous–Miocene deformation in the Caborca–Altar region of northwestern Sonora, Mexico
title_sort protolith age of the altar and carnero complexes and latest cretaceous miocene deformation in the caborca altar region of northwestern sonora mexico
topic Altar complex
Carnero complex
El Batamote belt
El Chanate Group
Mojave-Sonora megashear
Laramide orogeny
url https://rmcg.unam.mx/index.php/rmcg/article/view/784
work_keys_str_mv AT carlejacobson protolithageofthealtarandcarnerocomplexesandlatestcretaceousmiocenedeformationinthecaborcaaltarregionofnorthwesternsonoramexico
AT cesarjacquesayala protolithageofthealtarandcarnerocomplexesandlatestcretaceousmiocenedeformationinthecaborcaaltarregionofnorthwesternsonoramexico
AT andrewpbarth protolithageofthealtarandcarnerocomplexesandlatestcretaceousmiocenedeformationinthecaborcaaltarregionofnorthwesternsonoramexico
AT juancarlosgarciaybarragan protolithageofthealtarandcarnerocomplexesandlatestcretaceousmiocenedeformationinthecaborcaaltarregionofnorthwesternsonoramexico
AT janenpedrick protolithageofthealtarandcarnerocomplexesandlatestcretaceousmiocenedeformationinthecaborcaaltarregionofnorthwesternsonoramexico
AT josephlwooden protolithageofthealtarandcarnerocomplexesandlatestcretaceousmiocenedeformationinthecaborcaaltarregionofnorthwesternsonoramexico