Title
Zircon U-Pb geochronology and heavy mineral composition of the Camaná Formation, southern Peru: Constraints on sediment provenance and uplift of the Coastal and Western Cordilleras
Date Issued
01 August 2015
Access level
metadata only access
Resource Type
journal article
Author(s)
von Eynatten H.
Dunkl I.
Gerdes A.
University of Göttingen
Publisher(s)
Elsevier Ltd
Abstract
In the forearc of the Central Andes of southern Peru, the Cenozoic Camaná Basin (16°25'S to 17°15'S) forms a ~NW-SE elongated depression filled with coarse-grained deltaic and fluvial deposits. These deposits are termed Camaná Formation. We have applied for the first time, advanced multi-method analytical techniques to sediments of the Camaná Formation in order to define precise sedimentation ages, unravel sediment provenance, and to explain its tectono-sedimentary evolution.Zircon U-Pb geochronology and multiple geological evidences suggest that the Camaná Formation ranges in age from Late Oligocene to Late Miocene, and may even extend into the Pliocene. We propose a provenance model for the Camaná Formation based on U-Pb geochronology, heavy mineral analysis, and single-grain mineral chemistry by LA-ICP-MS. This model suggests that sediments of the lower part of the Camaná Formation derive from rocks forming the Coastal Cordillera (i.e. the Arequipa Massif and the San Nicolas Batholith) and the widespread ignimbrites of the ~24-10. Ma Huaylillas volcanic arc. In contrast, sediments of the upper part of the Camaná Formation derive predominantly from rocks forming the Western Cordillera (i.e. the Arequipa Massif, the Tacaza Group, and the Coastal Batholith) and products of the ~10-3. Ma Lower Barroso volcanic arc). Accordingly, we infer that uplift of the Coastal Cordillera has strongly influenced deposition of the Camaná Formation since Late Oligocene. A marked shift in provenance within the Camaná Formation at around Middle to Late Miocene time (14-12. Ma) suggests drastic uplift of the Western Cordillera at that time. This uplift has triggered increased relief and erosion in the Western Cordillera, and subsequent deposition of fluvial conglomerates in the Camaná Basin.
Start page
14
End page
32
Volume
61
Language
English
OCDE Knowledge area
Geología
Scopus EID
2-s2.0-84928622465
Source
Journal of South American Earth Sciences
ISSN of the container
08959811
Sponsor(s)
Financial support by the Deutscher Akademischer Austauschdienst (DAAD, Referat 416/PKZ A/09/98944) provided to AA to carry out this research is gratefully acknowledge. We thank Taylor Schildgen (Potsdam) for numerous critical remarks on an earlier version of the manuscript, and Mirian Mamani (Lima) for valuable discussions. Detailed and thoughtful comments by Luca Caracciolo (Calabria) and an anonymous reviewer helped to improve the manuscript. Supplementary data associated with this manuscript is available in the online version.
Sources of information: Directorio de Producción Científica Scopus