Sedimentology and Stratigraphy of the Upper Miocene El Boleo Fm, Santa Rosalía, Baja California, Mexico

The transtensional Upper Miocene Santa Rosalía basin, located in the east-central part of the Baja California Peninsula, consists of almost 500 m of non-marine to marine sedimentary deposits, and interbedded tuffaceous beds. The Santa Rosalía basin is a NW-SE elongated fault-bounded depocenter that...

Full description

Saved in:
Bibliographic Details
Main Authors: Lucas Ochoa-Landín, Joaquín Ruiz, Thierry Calmus, Efrén Pérez-Segura, Francisco Escandón
Format: Article
Language:English
Published: Universidad Nacional Autónoma de México 2018-07-01
Series:Revista Mexicana de Ciencias Geológicas
Subjects:
Online Access:https://rmcg.unam.mx/index.php/rmcg/article/view/1004
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849336812088066048
author Lucas Ochoa-Landín
Joaquín Ruiz
Thierry Calmus
Efrén Pérez-Segura
Francisco Escandón
author_facet Lucas Ochoa-Landín
Joaquín Ruiz
Thierry Calmus
Efrén Pérez-Segura
Francisco Escandón
author_sort Lucas Ochoa-Landín
collection DOAJ
description The transtensional Upper Miocene Santa Rosalía basin, located in the east-central part of the Baja California Peninsula, consists of almost 500 m of non-marine to marine sedimentary deposits, and interbedded tuffaceous beds. The Santa Rosalía basin is a NW-SE elongated fault-bounded depocenter that records the sedimentation from Upper Miocene to Pleistocene time. The sequence is divided in El Boleo, La Gloria, Infierno and Santa Rosalía Formations. The lower most stratigraphic unit is the El Boleo Formation, a 200 to 300 m thick section composed in its lower part by a 1 to 5 m thick basal limestone and gypsum bodies followed by 170 to 300 m of clastic coarsening upward fan-delta, marine and nonmarine deposits. The upper clastic part of the El Boleo Formation show intraformational unconformities, synsedimentary folds and faults, and unidirectional sedimentary structures. These occur in at least three well organized upward coarsening cycles (90-100 m thick). Each cycle represents a prograding fan-delta deposit formed probably as consequence of large and repeated vertical movements of the basin floor with respect to the source areas. This activity is related to the early stage of the opening of the Gulf of California. Each cycle started with the deposition of a unit composed by laminar fine-grained sediments accumulated in an extensive area covered by shallow standing fresh water with periodic introduction of subaqueous debris flows. Each fine unit hosts Cu-Co-Zn ore bodies in the Santa Rosalía mining district. Lateral and vertical facies changes are present in each depositional cycle, involving proximal coarse sandstone and conglomerates through fine sandstone characterized by planar and low angle cross bedding, alternating with siltstone and mudstone with ripple lamination. Early, during the formation of the Santa Rosalía basin, two ancient depocenters located north-northwest and south-southeast of the basin were developed. These depocenters were filled by sediments during the first cycle, and were separated by a ridge formed by the volcanic rocks of the Comondú Formation.
format Article
id doaj-art-bafe69bb439243f59d85fcd347e94a0d
institution Kabale University
issn 1026-8774
2007-2902
language English
publishDate 2018-07-01
publisher Universidad Nacional Autónoma de México
record_format Article
series Revista Mexicana de Ciencias Geológicas
spelling doaj-art-bafe69bb439243f59d85fcd347e94a0d2025-08-20T03:44:53ZengUniversidad Nacional Autónoma de MéxicoRevista Mexicana de Ciencias Geológicas1026-87742007-29022018-07-01172Sedimentology and Stratigraphy of the Upper Miocene El Boleo Fm, Santa Rosalía, Baja California, MexicoLucas Ochoa-Landín0Joaquín Ruiz1Thierry Calmus2Efrén Pérez-Segura3Francisco Escandón4Departamento de Geología, Universidad de Sonora, 83000 Hermosillo, Sonora, MéxicoGeosciences Department, University of Arizona, Tuczon ArizonaInstituto de Geología, UNAM, Estación Regional del Noroeste, 83000 Hermosillo, Sonora, MéxicoDepartamento de Geología, Universidad de Sonora, 83000 Hermosillo, Sonora, MéxicoMinera Curator, S.A. de C.V., Santa Rosalía, Baja California Sur, México The transtensional Upper Miocene Santa Rosalía basin, located in the east-central part of the Baja California Peninsula, consists of almost 500 m of non-marine to marine sedimentary deposits, and interbedded tuffaceous beds. The Santa Rosalía basin is a NW-SE elongated fault-bounded depocenter that records the sedimentation from Upper Miocene to Pleistocene time. The sequence is divided in El Boleo, La Gloria, Infierno and Santa Rosalía Formations. The lower most stratigraphic unit is the El Boleo Formation, a 200 to 300 m thick section composed in its lower part by a 1 to 5 m thick basal limestone and gypsum bodies followed by 170 to 300 m of clastic coarsening upward fan-delta, marine and nonmarine deposits. The upper clastic part of the El Boleo Formation show intraformational unconformities, synsedimentary folds and faults, and unidirectional sedimentary structures. These occur in at least three well organized upward coarsening cycles (90-100 m thick). Each cycle represents a prograding fan-delta deposit formed probably as consequence of large and repeated vertical movements of the basin floor with respect to the source areas. This activity is related to the early stage of the opening of the Gulf of California. Each cycle started with the deposition of a unit composed by laminar fine-grained sediments accumulated in an extensive area covered by shallow standing fresh water with periodic introduction of subaqueous debris flows. Each fine unit hosts Cu-Co-Zn ore bodies in the Santa Rosalía mining district. Lateral and vertical facies changes are present in each depositional cycle, involving proximal coarse sandstone and conglomerates through fine sandstone characterized by planar and low angle cross bedding, alternating with siltstone and mudstone with ripple lamination. Early, during the formation of the Santa Rosalía basin, two ancient depocenters located north-northwest and south-southeast of the basin were developed. These depocenters were filled by sediments during the first cycle, and were separated by a ridge formed by the volcanic rocks of the Comondú Formation. https://rmcg.unam.mx/index.php/rmcg/article/view/1004Sedimentology, Stratigraphy, Upper Miocene, El Boleo Formation, Santa Rosalía, Baja California, Mexico
spellingShingle Lucas Ochoa-Landín
Joaquín Ruiz
Thierry Calmus
Efrén Pérez-Segura
Francisco Escandón
Sedimentology and Stratigraphy of the Upper Miocene El Boleo Fm, Santa Rosalía, Baja California, Mexico
Revista Mexicana de Ciencias Geológicas
Sedimentology, Stratigraphy, Upper Miocene, El Boleo Formation, Santa Rosalía, Baja California, Mexico
title Sedimentology and Stratigraphy of the Upper Miocene El Boleo Fm, Santa Rosalía, Baja California, Mexico
title_full Sedimentology and Stratigraphy of the Upper Miocene El Boleo Fm, Santa Rosalía, Baja California, Mexico
title_fullStr Sedimentology and Stratigraphy of the Upper Miocene El Boleo Fm, Santa Rosalía, Baja California, Mexico
title_full_unstemmed Sedimentology and Stratigraphy of the Upper Miocene El Boleo Fm, Santa Rosalía, Baja California, Mexico
title_short Sedimentology and Stratigraphy of the Upper Miocene El Boleo Fm, Santa Rosalía, Baja California, Mexico
title_sort sedimentology and stratigraphy of the upper miocene el boleo fm santa rosalia baja california mexico
topic Sedimentology, Stratigraphy, Upper Miocene, El Boleo Formation, Santa Rosalía, Baja California, Mexico
url https://rmcg.unam.mx/index.php/rmcg/article/view/1004
work_keys_str_mv AT lucasochoalandin sedimentologyandstratigraphyoftheuppermioceneelboleofmsantarosaliabajacaliforniamexico
AT joaquinruiz sedimentologyandstratigraphyoftheuppermioceneelboleofmsantarosaliabajacaliforniamexico
AT thierrycalmus sedimentologyandstratigraphyoftheuppermioceneelboleofmsantarosaliabajacaliforniamexico
AT efrenperezsegura sedimentologyandstratigraphyoftheuppermioceneelboleofmsantarosaliabajacaliforniamexico
AT franciscoescandon sedimentologyandstratigraphyoftheuppermioceneelboleofmsantarosaliabajacaliforniamexico