Tectonic setting of Cretaceous porphyry copper deposits of northern Chile (28°-30° S) and its relations with magmatic evolution and metallogeny

ABSTRACT Cretaceous porphyry copper deposits of northern Chile (28°-29°30’ S) are genetically related with dacitic to dioritic porphyries and they represent a still poorly-explored target for Cu resources. The porphyries correspond to stocks distributed into two separated discontinuous NS...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Creixell,Christian, Fuentes,Javier, Bierma,Hessel, Salazar,Esteban
Lenguaje:	English
Publicado:	Servicio Nacional de Geología y Minería (SERNAGEOMIN) 2020
Materias:	Cretaceous Central Andes Porphyry copper Metallogenesis Orogenesis
Acceso en línea:	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062020000300469
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:scielo:S0718-71062020000300469
record_format	dspace
spelling	oai:scielo:S0718-710620200003004692020-10-14Tectonic setting of Cretaceous porphyry copper deposits of northern Chile (28°-30° S) and its relations with magmatic evolution and metallogenyCreixell,ChristianFuentes,JavierBierma,HesselSalazar,Esteban Cretaceous Central Andes Porphyry copper Metallogenesis Orogenesis ABSTRACT Cretaceous porphyry copper deposits of northern Chile (28°-29°30’ S) are genetically related with dacitic to dioritic porphyries and they represent a still poorly-explored target for Cu resources. The porphyries correspond to stocks distributed into two separated discontinuous NS trending belts of different age. The location of these porphyries is generally adjacent to orogen-parallel major fault systems that extend along the studied segment and also have a marked temporal relationship with deformation events registered along these structures. A first episode of Cu-bearing porphyry emplacement took place between 116 and 104 Ma (Mina Unión or Frontera, Cachiyuyo, Punta Colorada, Dos Amigos, Tricolor porphyries). These Early Cretaceous dacite to diorite porphyries are spatially associated with the eastern segments of the Atacama Fault System, which records sinistral transpression that started at 121 Ma producing ground uplift, consequent denudation and exhumation of the Early Cretaceous magmatic arc. This resulted in a change from marine to continental deposition with an angular unconformity in the site of the back-are basin after of eastward migration of the deformation around 112-110 Ma. At the scale of the continental margin, this deformation is correlated with early stage of the Mochica Orogenic event described in Perú. A second episode of Cu-bearing porphyry emplacement occurred between 92 and 87 Ma (Elisa, Johana, Las Campanas and La Verde deposits), which are spatially and temporally associated with the regional-scale Las Cañas-El Torito reverse fault, active between 89 and 84 Ma, during the Peruvian Orogenic Phase. This fault up thrust to the west part of the Chañarcillo Group rocks (Lower Cretaceous) over the younger upper levels of the Cerrillos Formation (Upper Cretaceous). The integrated geological mapping and geochemical data of the Early to Late Cretaceous volcanic rocks indicates that both Early Cretaceous sinistral transpression and Late Cretaceous east-west compression were not significant in promote changes in magma genesis, except for slight changes in trace element ratios (increase in Th/Ta, Nb/Ta and La/Yb) suggesting that the Late Cretaceous deformation event produced only slightly increase in crustal thickness (>40 km), but far from being comparable to major Cenozoic orogenic phases, at least along the magmatic arc to back-arc domains in the study area. Finally, our study give insights about regional geological parameters that can be used as a first order guide for exploration of Cu resources along Cretaceous magmatic belts of northern Chile, where both Early and Late Cretaceous Cu-bearing porphyry intrusions are restricted to a large structural block bounded to the west and east by Cretaceous fault systems.info:eu-repo/semantics/openAccessServicio Nacional de Geología y Minería (SERNAGEOMIN)Andean geology v.47 n.3 20202020-09-01text/htmlhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062020000300469en10.5027/andgeov47n3-3035
institution	Scielo Chile
collection	Scielo Chile
language	English
topic	Cretaceous Central Andes Porphyry copper Metallogenesis Orogenesis
spellingShingle	Cretaceous Central Andes Porphyry copper Metallogenesis Orogenesis Creixell,Christian Fuentes,Javier Bierma,Hessel Salazar,Esteban Tectonic setting of Cretaceous porphyry copper deposits of northern Chile (28°-30° S) and its relations with magmatic evolution and metallogeny
description	ABSTRACT Cretaceous porphyry copper deposits of northern Chile (28°-29°30’ S) are genetically related with dacitic to dioritic porphyries and they represent a still poorly-explored target for Cu resources. The porphyries correspond to stocks distributed into two separated discontinuous NS trending belts of different age. The location of these porphyries is generally adjacent to orogen-parallel major fault systems that extend along the studied segment and also have a marked temporal relationship with deformation events registered along these structures. A first episode of Cu-bearing porphyry emplacement took place between 116 and 104 Ma (Mina Unión or Frontera, Cachiyuyo, Punta Colorada, Dos Amigos, Tricolor porphyries). These Early Cretaceous dacite to diorite porphyries are spatially associated with the eastern segments of the Atacama Fault System, which records sinistral transpression that started at 121 Ma producing ground uplift, consequent denudation and exhumation of the Early Cretaceous magmatic arc. This resulted in a change from marine to continental deposition with an angular unconformity in the site of the back-are basin after of eastward migration of the deformation around 112-110 Ma. At the scale of the continental margin, this deformation is correlated with early stage of the Mochica Orogenic event described in Perú. A second episode of Cu-bearing porphyry emplacement occurred between 92 and 87 Ma (Elisa, Johana, Las Campanas and La Verde deposits), which are spatially and temporally associated with the regional-scale Las Cañas-El Torito reverse fault, active between 89 and 84 Ma, during the Peruvian Orogenic Phase. This fault up thrust to the west part of the Chañarcillo Group rocks (Lower Cretaceous) over the younger upper levels of the Cerrillos Formation (Upper Cretaceous). The integrated geological mapping and geochemical data of the Early to Late Cretaceous volcanic rocks indicates that both Early Cretaceous sinistral transpression and Late Cretaceous east-west compression were not significant in promote changes in magma genesis, except for slight changes in trace element ratios (increase in Th/Ta, Nb/Ta and La/Yb) suggesting that the Late Cretaceous deformation event produced only slightly increase in crustal thickness (>40 km), but far from being comparable to major Cenozoic orogenic phases, at least along the magmatic arc to back-arc domains in the study area. Finally, our study give insights about regional geological parameters that can be used as a first order guide for exploration of Cu resources along Cretaceous magmatic belts of northern Chile, where both Early and Late Cretaceous Cu-bearing porphyry intrusions are restricted to a large structural block bounded to the west and east by Cretaceous fault systems.
author	Creixell,Christian Fuentes,Javier Bierma,Hessel Salazar,Esteban
author_facet	Creixell,Christian Fuentes,Javier Bierma,Hessel Salazar,Esteban
author_sort	Creixell,Christian
title	Tectonic setting of Cretaceous porphyry copper deposits of northern Chile (28°-30° S) and its relations with magmatic evolution and metallogeny
title_short	Tectonic setting of Cretaceous porphyry copper deposits of northern Chile (28°-30° S) and its relations with magmatic evolution and metallogeny
title_full	Tectonic setting of Cretaceous porphyry copper deposits of northern Chile (28°-30° S) and its relations with magmatic evolution and metallogeny
title_fullStr	Tectonic setting of Cretaceous porphyry copper deposits of northern Chile (28°-30° S) and its relations with magmatic evolution and metallogeny
title_full_unstemmed	Tectonic setting of Cretaceous porphyry copper deposits of northern Chile (28°-30° S) and its relations with magmatic evolution and metallogeny
title_sort	tectonic setting of cretaceous porphyry copper deposits of northern chile (28°-30° s) and its relations with magmatic evolution and metallogeny
publisher	Servicio Nacional de Geología y Minería (SERNAGEOMIN)
publishDate	2020
url	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062020000300469
work_keys_str_mv	AT creixellchristian tectonicsettingofcretaceousporphyrycopperdepositsofnorthernchile2830sanditsrelationswithmagmaticevolutionandmetallogeny AT fuentesjavier tectonicsettingofcretaceousporphyrycopperdepositsofnorthernchile2830sanditsrelationswithmagmaticevolutionandmetallogeny AT biermahessel tectonicsettingofcretaceousporphyrycopperdepositsofnorthernchile2830sanditsrelationswithmagmaticevolutionandmetallogeny AT salazaresteban tectonicsettingofcretaceousporphyrycopperdepositsofnorthernchile2830sanditsrelationswithmagmaticevolutionandmetallogeny
_version_	1714205868522733568

Tectonic setting of Cretaceous porphyry copper deposits of northern Chile (28°-30° S) and its relations with magmatic evolution and metallogeny

Ejemplares similares