Cretaceous alkaline intra-plate magmatism in the Ecuadorian Oriente Basin: Geochemical, geochronological and tectonic evidence

Barragán, Roberto; Baby, Patrice; Duncan, Robert A.

doi:10.1016/j.epsl.2005.03.016

Cited by 37 publications

(18 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…7 Cartoons showing the Jurassic to Late Cretaceous evolution of the Ecuadorian continental margin (modified from Barragan et al 2005 on the basis of geochronologic data of this study and taking into account the Pallatanga accretion ages of Vallejo et al 2006). A 190-160 Ma: subduction-related magmatism (Zamora batholith and Misahualli volcanic sequence) and deposition of marine to continental rift deposits in the back-arc basin.…”

Section: Discussionmentioning

confidence: 99%

“…This accretionary event (known as Peltetec: Aspden and Litherland 1992) could have also caused uplift of the Eastern Cordillera and Subandean zone. Slab roll-back after collision of the above terranes with the western margin of the Amazon craton would have been responsible for Cretaceous back-arc alkaline magmatism in the Oriente basin, east of the Subandean zone (Barragan et al 2005). The wide range of imprecise K-Ar dates previously published for the Zamora batholith (∼150 to ∼100 Ma) is considered to reflect thermal disturbance caused by the Peltetec accretionary event (Litherland et al 1994).…”

Section: Geological Settingmentioning

confidence: 99%

“…A protracted period of uplift led to a ≥20-My hiatus in sedimentation (Barragan et al 2005) and unroofing of the Zamora batholith until the unconformable deposition, on top of the Zamora batholith and Misahualli unit, of the marine Hollín Formation (Aptian-Albian; Jaillard et al 2000;Pratt et al 2005). It is not clear why arc magmatism stopped at the end of the Jurassic and never resumed in the Subandean zone.…”

Section: Geological Settingmentioning

confidence: 99%

“…7). Deposition of the transgressive marine Hollín Formation occurred during the AptianAlbian directly on top of the Zamora batholith and Misahualli volcanic rocks and was accompanied by backarc alkaline volcanism related to slab roll-back (Barragan et al 2005; cartoon D in Fig. 7).…”

Section: Pacific Oceanmentioning

confidence: 99%

See 3 more Smart Citations

U–Pb, Re–Os, and 40Ar/39Ar geochronology of the Nambija Au-skarn and Pangui porphyry Cu deposits, Ecuador: implications for the Jurassic metallogenic belt of the Northern Andes

et al. 2008

View full text Add to dashboard Cite

New U-Pb, Re-Os, and 40 Ar/ 39 Ar dates are presented for magmatic and hydrothermal mineral phases in skarn-and porphyry-related ores from the Nambija and Pangui districts of the Subandean zone, southeastern Ecuador. Nambija has been one of the main gold-producing centers of Ecuador since the 1980s due to exceptionally high-grade ores (average 15 g/t, but frequently up to 300 g/t Au). Pangui is a recently discovered porphyry Cu-Mo district. The geology of the Subandean zone in southeastern Ecuador is dominated by the I-type, subduction-related, Jurassic Zamora batholith, which intrudes Triassic volcanosedimentary rocks. The Zamora batholith is in turn cut by porphyritic stocks, which are commonly associated with skarn formation and/or porphyry-style mineralization. High precision U-Pb and Re-Os ages for porphyritic stocks (UPb, zircon), associated prograde skarn (U-Pb, hydrothermal titanite), and retrograde stage skarn (Re-Os, molybdenite from veins postdating gold deposition) of the Nambija district are all indistinguishable from each other within error (145 Ma) and indicate a Late Jurassic age for the gold mineralization. Previously, gold mineralization at Nambija was considered to be Early Tertiary based on K-Ar ages Miner Deposita (2009) Ar and Re-Os ages for magmatic-hydrothermal minerals from the Pangui district, which range between 157 and 152 Ma. Mineralization at Nambija and Pangui is associated with porphyritic stocks that represent the last known episodes of a long-lived Jurassic arc magmatism (∼190 to 145 Ma). A Jurassic age for mineralization at Nambija and Pangui suggests that the Northern Andean Jurassic metallogenic belt, which starts in Colombia at 3°N, extends down to 5°S in Ecuador. It also adds a new mineralization style (Au-skarn) to the metal endowment of this belt.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Geological Settingmentioning

confidence: 99%

Section: Geological Settingmentioning

confidence: 99%

Section: Pacific Oceanmentioning

confidence: 99%

See 2 more Smart Citations

U–Pb, Re–Os, and 40Ar/39Ar geochronology of the Nambija Au-skarn and Pangui porphyry Cu deposits, Ecuador: implications for the Jurassic metallogenic belt of the Northern Andes

et al. 2008

View full text Add to dashboard Cite

show abstract

“…4.6 for cross-section) in northern Peru, where there is a narrow sub-Andean belt whose width coincides with the eastward pinch-out of evaporites of the Triassic-Jurassic Pucara Formation. In the Santiago Basin (Navarro et al 2005), as in the Colombian Eastern Cordillera and sub-Andes and Oriente Basin of Ecuador (Barragan et al 2005;see Figs 4.2 & 4.4), there is also a strong infl uence of inversion tectonics .…”

Section: The Vaupés Swell and The Fitzcarrald Archmentioning

confidence: 99%

Tectonic History of the Andes and Sub‐Andean Zones: Implications for the Development of the Amazon Drainage Basin

Mora

Baby

Roddaz

et al. 2009

Amazonia: Landscape and Species Evolution

110

118

View full text Add to dashboard Cite

show abstract

Cenozoic Sedimentary Evolution of the Amazonian Foreland Basin System

Roddaz

Hermoza

Mora

et al. 2009

Amazonia: Landscape and Species Evolution

View full text Add to dashboard Cite

In this chapter we present a synthesis of the Cenozoic evolution of the Amazonian foreland basin system, based on a review of the estimated ages, lithology and sedimentary structures, palaeontological content, and inferred depositional environments of sedimentary units in the basin. In addition, we have calculated maximum sedimentation rates for the Cenozoic formations of the northern Peruvian foreland basin and integrated these with existing data on sedimentation rates, subsidence analysis, migration of depocentre and depositional environments. Based on this information we propose a model for the Cenozoic evolution of the Amazonian foreland. The sedimentary architecture of this foreland basin indicates that Cenozoic evolution was marked by several periods, which were roughly synchronous and of similar effect, along the entire Amazonian foreland basin system. Tectonic loading of the Andes of Colombia, Ecuador, Peru and northern Bolivia, and development of the Amazonian foreland, was initiated during Late Cretaceous-Paleocene times and followed by an unloading stage during the Early-Middle Eocene period. The Middle-Late Eocene marine transgression and the increase in sedimentation rates, associated with westward migration of the depocentre, were all indicative of a renewed phase of tectonic loading of the Peruvian Western Cordillera and the Ecuadorian and Colombian Eastern Cordillera. Subsequent Oligo-Miocene increase in sedimentation rates and further migration of the depocentres towards the present-day sub-Andean zone, are all indicative for a thrust-induced uplift and loading of the Eastern Cordilleras of Peru, Bolivia and Colombia. This Oligo-Miocene loading stage maintained high subsidence rates that favoured the sedimentation of aggradational fl oodplain and coastal plain and tidally infl uenced deposits. Nevertheless, the processes that controlled the Early-Middle Miocene marine ingressions remain to be determined. Late Miocene ongoing thrust tectonic loading of the Eastern Cordillera, initial structuring of the sub-Andean zone and the onset of the main phase of Andean surface uplift induced fl exural subsidence in the foredeep depozones of the entire Amazonian foreland basin. This process also drove the Late Miocene marine transgressions that characterized the fi lled stage of the Ecuadorian, Peruvian and Bolivian Amazonian foreland basin system. Valley incisions and full relief development in the hinterland during the Late Miocene-Pliocene provided increased sediment supply and overfi lled the Amazonian foreland basin system. Finally, the fl at-slab subduction of the Nazca ridge induced Pliocene (~4 Ma) uplift of the Fitzcarrald Arch and subdivided the Amazonian foreland basin into the northern and southern Amazonian foreland basins.

show abstract

Cretaceous alkaline intra-plate magmatism in the Ecuadorian Oriente Basin: Geochemical, geochronological and tectonic evidence

Cited by 37 publications

References 53 publications

U–Pb, Re–Os, and 40Ar/39Ar geochronology of the Nambija Au-skarn and Pangui porphyry Cu deposits, Ecuador: implications for the Jurassic metallogenic belt of the Northern Andes

U–Pb, Re–Os, and 40Ar/39Ar geochronology of the Nambija Au-skarn and Pangui porphyry Cu deposits, Ecuador: implications for the Jurassic metallogenic belt of the Northern Andes

Tectonic History of the Andes and Sub‐Andean Zones: Implications for the Development of the Amazon Drainage Basin

Cenozoic Sedimentary Evolution of the Amazonian Foreland Basin System

Contact Info

Product

Resources

About