The Peninsular Ranges Batholith: an insight into the evolution of the Cordilleran batholiths of southwestern North America
The Peninsular Ranges Batholith of southern and Baja California is the largest segment of a Cretaceous magmatic arc that was once continuous from northern California to southern Baja California. In this batholith, the emplacement of igneous rocks took place during a single sequence of magmatic activ...
Published in: | Earth and Environmental Science Transactions of the Royal Society of Edinburgh |
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Cambridge University Press
1988
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Online Access: | https://doi.org/10.1017/s0263593300014152 |
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ftcaltechauth:oai:authors.library.caltech.edu:6jfyr-5hp53 2024-06-23T07:52:21+00:00 The Peninsular Ranges Batholith: an insight into the evolution of the Cordilleran batholiths of southwestern North America Silver, L. T. Chappell, B. W. 1988 https://doi.org/10.1017/s0263593300014152 unknown Cambridge University Press https://doi.org/10.1017/s0263593300014152 oai:authors.library.caltech.edu:6jfyr-5hp53 eprintid:115958 resolverid:CaltechAUTHORS:20220729-945022900 info:eu-repo/semantics/closedAccess Other Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 79(2-3), 105-121, (1988) Symposium on the Origin of Granites, Edinburgh, Scotland, 14-16 September 1987 asymmetry Baja California California Cretaceous gabbro geochemistry geochronology granite granodiorite isotopes petrogenesis plutonic plutonic arc tonalite General Earth and Planetary Sciences General Environmental Science info:eu-repo/semantics/article 1988 ftcaltechauth https://doi.org/10.1017/s0263593300014152 2024-06-12T05:48:46Z The Peninsular Ranges Batholith of southern and Baja California is the largest segment of a Cretaceous magmatic arc that was once continuous from northern California to southern Baja California. In this batholith, the emplacement of igneous rocks took place during a single sequence of magmatic activity, unlike many of the other components of the Cordilleran batholiths which formed during successive separate magmatic episodes. Detailed radiometric dating has shown that it is a composite of two batholiths. A western batholith, which was more heterogeneous in composition, formed as a static magmatic arc between 140 and 105 Ma and was intrusive in part into related volcanic rocks. The eastern batholith formed as a laterally transgressing arc which moved away from those older rocks between 105 and 80 Ma, intruding metasedimentary rocks. Rocks of the batholith range from undersaturated gabbros through to felsic granites, but tonalite is the most abundant rock throughout. Perhaps better than elsewhere in the Cordillera, the batholith shows beautifully developed asymmetries in chemical and isotopic properties. The main gradients in chemical composition from W to E are found among the trace elements, with Ba, Sr, Nb and the light rare earth elements increasing by more than a factor of two, and P, Rb, Pb, Th, Zn and Ga showing smaller increases. Mg and the transition metals decrease strongly towards the E, with Sc, V and Cu falling to less than half of their value in the most westerly rocks. Oxygen becomes very systematically more enriched in ¹â¸O from W to E and the Sr, Nd and Pb isotopic systems change progressively from mantle values in the W to a more evolved character on the eastern side of the batholith. In detail the petrogenesis of the Peninsular Ranges Batholith is not completely understood, but many general aspects of the origin are clear. The exposed rocks, particularly in the western batholith, closely resemble those of present day island arcs, although the most typical and average tonalitic composition is ... Article in Journal/Newspaper Day Island Caltech Authors (California Institute of Technology) Baja Earth and Environmental Science Transactions of the Royal Society of Edinburgh 79 2-3 105 121 |
institution |
Open Polar |
collection |
Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
unknown |
topic |
asymmetry Baja California California Cretaceous gabbro geochemistry geochronology granite granodiorite isotopes petrogenesis plutonic plutonic arc tonalite General Earth and Planetary Sciences General Environmental Science |
spellingShingle |
asymmetry Baja California California Cretaceous gabbro geochemistry geochronology granite granodiorite isotopes petrogenesis plutonic plutonic arc tonalite General Earth and Planetary Sciences General Environmental Science Silver, L. T. Chappell, B. W. The Peninsular Ranges Batholith: an insight into the evolution of the Cordilleran batholiths of southwestern North America |
topic_facet |
asymmetry Baja California California Cretaceous gabbro geochemistry geochronology granite granodiorite isotopes petrogenesis plutonic plutonic arc tonalite General Earth and Planetary Sciences General Environmental Science |
description |
The Peninsular Ranges Batholith of southern and Baja California is the largest segment of a Cretaceous magmatic arc that was once continuous from northern California to southern Baja California. In this batholith, the emplacement of igneous rocks took place during a single sequence of magmatic activity, unlike many of the other components of the Cordilleran batholiths which formed during successive separate magmatic episodes. Detailed radiometric dating has shown that it is a composite of two batholiths. A western batholith, which was more heterogeneous in composition, formed as a static magmatic arc between 140 and 105 Ma and was intrusive in part into related volcanic rocks. The eastern batholith formed as a laterally transgressing arc which moved away from those older rocks between 105 and 80 Ma, intruding metasedimentary rocks. Rocks of the batholith range from undersaturated gabbros through to felsic granites, but tonalite is the most abundant rock throughout. Perhaps better than elsewhere in the Cordillera, the batholith shows beautifully developed asymmetries in chemical and isotopic properties. The main gradients in chemical composition from W to E are found among the trace elements, with Ba, Sr, Nb and the light rare earth elements increasing by more than a factor of two, and P, Rb, Pb, Th, Zn and Ga showing smaller increases. Mg and the transition metals decrease strongly towards the E, with Sc, V and Cu falling to less than half of their value in the most westerly rocks. Oxygen becomes very systematically more enriched in ¹â¸O from W to E and the Sr, Nd and Pb isotopic systems change progressively from mantle values in the W to a more evolved character on the eastern side of the batholith. In detail the petrogenesis of the Peninsular Ranges Batholith is not completely understood, but many general aspects of the origin are clear. The exposed rocks, particularly in the western batholith, closely resemble those of present day island arcs, although the most typical and average tonalitic composition is ... |
format |
Article in Journal/Newspaper |
author |
Silver, L. T. Chappell, B. W. |
author_facet |
Silver, L. T. Chappell, B. W. |
author_sort |
Silver, L. T. |
title |
The Peninsular Ranges Batholith: an insight into the evolution of the Cordilleran batholiths of southwestern North America |
title_short |
The Peninsular Ranges Batholith: an insight into the evolution of the Cordilleran batholiths of southwestern North America |
title_full |
The Peninsular Ranges Batholith: an insight into the evolution of the Cordilleran batholiths of southwestern North America |
title_fullStr |
The Peninsular Ranges Batholith: an insight into the evolution of the Cordilleran batholiths of southwestern North America |
title_full_unstemmed |
The Peninsular Ranges Batholith: an insight into the evolution of the Cordilleran batholiths of southwestern North America |
title_sort |
peninsular ranges batholith: an insight into the evolution of the cordilleran batholiths of southwestern north america |
publisher |
Cambridge University Press |
publishDate |
1988 |
url |
https://doi.org/10.1017/s0263593300014152 |
geographic |
Baja |
geographic_facet |
Baja |
genre |
Day Island |
genre_facet |
Day Island |
op_source |
Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 79(2-3), 105-121, (1988) Symposium on the Origin of Granites, Edinburgh, Scotland, 14-16 September 1987 |
op_relation |
https://doi.org/10.1017/s0263593300014152 oai:authors.library.caltech.edu:6jfyr-5hp53 eprintid:115958 resolverid:CaltechAUTHORS:20220729-945022900 |
op_rights |
info:eu-repo/semantics/closedAccess Other |
op_doi |
https://doi.org/10.1017/s0263593300014152 |
container_title |
Earth and Environmental Science Transactions of the Royal Society of Edinburgh |
container_volume |
79 |
container_issue |
2-3 |
container_start_page |
105 |
op_container_end_page |
121 |
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1802643625720414208 |