CIG   05423
CENTRO DE INVESTIGACIONES GEOLOGICAS
Unidad Ejecutora - UE
artículos
Título:
The Sierra Norte-Ambargasta batholith: Late EdiacaraneEarly Cambrian
Autor/es:
IANNIZZOTTO, N.F.; RAPELA, C.W.; BALDO, E.G; GALINDO, C.; FANNING, C.M; PANKHURST, R.J
Revista:
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2013 vol. 42 p. 127 - 143
ISSN:
0895-9811
Resumen:
The Sierra Norte-Ambargasta batholith is one of the largest plutonic expressions of the Pampean orogeny in
western Argentina. A thorough petrographic, geochemical, isotopic (Sr and Nd) and geochronological (UePb
SHRIMP) study is reported. The batholith comprises granitoid rocks that may be subdivided into those
affected by Pampean D2 dextral shearing and mylonization and those emplaced after deformation had
ceased; representative samples gave UePb zircon ages of 537 4 Ma and 530 4 Ma respectively. The
earlier, dominant, groupwere derived largely frommetaluminous calc-alkaline subduction-related magmas,
whereas the late granites are peraluminous. However, all have relatively high initial 87Sr/86Sr ratios (0.706 to
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
earlier, dominant, groupwere derived largely frommetaluminous calc-alkaline subduction-related magmas,
whereas the late granites are peraluminous. However, all have relatively high initial 87Sr/86Sr ratios (0.706 to
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
SHRIMP) study is reported. The batholith comprises granitoid rocks that may be subdivided into those
affected by Pampean D2 dextral shearing and mylonization and those emplaced after deformation had
ceased; representative samples gave UePb zircon ages of 537 4 Ma and 530 4 Ma respectively. The
earlier, dominant, groupwere derived largely frommetaluminous calc-alkaline subduction-related magmas,
whereas the late granites are peraluminous. However, all have relatively high initial 87Sr/86Sr ratios (0.706 to
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
earlier, dominant, groupwere derived largely frommetaluminous calc-alkaline subduction-related magmas,
whereas the late granites are peraluminous. However, all have relatively high initial 87Sr/86Sr ratios (0.706 to
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
ePb
SHRIMP) study is reported. The batholith comprises granitoid rocks that may be subdivided into those
affected by Pampean D2 dextral shearing and mylonization and those emplaced after deformation had
ceased; representative samples gave UePb zircon ages of 537 4 Ma and 530 4 Ma respectively. The
earlier, dominant, groupwere derived largely frommetaluminous calc-alkaline subduction-related magmas,
whereas the late granites are peraluminous. However, all have relatively high initial 87Sr/86Sr ratios (0.706 to
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
earlier, dominant, groupwere derived largely frommetaluminous calc-alkaline subduction-related magmas,
whereas the late granites are peraluminous. However, all have relatively high initial 87Sr/86Sr ratios (0.706 to
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
ePb zircon ages of 537 4 Ma and 530 4 Ma respectively. The
earlier, dominant, groupwere derived largely frommetaluminous calc-alkaline subduction-related magmas,
whereas the late granites are peraluminous. However, all have relatively high initial 87Sr/86Sr ratios (0.706 to
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
87Sr/86Sr ratios (0.706 to
at least 0.710, strongly negative åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.
åNdt values (1.7 to5.9) and, in some cases inherited 600 Ma and 970Ma
zircon, similar to the isotopic and zircon provenance seen in the metamorphic host rocks. A high degree of
contamination of the magmas, possibly anatexis in the case of the post-mylonite granite, is related to
emplacement during the latestage transpressional docking of the Pampean terrane against the Rio de la Plata
craton. The absence of detrital zircon derived from the craton in either the Pampean metasedimentary host
rocks or the batholith supports this collisional model for the Pampean orogen.