K-Ar evidence for age and compositional zoning in the Puerto Vallarta-Río Santiago Batholith (Jalisco, Mexico)

Zimmermann, J.-L.; Stussi, J.M.; Partida, Eduardo González; Arnold, M.

doi:10.1016/0895-9811(88)90005-3

Cited by 27 publications

(13 citation statements)

References 9 publications

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“…The JB is formed by a distinctive stratigraphic assemblage consisting of Late Creta ceous to Early Tertiary rhyolitic ash-flow tuffs and subordinate andesites, volcaniclastic deposits, and turbiditic sequences intruded by granitoid plutons (Gastil et al, 1978;Allan, 1986;Köhler et al, 1988;Zimmermann et al, 1988;Lange and Carmichael, 1991;Righter et al, 1995). This succession is only exposed west of the Sayula half-graben, which clearly con stitutes the eastern boundary of the JB in the study area.…”

Section: Jalisco Blockmentioning

confidence: 88%

Stratigraphy and Tectonics of the Guadalajara Region and Triple-Junction Area, Western Mexico

Rosas-Elgukra

Ferrari²,

Martínez

et al. 1997

International Geology Review

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In the region between Guadalajara and the triple junction of the Tepic-Zacoalco, Chapala, and Colima rifts, the late Miocene to Quaternary volcanics of the Mexican Volcanic Belt (MVB) largely conceal the boundaries between the basement domains of the Sierra Madre Occidental (SMO) to the north and the Jalisco and Michoacán blocks to the south. Integrating previous work with new geologic mapping and isotopic age determinations, we propose a comprehensive regional stratigraphy for Guadalajara and the triple-junction area and attempt to define the boundaries between these basement domains. In the study area, the silicic succession of the SMO is restricted to the north of the Santa Rosa-Cinco Minas fault and the northern boundary faults of Lake Chapala. The succession of the MVB began with widespread mafic volcanism, and lacustrine sedimentation occurred at 11 to 8 Ma in several tectonic basins developed along the Tepic-Zacoalco and the Chapala rifts, suggesting that the extensional reactivation of the block boundaries took place earlier than previously suggested. Since latest Miocene time, volcanism has been dominated by silicic products in the north (Guadalajara area) and by more intermediate to mafic products in the south (Chapala and Zacoalco areas).

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Section: Jalisco Blockmentioning

confidence: 88%

Stratigraphy and Tectonics of the Guadalajara Region and Triple-Junction Area, Western Mexico

Rosas-Elgukra

Ferrari²,

Martínez

et al. 1997

International Geology Review

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“…The presence of ca. 100-70 Ma intrusions in Jalisco indicate that the western half was not truncated (Gastil et al, 1978;Zimmermann et al, 1988;Schaaf et al, 1995).…”

Section: Comparison With Batholiths Of Western Méxicomentioning

confidence: 98%

Geology and geochronology of granitic batholith complex, Sinaloa, México: Implications for Cordilleran magmatism and tectonics

Henry

McDowell²,

Silver³

2003

Tectonic Evolution of Northwestern Mexico and the Southwestern USA

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Most of southern Sinaloa is underlain by a large, composite batholith, a continuation of the better-known Cordilleran batholiths of California and BajaCalifornia. Field relations and extensive K-Ar and U-Pb dating within a 120-km-wide and 120-km-deep transect show that the Sinaloa batholith formed in several stages. Early layered gabbros have hornblende K-Ar ages of 139 and 134 Ma, although whether these record emplacement age, cooling from metamorphism, or excess Ar is unresolved. A group of relatively mafi c tonalites and granodiorites were emplaced before or during an episode of deformation and are restricted to within 50 km of the coast. These plutons, referred to here as syntectonic, show dynamic recrystallization textures that suggest deformation between 300° and 450 °C. A U-Pb zircon date on a probable syntectonic intrusion is 101 Ma. Hornblende K-Ar ages on defi nite syntectonic intrusions range between 98 and 90 Ma; these may record cooling soon after emplacement or following regional metamorphism.Numerous posttectonic intrusions crop out from within ~20 km of the coast, where they intrude syntectonic rocks, to the eastern edge of the Sierra Madre Occidental, where they are covered by middle Cenozoic ash-fl ow tuffs. Posttectonic rocks are dominantly more leucocratic granodiorites and granites. Three samples were analyzed by both U-Pb and K-Ar methods. Their biotite and hornblende ages are concordant at 64, 46, and 19 Ma and agree within analytical uncertainties with U-Pb zircon ages of 66.8, 47.8, and 20 Ma. These data and fi eld relations demonstrate that posttectonic intrusions were emplaced at shallow depths and cooled rapidly. Therefore, concordant K-Ar age pairs and hornblende ages in discordant samples approximate the time of emplacement. Discordance of biotite-hornblende age pairs is largely if not entirely a result of reheating by younger plutons. The combined age data indicate that posttectonic intrusions were emplaced nearly continuously between 90 and 45 Ma. One intrusion is 20 Ma. Based on outcrop area, volumes of intrusions were relatively constant through time.The combined geochronological data indicate that posttectonic magmatism shifted eastward between 1 and 1.5 km/Ma. Whether syntectonic magmatism also

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“…99-92 Ma). 92 and 65 Ma (Gastil et al, 1979;Köhler et al, 1988;Zimmermann et al, 1988;Schaaf et al, 1995). 1).…”

Section: Peninsular Range and Western Mexico Cretaceous-paleogene Batunclassified

Timing of rifting in the southern Gulf of California and its conjugate margins: Insights from the plutonic record

Duque-Trujillo

Ferrari

Orozco-Esquivel

et al. 2014

Geological Society of America Bulletin

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The Gulf of California is a young example of crustal stretching and transtensional shearing leading to the birth of a new oceanic basin at a formerly convergent margin. Previous studies focused along the southwestern rifted margin in Baja California indicated rifting was initiated after subduction and related magmatism ceased at ca. 14-12.5 Ma. However, the geologic record on the Mexico mainland (Sinaloa and Nayarit States) indicates crustal stretching in the region began as early as late Oligocene. The timing of cooling and exhumation of pre-and synrift plutonic rocks can provide constraints on the timing and rate of rifting. Here, we present results of a regional study on intrusive rocks in the southern Gulf of California sampled along the conjugate Baja California and Nayarit-Sinaloa rift margins, as well as plutonic rocks now exposed on submerged rifted blocks inside the gulf. Forty-one samples were dated via U/Pb zircon and 40 Ar/ 39 Ar mineral ages, providing emplacement age and thermochronological constraints on timing and rate of cooling. We found an extensive suite of early and middle Miocene plutons emplaced at shallow depths within the basement Cretaceous-Paleocene Peninsular Range and Sinaloa-Jalisco Batholiths. Early Miocene granitoids occur in an elongated WNW-ESE belt crossing the entire southern gulf from southern Baja California to Nayarit and Sinaloa. Most have an intermediate composition (<67 SiO 2 wt%), but a distinctive group of high-silica granites (>75 SiO 2 wt%) was emplaced 20.1-18.3 Ma, near the end of the early Miocene. Age span and chemical composition of the early Miocene silicic plutons essentially overlap ignimbrites and domes exposed in the southern Sierra Madre Occidental and in southern Baja Cali fornia, suggesting that eruptive sources for the early Miocene ignimbrite fl are-up may also have been located within the southern Gulf of California. Early Miocene plutons cooled below the 40 Ar-39 Ar biotite closure temperature (350-400 °C) in less than 2.5 m.y., which we interpret as evidence of a regional extensional event leading to the opening of the Gulf of California. A less widely distributed suite of intermediate-composition, middle Miocene granitoids (15-13 Ma) was sampled from the central-western part of the gulf, west of the Pescadero Basin, and these correspond to an episode of scarce volcanism recorded by the middle and upper members of the onshore Comondú Group in Baja California. Our widely spaced sampling of the generally sediment-covered igneous crust suggests that middle Miocene primary volcanic rocks are much less abundant than implied by previous models in which the gulf was the site of a robust Comondú arc. Thermobarometry data also indicate a very shallow depth (<5 km) of emplacement for the middle Miocene plutonic rocks. Some of these rocks also show a distinctive inequigranular texture indicative of at least two crystallization stages at different pressure. Early and middle Miocene granitoids away from the gulf axis yielded 40 Ar-39 Ar cooling ages very close to...

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K-Ar evidence for age and compositional zoning in the Puerto Vallarta-Río Santiago Batholith (Jalisco, Mexico)

Cited by 27 publications

References 9 publications

Stratigraphy and Tectonics of the Guadalajara Region and Triple-Junction Area, Western Mexico

Stratigraphy and Tectonics of the Guadalajara Region and Triple-Junction Area, Western Mexico

Geology and geochronology of granitic batholith complex, Sinaloa, México: Implications for Cordilleran magmatism and tectonics

Timing of rifting in the southern Gulf of California and its conjugate margins: Insights from the plutonic record

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