U-Pb Geochronology of Late Paleozoic to Early Mesozoic Igneous Rocks of the North Chilean Andes Between 20° and 31°S

Andean Geology 41 (3): 447-506. September, 2014 Andean Geology doi: 10.5027/andgeoV41n3-a01 formerly Revista Geológica de Chile www.andeangeology.cl

Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology of Late Paleozoic to Early Mesozoic igneous rocks of the north Chilean Andes between 20° and 31°S

Víctor Maksaev1, Francisco Munizaga1, 2, Colombo Tassinari3

1 Departamento de Geología, Universidad de Chile, Plaza Ercilla 803, Santiago, Chile. [email protected]; [email protected] 2 Geología, Facultad de Ingeniería, Universidad Andrés Bello, Salvador Sanfuentes 2375, Santiago, Chile. 3 Instituto de Geociencias, Universidade de Sao Paulo, Rua do Lago, 562-Cidade Universitária CEP 05508-080, Sao Paulo, Brasil. [email protected]

ABSTRACT. U-Pb zircon geochronological data provide record of about 130 Ma of igneous activity in the Andes of northern Chile, which extended episodically from the latest Early Carboniferous to Early Jurassic (328-194 Ma). The overall U-Pb data show that volcanism and plutonism were essentially synchronous and major episodes of igneous activity developed during the Late Carboniferous to Mid-Permian (310 to 260 Ma) and from Late Permian to Late Triassic (255-205 Ma), with less prominent episodes in the mid-Carboniferous (330 to 320 Ma), and Early Jurassic (200-190 Ma). Thus, from the Carboniferous to the Early Triassic dominantly silicic magmatism developed along the Chilean segment of the southwestern border of Gondwana supercontinent. Further magmatism developed during the Mid-Late Triassic (250-194 Ma) was bimodal and synchronous with rift-related, continental and/or marine sedimentary strata related to the early stages of break-up of Gondwana. Most of the silicic volcanic rocks of the Precordillera and Domeyko Cordillera of northern Chile (21°30’ to 25°30’S) are older than the silicic rocks assigned to the Choiyoi succession in Argentina, being instead equivalent in age to Carboniferous to Early Permian marine sedimentary sequences present in the eastern Argentinean foreland. On the other hand, silicic volcanic successions exposed in the easternmost part of northern Chile are equivalent in age to the Choiyoi succession of the San Rafael Block of Argentina. An eastward expansion or migration of the volcanism during the Mid-Permian to Early Triassic is inferred, interpretation that is consistent with expansion of the volcanism at that time in Argentina. The timing of the Late Paleozoic to Early Jurassic magmatism is coincident with that of the Andes of Perú and of western Argentina according to the available U-Pb data, revealing a rather consistent evolution in time of the magmatism along the southwestern, paleo-Pacific border of Gondwana.

Keywords: Geochronology, U-Pb, Andes, Gondwana, Choiyoi, Paleozoic, Carboniferous, Triassic. 448 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

RESUMEN. Temporalidad del magmatismo del borde paleo-Pacífico de Gondwana: geocronología U-Pb de rocas ígneas del Paleozoico tardío a Mesozoico temprano de los Andes del norte de Chile entre los 20° y 31°S. Los datos de U-Pb en circón registran aproximadamente 130 Ma de actividad ígnea en los Andes del norte de Chile, la que se extendió episódicamente desde el Carbonífero temprano hasta el Jurásico temprano (328-194 Ma). Los datos globales de U-Pb indican que el volcanismo y plutonismo fueron esencialmente sincrónicos con episodios mayores desde el Carbonífero tardío al Pérmico Medio (310-260 Ma) y durante el Pérmico Tardío a Triásico Tardío (255-205 Ma) y episodios menos prominentes durante el Carbonífero medio (330-320 Ma) y el Jurásico Temprano (200-190 Ma). Desde el Carbonífero hasta el Triásico Temprano se desarrolló magmatismo predominantemente félsico a lo largo del borde suroccidental del supercontinente de Gondwana, mientras que durante el Triásico medio a tardío (250-194 Ma) se desarrolló magmatismo bimodal sincrónico con estratos sedimentarios continentales y/o marinos relacionados con extensión (rift), durante las etapas tempranas de la desintegración de Gondwana. La mayor parte de las rocas volcá- nicas silíceas de la precordillera y la cordillera de Domeyko en el norte de Chile (21°30’ a 25°30’S) son más antiguas que las rocas silíceas asignadas a la sucesión Choiyoi en Argentina, y son, en cambio, equivalentes en edad con las secuencias sedimentarias marinas del Carbonífero al Pérmico temprano presentes en el antepaís argentino al oriente. Por otra parte, las sucesiones volcánicas félsicas expuestas en la parte más oriental del norte de Chile, de la cordillera de Domeyko y de la cordillera Frontal al sur de 25°S son equivalentes en edad a la sucesión Choiyoi de Argentina. Se infiere una migración o expansión del volcanismo hacia el este durante el Pérmico Medio a Triásico Temprano, interpretación que es consistente con la expansión del volcanismo en Argentina durante ese período. La temporalidad del magmatismo del Paleozoico tardío a Mesozoico temprano es coincidente con la de los Andes de Perú y del oeste de Argentina, de acuerdo a los datos U-Pb disponibles, lo que revela una evolución temporal del magmatismo concordante a lo largo del borde suroeste del Gondwana.

Palabras clave: Geocronología, U-Pb, Andes, Gondwana, Choiyoi, Paleozoico, Carbonífero, Triásico.

1. Introduction Mesozoic igneous rocks of northern Chile (north of 31°S latitude), which we have compiled in Tables The Late Paleozoic-Early Mesozoic magmatism 1 and 2 (references therein), but also in Argentina is a significant, but not completely understood (i.e., Pankhurst et al., 2006; Gulbranson et al., 2010; geological event, which has been recognized along Rocha-Campos et al., 2011). In this contribution we much of the length of western South America (e.g., present 41 new SHRIMP U-Pb dates for volcanic and Vaughan and Pankhurst, 2008). It is characterized plutonic rocks of northern Chile, which together with by a high proportion of felsic volcanic rocks and the compilation of U-Pb dates from previous studies, granitic plutons over intermediate and mafic igneous provide a more accurate timing for the Late Paleozoic rocks, and represents magmatism that developed to Early Jurassic magmatism of the north-Chilean along the southwestern paleo-Pacific border of segment of the southwestern border of Gondwana. Gondwana supercontinent (Llambías and Sato, The numerical ages are assigned to the International 1990; Sato and Llambías, 1993; Mpodozis and Kay, Stratigraphic Chart of the International Commission 1992; Strazzere et al., 2006; Munizaga et al., 2008; on Stratigraphy 2013 (Cohen et al., 2013). Vaughan and Pankhurst, 2008; Rocha-Campos et al., 2011). The previous K-Ar dating of this extensive 2. Geological background volcano-plutonic complex in northern Chile has yielded an overall range from 332 to 197 Ma for The Late Paleozoic to Triassic igneous units this magmatic activity (e.g., Huete et al., 1977; Nasi along the Andes of northern Chile and the Argen- et al., 1985; Mpodozis et al., 1993; Lucassen et al., tinean Frontal Cordillera are commonly known by 1999; Tomlinson et al., 2001; Tomlinson and Blanco, a variety of names, but Stipanicic et al. (1968) em- 2008). The K-Ar ages have mostly been obtained for ployed the name Choiyoi Group for volcanic rocks intrusive rocks, since volcanic rocks commonly are attributed to the Permian to Triassic outcropping in altered or show low-grade metamorphism, which have the Argentinean Cordillera, and this name has been prevented the application of the K-Ar dating method widely used to refer to ʻPermo-Triassicʼ magmatism or produced inaccurate dates. More recent studies in both countries, even though the actual timing of the have provided a more accurate geochronological igneous rocks was quite inaccurate and only limited database of U-Pb dates for the Late Paleozoic-Early and inaccurate geochronological data was available. Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 449 (2008) . (1993) (2013) . (2013) . (2006) (2009) . (1999) . (2012) . (2012) et al et al. . (2009) . (2009) . (2009) et al. et al et al et al. et al et al et al et al et al et al Reference Venegas and Blanco (2008) Tomlinson Salazar and Blanco (2008) Tomlinson Mpodozis Munizaga Jara Cornejo Venegas Jara Urzúa (2009) Masterman (2003) Marinovic (2007) Marinovic (2007) Hervé Hervé Jara Urzúa (2009) Urzúa (2009) Urzúa (2009) Urzúa (2009) and Blanco (2008) Tomlinson and Blanco (2008) Tomlinson Martin U-Pb age Formation or Unit Formation or La Tabla Collahuasi Cerro Bayo Collahuasi Collahuasi Collahuasi La Tabla La Tabla La Tabla La Tabla La Tabla Collahuasi Sierra del Jardín Sierra del Jardín La Tabla La Tabla La Tabla La Tabla La Tabla La Tabla La Tabla Collahuasi Collahuasi Guanaco Sonso Method LA-ICP-MS CA-TIMS LA-ICP-MS SHRIMP ID-TIMS SHRIMP LA-ICP-MS ID-TIMS LA-ICP-MS LA-ICP-MS LA-ICP-MS LA-ICP-MS ID-TIMS ID-TIMS Uncertain Uncertain LA-ICP-MS LA-ICP-MS LA-ICP-MS LA-ICP-MS LA-ICP-MS LA-ICP-MS LA-ICP-MS ID-TIMS 293±4 293±14 292±5 292±5 287±3 286±2 284±4 282±2 279±9 Ma±2σ 309.9±2.2 303.9±0.2 300.8±4.6 300.3±1.8 299.3±1.7 298.8±2.2 298.2±5.5 296.8±0.2 294.6±2.1 294.4±4.6 288.8±2.4 288.0±2.4 287.1±4.4 273.5±11.0 265.0±5.6 Lithology Rhyolitic tuff Rhyolite Rhyolite Rhyolitic tuff Rhyolite Dacite Rhyolite Rhyolite Rhyolitic tuff Andesite Dacite Rhyolite Rhyolite Rhyolite Andesite Andesite Rhyolite Andesite tuff Andesite tuff Andesite tuff Andesite tuff Dacite tuff Dacite tuff Rhyolite tuff 45” Longitude W 69°18’12.33” 68°57’18.24” 70°26’20. 68°58’25.42” 68°55’50.78” 68°51’00.67” 69°03’40” 69°00’45.45” 69°16’17.15” 69°03’40” 69°01’04.46” 68°41’59.07” 69°05’17.73” 69°09’27.15” 69°02’57” 69°02’57.31” 69°03’46.42” 69°03’13.07” 69°03’13.07” 69°00’42.13” 69°02’43.88” 68°56’58” 68°57’18” 70°01’58.13” Location (Geodetic WGS 84) Location (Geodetic ZIRCON AGES FOR VOLCANIC ROCKS OF NORTHERN CHILE. NORTHERN ROCKS OF VOLCANIC AGES FOR ZIRCON b Latitude S 25°11’05.24” 22°26’50.38” 28°46’30.58” 22°25’33.45” 22°35’22.00” 21°02’09.83” 24°12’53” 23°53’07.49” 25°17’53.27” 24°12’53” 24°20’20.45” 20°58’25.81” 23°41’19.97” 23°52’03.50” 24°14’37” 24°14’37.03” 24°13’04.72” 24°16’20.86” 24°16’20.86” 24°13’04.73” 24°16’15.37” 22°25’13” 22°24’50” 29°19’27.08” Sample VAM-137 CHT-59 D-9 CHT-201 LVN-317 CLL-76 Unidentified 78012 VAM-070 Unidentified ESC-50 R990259 MF-650 MF-653 Unidentified Unidentified Unidentified ESC-45 ESC-36 ESC-47 ESC-37 Unidentified Unidentified IJ-108.2 TABLE 1. COMPILED U-P TABLE 450 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... . (2013) . (2013) . (2013) . (2009) . (2009) . (2012, 2013) . (2013) . (2013) . (2013) . (2014) . (2012) et al et al et al et al et al et al et al et al et al et al et al Reference Cornejo Venegas Schmus Van Breitkreuz and (1996) Basso and Marinovic (2003) Basso and Marinovic (2003) and Blanco (2008) Tomlinson and Blanco (2008) Tomlinson Basso (2004) Cornejo and Blanco (2008) Tomlinson Padel Basso (2004) Hervé Salazar Salazar Venegas Venegas Salazar Salazar Marinovic (2007) U-Pb age Formation or Unit Formation or La Tabla La Tabla La Tabla Peine Group El Bordo El Bordo Quetena Quetena Sierra Miranda Quebrada del Salitre Cerros de Chuquicamata San Félix Sierra de Miranda Las Breas La Totora La Totora Quebrada del Salitre Quebrada del Salitre San Félix La Totora Cerro La Ballena Method ID-TIMS LA-ICP-MS ID-TIMS ID-TIMS ID-TIMS SHRIMP SHRIMP ID-TIMS ID-TIMS ID-TIMS LA-ICP-MS ID-TIMS SHRIMP LA-ICP-MS LA-ICP-MS LA-ICP-MS LA-ICP-MS LA-ICP-MS LA-ICP-MS ID-TIMS 248±3 233±12 220±19 Ma±2σ 262.9±2.0 259.0±3.4 240.8±0.3 238.7±0.4 235.4±1.6 234.5±3.2 232.9±0.2 231.6±0.5 222.8±2.1 219.5±1.7 217.9±1.4 216.2±1.6 214.2±2.0 212.8±2.0 212.4±2.6 210.4±2.9 194.0±9.2 Lithology Rhyolite Altered tuff Ignimbrite Tuff Tuff Andesitic breccias Volcanoclastic sandstone Rhyolitic tuff Rhyolite Dacite Rhyolitic tuff Rhyolite Dacitic ignimbrite Rhyolitic tuff Rhyolitic tuff Andesite Dacite Rhyolitic tuff Basaltic andesite Tuff Longitude W 69°05’34.66” 69°13’45.52” 68°00’50” 68°36’ 68°36’ 68°59’17.5” 68°59’24.3” 69°59’21.41” 69°19’13.96” 68°51’25” 70°24’00.99” 69°47’38.55” 70°30’38.7” 70°09’50.23” 70°08’22.65” 69°09’14.64” 69°11’22.20” 70°24’48.83 70°23’16.60” 69°04’35.0” Location (Geodetic WGS 84) Location (Geodetic Latitude S 25°34’42.40” 25°01’53.27” 23°40’06” 23°09’ 23°09’ 22°25’36.5” 22°25’34” 23°00’16.35” 25°59’30.40” 22°12’51” 28°42’35.34” 23°04’11.18” 29°49’54.3” 28°39’32.42” 28°34’03.42” 25°17’58.75” 25°07’06.16” 28°47’44.23” 28°41’09.64” 23°37’51.6” table 1 continued. Sample DCC-130 CV-130321-02 CC-44-130-138-168 Unidentified Unidentified CHT-192 CHT-193 BF-225 DCC-124 Unidentified St-62d BF-2 FO 06 95 ST-93Ad ST196d CV-111212-02 VAM-167 ST-175d ST-65d MF-646 Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 451 . (1993) . (2008) . (2008) . (2008) . (2008) . (2008) . (2008) . (2008) . (2008) . (2013) . (2013) . (2013) . (2013) . (2012) . (1990) . (2012) . (2012) . (2012) et al et al et al et al et al et al et al et al et al et al et al et al et al et al et al et al et al et al Reference Pineda and Calderón (2008) Venegas Venegas Cortés (2000) Munizaga Munizaga Munizaga Munizaga and Blanco (2008) Tomlinson Munizaga Mpodozis and Blanco (2008) Tomlinson Hervé Venegas Urzúa (2009) Munizaga Damm Munizaga Munizaga and Blanco (2008) Tomlinson Hervé Hervé Venegas Coloma U-Pb age Method SHRIMP LA-ICP-MS LA-ICP-MS ID-TIMS SHRIMP SHRIMP SHRIMP SHRIMP ID-TIMS SHRIMP ID-TIMS ID-TIMS Uncertain LA-ICP-MS SHRIMP SHRIMP ID-TIMS SHRIMP SHRIMP ID-TIMS Uncertain Uncertain LA-ICP-MS LA-ICP-MS 303±5 Ma±2σ 328.1±2.8 328.3±3.4 323.9±2.6 310.1±4.8 308.5±2.2 307.9±2.8 304.6±3.2 303.9±3.0 303.8±0.7 303.2±2.0 302.4±0.8 300.1±3.5 299.4±2.5 298.9±2.6 298.3±2.1 298.0±1.5 297.6±2.4 296.9±4.3 296.9±2.1 296.8±3.2 296.6±4.4 296.3±2.9 296.1±4.8 Lithology Foliated muscovite-biotite granite Rhyolitic porphyry Monzogranite Monzogranite Rhyolitic porphyry Rhyolitic porphyry Rhyolitic porphyry Rhyolitic porphyry Rhyolitic porphyry Granitic porphyry Foliated diorite Rhyolitic porphyry Tonalite Rhyolitic porphyry Quartz Porphyry Rhyolitic porphyry Granite Rhyolitic porphyry Dacitic porphyry Granite Monzodiorite porphyry Monzogranite porphyry Dacitic porphyry Muscovite-biotite Granodiorite Location WGS84) (Geodetic Longitude W 70°30’17.56” 69°17’04.78” 69°05’02.91” 69°31’46.70” 68°42’24.01” 68°50’39.71” 68°42’24.01” 68°42’28.01” 68°52’47” 68°49’01.01” 68°57´11.24” 68°49’59” 69°03’08” 69°01’17.56” 69°03’19.82” 68°42’17.56” 68°55’00” 68°39’42.14” 68°38’09.68” 68°51’20” 69°03’43” 69°03’08” 69°09’04.60” 70°25’51.27” ZIRCON AGES FOR INTRUSIVE ROCKS OF NORTHERN CHILE. NORTHERN AGES FOR INTRUSIVE ROCKS OF ZIRCON b Latitude S 30°44’19.54” 25°15’29.74” 25°23’00.03” 23°40’30.56” 20°58’04.34” 21°02’09.81” 20°58’04.34” 20°57’54.34” 21°59’49” 20°59’59.33” 22°39’58.46” 21°40’06” 24°17’03” 25°02’08.20” 24°12´50.10” 20°58’08.70” 22°40’15” 21°09’54.54” 20°59’21.05” 22°16’30” 24°17’03” 24°17’03” 25°18’35.21” 28°50’15.97” Sample GP-2089 VAM-053 VAV Unidentified CLL-238 CLL-75 CLL-114 CLL-237 Unidentified CLL-44 LVN-291 Unidentified Unidentified CV-120118-05 ZERD356 CLL-223 84-22-12 CLL-85 CLL-221 Unidentified Unidentified Unidentified VAV-006 ST-9d TABLE 2 COMPILED U-P TABLE 452 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... . (1995) . (1995) . (1995) . (1995) . (1993) . (1996) . (2008) . (1999) . (2013) . (2006) . (2006) . (2012) . (2012) . (2013) .(2014) . (2014) . (2014) . (2012) et al et al et al et al et al et al et al . (1983) et al et al et al et al et al et al et al et al et al et al et al et al Reference Venegas Coloma Urzúa (2009) Marinovic Pineda and Calderón (2008) Urzúa (2009) Munizaga Marinovic Coloma Berg Hervé Richards Urzúa (2009) Hervé Mpodozis Hervé Marinovic Hervé Pankhurst Cornejo Marinovic (2007) Marinovic Cornejo Salazar U-Pb age Method LA-ICP-MS LA-ICP-MS SHRIMP ID-TIMS SHRIMP LA-ICP-MS SHRIMP ID-TIMS LA-ICP-MS ID-TIMS SHRIMP LA-ICP-MS Uncertain SHRIMP ID-TIMS SHRIMP ID-TIMS Uncertain ID-TIMS ID-TIMS ID-TIMS ID-TIMS ID-TIMS LA-ICP-MS 294±3 292±5 290±4 290±2 288±5 277±4 273±4 Ma±2σ 295.6±2.6 295.4±3.3 294.2±2.4 293.7±2.4 293.0±6.0 292.7±1.9 291.5±3.4 291.8±14.3 291.2±2.7 289.7±1.8 288.3±1.4 288.2±1.5 287.6±3.3 285.7±0.6 283.6±2.8 279.0±2.4 270.8±4.0 nde-biotite granodiorite Lithology Syenogranite Muscovite-biotite Granodiorite Rhyolitic Porphyry Foliated biotite-muscovite tonalite Foliated tonalite Monzogranite porphyry Granitic porphyry Foliated hornblende-biotite tonalite Biotite tonalite Syenogranite Hornble Rhyolitic porphyry Monzonite Biotite-muscovite granite Biotite granite Foliated hornblende-biotite tonalite Foliated biotite tonalite Quartz Monzodiorite porphyry Hornblende-biotite granodiorite Diorite Granite Muscovite-biotite granodiorite Diorite Tonalite Location WGS84) (Geodetic Longitude W 69°14’03.20” 70°17’50.35” 69°03’12.71” 69°10’48” 70°30’35.30” 69°02’57” 68°50’39.72” 69°12’19” 70°17’26.99” 70°37’00” 70°30’21” 69°04’25” 69°59’18.25” 70°24’39” 68°57’46.29” 70°22’59.9” 69°12’22” 69°02’57.31” 70°17’14.28” 69°01’29.79” 69°03’38.12” 69°10’12” 69°00’40.85” 70°04’37.73” Latitude S 25°05”30.67” 28°42’56.55” 24°11’59.70” 24°35’36” 30°56’53.40” 24°12’56” 21°01’53.71” 24°36’46” 28°41’39.54” 25°54’38” 29°51’42” 24°13’13” 24°18’45.22” 30°08’08” 22°39’38.95” 29°50’46.0” 24°38’45” 24°14’37.03” 28°51’57.58” 23°51’55.95” 23°51’38.64” 24°59’45” 23°53’29.88” 28°45’34.06” table 2 continued. Sample VAM-031 ST-72d QFP1 CAB-267A AM-25 ZERD958 CLL-73 CAB-301A ST-4d 7 FO 06 96 ZAL3 ESC-49 FO 06 98 LVN-293 FO 06 94 CAB-252A Unidentified CON-90-1 78009 MF-651 CAB-292A 78001 CT-160d Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 453 . (2008) . (2008) . 2008 (2013) . (2012) . (2012) . (2013) . (2013) . (2013) . (2013) . (1990) . (1999) . (1999) . (1999) . (2014) . (2014) . (2014) et al et al et al et al et al et al. et al et al et al et al et al et al et al et al et al et al et al Reference Damm Niemeyer (2013) Álvarez Niemeyer (2013) Salazar Niemeyer (2013) Salazar Hervé Niemeyer (2013) Thomas (1984) and Vergara Niemeyer (2013) Martin Munizaga Álvarez Coloma Hervé Masterman (2003) Munizaga Munizaga Hervé Martin Martin Álvarez Coloma U-Pb age Method ID-TIMS LA-ICP-MS LA-ICP-MS LA-ICP-MS LA-ICP-MS LA-ICP-MS LA-ICP-MS SHRIMP LA-ICP-MS ID-TIMS LA-ICP-MS ID-TIMS SHRIMP LA-ICP-MS LA-ICP-MS SHRIMP LA-ICP-MS SHRIMP SHRIMP SHRIMP ID-TIMS ID-TIMS LA-ICP-MS LA-ICP-MS Ma±2σ 268±5 245±12 267.3±2.5 266.1±3.5 266.1±3.5 257.0±1.9 256.0±2.0 255.3±4.0 255.2±1.8 254.2±2.3 252.5±2.8 252.0±2.8 249.7±3.2 248.7±3.3 247.7±3.4 247.0±3.1 245.0±2.3 244.8±2.5 243.2±2.1 242.6±2.2 242.5±1.5 242.0±1.5 241.7±3.0 240.3±1.7 Lithology Granodiorite Monzodiorite Foliated biotite granodiorite Monzodiorite Tonalite Diorite Felsic band of mylonite Clinopyroxene gabbro Feldspar porpyhry Granite Monzogranite Granitic porphyry Granitic porphyry Biotite granite Muscovite-biotite granodiorite Biotite leucogranite Granodiorite porphyry Dacitic porphyry Granitic porphyry Leucogranite Quartz Porphyry Dacite porphyry Biotite-hornblende tonalite Monzogranite 30.39” Location WGS84) (Geodetic Longitude W 68°23’49.96” 68°21’07.38” 70°10’11.99” 68°22’35.49” 70°14’ 68°26’10.46” 70°14’30.39” 70°04’31.9” 68°24’19.23” 68°42’00” 68°23’09.91” 70°00’26.90” 68°45’05.31” 70°10’12.87” 70°12’49.77” 70°14’51.7” 68°41’55.38” 68°36’54.02” 68°45’10.00” 70°10’05.8” 70°01’46.95” 70°02’03.51” 70°13’01.01” 70°08’25.83” 0” Latitude S 23°40’44.23” 23°45’30.52” 28°45’53.92” 23°41’10.18” 28°58’29.89” 23°43’15.47” 28°58’29.89” 30°05’37.2” 23°46’41.2 20°49’25” 23°41’56.42” 30°05’22.63” 20°50’49.68” 28°58’39.93” 28°59’06.54” 28°57’46.4” 20°58’38.69” 21°00’04.34” 20°50’22.34” 28°58’27.5” 29°19’20.66” 29°19’09.17” 28°59’26.23” 28°51’48.20” table 2 continued. Sample 84-19-01 CL2-HN11/07 JA01 CL4-HN09 CT-358d Di01-HN09 CT-358Bd FO 06 87 CL15-HN04 D-1 CHIN01-HN9 IM83-4 CLL-297 Ja-02 ST-16d FO10104B R200085 CLL-30 CLL-32 FO10100 IM-108.1 IM-113.1 Ja-94 ST-102d 454 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... . (2001) . (2001) . (2013) et al et al . (2014) . (2014) . (2014) et al et al et al et al Method and Blanco (2008) Tomlinson and Blanco (2008) Tomlinson and Blanco (2008) Tomlinson and Blanco (2008) Tomlinson and Baumann (1985) Berg Tomlinson Tomlinson Urzúa (2009) Hervé and Blanco (2008) Tomlinson Urzúa (2009) and Blanco (2008) Tomlinson and Baumann (1985) Berg Hervé Hervé Casquet Marinovic and García (1999) Marinovic and García (1999) U-Pb age Method LA-ICP-MS LA-ICP-MS SHRIMP SHRIMP ID-TIMS ID-TIMS ID-TIMS LA-ICP-MS SHRIMP LA-ICP-MS LA-ICP-MS LA-ICP-MS ID-TIMS SHRIMP SHRIMP SHRIMP ID-TIMS ID-TIMS Ma±2σ 230±8 227±3 224±5 223±4 217±12 208±2 237.6±1.4 233.6±1.5 233.1±2.2 231.4±2.0 229.0±2.0 227.2±2.0 225.9±1.8 222.0±4.9 215.8±1.2 215.6±1.9 206.1±1.0 205.9±0.5 Lithology Dacite dike Granodiorite Granodiorite Granodiorite Monzogranite Granodiorite Granodiorite Feldspar porphyry Porphyritic granite Granodiorite Feldspar porphyry Dacitic dike Monzogranite Biotite granite Cordierite-muscovite granodiorite Hornblende-biotite tonalite Dacitic porphyry Dacitic porphyry Location WGS84) (Geodetic 68°54’50” 68°54’50” 68°53’07” 68°53’07” 70°35’36” 68°52’10” 68°53’14” 69°01’35.05” 70°06’37.7” 68°54’50” 68°58’20.28” 68°54’50” 70°28’58” 70°26’11.4” 70°20’22.2” 70°30’54.5” 69°02’52” 69°05’50” Longitude W 22°22’40” 22°22’40” 22°16’02” 22°16’02” 26°13’05” 22°15’20” 22°17’13” 24°11’27.64” 29°58’05.8” 22°22’40” 24°16’20.88” 22°22’40” 26°20’28” 30°07’01.7” 29°52’39.5” 23°05’46.1” 23°24’09” 23°09’41” Latitude S table 2 continued. Sample Unidentified Unidentified Unidentified Unidentified I-21 QT-460 QT-459 ESC-51 FO 06 89 Unidentified ESC-52 Unidentified II-15 FO 06 97 FO 06 93 MEJ-18024 Unidentified Unidentified Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 455

The Choiyoi igneous province consists of volcano- of the Andes of northern Chile, modified according plutonic complexes (Kay et al., 1989; Llambías et to the new geochronological data. al., 1993; Llambías and Sato, 1995) that cover an The exposed Late Paleozoic to Mid-Triassic estimated area of ~500,000 km2, which extends for volcanic succession along the Andes in northern about 2,500 km, from the Collahuasi area in north- Chile has uneven thickness, visible successions ern Chile (20°30’S) to Neuquén and the northern typically range between 750 and 2,600 m, but Patagonian Andes of southern Argentina (44°S; exceeding 3,200 m in the Collahuasi area of the Jordan et al., 1983; Mpodozis and Ramos, 1989; Precordillera (21°S latitude; Vergara and Thomas, Ramos and Folguera, 2009; Ramos, 2009). Besides, 1984). These successions are mostly formed of it is also correlated with the Mitu Group (Carlier felsic volcanic rocks that include extensive rhyo- et al., 1982) and the Yura Group of southern Perú litic and dacitic ash flow tuffs (ignimbrites), and (Sempere et al., 2002; Boekhout et al., 2013), and banded rhyolite and dacitic domes and lava-flows. geological and geochronological data from magmatic A lesser proportion is composed of basaltic and and migmatitic rocks of the Northern Andes have andesitic lavas, and pyroclastic deposits of the shown that the Late Paleozoic to Triassic magmatism same petrographic composition. Sedimentary was also extensively recorded from northern Perú intercalations of volcanic sandstones, minor con- to the Central Cordillera of the Colombian Andes glomerates, and local limestones (i.e., Collahuasi (Restrepo et al., 1991; Noble et al., 1997; Ordóñez area; Vergara and Thomas, 1984), are also locally and Pimentel, 2002; Vinasco et al., 2006; Chew et present. The volcanic successions unconformably al., 2007; Ibáñez-Mejía et al., 2008; Cardona et al., overlie Devonian to Early Carboniferous shallow- 2008, 2009). marine, sedimentary successions, but its base is The main outcrops of Late Paleozoic to Early only locally exposed (Mercado, 1982; Niemeyer Jurassic igneous rocks in northern Chile are ex- et al., 1985, 1997; Mpodozis and Cornejo, 1988; posed in a semi-continuous belt from about 21°S to Nasi et al., 1990; Marinovic et al., 1995). In addi- 31°S latitudes. These rocks are prominent along the tion, calcareous and terrigenous, shallow-marine Domeyko Cordillera (24° to 27°S) and its northern sedimentary successions, containing Early Per- extension, the so called Chilean Precordillera (20° mian fossils are exposed in the western foothills to 24°S), but also along the High Andes from 27° of the High Andes and in the Central Depression. to 31°S, which are commonly referred as Chilean These sedimentary units represent Early Permian Frontal Cordillera. Late Carboniferous and Triassic carbonate sedimentation within a shallow-marine granitic plutons are also scattered from 21°S latitude platform, but some of them are either overlying or southwards along the Coastal Cordillera and then interstratified with rhyolitic rocks (Sepúlveda and forming an almost continuous intrusive belt between Naranjo, 1982; Marinovic et al., 1995; Iriarte et al., 33° to 38°S (e.g., Deckart et al., 2014). 1996; Cortés, 2000; Díaz-Martínez et al., 2000). The isolation of outcrops, fault-bounded blocks, Middle to Late Triassic successions are sedimen- volcanic deposits of similar petrographic composi- tary-volcanic in nature and are separated from older tions, lack of accurate geochronological data, and rocks by unconformities. A bimodal suite composed the absence of guide horizons, have made difficult of basalts and rhyolites, locally with pillow lavas, to know the exact stratigraphic-structural relation- and associated rhyolitic and dacitic sills, domes ships between separate exposures. Thus, a number and ash-flow deposits occur within the Mid-Late of lithostratigraphic units were assigned by differ- Triassic to Early Jurassic successions (Naranjo and ent authors to specific time-spans and correlated Puig, 1984; Suárez and Bell, 1992; Tomlinson et al., with other exposures, which at times proved to be 1999; Cornejo and Mpodozis, 1996, 1997; Cornejo incorrect as geochronological data become avail- et al., 2009). The Late Triassic to Early Jurassic able. This is reflected by a profuse stratigraphic magmatism is fairly common, but it has been poorly nomenclature used in previous studies to refer to investigated (e.g., Franz et al., 2006), and has not Late Paleozoic to Early Mesozoic successions of always been recognized as a distinct unit from older the Andes of northern Chile (e.g., Charrier et al., Carboniferous-Triassic rocks. 2007); for unambiguousness figures 1 and 2 illustrate Carboniferous to Triassic granitic, granodioritic, preliminary stratigraphic schemes for two segments and tonalitic batholiths and lesser dioritic or gabbroic 456 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

W Coastal Intermediate Domeyko E Cordillera Depression Cordillera High Andes Early Jurassic Sama Fm. Quetena Beds-Cos. to Riolitas de Sierra Chuquicamata volc. Miranda-Cerro Las Lomas Beds Late Triassic strata Camaleón Co. Minado Beds assigned to the Co. Guanaco Beds Agua Dulce Fm. Late Triassic Cifuncho Fm. Co. La Ballena Fm. Pular Fm. Profeta Fm. Qda. del Salitre Fm. Tuina Fm. Middle Triassic El Bordo Beds Cerros Negros Fm. Early Triassic Sierra de Varas Fm. Peine Group Permian Early Permian Juan de Morales Fm. Collahuasi Fm. Cerros de Quipisca Fm. Agua Dulce Fm. to Cuevitas Fm. Early Cerro El Árbol Fm. Riolitas de Sierra Carboniferous del Jardín La Tabla Fm.

Early El Toco Fm. Carboniferous Sierra del Tigre Fm. to Devonian Las Tórtolas Fm.

FIG. 1. Late Paleozoic to Early Jurassic stratigraphic units of northern Chile from 20° to 26°S, ordered according to the new geochronological data. The different units are ordered geographically from western (left) to eastern exposures (right) and face each other according to their approximate latitude of occurrence. The reader is referred to the work of Charrier et al. (2007 and references therein) for the units that are not mentioned in text.

W Coastal Intermediate High Andes E Cordillera Depression Early Jurassic Cifuncho Fm. Pan De Azúcar Fm. to Agua Chica Fm. Late Triassic Canto del Agua Fm. La Ternera Fm. La Ternera Fm. La Totora Fm. San Félix Fm. Los Tilos Seq. Middle Triassic Las Breas Fm. Early Triassic La Tabla Fm. Pantanoso Fm. Permian Guanaco Sonso Seq. Matahuaico Fm. San Rafael Orogenic Phase Cerro 2484 Beds La Coipa Beds Early Permian La Corvina Beds Las Represas Beds El Mono Beds to Huentelauquén Fm. Early Carboniferous Paipote valley Elba Beds Rhyolites Cerro Bayo Beds Las Placetas Fm. Early Carboniferous Las Tórtolas Fm. Chinches Fm. to Devonian Chañaral Complex Hurtado Fm.

FIG. 2. Late Paleozoic to Early Jurassic stratigraphic units of northern Chile from 26° to 31°S, ordered according to the new geochronological data. The different units are ordered geographically from western (left) to eastern exposures (right) and face each other according to their approximate latitude of occurrence. The reader is referred to the work of Charrier et al. (2007 and references therein) for the units that are not mentioned in text. Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 457 plutons were emplaced in different segments along compositions with subduction-related affinity, and the Precordillera (21°-24°S), Domeyko Cordillera concluded that they were part of the same magmatic (24°-27°S) and an extensive sector of the Chilean arc split during Mesozoic extension. Frontal Cordillera between 28° and 31°S (Figs. 3 The Middle to Late Triassic igneous rocks show and 4) is formed of granitic rocks of Late Paleozoic a distinct bimodal composition with a within plate to Triassic age (Parada et al., 1981, 2007; Nasi et al., tendency, consistent with an origin in an extensional, 1985; Mpodozis and Kay, 1990, 1992; Mpodozis et rift-related setting (Vergara et al., 1991; Parada et al., 1993; Cornejo et al., 1998; Tomlinson et al., 1999; al., 1991; Morata et al., 2000; Vásquez et al., 2011; Tomlinson et al., 2001; Tomlinson and Blanco, 2008; Parada, 2013). Hervé et al., 2014). Scattered Late Carboniferous and Triassic granitic plutons also extend from 21°S 3. Previous U-Pb geochronological data latitude southwards along the Coastal Cordillera, and then forming an almost continuous intrusive belt U-Pb geochronological data for Late Paleozoic to between 33° to 38°S (Berg et al., 1983; Shibata et Early Mesozoic rocks compiled from previous studies al., 1984; Maksaev and Marinovic, 1980; Skarmeta are presented in Tables 1 and 2 and figures 3 and 4. and Marinovic, 1981; Berg and Baumann, 1985; The oldest zircon U-Pb ages compiled for volca- Mpodozis and Kay, 1992; Parada et al., 2007; nic rocks range from 309.9±2.2 to 273.5±11.0 Ma Deckart et al., 2014). Some of the Carboniferous (Table 1; Fig. 3); these rocks are exposed from and Early Permian plutons show foliation with 20°30’ to 25°30’S in a ~50 km wide, longitudinal preferred orientation of their tabular minerals, and belt along ~69°W longitude along the Precordillera local bands of mylonites with high-temperature, and the Domeyko Cordillera (Fig. 3), and according ductile, shearing deformation (Nasi et al., 1985; to the U-Pb data represent a Late Carboniferous to Ribba et al., 1988; Marinovic et al., 1995; Murillo Early Permian, felsic volcanism and subordinate et al., 2012; Hervé et al., 2014). Close associations of intermediate and basic volcanic rocks, and minor granitic plutons and ignimbrites in the Andes have sedimentary intercalations (Collahuasi, Agua Dulce been interpreted as large relict calderas (Davidson et and La Tabla Formations, and the Sierra del Jardín al., 1985; Breitkreuz, 1995; Tomlinson et al., 2001). Rhyolites; Vergara and Thomas, 1984; Mpodozis et In addition, a belt of porphyry copper prospects and al., 1993; Marinovic and García, 1999; Masterman, hydrothermal alteration zones are associated with 2003; Cornejo et al., 2006; Marinovic, 2007; Munizaga the Permian and Triassic intrusions in Chile and et al., 2008; Tomlinson and Blanco, 2008; Urzúa, Argentina (Sillitoe, 1977; Camus, 2003; Cornejo et 2009; Jara et al., 2009; Hervé et al., 2012). The Late al., 2006; Tomlinson and Blanco, 2008). Carboniferous to Early Permian volcanism is less The Carboniferous to Mid-Triassic igneous known southward of 25°30’S, but a U-Pb zircon age rocks constitute a calc-alkaline to potassium-rich of 300.8±4.6 Ma has been reported by Salazar et al. calc-alkaline suite, are metaluminous to peralumi- (2013) for rhyolites outcropping in the El Tránsito nous in composition, and have overall geochemical river valley in the High Andes, 65 km west of the characteristics consistent with subduction-related, divide (28°46’S; Fig. 4). magmatic arc origin, but with evolution into exten- Rhyolitic volcanic rocks exposed along the sional magmatism and significant involvement of Domeyko Cordillera and Frontal Cordillera south crustal melts, evidencing significant crustal recycling of 25°30’S latitude have yielded U-Pb ages of (Nasi et al., 1985; Kay et al., 1989; Breitkreuz et 262.9±2.0 and 265.0±5.6 Ma (Table 1; Fig. 4), thus al., 1989; Mpodozis and Kay, 1990, 1992; Mpodozis essentially representing a Mid-Permian felsic vol- et al., 1993; Breitkreuz and Zeil, 1994; Marinovic canism, which has been previously ascribed to the et al., 1995; Lucassen et al., 1999; Llambías et al., to the Permian-Triassic (Martin et al., 1999) or to 2003; Parada et al., 2007; Urzúa, 2009; Vásquez et the Carboniferous-Permian (Cornejo et al., 2009). al., 2011; Parada, 2013). Brown (1990) compared A U-Pb zircon U-Pb age of 248±3 Ma, resulting the major and trace elements geochemistry of the from combining analyses of four separate samples, Permian to Middle Triassic Coastal granitic plutons was reported by Breitkreuz and van Schmus (1996) at latitude 26°S with those exposed some 120 km for felsic volcanic rocks of the Peine Group, exposed to the east in the High Andes, showing their similar in on the eastern border of the Salar de Atacama salt 458 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

70°W 69°W 68°W 20°S 20°S Quipisca Fm. Iquique

308.5±2.2 248.7±3.3 304.6±3.2 243.2±2.1 303.9±3.0 298.3±2.1 252.5±2.8 293±14 245±12 296.9±4.3 Collahuasi Fm. 244.8±2.5 21°S 303.2±2.0 21°S 298.8±2.2 292.7±1.9

Coastal Cordillera 307.9±2.8 297.6±2.4 Intermediate Depression

P a c i f i c O c e a n 302.4±0.8 303.8±0.7 B o l i v i a 229.0±2.0 227.2±2.0 22°S 273.5±11.0 22°S 231.6±0.5 Tocopilla 233.1±2.2 279±9 231.4±2.0 235.4±1.6 297.6±2.4 234.5±3.2 300.3±1.8 Chuquicamata 231.4±2.0 303.9±0.2 233.6±1.5 Calama 224±5 299.3±1.7 Limon Verde 298.0±1.5 222.0±4.9 288.3±1.4 Tuina Fm. 303±5

23°S 233±12 23°S 240.8±0.3 220±19 El Bordo Beds 238.7±0.4 205.9±0.5 Pampa Salar 320.1±9.0 Elvira 206.1±1.0 de 248±3 310.1±4.8 194.0±9.2 283.6±2.8 296.8±0.2 Atacama 255.9±6.2 268±5 Antofagasta Peine Group 292±5 273±4 Cerros 292±5 Cas & Peine Fm. Sierra de Lila Mariposas 227±3 242.7±5.8 24°S 279.0±2.4 294.2±2.4 298.9±2.6 293.0±6.0 24°S 298.2±5.5 294.4±4.6 290±4 287.1±4.4 La Escondida 284±4 300.1±3.5 288.0±2.4 296.8±3.2 288.8±2.4 296.6±4.4 290±2 287.6±3.3 La Tabla Fm. 287±3 294±3 286±2 292±5 282±2 Coastal Cordillera 288±5 223±4 277±4 293±4 25°S 259.0±3.4 299.4±2.5 25°S 295.6±2.6 328.3±3.4 309.9±2.2 SOUTH 294.6±2.1 296.3±2.9 AMERICA 323.9±2.6 262.9±2.0

Quebrada

Intermediate Depression del 232.9±0.2 Salitre Fm. Area of Figure Domeyko Cordillera 291.8±14.3 A r g e n t i n a 26°S 26°S 70°W 69°W 68°W Mid-Late Triassic 0 50 100 km Volcano-sedimentary rocks Triassic Granitoids Mid-Permian to Early Triassic Volcanic rocks Late Carboniferous to Permian Late Carboniferous to Early Permian Granitoids Volcanic rocks

FIG. 3. Map showing the distribution of the Late Paleozoic to Late Triassic rocks of northern Chile between latitudes 20° and 26°S and location of U-Pb zircon ages (Ma±2σ). New SHRIMP U-Pb ages in bold; previous U-Pb dates compiled from previous works in italics (references in Tables 1 and 2). Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 459

71°W 70°W 69°W 26°S 26°S 280.6±4.2 230±8 Sierra Castillo 269.5±4.0 Pan de 287.0±4.2 batholith 276.6±3.6 Azúcar 276.6±4.0 217±12 285.3±6.4 273.9±6.6 272.6±6.8 246.5±4.0 Cerros 264.6±7.0 del 282.0±11.4 270.4±4.6 237.0±4.0 Vetado Pedernales 264.9±7.0 batholith 262.0±2.8 Caballo 263.5±3.4 267.9±3.8 Muerto Coastal Cordillera

Intermediate Depression El Mono 27°S Beds 27°S 296.6±4.2 El Hielo Paipote valley batholith Pantanoso Fm. 292.2±4.2 291.5±4.0 Copiapó 270.3±4.2 La Ternera F. 269.9±4.0 266.1±4.4

28°S 28°S

Atacama Region Montosa-El Potro 295.4±3.3 batholith 291.5±3.4 222.8±2.1 La Totora Fm. 221.0±2.6 300.8±4.6 P a c i f i c O c e a n 258.9±5.0 Vallenar 249.7±3.8 324.7±4.0 217.9±1.4 323.1±5.8 El Tránsito 240.3±1.7 A r g e n t i n a valley 285.7±0.6 296.1±4.8 242.6±2.2 29°S 29°S 315.7±4.6 San Félix Fm. Chollay 244.0±2.8 307.1±4.8 batholith 286.3±6.2 247.0±3.1 154.3±3.8 242.5±1.5 311.9±6.0 265.0±5.6 229.6±5.2 232.1±4.6 215.6±1.9 288.2±1.5 221.6±3.4 219.5±1.7 Los Tilos Sequence. 224.0±3.4 291.2±2.7 La Serena Elqui-Limarí 225.9±1.8 255.2±1.8 30°S batholith 30°S 249.7±3.2 215.8±1.2 289.7±1.8 Guanaco Sonso Sequence SOUTH AMERICA

328.1±2.8

Area of Figure

Coastal Cordillera 293.7±2.4 31°S 31°S 71°W 70°W 69°W Mid-Late Triassic 0 50 100 km Volcano-sedimentary rocks Mid-Permian to Early Triassic Triassic Granitoids Volcanic rocks Late Carboniferous to Early Permian Late Carboniferous to Permian Volcanic rocks Granitoids

FIG. 4. Map showing the distribution of the Late Paleozoic to Late Triassic rocks of northern Chile between latitudes 26° and 31°S and location of U-Pb zircon ages (Ma±2σ). New SHRIMP U-Pb ages in bold; previous U-Pb dates compiled from previous works in italics (references in Tables 1 and 2). 460 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... flat at about 23°30’S (Fig. 3). Thus, these eastern- included crushing, washing, and heavy liquid and most outcrops of northern Chile represent an Early magnetic separation. Hand-picked zircon grains were to Middle Triassic volcanism, which originally was mounted in epoxy, together with chips of the Temora assigned to the Late Permian by Breitkreuz and van reference zircons, sectioned approximately in one half, Schmus (1996), as befitted to the geologic time and polished in Brazil. Cathodoluminescence (CL) scale in that year. Scanning Electron Microscope (SEM) images were Middle Triassic to Early Jurassic volcanism has prepared for all zircons. The CL images were used yielded U-Pb dates from 249.7±3.8 to 194.0±9.2 Ma to decipher the internal structures of the sectioned (Table 1). During this time span andesitic to basaltic grains and to ensure that the ~20 μm SHRIMP spot volcanism coexisted with rhyolitic volcanism (bimodal was wholly within a single age component within volcanism), and was synchronous with rift-related, the sectioned grains. Uranium-Th-Pb analyses were continental and/or marine sedimentary deposits made using a sensitive high resolution ion microprobe widely distributed in northern Chile (Naranjo and (SHRIMP II) for determining the respective zircon Puig, 1984; Charrier, 1979; Suaárez and Bell, 1992; Concordia U-Pb ages following procedures given in Martin et al., 1999; Tomlinson et al., 1999; Cornejo Williams (1998, and references therein). Each analy- and Mpodozis, 1996, 1997; Cornejo et al., 2009). sis consisted of six scans through the mass range, The zircon U-Pb ages for intrusive rocks exposed with a Temora U-Pb reference grain analyzed for along the High Andes and Domeyko Cordillera every three unknown analyses. The data have been range from 328.1±2.8 to 205.9±0.5 Ma (Table 2), reduced using the SQUID Excel Macro of Ludwig overlapping with the corresponding interval of (2001); U-Pb ratios have been normalized relative U-Pb dates of volcanic rocks (ca. 310 to 194 Ma; to a value of 0.0668 for the Temora reference zircon, Table 1). The intrusions include coarse-grained equivalent to an age of 417 Ma (Black et al., 2003). granitoids and porphyritic felsic plutons; the late Uncertainties given for individual analyses (ratios are closely related to the volcanic rocks. Foliated and ages) are at the one-sigma level (Appendix 2). plutons (ductile deformation) show U-Pb ages in Tera and Wasserburg (1972) concordia plots, and the range 328 to 288 Ma (Table 2). mean U-Pb age calculations were carried out using There are scarce and inaccurate previous U-Pb ISOPLOT/EX (Ludwig, 2003). The data tabulations dates for granitic plutons scattered along the Coastal for all 43 samples are presented in Appendix 1 and 2. Cordillera of northern Chile from 21° to 31°S, which range from 291.8±14.3 to 217±12 Ma (Berg et al., 5. Results 1983; Berg and Baumann, 1985). Yet, a number of whole rock Rb-Sr dates that range from 296±5.4 to The new SHRIMP U-Pb zircon concordia ages 222±3 Ma have been published (Berg et al., 1983; are summarized in Tables 3 and 4 for volcanic and Shibata et al., 1984; Berg and Baumann, 1985), and intrusive rocks, respectively and sample locations are biotite K-Ar dates of 318±6 and 322±5 Ma (Maksaev shown in figures 3 and 4; Tera-Wasserburg concor- and Marinovic, 1980; Skarmeta and Marinovic, 1981). dia plots and SHRIMP zircon U-Pb analytical data Besides, eight U-Pb ages ranging from 319.6±2.4 to are included in the Appendix 1 and 2, respectively. 308.9±2.4 Ma have been recently obtained for the granitoids that are exposed from 33° to 38°S along 5.1. Volcanic rocks the Coastal Cordillera of central-southern Chile (Deckart et al., 2014). The new zircon U-Pb ages for volcanic rocks range from 324.7±4.0 to 221.0±2.6 Ma (Table 3), which is 4. Analytical methods consistent with the ca. 310 to 194 Ma interval showed by the compiled U-Pb dates (Table 1). Nevertheless, SHRIMP II U-Pb analyses of zircon grains were we obtained some of the oldest age determinations carried out at the Geochronological Research Center for Late Paleozoic volcanic rocks in Chile to date, (Centro de Pesquisas Geocronológicas) of the Sao particularly for volcanic deposits exposed in the Paulo University, Brazil. Zircon grains were obtained current Intermediate Depression and the western from rock samples following normal mineral sepa- foothills of the High Andes. These include U-Pb ages ration procedures in Universidad de Chile, which of 324.7±4.0 and 323.1±5.8 for rhyolites outcropping Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 461

TABLE 3. SUMMARY OF NEW SHRIMP ZIRCON U-Pb CONCORDIA AGES FOR VOLCANIC ROCKS.

Location (Geodetic-WGS 84) U-Pb age Sample Lithology Unit Latitude S Longitude W Ma±2σ

CHY-50 28°46’19.39” 70°26’15.80” Rhyolite 324.7±4.0 Cerro Bayo Beds CHY-11 28°46’38.77” 70°25’49.51” Rhyolite 323.1±5.8 Cerro Bayo Beds FO-11-35 23°38’04.96” 69°30’27.27” Rhyolitic ignimbrite 320.1±9.0 Cerro del Árbol Fm. CHY-29 27°06’58.71” 69°44’28.75” Rhyolite 296.6±4.2 Paipote valley CHY-31 27°06’50.51” 69°43’59.49” Rhyolite 292.2±4.2 Paipote valley CHY-33 27°03’15.21” 69°17’42.15” Andesitic tuff 291.5±4.0 El Mono Beds CHY-14 26°28’49.60” 69°19’04.29” Rhyolitic tuff 282.0±11.4 La Tabla Formation *311.3±8.2 CHY-18 26°25’11.76” 69°16’56.65” Rhyolitic tuff 276.6±4.0 La Tabla Formation CHY-17 26°26’05.81” 69°16’58.77” Rhyolitic tuff 273.9±6.6 La Tabla Formation CHY-15 26°28’42.56” 69°19’12.39” Rhyolitic tuff 272.6±6.8 La Tabla Formation CHY-22 26°28’41.13” 69°18’13.19” Banded rhyolite 270.4±4.6 La Tabla Formation CHY-25 27°09’37.98” 69°18’42.56” Dacite 270.3±4.2 Pantanoso Formation CHY-27 27°10’24.48” 69°18’31.21” Dacitic tuff 269.9±4.0 Pantanoso Formation CHY-26 27°09’49.87” 69°18’30.97” Rhyolitic ignimbrite 266.1±4.4 Pantanoso Formation CHY-36 26°49’46.33” 69°10’06.58” Fluidal rhyolite 262.0±2.8 La Tabla Formation FO-11-27 23°40’23.32” 68°01’07.42” Rhyolitic ignimbrite 255.9±6.2 Cas Formation CHY-56 28°42’30.38” 70°12’34.79” Basaltic tuff 249.7±3.8 La Totora Formation *323.6±5.8 FO-11-26 23°39’59.19” 67°59’50.29” Rhyolite 242.7±5.8 Cas Formation CHY-10 29°24’57.58” 70°13’13.05” Banded Rhyolite 232.1±4.6 Los Tilos Sequence CHY-01 29°25’00.02” 70°13”01.99” Banded rhyolite 224.0±3.4 Los Tilos Sequence CHY-02 29°24’50.60” 70°13’01.87” Rhyolitic tuff 221.6±3.4 Los Tilos Sequence CHY-57 28°39’14.52” 70°10’37.43” Basalt 221.0±2.6 La Totora Formation CHY-08 29°17’38.46” 70°21’41.86” Andesite 154.3±3.8 Lagunillas Formation

* Samples CHY-14 and CHY-56 are tuffs that returned bimodal age distributions; the older population of U-Pb ages correspond to inherited older zircon cores as seen in the cathode luminescence images. in the El Tránsito river valley (at 28°46’S; Fig. 4), part of a rhyolitic volcanic succession that underlies which were previously mapped as the Permian to and is partly interfingered with carbonate strata that Triassic Pastos Blancos Formation (Moscoso et al., contains Early Permian marine fossils in its upper 2010), but were recognized as an older separate unit section (Cerro del Árbol Formation; Marinovic et named Cerro Bayo Formation by Salazar et al. (2013). al., 1995; Marinovic, 2007). In addition, U-Pb ages Besides, a U-Pb age of 320.1±9.0 Ma was obtained of 296.6±4.2 and 292.2±4.2 Ma were obtained for for an ignimbrite outcropping in the Intermediate rhyolites that are part of a succession exposed in the Depression of the Antofagasta Region, which is Paipote valley which was assigned to the Pantanoso 462 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

TABLE 4. SUMMARY OF NEW SHRIMP ZIRCON U-Pb CONCORDIA AGES FOR INTRUSIVE ROCKS.

Location (Geodetic-WGS 84) U-Pb age Sample Lithology Unit Latitude S Longitude W Ma±2σ

CHY-05 29°08’19.52” 70°22’41.82” Biotite monzogranite 315.7±4.6 Guachicay pluton

CHY-09 29°20’25.47” 70°19’14.69” Biotite syenogranite 311.9±6.0 Guanta pluton

CHY-06 29°09’16.19” 70°21’31.11” Biotite-hornblende tonalite 307.1±4.8 Guanta pluton

CHY-24 26°22’07.72” 69°16’37.94” Hornblende-biotite quartz 287.0±4.2 Pedernales batholith monzodiorite CHY-07 29°10’10.89” 70°20’59.70” Muscovite-biotite 286.3±6.2 Burro Muerto pluton monzogranite CHY-19a 26°23’34.30” 69°29’24.72” Foliated biotite-hornblende 285.3±6.4 Sierra Castillo tonalite batholith CHY-23 26°20’58.88” 69°15’42.50” Biotite monzogranite 280.6±4.2 Pedernales batholith

CHY-48 26°16’27.71” 70°39’22.80” Muscovite-biotite 276.6±3.6 Pan de Azúcar pluton monzogranite CHY-47 26°07’21.74” 70°31’53.93” Muscovite leucogranite 269.5±4.0 Pan de Azúcar pluton

CHY-35 27°08’21.17” 69°22’05.53” Biotite monzogranite 267.9±3.8 El Hielo batholith

CHY-12 26°28’53.10” 69°19’25.75” Biotite-hornblende 264.9±7.0 Pedernales batholith monzogranite CHY-16 26°28’19.36” 69°17’50.67” Andesitic dike 264.6±7.0 Dike in La Tabla Fm.

CHY-38 26°50’46.18” 69°08’50.32” Biotite monzogranite 263.5±3.4 Caballo Muerto Pluton CHY-58 28°39’59.13” 70°10’55.94” Biotite-bearing mylonitized 258.9±5.0 Quebrada Pintado tonalite tonalite CHY-46 26°18’22.54” 70°27’05.87” Biotite-muscovite 246.5±4.0 Cerros del Vetado leucogranite Pluton CHY-60 28°58’18.69” 70°09’44.14” Biotite monzogranite 244.0±2.8 Chollay batholith

CHY-45 26°22’41.05” 70°27’36.16” Biotite monzogranite 237.0±4.0 Cerros del Vetado pluton CHY-03 29°24’29.70” 70°14’24.51” Syenogranite 229.6±5.2 La Coneja pluton; Colorado unit

Formation (Sepúlveda and Naranjo, 1982; Iriarte et fault (Quebrada de Las Represas Beds; Mpodozis al., 1996) and unconformably underlies Late Trias- and Allmendinger, 1993; Iriarte et al., 1996). sic conglomerates of La Ternera Formation in the In the High Andes a U-Pb age of 291.5±4.0 Ma Atacama Region (Fig. 4). The same rhyolitic unit was obtained for an andesitic tuff intercalated in the underlies limestone beds with Early Permian marine upper section of El Mono Beds (sensu Mercado, fossils in the region, though the contact between 1982; Mpodozis et al., 2012), which is a mostly them has been interpreted as a low-angle, normal alluvial and lacustrine sedimentary succession, Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 463 ca. 1,000 m thick, formed of sandstone and conglom- A U-Pb age of 270.3±4.2 Ma was obtained for erate strata that unconformably overlie Devonian a basal dacite horizon and additional U-Pb ages to Early Carboniferous sandstones of the Chinches of 269.9±4.0 and 266.1±4.4 Ma were obtained for Formation in the High Andes at ~27°S (Fig. 4) and dacitic tuff and rhyolitic ignimbrite of the Pantanoso underlies in apparent conformity Jurassic marine Formation (Mercado, 1982; Mpodozis et al., 2012), strata (Mercado, 1982; Mpodozis et al., 2012). This at its type locality (Table 3; Fig. 4). The Pantanoso sedimentary-volcanic succession was previously Formation is crosscut by granite of the El Hielo attributed to the Late Triassic based on fossil flora batholith that yielded a U-Pb age of 267.9±3.8 Ma and conchostracans (Davidson et al., 1978; Mer- (Table 4). The Pantanoso Formation is a 1,000 thick cado, 1982; Suárez and Bell, 1991; Blanco, 1994; succession of rhyolitic and dacitic volcanic rocks Cornejo et al., 1998; Gallego and Covacevich, 1998; and minor conglomerate and volcanic sandstone Mpodozis et al., 2012). intercalations exposed in the High Andes at 27°28’S U-Pb dates ranging from 282.0±11.4 to latitude, and according to the new U-Pb data it rep- 270.4±4.6 Ma were obtained for 4 samples of resent Mid-Permian volcanism. It unconformably banded rhyolites and rhyolitic tuff from the type overlies mainly Devonian to Early Carboniferous locality of La Tabla Formation, (sensu García, sandstones of the Chinches Formation (Mercado, 1967), in the eastern part of the Domeyko Cor- 1982; Bell, 1985), but also a local lens of folded dillera and southwest of the Pedernales Salar sandstone and conglomerate beds up to 200 m in the Atacama Region (26°30’S; Fig. 4). One thick of the Elba Beds, which were ascribed to the sample (CHY-14; Table 3) returned a bimodal Carboniferous-Permian by Mercado (1982). age distribution with an older population at U-Pb zircon ages of 255.9±6.2 and 242.7±5.8 Ma 311.3±8.2 Ma and a younger one at 282.0±11.4; (Table 3) were obtained for samples of ignimbrite the analytic spots on the cathode luminescence and rhyolite from the Cas Formation (sensu Ramírez images of the zircons indicate that the older and Gardeweg, 1982), which is a succession of about age population corresponds to inherited zircon 300 m thick (without exposed base), outcropping cores, while the younger ages to zircon rims, immediately east of the Peine town, in the eastern thus the younger population corresponding to part of the Antofagasta Region (Fig. 3). The new the actual crystallization age of the dated rock. U-Pb ages are consistent with the mean weighted The La Tabla Formation is an 800 m thick succes- U-Pb age of 248±3 based on 4 separate determi- sion formed of rhyolites, rhyolitic tuffs, breccias, nations published by Breitkreuz and van Schmus and basaltic intercalations (without exposed base) (1996) and indicate that the rhyolitic rocks of the which originally was thought to be Early Triassic Cas Formation represent a Late Permian to Early in age (García, 1967), but later assigned to the Triassic felsic volcanism. Late Paleozoic by Tomlinson et al. (1999), based A sample of basaltic tuff from the basal meters on K-Ar ages of intrusions that crosscut the unit. of the mostly basaltic-andesitic La Totora Formation The volcanic rocks of La Tabla Formation are in the homonymous creek in the High Andes of crosscut by granitoids of the Pedernales Batholith the Vallenar region (28º42’; Fig. 4) yielded a U-Pb and andesitic dikes that yielded U-Pb ages from age of 249.7±3.8 Ma. The dated sample (CHY-56) 287.0±4.2 to 264.6±7.0 Ma (Table 4). According to actually returned a bimodal age distribution with an the new U-Pb dates it represent Permian volcanism, older population at 323.6±5.8 Ma; the analytic spots which is a bit younger but overlapping with the on the cathode luminescence images of the zircons U-Pb ages from 309.9±2.2 to 282±2 Ma published indicate that the older age population corresponds for rocks assigned to the La Tabla Formation along to inherited zircon cores, while the younger ages to the Domeyko Cordillera north of 25°30’S latitude zircon rims, thus the younger population corresponding (Table 1). In addition, a U-Pb age of 262.0±2.8 was to the actual crystallization age of the dated rock. obtained for a sample of fluidal rhyolite farther south Another sample of basalt of the same succession in the (26°49’S; Table 3), mapped as La Tabla Formation Totora creek yielded an U-Pb age of 221.0±2.6 Ma; by Cornejo et al. (1998) that is part of a succession these ages are coherent with the U-Pb ages from crosscut by granite of the Caballo Muerto Pluton, 217.9±1.4 to 210.4±2.9 Ma published by Salazar which yielded a U-Pb age of 263.5±3.4 Ma (Table 4). et al. (2013) for the same formation. This volcanic 464 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... unit unconformably overlies a mylonitized tonalite include: a U-Pb age of 285.3±6.4 Ma for a foliated of the Quebrada Pintado intrusive unit (sensu Salazar tonalite that is part of the Sierra Castillo batholith et al., 2013) for which we obtained a U-Pb age of (sensu Tomlinson et al., 1999; Fig. 4); a U-Pb age of 258.9±5.0 Ma (Table 4), and conformably underlies 287.0±4.2 Ma for a hornblende-biotite monzodiorite fossiliferous, Mid-Late Jurassic (Sinemurian) marine and U-Pb ages of 280.6±4.2, and 264.9±7.0 Ma limestones (Reutter, 1974; Nasi et al., 1990; Salazar for biotite-hornblende, monzogranite plutons of the et al., 2013); stratigraphic position that is consistent Pedernales batholiths (sensu Tomlinson et al., 1999; with the new U-Pb data. In addition, strata of the Fig. 4); a U-Pb age of 263.5±3.4 Ma for monzogranite western belt of La Totora Formation are in part of the Caballo Muerto pluton (sensu Cornejo et al., conformably overlying the 4,000 m thick, mostly 1998); and a U-Pb age of 267.9±3.8 Ma for leuco- clastic-sedimentary Mid-Late Triassic San Felix cratic, monzogranite of the El Hielo batholith (sensu Formation to the southwest (Salazar et al., 2013). Mercado, 1982; Bell, 1985; Mpodozis et al., 2012) U-Pb ages of 232.1±4.6, 224.0±3.4, and 221.6±3.4 in the High Andes of the Atacama Region (Fig. 4). were obtained for samples of banded rhyolites and A U-Pb age of 244.0±2.8 Ma was obtained for a rhyolitic tuffs from the Los Tilos sequence of the coarse-grained monzogranite of the Chollay Batholith Pastos Blancos Group (sensu Martin et al., 1999), (Fig. 4), which is consistent with U-Pb ages from exposed in the Potrerillos river valley in the High 247.7±3.4 to 240.3±1.7 Ma that have recently been Andes, 20 km west of the divide (29°30’S; Fig. 4); reported for the same batholith (Coloma et al., 2012; this new U-Pb data confirms the Late Triassic age of Salazar et al., 2013; Álvarez et al., 2013; Hervé et the Los Tilos volcanic sequence of the Pastos Blancos al., 2014). These U-Pb ages confirm the Mid-Triassic Group, which unconformably overlies the Permian age ascribed to the granitic Chollay batholith by Nasi silicic volcanics of the Guanaco Sonso sequence as et al. (1985) and Martin et al. (1999). defined by Martin et al. (1999). The dating of plutons of the northern part of the A U-Pb age of 154.3±3.8 Ma was obtained for composite Elqui-Limarí Batholith in the Frontal andesite that is part of a succession outcropping in the Cordillera of the Atacama Region (Fig. 4) have yield west flank of the El Carmen river valley (29°17’S; U-Pb ages from 315.7±4.6 to 229.6±5.2 Ma (Table 4). Fig. 4). This intermediate volcanic unit was origi- These are consistent with the 330 to 215 U-Pb in- nally mapped as part of the Late Paleozoic-Triassic terval of recently published U-Pb ages for the same Pastos Blancos Formation (with a question mark) batholith (e.g., Pineda and Calderón, 2008; Salazar et by Nasi et al. (1990). Actually, the new U-Pb age al., 2009, 2013; Coloma et al., 2012, Álvarez et al., shows that these andesitic rocks are Late Jurassic 2013; Hervé et al., 2014). We have obtained a U-Pb in age, being equivalent in age and lithology to the age of 315.7±4.6 Ma for a coarse-grained, biotite Picudo Formation (Reutter, 1974; Moscoso et al., monzogranite from the Guachicay pluton (sensu 2010) exposed in the El Tránsito river valley and to Nasi et al., 1985) exposed in the Del Carmen river the Lagunillas Formation, which has been recogni- valley and 311.9±6.0 Ma for a coarse-grained, biotite zed farther north between 27°30’ and 28°30´S in syenogranite exposed in the Potrerillos river valley. the High Andes of the Atacama Region and these The latter was included in the extensive tonalitic represent Late Jurassic back-arc volcanism (Iriarte Guanta pluton by Nasi et al. (1985, 1990). In addi- et al., 1999; Oliveros et al., 2011). tion, we obtained a zircon U-Pb age of 307.1±4.8 Ma for a foliated, coarse-grained, biotite-hornblende 5.2. Intrusive rocks tonalite of the Guanta pluton (sensu Nasi et al., 1985, 1990) exposed in the Del Carmen river valley, and a The new zircon U-Pb ages for Late Paleozoic U-Pb zircon age of 286.3±6.2 Ma was obtained for a intrusive rocks range from 315.7±4.6 to 229.6±5.2 Ma coarse-grained, muscovite-biotite granite of the Burro (Table 4), well within the 328 to 206 Ma interval of Muerto pluton (sensu Nasi et al., 1985), which is the compiled U-Pb dates (Table 2). emplaced within the foliated tonalite of the Guanta Granitoids exposed along the Domeyko Cordillera pluton in the El Carmen river valley, and corresponds and its southern continuation in the Frontal Cordillera to the Cochiguaz intrusive unit of Nasi et al. (1985, yielded U-Pb ages from 287 to 263 Ma (Table 4; Fig. 4), 1990); and a U-Pb zircon age of 229.6±5.2 Ma was representing Permian granitic plutonism, these obtained for a brick-red, fine-grained, syenogranite Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 465 of the La Coneja pluton (sensu Nasi et al., 1985) that Represas Beds in the Atacama Region; Iriarte et al., corresponds to the Colorado intrusive unit of Nasi 1996). While, the rhyolitic succession exposed in et al. (1985, 1990). the El Tránsito river valley includes conglomerates, A U-Pb zircon age of 258.9±5.0 Ma (Late Per- sandstones and andesites (Cerro Bayo Formation; mian) was obtained for mylonitized tonalite of the Salazar, 2012; Salazar et al., 2013). Quebrada Pintado tonalitic unit of Salazar et al. The mainly felsic volcanic rocks widely exposed (2013) in the La Totora creek (28°40’S; Fig 4). The along the Domeyko Cordillera and Precordillera of mylonites at La Totora creek show a N35°E/75°E northern Chile north of 25°30’S latitude have yielded foliation and centimetric to decimetric white, felsic U-Pb ages from 310 to 282 Ma Tables 1 and 3), thus bands alternating with dark gray, biotitic bands. represent a Late Carboniferous to Early Permian This mylonitized intrusion unconformably underlies volcanism that is older than the Choiyoi succession the Mid-Late Triassic volcanic rocks of La Totora of the San Rafael Block in western Argentina for Formation. which U-Pb ages from 281 to 251 Ma have been Along the Pacific coast north of Chañaral, published (Rocha-Campos et al., 2011). Actually, about 120 km west of the High Andes, U-Pb ages the Chilean Carboniferous to Early Permian volcanic of 276.6±3.6 and 264.6±7.0 Ma were obtained rocks are chronologically equivalent to sedimentary for biotite-muscovite, monzogranite of the Pan de successions with submarine volcanic deposits that Azúcar pluton (sensu Mercado, 1980; Godoy and are present farther east in Argentina (Azcuy et al., Lara, 1998), while two U-Pb ages of 246.5±4.0 1999; López-Gamundí, 2006; Koukharsky et al., and 237.0±4.0 were obtained for coarse-grained, 2009; Gulbranson et al., 2010). Therefore, when muscovite-biotite monzogranite of the Cerros del the Carboniferous to Early Permian magmatism was Vetado pluton of the Coastal Cordillera immediately active along the current Domeyko Cordillera and east of Chañaral (Fig. 4). Precordillera northwards, in Argentina farther east developed contemporary marine basins; this situation 6. Discussion has been interpreted as a magmatic arc and back-arc basins by Gulbranson et al. (2010). The U-Pb data provide evidence for the onset of The U-Pb age of 291.5±4.0 Ma that we obtained volcanism at ~325 Ma (by the end of the Missisip- for an andesitic tuff intercalated in the upper part pian), which is approximately coeval with the onset of El Mono Beds at its type locality (Mpodozis et of granitic plutonism at ~328 Ma (Tables 2 and 3), al., 2012), in the High Andes at ~27°S, indicates confirming a previous conclusion of Hervé et al. an Early Permian age for the upper part of the (2014). This marks reestablishment of magmatism succession. Even though it underlies in apparent during the Carboniferous after a gap in igneous acti- conformity Jurassic marine strata, implying a hiatus vity during the Devonian in northern Chile and Perú in what was considered a continuous sedimentary (e.g., Charrier et al., 2007; Boekhout et al., 2013). sequence (e.g., Blanco, 1994). The mostly clastic, alluvial and lacustrine sedimentary El Mono Beds 6.1. Volcanic rocks have previously been assigned to the Late Triassic, based mainly on fossil flora attributed to Dicroidium The oldest rhyolitic rocks (325 to 292 Ma; Table sp. (Mercado, 1982; Suárez and Bell, 1991; Blanco, 1 and 3) are present within the current Intermediate 1994; Cornejo et al., 1998; Gallego and Covacevich, Depression and the western foothills of the High 1998; Mpodozis et al., 2012). We cannot exclude the Andes of northern Chile (Figs. 3 and 4). Part of this possibility that Triassic sedimentary rocks exists in the initial volcanism developed within a shallow marine same region, but the new U-Pb age of 291.5±4.0 Ma platform represented by carbonate strata with Late is consistent with the stratigraphic position of the Permian marine fossils that are overlying and partly El Mono Beds unconformably overlying Devonian interfingered with the dated rhyolitic rocks (Juan de to Early Carboniferous sandstones of the Chinches Morales Formation in the Tarapacá Region; Galli, Formation (Bell, 1985; Mpodozis et al., 2012), and 1956, 1968; Díaz-Martínez et al., 2000; Cerro del evidences that this unit represents a Late Carbonife- Árbol Formation in Antofagasta Region; Marinovic rous to Early Permian sedimentation and coetaneous et al., 1995; Marinovic, 2007; and Quebrada de Las pyroclastic volcanism, at least where sampled for 466 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... dating. Therefore, El Mono Beds could be equivalent to the west along the Domeyko Cordillera (e.g., to a sedimentary unit with Late Carboniferous flora Sierra del Jardín Rhyolites; Marinovic, 2007), even and marine fossils exposed near the watershed of the though the latter were mapped as the same formation Andes at ~29°S latitude (Las Placetas Formation; by Mpodozis et al. (1993). Reutter, 1974; Nasi et al., 1990); these sedimentary The occurrence of Mid-Permian to Early Triassic deposits probably represent the westernmost part volcanic rocks eastward from the Carboniferous to of sedimentary basins developed mainly farther Early Permian volcanic rocks in Chile is interpreted east in Argentina during the Carboniferous to Early as a Mid-Permian to Early Triassic expansion and/ Permian (Azcuy et al., 1999; López-Gamundí, 2006; or eastward migration of the volcanic front, which Koukharsky et al., 2009; Gulbranson et al., 2010). is consistent with evidences of expansion of the Rhyolitic volcanism with andesitic and basaltic volcanic activity farther east in Argentina at that time intercalations persisted during the Permian along (e.g., Ramos and Folguera, 2009; Ramos, 2009). the current Domeyko Cordillera and the Chilean Middle Triassic to Early Jurassic volcanic rocks yiel- Frontal Cordillera (High Andes) as the volcanic ded zircon U-Pb ages from 249.7±3.8 to 194.0±9.2 Ma, rocks exposed south of 25°30’S latitude have yiel- their outcrops are more discontinuous (patchy) and ded U-Pb ages from 282 to 262 Ma (Figs. 3 and 4). dispersed compared to the older volcanic rocks, These are represented by the La Tabla, and Pantanoso and are separated from them by erosional surfaces. Formations, and the Guanaco Sonso Sequence of the During this period andesitic to basaltic volcanism Pastos Blancos Group (Mercado, 1982; Cornejo et coexisted with felsic volcanism (bimodal volcanism), al., 1993, 1998, 2009; Martin et al., 1999; Tomlinson and was synchronous with rift-related, continental et al., 1999; Mpodozis et al., 2012) and their U-Pb and/or marine sedimentary deposits in northern ages fall well within the 281 to 251 Ma time span of Chile (e.g., Suárez and Bell, 1992; Bell and Suarez, U-Pb ages published by Rocha-Campos et al. (2011) 1994). Middle to Upper Triassic strata show strong for the Choiyoi Succession of the San Rafael Block facies changes along the longitudinal axis of the in western Argentina. High Andes, for example according to the U-Pb data The U-Pb age of 270.3±4.6 Ma for the basal unit of the mostly basaltic-andesitic La Totora Formation the Pantanoso Formation (Table 3) indicates the onset (250-210 Ma) overlaps in age with the upper part of of volcanic accumulation in the current High Andes the mainly clastic, sedimentary San Félix Formation at ~27°S latitude unconformably on top of deformed (223-212 Ma), but also with rhyolites of Los Tilos Devonian to Early Carboniferous sedimentary rocks Sequence (232-221 Ma), within less than 100 km (Chinches Formation; Mercado, 1982; Bell, 1985), in the Atacama Region. These striking north-south but also over folded sandstone and conglomerate facies changes probably reflect the main northwest beds ascribed to the Carboniferous-Permian (Elba orientation of extensional basins that developed Beds; Mercado, 1982). Thus, according to the new in the Mid-Late Triassic in Chile and Argentina U-Pb data the accumulation of the volcanic rocks of (Charrier, 1979; Chong and Von Hillebrandt, 1985; the Pantanoso Formation at its type locality occurred Uliana et al., 1989; Ramos and Kay, 1991; Jenchen at least 20 My later than the rhyolitic succession that and Rosenfeld, 2002; Charrier et al., 2007; Barredo is exposed 47 km to the west in the Paipote valley, et al., 2012). which in previous works has also been assigned to A probability density plot and stacked histogram the Pantanoso Formation (Iriarte et al., 1996). of all U-Pb ages for volcanic rocks exposed along Late Permian to Early Triassic rhyolitic volcanism the segment of the Chilean Andes from 20° to 31°S is represented by the Cas Formation that yielded U-Pb (Fig. 5) evidences a protracted volcanic activity that ages from 256 to 243 Ma (Fig. 3; Tables 1 and 3) extended for about 130 million years, from about 325 and is exposed in the easternmost part of Chile to 194 Ma (Late Mississippian to Early Jurassic). The (68°W), along the eastern side of the Salar de Ata- histogram (Fig. 5) shows two largest concentrations cama salt flat in the Antofagasta Region (Ramírez of U-Pb dates from 310 to 250 Ma and from 240 to and Gardeweg, 1982; Breitkreuz and van Schmus, 210 Ma, and other less prominent concentrations of 1996). The rhyolitic rocks of the Cas Formation at U-Pb ages from 330 to 320 Ma and at about 190 Ma. its type locality are significantly younger than the Even though the histogram probably is biased to Early Permian rhyolitic rocks exposed some 90 km zircon-bearing rocks and easily accessible outcrops Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 467

7 Relati

6 v e

5 pro b ber

4 abili Nu m t y 3

0 180 200 220 240 260 280 300 320 340 360 U-Pb ages for Volcanic Rocks (Ma) FIG. 5. Probability density plot and stacked histogram of zircon U-Pb ages for volcanic rocks. for sampling, the statistical analysis of the U-Pb data attest that plutonism was active during the whole may signify that major volcanic episodes extended Permian in northern Chile, when there was a strong from the Late Carboniferous to Late Permian and then predominance of coarse-grained monzogranite plu- from Mid- to Late Triassic, but were preceded by a tons, both equigranular and porphyritic, followed mid-Carboniferous volcanic episode and followed by coarse-grained biotite-hornblende tonalites, and by an Early Jurassic one. only minor monzonite, diorite and gabbro intrusions; two-mica (S-type) granites, granodiorites, 6.2 Intrusive rocks and tonalites also intruded during this time span. Most of the Permian plutons are exposed along the U-Pb data for plutonic rocks show that earliest High Andes and Domeyko Cordillera, but Permian intrusions crystallized from 328.1±2.8 to 311.9±6.0 Ma, granites with U-Pb ages of 277-270 Ma are also including coarse-grained, biotite-muscovite granite present some 120 km west in the Pacific coast (Pan to granodiorite (S-type) and biotite monzogranite de Azúcar pluton, Fig 4). and biotite-hornblende granodiorite plutons (I-type). Triassic plutonism is represented by granitic por- From 308.5±2.2 to 290±2 Ma rhyolitic and granitic phyries, biotite- and two-mica granites, granodiorites, porphyries and equigranular monzogranite plutons and brick-red syenogranite intrusions with U-Pb crystallized and biotite-muscovite granitic and gra- ages that range from 247.0±3.1 to 215.6±1.9 Ma. nodioritic plutons, and hornblende-diorite tonalitic Some of these intrusions are of large volume, as to dioritic plutons were emplaced. Furthermore, most of the Chollay and Montosa granitic batholiths 33 compiled and 9 new U-Pb zircon ages, which are formed of Triassic medium to coarse-grained altogether range from 298.9±2.6 to 252.5±1.8 Ma monzogranites for which U-Pb ages of 245.0±3.1 468 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... and 240.3±1.7 Ma have been reported (Coloma et The new U-Pb data from 277 to 237 Ma (Table 4) al., 2012; Hervé et al., 2014) and we obtained a confirm that Permian and Mid-Triassic granitic U-Pb age of 244.0±2.8 Ma. Triassic granitic plutons magmatism is also exposed in the current coastal are also present in the current Coastal Cordillera area, which combined with previously published as Cerros del Vetado pluton yielded U-Pb ages of geochronological data suggests a protracted plutonism 247-237 Ma (Fig. 4). extending from 322 to 217 Ma along the Coastal The U-Pb data now available evidence that Cordillera of northern Chile from 21° to 33°S (Maksaev muscovite-bearing intrusive, with S-type granite and Marinovic, 1980; Skarmeta and Marinovic, characteristics, were not confined to a single discrete 1981; Berg et al., 1983; Shibata et al., 1984; Berg Permian magmatic episode as previously thought, and Baumann, 1985). However, there appears to be but crystallized within the entire time span from Late a difference with the Coastal Batholith exposed to Carboniferous to Late Triassic and synchronically the south between 33° to 38°S, which has yielded with biotite- and hornblende-bearing intrusions with eight 320 to 300 Ma (Pennsylvanian) U-Pb zircon petrographic characteristics of I-type granitoids; this ages (Deckart et al., 2014), but to date there are no is in agreement with a similar conclusion based on Permian and Early Triassic granitoids intruded in U-Pb data for the Elqui-Limarí Batholith (Hervé et al., the main body of this Coastal Batholith of central- 2014). Actually, the synchronic emplacement of I- and southern Chile, and only some small Late Triassic- S-Type granitoids was already noted and sustained Early Jurassic stocks of calc-alkaline to transitional by chemical data by Marinovic et al. (1995) in the A-type affinities, with U-Pb zircon ages from 225 Domeyko Cordillera, though it was attributed to a to 197 Ma that are emplaced into its metamorphic local phenomenon related to a hypothetical longitu- envelope (Vásquez et al., 2011; Hervé et al., 2014). dinal segmentation of the Late Paleozoic to Triassic A probability density plot and stacked histogram plutonism, rather than to a regional characteristic. of all U-Pb ages for intrusive rocks (Fig. 6) shows

8 Relati v e

6 pro b ber abili Nu m t

4 y

0 200 220 240 260 280 300 320 340 360 U-Pb ages for Intrusive Rocks (Ma)

FIG. 6. Probability density plot and stacked histogram of zircon U-Pb ages for intrusive rocks. Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 469 that plutonic activity extended for at least 120 My interpreted as the major magmatic episodes developed from about 328 to 206 Ma (Late Missisipian to during from the Late Carboniferous to Mid-Permian Late Triassic) with a largest concentration of U-Pb and from Late Permian to Late Triassic. Other less dates between 310 and 280 Ma, followed by another prominent U-Pb age concentrations reveal a mid- significant concentration of U-Pb dates from 255 to Carboniferous episode (330 to 320 Ma) and an Early 205 Ma, and other less prominent U-Pb age concen- Jurassic episode (200-190 Ma). trations from 330 to 310 Ma and 280 to 260 Ma. This The magmatic episodes of the Chilean Andes fall statistical analysis of the U-Pb data may signify that well within the 336 to 230 Ma interval of published major intrusive episodes took place from the Late U-Pb geochronological data for igneous rocks of Carboniferous to Early Permian and from the Late Argentina (Pankhurst, 2006; Gulbranson et al., 2010; Permian to Late Triassic, but also there were mid- Rocha-Campos et al., 2011; Barredo et al., 2012; Carboniferous and mid-Permian intrusive episodes. Suárez et al., 2012; Gregori and Benedini, 2013), The inferred plutonic episodes are fundamentally but also with the interval from 342 to 190 of U-Pb coincident with the major episodes of volcanism data from the Andes of Perú, Ecuador and Colombia inferred from the statistical analysis of U-Pb data (Restrepo et al., 1991; Noble et al., 1997; Ordoñez (Figs. 5 and 6). A sequential plot of the U-Pb ages and Pimentel, 2002; Vinasco et al., 2006; Chew et (Fig. 7) shows that there are no apparent periods al., 2007; Ibáñez-Mejía et al., 2008; Cardona et al., when the volcanism or plutonism prevailed, but both 2008, 2009; Mišković et al., 2009, Mišković and developed simultaneously from the Carboniferous Shaltegger, 2009; Witt et al., 2013; Boekhout et to the Early Jurassic. A probability density plot and al., 2013). Therefore, despite local particularities, stacked histogram of all U-Pb ages for igneous rocks there was a rather consistent evolution in time of the (Fig. 8) show the largest concentration of dates from magmatism along the southwestern, paleo-Pacific 310 to 260 Ma and from 255 to 205 Ma, which are border of Gondwana.

180 b o x heig hts are 2σ 190 200 210 220 230 240 250 Ma 260 270 280 290 300 310 320 330 340

FIG. 7. Plot of all zircon U-Pb ages for Late Paleozoic to Early Jurassic intrusive and volcanic rocks ordered from older to younger with 2σ error bars; black bars=intrusive rocks and gray bars=volcanic rocks. 470 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

16 Rela 14 t 12 i v e pr o ber 10 b a b i Nu m

8 li t y 6

0 180 200 220 240 260 280 300 320 340 360 U-Pb ages for all igneous rocks (Ma)

FIG. 8. Probability density plot and stacked histogram of all zircon U-Pb ages for igneous rocks.

7. Conclusions or marine sedimentary strata related to the early stages of break-up of Gondwana. U-Pb zircon geochronological data provide Most of the siliceous volcanic rocks of the Pre- record of about 130 Ma of igneous activity in the cordillera and Domeyko Cordillera of northern Chile Andes of northern Chile that extended episodica- (21°30’ to 25°30’S) are older than the silicic rocks lly from the latest Early Carboniferous to Early assigned to the Choiyoi succession in Argentina, Jurassic (328-194 Ma). The overall U-Pb data show being instead equivalent in age to Carboniferous that volcanism and plutonism were essentially syn- to Early Permian marine sedimentary sequences chronous and inferred major episodes of igneous present in the eastern Argentinean foreland. On activity developed during the Late Carboniferous the other hand, silicic volcanic successions ex- to Permian (310 to 260 Ma) and from Late Permian posed in the easternmost part of northern Chile to Late Triassic (255-205 Ma), with less prominent are equivalent in age to the Choiyoi succession of episodes in the mid-Carboniferous (330 to 320 Ma), the San Rafael Block of Argentina. An eastward and Early Jurassic (200-190 Ma). Thus, from the expansion or migration during the Mid-Permian Carboniferous to the Early Triassic dominantly to Early Triassic is inferred by the age difference silicic magmatism developed along the Chilean between older western rhyolitic deposits and segment of the southwestern border of Gondwana younger eastern rhyolitic volcanic that originally supercontinent. Further magmatism developed during were supposed to be of the same age; interpretation the Mid-Late Triassic (250-194 Ma) was bimodal that is consistent with expansion of the volcanism and synchronous with rift-related, continental and/ at that time in Argentina. Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 471

The timing of the magmatism is coincident with Basso, M. 2004. Carta Baquedano, Región de Antofagas- that of the Andes of Perú and of Argentina according ta. Servicio Nacional de Geología y Minería, Carta to the available U-Pb data, revealing a rather consis- Geológica de Chile, Serie Geología Básica 82: 26 p. tent evolution in time of the magmatism along the 1 mapa escala 1:100.000. Santiago. southwestern, paleo-Pacific border of Gondwana. Basso, M.; Marinovic, N. 2003. Antecedentes geocro- The correct allocation of lithostratigraphic units nológicos de volcanismo Triásico en la zona de los to the geological time results in changes in the stra- Estratos El Bordo, Antofagasta, Chile. In Congreso tigraphy modifying the tectonic interpretation and Geológico Chileno, No. 10, Sesión Temática 5: CD- evolution of the studied volcano-plutonic event. ROM. Concepción. The current U-Pb data allow a better understanding Bell, C.M. 1985. The Chinches Formation: an early of the temporal evolution of the Late Paleozoic to Carboniferous lacustrine succession in the Andes of Early Jurassic volcano-plutonic event in northern northern Chile. Revista Geológica de Chile 24: 29-48. Chile, but certainly further work is required to solve doi: 10.5027/andgeoV12n1-a03. particularly stratigraphic problems still remaining Bell, C.M.; Suárez, M. 1994. The sedimentation and and some outcrops that have not been sampled by tectonics of a marine fan-delta developed on anactive logistic reasons. continental margin: the Triassic San Felix Formation in the Andes of northern Chile. Journal of South Acknowledgements American Earth Sciences 7 (3-4): 403-413. This study was supported by CONICYT, Chile, Berg, K.; Baumann, A. 1985. Plutonic and metasedimentary through Fondecyt 1110093 grant to V. Maksaev and rocks from the Coastal Range of northern Chile: Rb- F. Munizaga (Universidad de Chile). We are obliged to Sr and U-Pb systematic. Earth and Planetary Science F. Hervé and his Fondecyt project 1095099 for sharing Letters 75: 101-115. data from the Elqui-Limarí batholith and provided Berg, K.; Breitkreuz, C.; Damm, K-W.; Pichowiak, S.; some samples for dating during this study. We thank Zeil, W. 1983. The North-Chilean Coast Range-an K. Sato in charge of the SHRIMP and the staff of the Example for the Development of an Active Continen- Geochronological Research Center (Centro de Pesqui- tal Margin. Geologische Rundschau 72 (2): 715-731. sas Geocronológicas) of the University of Sao Paulo, Black, L.P.; Kamo, S.L.; Allen, C.M.; Aleinikoff, J.N.; Brazil, for their cooperation during the U-Pb dating on Davis, D.W.; Korsch, R.J.; Foudoulis, C. 2003. TE- the SHRIMP. Reviews by V. Oliveros and C. Mpodozis MORA1: a new zircon standard for phanerozoic U-Pb contributed to improve this paper. geochronology. Chemical Geology 200: 155-170. Blanco, N. 1994. Sedimentología y ambientes sedimen- References tarios de los estratos El Mono, Triásico de la Región de Atacama, Chile. In Congreso Geológico Chileno, Álvarez, J.; Mpodozis, C.; Blanco-Quintero, I.; García- No. 7, Actas 1: 409-413. Concepción. Casco, A.; Arriagada, C.; Morata, D. 2013. U-Pb ages Boekhout, F.; Sempere, T.; Spikings, R.; Schaltegger, U. and metamorphic evolution of the La Pampa Gneisses: 2013. Late Paleozoic to Jurassic chronostratigraphy Implications for the evolution of the Chilenia Terrane of coastal southern Perú: Temporal evolution of se- and Permo-Triassic tectonics of north Central Chile. dimentation along an active margin. Journal of South Journal of South American Earth Sciences 47: 100-115. American Earth Sciences 47: 179-200. doi: 10.1016/j.jsames.2013.07.001. Breitkreuz, C. 1995. The Late Permian Peine and Cas Azcuy, C.L.; Carrizo, H.A.; Caminos, R. 1999. Carbonífero Formations at the Eastern margin of the Salar de y Pérmico de las Sierras Pampeanas, Famatina, Pre- Atacama, Northern Chile: stratigraphy, volcanic cordillera, Cordillera Frontal y Bloque de San Rafael. facies, and tectonics. Revista Geológica de Chile 22 Geología Argentina, Anales del Instituto de Geología (1): 3-23. doi: 10.5027/andgeoV22n1-a01. y Recursos Minerales 29: 261-318. Breitkreuz, C.; Zeil, W. 1994. The Late Carboniferous to Barredo, S.; Chemale, F.; Marsicano, C.; Ávila, J.N.; Triassic Volcanic Belt in Northern Chile. In Tectonics Ottone, E.G.; Ramos, V. 2012. Tectono-sequence of the Southern Andes (Reutter, K.J.; Scheuber, E.; stratigraphy and U-Pb zircon ages of the Rincón Wigger, P.J.; editors). Springer: 277-292. Blanco Depocenter, northern Cuyo Rift, Argentina. Breitkreuz, C.; Van Schmus, W.R. 1996. U-Pb geochro- Gondwana Research 21: 624-536. nology and significance of Late Permian ignimbrites 472 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

in Northern Chile. Journal of South American Earth Chew, D.M.; Schaltegger, U.; Kosler, J.; Whitehouse, Sciences 9: 281-293. M.J.; Gutjahr, M.; Spikings, R.A.; Miskovíc, A. 2007. Breitkreuz, C.; Bahlburg, H.; Delakowitz, B.; Pichowiak, S. U-Pb geochronologic evidence for the evolution of 1989. Paleozoic volcanic events in the Central An- the Gondwanan margin of the north-central Andes. des. Journal of South American Earth Sciences 2: Geological Society of America Bulletin 119 (5-6): 171-189. 697-711. Brown, M. 1990. Comparative geochemical interpreta- Chong, G.; Von Hillebrandt, A. 1985. El Triásico prean- tion of Permian-Triassic plutonic complexes of the dino de Chile entre los 23º30’ y 26º00’ de lat. Sur. In Coastal Range and Altiplano (25º30’ to 26º30’S), Congreso Geológico Chileno, No. 4, Actas 1: 138-154. northern Chile. In Andean Magmatism and its Tec- Antofagasta. tonic Setting (Harmon, R.S.; Rapela, C.E.; editors). Cohen, K.M.; Finney, S.; Gibbard, P.L. 2013. International Geological Society of America, Special Paper 265: Chronostratigraphic Chart, v2013/01. International 157-177. Commission on Stratigraphy. http//www.stratigraphy. Camus, F. 2003. Geología de los sistemas porfíricos en org/ICSchart/ChronostratChart2013-01.pdf: 1 p. los Andes de Chile. Servicio Nacional de Geología y Coloma, F.; Salazar, E.; Creixell, C. 2012. Nuevos ante- Minería: 267 p. Santiago. cedentes acerca de la construcción de los plutones Cardona, A.; Cordani, U.; Nutman, A. 2008. U-Pb Pérmicos y Permo-Triásicos en el valle del río Tránsito, SHRIMP zircon, 40Ar/39Ar geochronology and Nd Región de Atacama, Chile. In Congreso Geológico isotopes from gneissic and granitoid rocks of the Chileno, No. 13, Actas: 330-332. Antofagasta. Illescas massif, Perú: a southern extension of a frag- Cornejo, P.; Mpodozis, A.C. 1996. Geología de la región mented Late Paleozoic orogen? In South American de Sierra Exploradora (25°-26ºS). Servicio Nacional Symposium on Isotope Geology, No. 6. Proceedings, de Geología y Minería, Informe Registrado IR-96-09: Abstract: p. 78. San Carlos de Bariloche. 330 p. Santiago. Cardona, A.; Cordani, U.G.; Ruiz, J.; Valencia, V.A.; Cornejo, P.; Mpodozis, C. 1997. El rift Triásico-Sinemu- Armstrong, R.; Chew, D.; Nutman, A.; Sanchez, W. riano de Sierra Exploradora, Cordillera de Domeyko 2009. U-Pb Zircon Geochronology and Nd Isotopic (25°-26°): asociaciones de facies y reconstrucción Signatures of the Pre-Mesozoic Metamorphic Base- tectónica. In Congreso Geológico Chileno, No. 8, ment of the Eastern Peruvian Andes: Growth and Actas 1: 550-554. Antofagasta. Provenance of a Late Neoproterozoic to Carboniferous Cornejo, P.; Mpodozis, C.; Ramírez, C.F.; Tomlinson, A. Accretionary Orogen on the Northwest Margin of 1993. Estudio geológico de la región de Potrerillos y Gondwana. The Journal of Geology 117 (3): 285-305. El Salvador (26°-27° Lat. S). Servicio Nacional de Carlier, G.; Grandin, G.; Laubacher, G.; Marocco, R.; Geología y Minería, Informe Registrado IR-93-01: Megard, F. 1982. Present knowledge of the mag- 258 p. Santiago. matic evolution of the eastern Cordillera of Perú. Cornejo, P.; Mpodozis, A.C.; Tomlinson, A.J. 1998. Hoja Earth-Science Reviews 18: 253-283. Salar de Maricunga, Región de Atacama. Servicio Casquet, C.; Hervé, F.; Pankhurst, R.J.; Baldo, E.; Calderón, Nacional de Geología y Minería, Mapas Geológicos M.; Fanning, C.M.; Rapela, C.W.; Dahlquist, J. 2014. 7, 1 mapa escala 1:100.000. Santiago. The Mejillonia suspect terrane (Northern Chile): Late Cornejo, P.; Matthews, S.; Marinovic, N.; Pérez de Arce, Triassic fast burial and metamorphism of sediments in C.; Basso, M.; Alfaro, J.; Navarro, M. 2006. Alteración a magmatic arc environment extending into the Early hidrotermal y mineralización recurrente de Cu y Cu- Jurassic. Gondwana Research 25 (3): 1272-1286. doi: Mo durante el Pérmico y el Triásico en la Cordillera 10.1016/j.gr.2013.05.016. de Domeyko (Zona de Zaldívar-Salar de los Morros): Charrier, R. 1979. El Triásico en Chile y regiones adyacen- antecedentes geocronológicos U-Pb, 40Ar/39Ar y Re- tes de Argentina: Una reconstrucción paleogeográfica Os. In Congreso Geológico Chileno, No. 11, Actas 2: y paleoclimática. Universidad de Chile, Departamento 219-222. Antofagasta. de Geología. Comunicaciones 26: 1-47. Santiago. Cornejo, P.; Mpodozis, C.; Rivera, O.; Matthews, S.J. Charrier, R.; Pinto, L.; Rodríguez, M.P. 2007. Tectono- 2009. Carta Exploradora, Región de Antofagasta y stratigraphic evolution of the Andean Orogen in Chile. Atacama. Servicio Nacional de Geología y Minería, In The Geology of Chile (Moreno, T.; Gibbons, W.; Carta Geológica de Chile, Serie Geología Básica 119: editors). The Geological Society: 21-114. London. 100 p. Santiago. Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 473

Cortés, J. 2000. Hoja Palestina, Región de Antofagasta. Galli, C. 1968. Cuadrángulo Juan de Morales, Provincia Servicio Nacional de Geología y Minería, Mapas de Tarapacá. Instituto de Investigaciones Geológicas, Geológicos 19, 1 mapa escala 1:100.000. Santiago. Carta Geológica de Chile 18: 53 p. Santiago. Damm, W.; Pichowiak, S.; Harmon, R.S.; Todt, W.; Kelley, García, F. 1967. Geología del Norte Grande de Chile. In S.; Omarini, R.; Niemeyer, H. 1990. Pre-Mesozoic Simposio sobre el Geosinclinal Andino. Sociedad evolution of the Central Andes, the basement revis- Geológica de Chile, Publicación 3: 138 p. Santiago. ited. In Plutonism from Antarctica to Alaska (Kay, Godoy, E.; Lara, L. 1998. Hojas Chañaral y Diego de M.S.; Rapela, C.W.; editors). Geological Society of Almagro, Región de Atacama. Servicio Nacional de America, Special Papers 241: 101-126. Geología y Minería, Mapa Geológico 5-6, 1 mapa Davidson, J.; Mpodozis, C.; Bunger, C.; Cornejo, P.; escala 1:100:000. Santiago. Faunes, A.; Foerster, H.; Fuster, N.; Gardeweg, M.; Gregori, D.; Benedini, L. 2013. The Cordón del Portillo Godoy, S.; Jannas, R.; Muzzio, G.; Reyes, J.C.; Sali- Permian magmatism, Mendoza, Argentina, pluto- nas, P.; Sepúlveda, J.; Solano, A.; Velasco, L. 1978. nic and volcanic sequences at the western margin Geología de la Precordillera de Copiapó: las nacientes of Gondwana. Journal of South American Earth de la quebrada Paipote al oeste del Salar de Maricunga Sciences 42: 61-73. (resultados del curso de Geología de Campo II, 1977). Gulbranson, E.L.; Montañez, I.P.; Schmitz, M.D.; Universidad de Chile, Departamento de Geología, Limarino, C.O.; Isbell, J.L.; Marenssi, S.A.; Comunicaciones 23: 1-34. Crowley, J.L. 2010. High-precision U-Pb calibration Davidson, J.; Ramírez, C.F.; Gardeweg, M.; Brook, M.; of Carboniferous glaciation and climate history, Pankhurst, M. 1985. Calderas del Palaeozoico Paganzo Group, NW Argentina. Geological Society superior-Triásico Inferior y mineralización asociada. of America, Bulletin 122 (9-10): 1480-1498. Universidad de Chile, Departamento de Geología, Hervé, F.; Fanning, C.M.; Calderón, M.; Mpodozis, C. Comunicaciones 35: 53-57. Santiago. 2014. Early Permian to Late Triassic batholiths of the Deckart, K.; Hervé, F.; Fanning, M.; Ramírez, V.; Chilean Frontal Cordillera (28°-31°S): SHRIMP U-Pb Calderón, M.; Godoy, E. 2014. Geocronología U-Pb zircon ages and Lu-Hf and O isotope systematic. Lithos e isótopos de Hf-O en circones del batolito de la costa 184-187: 436-446. doi: 10.1016/j.lithos.2013.10.018. Pensilvaniana, Chile. Andean Geology 41 (1): 49-82. Hervé, M.; Sillitoe, R.H.; Wong, C.; Fernández, P.; doi: 10.5027/andgeoV41n1-a03. Crignola, F.; Ipinza, M.; Urzúa, F. 2012. Geologic Díaz-Martínez, E.; Mamet, B.; Isaacson, P.E.; Grader, Overview of the Escondida Porphyry Copper Dis- G.W. 2000. Permian marine sedimentation in northern trict, Northern Chile. In Geology and Genesis of Chile: new paleontological evidence from Juan de Major Copper Deposits and Districts of the World: Morales Formation, and regional paleogeographic A Tribute to Richard H. Sillitoe (Hedenquist, J.W.; implications. Journal of South American Earth Sci- Harris, M.; Camus, F.; editors). Society of Economic ences 13 (6): 511-525. Geologists, Special Publication 16: 55-78. Franz, G.; Lucassen, F.; Kramer,W.; Trumbull, R.B.; Huete, C.; Maksaev, V.; Moscoso, R.; Ulriksen, C.; Romer, R.L.; Wilke, H.-G.; Viramonte, J.G.; Bec- Vergara, H. 1977. Antecedentes geocronológicos de chio, R.; Siebel, W. 2006. Crustal evolution at the rocas intrusivas y volcánicas de la Cordillera de los Central Andean continental margin: a geochemical Andes comprendida entre la Sierra de Moreno y el río record of crustal growth, recycling and destruction. Loa y los 21º y 22º de latitud Sur, II Región, Chile. In The Andes-Active Subduction Orogeny (Oncken, Revista Geológica de Chile 4: 35-41. doi: 10.5027/ O.; Chong, G.; Franz, G.; Giese, P.; Götze, H.-J.; andgeoV4n1-a03. Ramos, V.; Strecker, M.R.; Wigger, P.; editors). Ibáñez-Mejía, M.; Jaramillo-Mejía, J.M.; Valencia, V. Springer: 45-64. 2008. U-Th/Pb zircon geochronology by multicollector Gallego, O.F.; Covacevic, V. 1998. Conchostracos triásicos LA-ICP-MS of the Samaná Gneiss: a Middle Triassic de las regiones de Antofagasta, Atacama y Coquimbo, syn-tectonic body in the Central Andes of Colombia, Chile. Revista Geológica de Chile 25 (2): 115-131. related to the latter stages of Pangea assembly. In doi: 10.5027/andgeoV25n2-a01. South American Symposium on Isotope Geology, Galli, C. 1956. Nota sobre el hallazgo del Palaeozoico No. 6, Extended Abstracts. San Carlos de Bariloche. superior en la Provincia de Tarapacá. Revista Mine- Iriarte, S.; Arévalo, C.; Mpodozis, C.; Rivera, O. 1996. rales 53-54: 30-31. Hoja Carrera Pinto, Región de Atacama. Servicio 474 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

Nacional de Geología y Minería, Mapas Geológicos 3, constraints and common characteristics. Journal of 1 mapa escala 1:100.000. Santiago. South American Earth Sciences 22: 227-238. Iriarte, S.; Arévalo, C.; Mpodozis, C. 1999. Hoja La Lucassen, F.; Franz, G.; Thirlwall, M.F.; Mezger, K. Guardia, Región de Atacama. Servicio Nacional de 1999. Crustal recycling of metamorphic basement, Geología y Minería, Mapas Geológicos 13, 1 mapa Late Paleozoic granitoids of northern Chile (~22°S): escala 1:100.000. Santiago. implications for the composition of the Andean crust. Jara, C.; Rabbia, O.; Valencia, V. 2009. Petrología y data- Journal of Petrology 40: 1527-1551. ciones U-Pb del depósito tipo pórfido Cu Zaldívar, II Ludwig, K.R. 2001. SQUID 1.02, A User’s Manual. Ber- Región de Antofagasta, Chile. In Congreso Geológico keley Geochronology Center, Special Publication 2, Chileno, No. 12, Actas 4: 4 p. Santiago. 2455 Ridge Road, Berkeley, CA 94709, USA. Jenchen, U.; Rosenfeld, U. 2002. Continental Triassic in Ludwig, K.R. 2003. User’s Manual for Isoplot/Ex, Version Argentina: response to tectonic activity. Journal of 3.0, A Geochronological Toolkit for Microsoft Excel. South American Earth Sciences 15: 461-479. Berkeley Geochronology Center, Special Publica- Jordan, T.E.; Isacks, B.L.; Allmendinger, R.W.; tion 4, 2455 Ridge Road, Berkeley CA 94709, USA. Brewer, J.A.; Ramos, V.A.; Ando, C.J. 1983. Andean Maksaev, V.; Marinovic, N. 1980. Cuadrángulos Cerro tectonics related to geometry of subducted Nazca de la Mica, Quillagua, Cerro Posada y Oficina plate: Geological Society of America Bulletin 94: Prosperidad, Región de Antofagasta. Instituto de 341-361. Investigaciones Geológicas, Carta Geológica de Kay, S.M.; Ramos, V.A.; Mpodozis, C.; Sruoga, P. 1989. Chile 45-48: 63 p. Late Palaeozoic to Jurassic silicic magmatism at the Marinovic, N. 2007. Carta Oficina Domeyko, Región de Gondwana margin: Analogy to the middle Proterozoic Antofagasta. Servicio Nacional de Geología y Minería, in North America? Geology 17: 324-328. Carta Geológica de Chile, Serie Geología Básica 105: Koukharsky, M.; Kleiman, L.; Etcheverría, M.; 41 p., 1 mapa escala 1:100.000. Santiago. Quenardelle, S.; Bercowski, F. 2009. Upper Car- Marinovic, N.; Smoje, I.; Maksaev, V.; Hervé, M.; boniferous retroarc volcanism with submarine and Mpodozis, C. 1995. Hoja Aguas Blancas, Región de subaerial facies at the western Gondwana margin of Antofagasta. Servicio Nacional de Geología y Minería, Argentina. Journal of South American Earth Sciences Carta Geológica de Chile 70: 142 p. 1 mapa escala 27: 299-308. 1:250.000. Santiago. Llambías, E.J.; Sato, A.M. 1990. El Batolito de Colangüil, Marinovic, N.; García, M. 1999. Hoja Pampa Unión, cordillera frontal de Argentina: Estructura y marco Región de Antofagasta. Servicio Nacional de Geo- tectónico. Revista Geológica de Chile 17 (1): 89-108. logía y Minería, Mapas Geológicos 9, 1 mapa escala doi: 10.5027/andgeoV17n1-a04. 1:100.000. Santiago. Llambías, E.J.; Sato, A.M. 1995. El Batolito de Colangüil: Martin, M.W.; Clavero, J.; Mpodozis, C. 1999. Late transición entre orogénesis y anorogénesis. Revista de Palaeozoic to Early Jurassic tectonic development of la Asociación Geológica Argentina 50 (1-4): 111-131. the high Andean Principal Cordillera, El Indio region, Buenos Aires. Chile (29º-30ºS). Journal of South American Earth Llambías, E.J.; Kleiman, L.E.; Salvarredi, J.A. 1993. El Sciences 12: 33-49. Magmatismo Gondwánico. In Geología y Recursos Masterman, G.L. 2003. Structural and geochemical evo- Naturales de Mendoza (Ramos, V.; editor). Congreso lution of the Rosario Copper-molybdenum porphyry Geológico Argentino, No. 12 y Congreso de Explo- deposit and related copper veins, Collahuasi District, ración de Hidrocarburos, No. 2. Relatorio: 53-64. Northern Chile. Doctorate Thesis (Unpublished), Mendoza. University of Tasmania: 253 p. Australia. Llambías, E.J.; Quenardelle, S.; Montenegro, T. 2003. Mercado, M. 1980. Geología del área Pan de Azúcar, The Choiyoi Group from central Argentina: a sub- Región de Atacama. Servicio Nacional de Geología y alkaline transitional to alkaline association in the Minería, Carta Geológica de Chile 37: 30 p., 1 mapa craton adjacent to the active margin of the Gondwana escala 1:100.000. Santiago. continent. Journal of South American Earth Sciences Mercado, M. 1982. Geología de la Hoja Laguna del Negro 16: 243-257. Francisco, Región de Atacama. Servicio Nacional de López-Gamundí, O. 2006. Permian plate margin volcanism Geología y Minería, Carta Geológica de Chile 56: 73 p., and tuffs in adjacent basins of west Gondwana: Age 1 mapa escala 1:100.000. Santiago. Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 475

Miskovic, A.; Schaltegger, U. 2009. Crustal growth along Atacama. Servicio Nacional de Geología y Minería, a non-collisional cratonic margin: A Lu-Hf isotopic Carta Geológica de Chile, Serie Geología Básica 145: survey of the Eastern Cordilleran granitoids of Perú. 30 p. 1 mapa escala 1:100.000. Santiago. Earth and Planetary Science Letters 279 (3-4): 303-315. Munizaga, F.; Maksaev, V.; Fanning, C.M.; Giglio, S.; Miskovic, A.; Spikings, R.A.; Chew, D.M.; Kosler, J.; Yaxley, G.; Tassinari, C.C.G. 2008 Late Paleozoic- Ulianov, A.; Schaltegger, U. 2009. Tectonomagma- Early Triassic magmatism on the western margin of tic evolution of Western Amazonia: Geochemical Gondwana: Collahuasi area, Northern Chile. Gond- characterization and zircon U-Pb geochronologic wana Research 13: 407-427. constraints from the Peruvian Eastern Cordilleran Murillo, I.; Álvarez, J.; Arriagada, C.; Calderón, M.; granitoids. Geological Society of America Bulletin Charrier, R. 2012. Geología estructural del Valle de 121 (9-10): 1298-1324. El Tránsito con énfasis en las Milonitas El Portillo, Morata, D.; Aguirre, L.; Oyarzún, M.; Vergara, M. 2000. III Región, Chile. In Congreso Geológico Chileno, Crustal contribution in the genesis of the bimodal No. 13, T2: 314-316. Antofagasta. Triassic volcanism from the Coastal Range, central Naranjo, J.A.; Puig, A. 1984. Hojas Taltal y Chañaral, Chile. Revista Geológica de Chile 27 (1): 83-98. doi: Regiones de Antofagasta y Atacama. Servicio Nacional 10.5027/andgeoV27n1-a06. de Geología y Minería, Carta Geológica de Chile 62- Moscoso, R.; Mpodozis, C.; Nasi, C.; Ribba, L.; Arévalo, C. 63: 140 p., 1 mapa escala 1:250.000. Santiago. 2010. Geología de la Hoja El Tránsito, Región de Nasi, C.; Mpodozis, C.; Cornejo, P.; Moscoso, R.; Maksaev, V. Atacama. Servicio Nacional de Geología y Minería, 1985. El Batolito Elqui-Limarí (Paleozoico Superior- Carta Geológica de Chile, Serie Preliminar 7: 17 p., Triásico): características petrográficas, geoquímicas 1 mapa escala 1:250.000. Santiago. y significado tectónico. Revista Geológica de Chile Mpodozis, C.; Cornejo, P. 1988. Hoja Pisco Elqui, IV 25-26: 77-11. doi: 10.5027/andgeoV12n2-3-a06. Región de Coquimbo. Servicio Nacional de Geología Nasi, C.; Moscoso, R.; Maksaev, V. 1990. Hoja Guanta, y Minería, Carta Geológica de Chile 68: 164 p., 1 Regiones de Atacama y Coquimbo. Servicio Nacional mapa escala 1:250.000. Santiago. de Geología y Minería, Carta Geológica de Chile 67: Mpodozis, C.; Ramos, V. 1989. The Andes of Argentina 140 p., 1 mapa escala 1:250.000. Santiago. and Chile. In Geology of the Andes and its relation to Niemeyer, H. 2013. Geología del Cerro Lila-Peine, Re- hydrocarbon and mineral resources (Ericksen, G.E.; gión de Antofagasta. Servicio Nacional de Geología Cañas Pinochet, M.T.; Reinemund, J.A.; editors). y Minería, Carta Geológica de Chile, Serie Geología Circumpacific Council for Energy and Mineral Básica 147. Resources, Earth Science Series 11: 59-90. Niemeyer, H.; Venegas, R.; Baeza, L.; Soto, H. 1985. Mpodozis, C.; Kay, S. 1990. Provincias magmáticas ácidas Reconocimiento geológico del sector sur-occidental y evolución tectónica de Gondwana: Andes chilenos del Cuadrángulo Cerro Yocas, ubicado en la zona (28-31°S). Revista Geológica de Chile 17 (2): 153-180. de falla Quebrada Blanca-Chuquicamata, Región de doi: 10.5027/andgeoV17n2-a03. Antofagasta. In Congreso Geológico Chileno, No. 4, Mpodozis, C.; Kay, S. 1992. Late Paleozoic to Triassic Actas 1: 629-653. Antofagasta. evolution of the pacific Gondwana margin: evidence Niemeyer, H.; Urzúa, F.; Rubinstein, C. 1997. Nuevos from Chilean frontal Cordilleran batholiths. Geological antecedentes estratigráficos y sedimentológicos de la Society of America Bulletin 104: 999-1014. Formación Zorritas, Devónico-Carbonífero de Sierra Mpodozis, C.; Allmendinger, R.W. 1993. Extensional tec- de Almeida, Región de Antofagasta, Chile. Revista tonics, Cretaceous Andes, northern Chile (27°S). Geo- Geológica de Chile 24 (1): 25-43. doi: 10.5027/ logical Society of America Bulletin 105: 1462-1477. andgeoV24n1-a02. Mpodozis, C.; Marinovic, N.; Smoje, I.; Cuitiño, L. 1993. Noble, S.R.; Aspden, J.A.; Jemelita, R. 1997. Northern Estudio Geológico-Estructural de la Cordillera de Andean crustal evolution: New U-Pb geochronologi- Domeyko entre Sierra Limón Verde y Sierra Mari- cal constraints from Ecuador. Geological Society of posas, Región de Antofagasta. Servicio Nacional de America Bulletin, 109: 789-798. Geología y Minería, Informe Registrado IR-93-04: Oliveros, V.; Labbé, M.; Rossel, P.; Charrier, R.; Encinas, 282 p. Santiago. A. 2011. Late Jurassic paleogeographic evolution Mpodozis, C.; Iriarte, S.; Gardeweg, M.; Valenzuela, M. of the Andean back-arc basin: New constrains from 2012. Carta Laguna del Negro Francisco, Región de the Lagunillas Formation, northern Chile (27°30’- 476 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

28°30’S). Journal of South American Earth Sciences Ramos, V. 2009. Anatomy and global context of the An- 37: 25-40. des: Main geologic features and the Andean orogenic Ordóñez, O.; Pimentel, M. 2002. Rb-Sr and Sm-Nd isotopic cycle. The Geological Society of America, Memoir study of the Puqui complex, Colombian Andes. Jour- 204: 31-65. nal of South American Earth Sciences 15: 173-182. Ramos, V.A.; Kay, S.M. 1991. Triassic rifting and asso- Padel, M.; Salazar, E.; Coloma, F. 2012. Arquitectura y ciated basalts in the Cuyo basin, central Argentina. In evolución tectonoestratigráfica del Depocentro de Andean magmatism and its tectonic setting (Harmon, San Félix, Triásico Medio a Superior: Resultados R.S.; Rapela, C.W.; editors). Geological Society of preliminares. In Congreso Geológico Chileno, No. America, Special Papers 265: 79-91. Boulder. 13, T5: 715-717. Antofagasta. Ramos, V.; Folguera, A. 2009. Andean flat-slab sub- Pankhurst, R.; Millar, I.; Hervé, F. 1996. A Permo-Carbo- duction through time. Geological Society Special niferous U-Pb age for part of the Guanta unit of the Publication 327: 31-54. London. Elqui-Limarí Batholith at Río del Tránsito, Northern Restrepo, J.J.; Toussaint, J.F.; González, H.; Cordani, U.; Chile. Revista Geológica de Chile 23 (1): 35-42. doi: Kawashita, K.; Linares, E.; Patricia, C. 1991. Precisio- 10.5027/andgeoV23n1-a03. nes geocronológicas sobre el occidente Colombiano. Pankhurst, R.J.; Rapela, C.W.; Fanning, C.M.; Márquez, M. In Simposio sobre magmatismo andino y su marco 2006. Gondwanide continental collision and the origin tectónico, Manizales 1: 1-21. of Patagonia. Earth-Science Reviews 76: 235-257. Reutter, K.J. 1974. Entwicklung und Bauplan der chilenis- Parada, F. 2013. Geoquímica de las rocas ígneas del chen Hochkordillere im Bereich 29º südlicher Breite. Carbonífero-Triásico de la Alta Cordillera, Región Neues Jahrbuch für Geologie und Paläontologie 146: de Atacama, Chile. Memoria de Título (Inédito), 153-178. Universidad de Chile, Departamento de Geología: Ribba, L.; Mpodozis, C.; Hervé, F.; Nasi, C.; Moscoso, R. 93 p. Santiago. 1988. El basamento del valle del Tránsito, Cordillera Parada, M.A.; Munizaga, F.; Kawashita, K. 1981. Edades de Vallenar: Eventos magmáticos y metamórficos y su Rb-Sr roca total del Batolito compuesto de los ríos relación con la evolución paleozoica de los Andes Chi- Elqui-Limarí a la latitud 30°S. Revista Geológica de leno-Argentinos. Revista Geológica de Chile 15 (2): Chile 13-14: 87-93. doi: 10.5027/andgeoV8n2-3-a07. 129-149. doi: 10.5027/andgeoV15n2-a03. Parada, M.A.; Levi, B.; Nystrom, J.O. 1991. Geochem- Richards, J.P.; Noble, S.R.; Pringle, M.S. 1999. A revised istry of the Triassic to Jurassic plutonism of Central late Eocene age for porphyry Cu magmatism in the Chile (30 to 33°S); petrogenetic implications and a Escondida area, northern Chile. Economic Geology tectonic discussion. In Andean Magmatism and its 94: 1231-1247. Tectonic Setting (Harmon, R.S.; Rapela, C.W.; edi- Rocha-Campos, A.C.; Basei, M.A.; Nutman, A.P.; Klei- tors). Geological Society of America, Special Papers man, L.; Varela, R.; Llambías, E.; Canile, F.M.; da 265: 99-112. Boulder. Rosa, O. de C.R. 2011. 30 million years of Permian Parada, M.A.; López-Escobar, L.; Oliveros, V.; Fuentes, F.; volcanism recorded in the Choiyoi igneous province Morata, D.; Calderón, M.; Aguirre, L.; Féraud, G.; (W Argentina) and their source for younger ash fall Espinoza, F.; Moreno, H.; Figueroa, O.; Muñoz, J.; deposits in the Paraná Basin: SHRIMP U-Pb zircon Troncoso, R.; Stern, C.R. 2007. Andean Magmatism. geochronology evidence. Gondwana Research 19 In The Geology of Chile (Moreno, T.; Gibbons, W.; (2): 509-523. editors). The Geological Society, Special Publication 4: Salazar, E. 2012. Evolución tectonoestratigráfica post- 115-146. London. Paleozoica de la Cordillera de Vallenar. Tesis de Pineda, G.; Calderón, M. 2008. Geología del área Monte Magister en Ciencias, Mención Geología (Inédito), Patria-El Maqui, Región de Coquimbo. Servicio Universidad de Chile, Departamento de Geología: Nacional de Geología y Minería, Carta Geológica de 126 p. Santiago. Chile, Serie Geología Básica 116: 44 p., 1 mapa escala Salazar, E.; Arriagada, C.; Mpodozis, M.; Martínez, F.; Peña, 1:100.000. Santiago. M.; Álvarez, J. 2009. Análisis estructural del Oroclino Ramírez, C.F.; Gardeweg, M. 1982. Geología de la Hoja de Vallenar. Resultados preliminares. In Congreso Toconao, Región de Antofagasta. Servicio Nacional Geológico Chileno, No. 12, Abstract: S9-026. Santiago. de Geología y Minería, Carta Geológica de Chile 54: Salazar, E.; Mpodozis, C.; Arriagada, C.; Coloma, F. 117 p., 1 mapa escala 1:250.000. Santiago. 2012. Evolución tectonoestratigráfica post-paleozoica Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 477

de la Cordillera de Vallenar. In Congreso Geológico In Congreso Geologico Chileno, No. 13, Proceedings, Chileno, No. 13, T2: 259-261. Antofagasta. CD-ROM. Antofagasta. Salazar, E.; Coloma, F.; Creixell, C. 2013. Geología del área Tera, F.; Wasserburg, G. 1972. U-Th-Pb systematics in El Tránsito-Lagunillas, Región de Atacama. Servicio three Apollo 14 basalts and the problem of initial Pb Nacional de Geología y Minería, Carta Geológica de in lunar rocks. Earth and Planetary Science Letters Chile, Serie Geología Básica 149. 14: 281-304. Sato, A.M.; Llambías, E.J. 1993. El Grupo Choiyoi, Tomlinson, A.J.; Blanco, N. 2008. Geología de la franja provincia de San Juan: equivalente del Batolito de El Abra-Chuquicamata, II Región (21°45ʼ-22°30ʼS). Colangüil. In Congreso Geológico Argentino, No. 12, Servicio Nacional de Geología y Minería, Informe Actas 4: 156-165. Mendoza. Registrado IR-08-35: 196 p. Santiago. Sempere, T.; Carlier, G.; Soler, P.; Fornari, M.; Carlotto, V.; Tomlinson, A.; Cornejo, P.; Mpodozis, C. 1999. Hoja Jacay, J. 2002. Late Permian-Middle Jurassic litho- Potrerillos, Región de Atacama. Servicio Nacional de spheric thinning in Perú and Bolivia, and its bearing Geología y Minería, Mapas Geológicos 14, 1 mapa on Andean-age tectonics. Tectonophysics 345 (1-4): escala 1:100.000. Santiago. 153-181. Tomlinson, A.J.; Blanco, N.; Maksaev, V.; Dilles, J.H.; Sepúlveda, P.; Naranjo, J.A. 1982. Geología de la Hoja Grunder, A.L.; Ladino, M. 2001. Geología de la Carrera Pinto, Región de Atacama. Servicio Nacional Precordillera Andina de Quebrada Blanca-Chuqui- de Geología y Minería, Carta Geológica de Chile 53: camata, Regiones I y II (20°30’-22°30’S). Servicio 60 p. 1 mapa escala 1:100.000. Santiago. Nacional de Geología y Minería, Informe Registrado Shibata, K.; Ishihara, S.; Ulriksen, C. 1984. Rb-Sr Ages IR-01-20: 444 p. Santiago. and Initial 87Sr/86Sr ratios of Late Paleozoic Granitic Uliana, M.A.; Biddle, K.T.; Cerdan, J. 1989. Mesozoic Rocks from Northern Chile. Bulletin of the Geological extension and the formation of Argentine sedimen- Survey of Japan 35 (11): 537-545. tary basins. In Extensional Tectonics and Stratigra- Sillitoe, R.H. 1977. Permo-Carboniferous, Upper Creta- phy of the North Atlantic Margins (Tankard, A.J.; ceous, and Miocene porphyry copper-type minerali- Balkwill, H.R.; editors). American Association of zation in the Argentinean Andes. Economic Geology Petroleum Geologists, Memoir 46: 599-614. 72: 99-109. Urzúa, F. 2009. Geology, geochronology and structural Skarmeta, J.; Marinovic, N. 1981. Geología de la Hoja evolution of La Escondida copper district, northern Quillagua, Región de Antofagasta. Instituto de Inves- Chile. Ph.D. Thesis (Unpublished), University of tigaciones Geológicas, Carta Geológica de Chile 51: Tasmania: 486 p. Hobart, Australia. 63 p. 1 mapa escala 1:250.000. Santiago. Vásquez, P.; Glodny, J.; Franz, G.; Frei, D.; Romer, R.L. Stipanicic, P.; Rodrigo, F.; Baulier, O.; Martínez, C. 2011. Early Mesozoic Plutonism of the Cordillera de 1968. Las Formaciones Presenonianas en el denomi- la Costa (34°-37°S), Chile: Constraints on the Onset nado Macizo Norpatagónico y regiones adyacentes. of the Andean Orogeny. The Journal of Geology 119 Revista de la Asociación Geológica Argentina 23: (2): 159-184. 67-98. Vaughan, A.P.M.; Pankhurst, R.J. 2008. Tectonic overview Strazzere, D.A.; Gregori, D.A.; Dristas, J.A. 2006. Genetic of the West Gondwana margin. Gondwana Research evolution of Permo-Triassic volcaniclastic sequences 13: 150-162. at Uspallata, Mendoza Precordillera, Argentina. Gond- Venegas, C.; Cervetto, M.; Astudillo, N.; Espinoza, F. wana Research 9: 485-499. 2013. Carta Sierra Vaquillas Altas, Regiones de Anto- Suárez, M.; Bell, M. 1991. Sedimentos lacustres de pro- fagasta y Atacama. Servicio Nacional de Geología y bable edad triásica en el área de La Coipa, Región de Minería, Carta Geológica de Chile, Serie Geología Atacama, Chile. In Congreso Geológico Chileno, No. 6, Básica 159. Actas 1: 660-663. Viña del Mar. Vergara, H.; Thomas, A. 1984. Hoja Collacagua, Región Suárez, M.; Bell, M. 1992. Triassic rift-related sedimen- de Tarapacá, Servicio Nacional de Geología y Minería, tary basins in northern Chile (24º-29ºS). Journal of Carta Geológica de Chile 59: 79 p., 1 mapa escala South American Earth Sciences 6: 109-121. 1:250.000. Santiago. Suárez, M.; Fanning, C.M.; Etchart, H.; De La Cruz, R. Vergara, M.; López-Escobar, L.; Cancino, A.; Levi, B. 2012. New Carboniferous to Toarcian U-Pb SHRIMP 1991. The Pichidangui Formation; some geochemical ages from Cordillera del Viento, Neuquén, Argentina. characteristics and tectonic implications of the Triassic 478 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

marine volcanism in central Chile (31º55’ to 32º20’S). Williams, I.S. 1998. U-Th-Pb geochronology by ion micro- In Andean Magmatism and its Tectonic Setting (Har- probe. In Applications of Microanalytical Techniques mon, R.S.; Rapela, C.W.; editors). Geological Society to Understanding Mineralizing Processes (McKibben, of America, Special Paper 265: 93-98. M.A.; Shanks III, W.C.; Ridley, W.I.; editors). Reviews Vinasco, C.J.; Cordani, U.; González, G.; Weber, M.; in Economic Geology 7: 1-35. Peláez, C. 2006. Geochronological, isotopic, and Witt, W.K.; Hagemann, S.G.; Villanes, C.; Zeng, Q. 2013. geochemical data from Permo-Triassic granitic New geochronological results and structural evolution gneisses and granitoids of the Colombian Central of the Pataz gold mining district: Implications for the Andes. Journal of South American Earth Sciences timing and origin of the batholith-hosted veins. Ore 21: 355-371. Geology Reviews 50: 143-170.

Manuscript received: November 26, 2013; revised/accepted: May 12, 2014; available online: May 14, 2014. Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 479

APPENDIX 1

Tera-Wasserburg concordia plots of SHRIMP U-Pb zircon ages for samples dated during this study (ordered according Tables 3 and 4). Ellipses and error in ages in the inset are at 1σ; decay constant errors included.

data point ellipses are 68.3% conf. data point ellipses are 68.3% conf. 0.12 0.062 CHY-50 Concordia Age = 324.7±2.0 Ma CHY-11 Concordia Age = 323.1±2.9 Ma MSWD (of concordance) = 0.066 MSWD (of concordance) = 0.27 Probability (of concordance) = 0.79 0.10 Probability (of concordance) = 0.60 0.058 b b 0.08 P P 0.054 206 206 b/ b/

600 350 P P 330 0.06 310 500 207 400 207 0.050 300

0.046 0.04

0.042 0.02 17.5 18.5 19.5 20.5 21.5 15 19 23 238U/206Pb 238U/206Pb

FO-11-35 Concordia Age = 320.1±4.5 Ma 0.064 CHY-29 Concordia Age = 296.6±2.1 Ma 0.07 MSWD (of concordance) = 0.44 MSWD (of concordance) = 0.016 Probability (of concordance) = 0.90 Probability (of concordance) = 0.51 0.060 b

b 0.056 P P 0.06 206 206 b/ b/ 0.052 P P 207 207 0.05 0.048

0.044

0.04 0.040 16 18 20 22 18.5 19.5 20.5 21.5 22.5 23.5 238U/206Pb 238U/206Pb

0.066 CHY-31 Concordia Age = 292.2±2.1 Ma 0.062 CHY-33 Concordia Age = 291.5 ±2.0 Ma MSWD (of concordance) = 2.0 MSWD (of concordance) = 0.53 0.062 Probability (of concordance) = 0.16 Probability (of concordance) = 0.47 0.058 b

b 0.058 P P

206 0.054 206 b/ b/

0.054 P P 207 207 0.050 0.050 0.046 0.046

0.042 0.042 19.5 20.5 21.5 22.5 23.5 19 20 21 22 23 24 238U/206Pb 238U/206Pb 0.14 0.14 CHY-14 Concordia Age = 311.3±4.1 Ma CHY-14 Concordia Age = 282.0±5.7 Ma 0.12 MSWD (of concordance) = 2.8 0.12 MSWD (of concordance) = 0.13 Probability (of concordance) = 0.094 Probability (of concordance) = 0.72 0.10 0.10 b b P P 206 0.08 206 0.08 b/ b/ P P 207 0.06 207 0.06

0.04 0.04

0.02 0.02

0.00 0.00 10 14 18 22 26 30 34 10 14 18 22 26 30 34 238U/206Pb 238U/206Pb 480 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

data point ellipses are 68.3% conf. data point ellipses are 68.3% conf. 0.12 0.14 CHY-18 Concordia Age = 276.6±2.0 Ma CHY-17 Concordia Age = 273.9±3.3 Ma MSWD (of concordance) = 0.21 0.12 MSWD (of concordance) = 3.1 0.10 Probability (of concordance) = 0.65 Probability (of concordance) = 0.077 0.10 0.08 b b 0.08 P P 206 206 0.06 b/ b/ 0.06 P P 207 207 0.04 0.04

0.02 0.02 0.00 10 14 18 22 26 30 34 38 0.00 238 206 15 17 19 21 23 25 27 29 U/ Pb 238U/206Pb 0.10 CHY-15 Concordia Age = 272.6±3.4 Ma CHY-22 Concordia Age = 270.4±2.3 Ma 0.14 MSWD (of concordance) = 0.002 MSWD (of concordance) = 0.049 Probability (of concordance) = 0.998 0.08 Probability (of concordance) = 0.82 0.12 b b P 0.06 P

206 0.10 206 b/ b/ P P 207 207 0.04 0.08

0.06 0.02 250 0.04 290 0.00 19 21 23 25 27 29 14 18 22 26 30 34 238U/206Pb 238U/206Pb 0.08 CHY-25 Concordia Age = 270.3±2.1 Ma CHY-27 Concordia Age = 269.9±2.0 Ma 0.12 MSWD (of concordance) = 0.36 MSWD (of concordance) = 0.53 Probability (of concordance) = 0.55 Probability (of concordance) = 0.47 0.07 b b 0.10 P P 206 206 b/ b/ P P 0.06 207 207 0.08

0.05 0.06

0.04 0.04 20.5 21.5 22.5 23.5 24.5 25.5 26.5 21 22 23 24 25 26 238U/206Pb 238U/206Pb 0.064 0.064 CHY-26 Concordia Age = 266.1±2.2 Ma CHY-36 Concordia Age = 262.0±1.4 Ma MSWD (of concordance) = 0.033 MSWD (of concordance) = 0.084 0.060 Probability (of concordance) = 0.86 0.060 Probability (of concordance) = 0.77 b b 0.056 P P 0.056 206 206 b/ b/ P

P 0.052 0.052 207 207 0.048 0.048

0.044 0.044

0.040 0.040 20.5 21.5 22.5 23.5 24.5 25.5 26.5 21.5 22.5 23.5 24.5 25.5 26.5 238U/206Pb 238U/206Pb Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 481

data point ellipses are 68.3% conf. data point ellipses are 68.3% conf. 0.062 FO-11-27 Concordia Age = 255.9±3.1 Ma CHY-56 Concordia Age = 249.7±1.9 Ma 0.062 MSWD (of concordance) = 0.18 MSWD (of concordance) = 0.040 Probability (of concordance) = 0.67 0.058 Probability (of concordance) = 0.84 0.058 Pb

Pb 0.054 206 0.054 206 Pb/ Pb/

207 0.050 0.050 207

0.046 0.046

0.042 0.042 20 22 24 26 28 30 22.5 23.5 24.5 25.5 26.5 27.5 28.5 238U/206Pb 238U/206Pb 0.060 FO-11-26 Concordia Age = 242.7±2.9 Ma CHY-10 Concordia Age = 232.1±2.3 Ma 0.09 MSWD (of concordance) = 0.045 MSWD (of concordance) = 0.32 0.056 Probability (of concordance) = 0.83 Probability (of concordance) = 0.57 0.08

0.052 Pb Pb 206 0.07 206 Pb/ Pb/

0.048 207 0.06 207

0.044 0.05

0.040 0.04 22 24 26 28 30 23 25 27 29 31 238U/206Pb 238U/206Pb 0.064 CHY-01 Concordia Age = 224.0±1.7 Ma 0.068 CHY-02 Concordia Age = 221.6±1.7 Ma MSWD (of concordance) = 0.19 MSWD (of concordance) = 0.30 0.060 Probability (of concordance) = 0.67 0.064 Probability (of concordance) = 0.58

0.056 0.060 Pb

Pb 0.056

0.052 206 206

Pb/ 0.052 Pb/

0.048 207 207 0.048 0.044 0.044

0.040 0.040 24 26 28 30 32 25 27 29 31 238U/206Pb 238U/206Pb 0.08 0.12 CHY-57 Concordia Age = 221.0±1.3 Ma CHY-08 Concordia Age = 154.3±1.9 Ma MSWD (of concordance) = 0.0015 MSWD (of concordance) = 0.61 0.10 Probability (of concordance) = 0.43 Probability (of concordance) = 0.9 0.07 0.08 Pb Pb 206

0.06 206 0.06 Pb/ Pb/ 207

207 0.04 0.05 0.02

0.04 0.00 25 27 29 31 33 20 30 40 50 60 238U/206Pb 238U/206Pb 482 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

data point ellipses are 68.3% conf. data point ellipses are 68.3% conf. 0.10 0.068 CHY-05 Concordia Age = 315.7±2.3 Ma CHY-09 Concordia Age = 311.9±3.0 Ma MSWD (of concordance) = 0.104 MSWD (of concordance) = 0.104 0.09 0.064 Probability (of concordance) = 0.75 Probability (of concordance) = 0.75

0.060 0.08 Pb Pb

206 0.056 206 0.07 Pb/ Pb/

207 0.052 207 0.06 0.048

0.044 0.05

0.040 0.04 17.5 18.5 19.5 20.5 21.5 22.5 17.5 18.5 19.5 20.5 21.5 22.5 238U/206Pb 238U/206Pb 0.08 0.068 CHY-06 Concordia Age = 307.1±2.4 Ma CHY-24 Concordia Age = 287.0±2.1 Ma MSWD (of concordance) = 0.66 MSWD (of concordance) = 1.06 0.064 Probability (of concordance) = 0.42 Probability (of concordance) = 0.30 0.07 0.060 Pb Pb

206 0.056 0.06 206 Pb/

0.052 Pb/ 207 207 0.048 0.05 0.044

0.040 0.04 18 19 20 21 22 23 19 21 23 25 238U/206Pb 238U/206Pb

CHY-07 Concordia Age = 286.3±3.1 Ma CHY-19a Concordia Age = 285.3±3.2 Ma 0.08 0.07 MSWD (of concordance) = 0.15 MSWD (of concordance) = 0.032 Probability (of concordance) = 0.70 Probability (of concordance) = 0.86 0.07 0.06 Pb Pb 206

206 0.06 Pb/ Pb/ 207

207 0.05 0.05

0.04 0.04 19.5 20.5 21.5 22.5 23.5 24.5 25.5 17 19 21 23 25 27 238U/206Pb 238U/206Pb 0.068 CHY-23 Concordia Age = 280.6±2.1 Ma CHY-48 Concordia Age = 276.6±1.8 Ma 0.08 0.064 MSWD (of concordance) = 0.096 (MSWD (of concordance) = 0.040 Probability (of concordance) = 0.76 Probability (of concordance) = 0.84 0.060 0.07 Pb

0.056 Pb 206 206

Pb/ 0.06

0.052 Pb/ 207 207 0.048 0.05 0.044

0.040 0.04 20 21 22 23 24 25 20 21 22 23 24 25 238U/206Pb 238U/206Pb Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 483

data point ellipses are 68.3% conf. data point ellipses are 68.3% conf. 0.08 0.068 CHY-47 Concordia Age = 269.5±2.0 Ma CHY-35 Concordia Age = 267.9±1.9 Ma MSWD (of concordance) = 0.006 0.064 MSWD (of concordance) = 0.34 Probability (of concordance) = 0.94 Probability (of concordance) = 0.56 0.07 0.060

0.056 Pb Pb

0.06 206 206 0.052 Pb/ Pb/ 207 207 0.048 0.05 0.044

0.04 0.040 20 22 24 26 21 22 23 24 25 26 238U/206Pb 238U/206Pb

CHY-12 Concordia Age = 264.9±3.5 Ma CHY-16 Concordia Age = 264.6±3.5 Ma 0.12 0.10 MSWD (of concordance) = 0.031 MSWD (of concordance) = 0.0066 Probability (of concordance) = 0.86 Probability (of concordance) = 0.94 0.10 Pb

Pb 0.08 206 206 0.08 Pb/ Pb/ 207 207 0.06 0.06

0.04 0.04 19 21 23 25 27 29 31 19 21 23 25 27 238U/206Pb 238U/206Pb

CHY-38 Concordia Age = 263.5±1.7 Ma CHY-58 Concordia Age = 258.9±2.5 Ma 0.12 0.08 (MSWD (of concordance) = 0.20 (MSWD (of concordance) = 0.73 Probability (of concordance) = 0.65 Probability (of concordance) = 0.69 0.10 0.07 Pb Pb 206 206 Pb/ Pb/ 0.08 0.06 207 207

0.06 0.05

0.04 0.04 21 22 23 24 25 26 27 22 23 24 25 26 27 238U/206Pb 238U/206Pb 0.09 CHY-46 Concordia Age = 246.5±2.0 Ma CHY-60 Concordia Age = 244.0±1.4 Ma 0.07 MSWD (of concordance) = 0.027 MSWD (of concordance) = 0.043 Probability (of concordance) = 0.87 0.08 Probability (of concordance) = 0.95

0.07 0.06 Pb Pb 206 206

Pb/ 0.06 Pb/ 207

207 0.05 0.05

0.04 0.04 22 24 26 28 22 24 26 28 238U/206Pb 238U/206Pb 484 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology...

data point ellipses are 68.3% conf. data point ellipses are 68.3% conf. 0.08 CHY-45 Concordia Age = 237.0±2.0 Ma CHY-03 Concordia Age = 229.6±2.6 Ma 0.07 MSWD (of concordance) = 0.086 MSWD (of concordance) = 0.012 Probability (of concordance) = 0.77 0.07 Probability (of concordance) = 0.91

0.06 Pb Pb

206 0.06 206 Pb/ Pb/ 207 207 0.05 0.05

0.04 0.04 24 25 26 27 28 29 24 26 28 30 238U/206Pb 238U/206Pb Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 485 ±1σ error 6.8 6.8 6.8 6.8 6.6 6.7 6.5 6.7 6.7 6.9 7.0* 6.9* 6.6 9.4 9.8 9.9 9.9 8.9 9.3 9.9 9.7 10.0 10.3 10.1 U 238 Pb/ 311.1 327.8 331.6 323.6 331.4 324.3 323.5 320.9 319.3 330.9 322.5 342.7* 342.3* 316.2 324.4 322.2 332.3 325.9 323.5 331.3 312.2 318.8 323.3 328.1 Age Ma 206 Pb corrected 204 % error 1.44 5.31 4.37 1.90 2.36 2.79 4.13 5.50 1.70 5.97 2.67 1.34 5.80 3.85 6.34 5.17 6.30 4.62 7.17 14.62 10.08 14.42 17.41 10.78 Pb 206 Pb/ 0.0532 0.0518 0.0532 0.0522 0.0535 0.0519 0.0529 0.0526 0.0539 0.0516 0.0542 0.0550 0.0532 0.0525 0.0563 0.0529 0.0529 0.0542 0.0534 0.0534 0.0530 0.0558 0.0512 0.0521 207 Radiogenic % 2.11 2.11 2.15 2.10 2.09 2.13 2.09 2.15 2.08 2.20 2.10 2.07 2.14 2.97 3.18 3.16 3.08 3.14 3.06 2.93 2.99 3.15 3.18 3.15 error Pb 206 U/ 19.17 18.94 19.42 18.95 19.38 19.43 19.59 19.69 18.98 19.49 18.31 18.34 19.89 19.38 19.51 18.89 19.28 19.43 18.96 20.14 19.72 19.43 20.21 19.14 238 Radiogenic % 1.22 3.07 2.25 1.44 1.55 1.43 2.15 1.90 1.41 1.90 1.67 1.16 2.32 1.99 2.25 5.19 3.92 1.94 2.00 1.81 3.37 6.70 5.03 2.61 error CHY-11 Pink rhyolite, Cerro Bayo Formation; Concordia U-Pb age = 323.1±2.9 Ma Pink rhyolite, Cerro CHY-11 Pb CHY-50 Greenish rhyolite, Cerro Bayo Formation; Concordia U-Pb age = 324.7±2.0 Ma rhyolite, Cerro Greenish CHY-50 206 Total Pb/ 0.054223 0.057306 0.057757 0.053387 0.056494 0.055371 0.056876 0.061257 0.056802 0.058539 0.057580 0.055084 0.061030 0.056601 0.067239 0.070556 0.067292 0.060639 0.062202 0.059814 0.064071 0.077737 0.074676 0.070625 207 % 2.11 2.10 2.14 2.10 2.09 2.13 2.08 2.13 2.08 2.18 2.09 2.07 2.12 2.96 3.16 3.06 3.03 3.13 3.04 2.92 2.97 3.08 3.05 3.10 error Pb 206 U/ Total 19.15 18.81 19.31 18.92 19.31 19.34 19.49 19.47 18.92 19.32 18.23 18.34 19.69 19.28 19.24 18.48 18.93 19.27 18.75 19.98 19.45 18.90 19.62 18.70 238 Pb 206 Pb/ 0.000311 0.000068 0.000377 0.000083 0.000204 0.000238 0.000275 0.000594 0.000196 0.000475 0.000229 0.000005 0.000537 0.000283 0.000747 0.001205 0.000983 0.000439 0.000599 0.000439 0.000753 0.001502 0.001603 0.001266 204 Pb 9.58 ppm 206 11.04 11.23 29.87 14.91 22.87 19.33 23.21 24.85 13.89 23.34 13.30 17.31 38.83 12.94 27.43 18.04 12.76 14.17 22.26 22.56 41.47 21.66 12.38 Radiogenic U 238 0.60 0.35 0.41 0.56 0.32 0.28 0.24 0.43 0.24 0.62 0.44 0.28 0.63 0.97 1.13 0.60 0.87 0.79 0.77 1.07 0.85 1.03 1.04 0.98 Th/ 232 Th 85.94 ppm 110.20 118.07 385.62 275.23 135.98 141.96 133.46 132.15 178.11 157.89 225.72 181.76 579.43 443.00 158.88 261.46 382.10 368.26 404.42 271.05 252.76 230.79 1002.59 ANALYTICAL DATA. ANALYTICAL b U ppm 665.79 326.52 215.24 503.78 434.45 522.45 563.87 314.83 513.88 299.20 367.37 828.74 296.52 615.42 403.98 274.43 312.31 499.46 492.39 964.64 490.36 272.25 252.09 244.45 Pb % 0.12 0.69 0.57 0.15 0.37 0.43 0.50 1.08 0.36 0.87 0.42 0.01 0.98 0.42 0.52 1.65 1.34 0.68 0.98 0.21 0.18 2.84 1.72 1.71 206 Common Grain Spot Sample CHY-50 CHY50-1.1 CHY50-2.1 CHY50-3.1 CHY50-4.1 CHY50-5.1 CHY50-6.1 CHY50-7.1 CHY50-8.1 CHY50-9.1 CHY50-10.1 CHY50-11.1 CHY50-12.1 CHY50-13.1 Sample CHY-11 CHY11-1.1 CHY11-2.1 CHY11-3.1 CHY11-4.1 CHY11-5.1 CHY11-6.1 CHY11-7.1 CHY11-8.1 CHY11-9.1 CHY11-10.1 CHY11-11.1 APPENDIX 2. SHIMP ZIRCON U-P APPENDIX 2. SHIMP 486 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... 6.5 7.1 6.5 6.4 5.9 6.0 7.0* 6.5 6.3 6.3 ±1σ 14.8 13.7 13.2 13.8 13.6 20.3* 13.8 12.8 13.3 43.2* 19.9* 14.5 13.2 error U 238 Pb/ 324.9 312.2 316.5 330.1 321.9 492.8* 329.6 313.8 320.0 494.4* 337.9 318.4 294.7 301.4 302.6 307.7 288.7 293.5 338.9* 293.7 294.6 295.8 Age Ma 1006.5* 206 Pb corrected 204 % 7.74 4.92 5.33 5.76 9.84 8.34 1.59 3.59 1.76 1.63 9.71 7.97 7.96 4.99 6.93 4.70 1.76 4.57 5.65 7.16 7.84 error 10.76 10.28 Pb 206 Pb/ 0.05110 0.05216 0.05190 0.05132 0.05422 0.05407 0.05567 0.05234 0.05344 0.07703 0.05690 0.06475 0.05223 0.05242 0.05372 0.05227 0.05308 0.05080 0.05240 0.05333 0.05246 0.05309 0.05295 207 Radiogenic % 4.68 4.49 4.27 4.28 4.31 4.27 4.31 4.17 4.26 4.63 4.18 4.41 4.26 2.25 2.43 2.18 2.15 2.10 2.08 2.12 2.27 2.18 2.18 error Pb 206 5.92 U/ 19.34 20.15 19.87 19.03 19.52 12.58 19.05 20.05 19.64 12.54 18.57 19.74 21.37 20.89 20.80 20.45 21.83 21.47 18.52 21.45 21.38 21.29 238 Radiogenic CHY-29 Pinkish rhyolite, Paipote Valley; Concordia U-Pb age = 296.6±2.1 Ma Valley; Pinkish rhyolite, Paipote CHY-29 % 1.11 3.53 2.36 2.77 2.66 5.18 3.35 2.17 2.63 1.28 1.37 2.98 2.20 3.62 2.73 2.40 2.42 2.43 1.50 1.78 2.45 3.56 2.54 error Pb 206 Total Pb/ 0.058986 0.055744 0.056543 0.059167 0.063071 0.066508 0.073316 0.053605 0.058135 0.078951 0.059864 0.081399 0.072296 0.062980 0.060991 0.059465 0.057358 0.056842 0.052742 0.058716 0.060345 0.064405 0.065397 207 % 4.66 4.48 4.27 4.27 4.28 4.25 4.26 4.17 4.26 4.63 4.18 4.36 4.22 2.21 2.38 2.17 2.10 2.09 2.07 2.11 2.25 2.16 2.14 error FO-11-35 Rhyolitic ignimbrite, underlies Cerro del Árbol Formation; Concordia U-Pb age = 320.1±4.5 Ma Rhyolitic ignimbrite, underlies Cerro FO-11-35 Pb 206 5.90 U/ Total 19.18 20.03 19.75 18.84 19.31 12.39 18.63 20.02 19.53 12.50 18.18 19.25 21.09 20.70 20.62 20.34 21.67 21.46 18.40 21.24 21.08 20.96 238 Pb 206 Pb/ 0.000466 0.000317 0.000317 0.000535 0.000606 0.000851 0.001210 0.000086 0.000321 0.000136 0.000203 0.001154 0.001370 0.000721 0.000497 0.000491 0.000292 0.000411 0.000023 0.000368 0.000539 0.000773 0.000850 204 Pb ppm 206 7.15 6.45 7.59 8.31 9.62 17.05 12.54 17.90 10.13 23.99 21.68 76.61 13.25 42.24 46.60 13.85 19.41 19.40 14.35 19.03 29.29 19.20 12.11 Radiogenic U 238 0.60 0.59 0.45 0.69 0.70 0.38 1.03 0.94 0.64 0.33 0.40 0.79 0.62 0.53 0.55 0.66 0.54 1.69 0.76 0.71 0.54 0.49 0.65 Th/ 232 Th ppm 92.32 92.24 81.05 97.17 97.53 226.33 126.88 261.75 153.81 127.20 467.96 187.74 259.40 224.43 262.44 296.24 178.15 782.97 539.89 282.32 157.05 146.72 1,625.62 U ppm 411.12 159.54 397.46 288.28 392.57 227.66 345.81 470.13 301.23 290.18 677.99 293.14 434.85 158.38 182.86 465.47 339.83 480.03 731.55 299.28 203.91 234.69 1,784.84 Pb % 206 0.85 0.58 0.58 0.97 1.10 1.53 2.20 0.16 0.58 0.23 0.36 2.10 2.49 1.32 0.91 0.90 0.53 0.75 0.04 0.67 0.98 1.41 1.55 Common Grain Spot Sample FO-11-35 appendix 2 continued. FO11-35-1.1 FO11-35-2.1 FO11-35-3.1 FO11-35-4.1 FO11-35-5.1 FO11-35-6.1 FO11-35-7.1 FO11-35-8.1 FO11-35-9.1 FO11-35-10.1 FO11-35-11.1 FO11-35-10.2 FO11-35-12.1 Sample CHY-29 CHY29-1.1 CHY29-2.1 CHY29-3.1 CHY29-4.1 CHY29-5.1 CHY29-6.1 CHY29-7.1 CHY29-8.1 CHY29-9.1 CHY29-10.1 Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 487 ±1σ error 7.6 7.5 6.8 6.7 7.5 7.4 6.8 6.8 7.1 7.0 7.1 6.9 6.0 2.8* 6.5 5.7 5.8 5.9 6.2 5.8 5.6 5.8 U 238 Pb/ Age Ma 206 288.0 292.3 291.0 286.6 280.5 293.9 292.7 288.6 294.0 291.8 295.0 298.5 298.4 143.7* 287.9 291.5 293.3 289.5 301.4 290.3 283.9 288.4 Pb corrected 204 % error 3.86 5.17 4.99 4.18 3.84 4.59 7.98 5.86 3.10 5.64 2.97 6.16 1.94 3.08 3.51 4.00 2.65 5.72 2.84 3.92 3.26 16.34 Pb 206 Pb/ 207 Radiogenic 0.05224 0.05240 0.05177 0.05277 0.05085 0.05229 0.05241 0.05442 0.05313 0.05495 0.05262 0.05385 0.05187 0.04912 0.05284 0.05383 0.05508 0.05177 0.05264 0.05250 0.05152 0.05219 % error 2.71 2.61 2.39 2.37 2.71 2.58 2.37 2.41 2.48 2.47 2.45 2.36 2.06 2.00 2.29 1.99 2.04 2.08 2.10 2.03 2.03 2.05 Pb 206 U/ 21.88 21.56 21.65 21.99 22.47 21.43 21.52 21.84 21.43 21.60 21.35 21.10 21.10 44.36 21.89 21.61 21.48 21.77 20.89 21.71 22.21 21.85 238 Radiogenic CHY-31 Purple rhyolite, Paipote Valley; Concordia U-Pb age = 292.2±2.1 Ma Valley; Purple rhyolite, Paipote CHY-31 % error 1.44 3.47 2.48 2.17 7.92 1.22 3.36 4.70 3.71 2.74 3.17 1.40 3.45 1.05 1.93 1.37 3.44 1.67 1.88 1.90 1.59 1.57 CHY-33 Light-gray, andesitic tuff, El Mono Beds; Concordia U-Pb age = 291.5±2.0 Ma Light-gray, CHY-33 Pb 206 Total Pb/ 207 0.056511 0.056968 0.057001 0.058984 0.075182 0.056873 0.057818 0.063773 0.058587 0.058686 0.057886 0.056871 0.055709 0.051838 0.055963 0.058869 0.058440 0.056040 0.056823 0.058143 0.056724 0.056190 % error 2.70 2.60 2.38 2.36 2.65 2.57 2.37 2.38 2.47 2.47 2.44 2.35 2.04 2.00 2.29 1.98 2.03 2.08 2.08 2.03 2.02 2.04 Pb 206 U/ Total 21.77 21.44 21.51 21.82 21.78 21.31 21.38 21.58 21.28 21.49 21.21 21.02 21.00 44.20 21.80 21.48 21.39 21.65 20.78 21.56 22.07 21.74 238 Pb 206 Pb/ 204 0.000292 0.000312 0.000357 0.000424 0.001658 0.000313 0.000369 0.000640 0.000373 0.000256 0.000360 0.000206 0.000262 0.000185 0.000213 0.000345 0.000230 0.000291 0.000286 0.000385 0.000355 0.000273 Pb ppm 206 11.40 24.09 36.41 23.22 29.55 17.48 33.13 28.77 14.67 21.13 23.92 20.58 25.34 12.16 75.04 15.24 27.40 22.03 15.50 14.86 21.36 24.86 Radiogenic U 238 Th/ 0.62 0.77 0.57 0.52 0.53 0.52 0.79 0.49 0.67 0.73 0.77 0.65 0.33 0.18 0.85 0.51 0.85 0.44 0.18 0.52 0.61 0.56 232 Th ppm 93.99 66.51 367.77 673.34 322.37 376.92 229.42 410.70 548.74 173.97 340.35 424.21 380.47 390.53 684.28 318.87 338.48 232.58 236.69 186.79 326.12 343.26 U ppm 610.30 908.38 581.32 750.62 443.30 821.93 715.94 368.60 523.39 598.41 508.16 619.81 297.35 386.75 685.03 283.74 555.16 374.99 372.87 548.57 629.12 3,860.99 Pb % 206 0.53 0.57 0.65 0.77 3.03 0.57 0.67 1.17 0.68 0.47 0.66 0.38 0.48 0.34 0.39 0.63 0.42 0.53 0.52 0.70 0.65 0.50 Common Grain Spot Sample CHY-31 appendix 2 continued. CHY31-1.1 CHY31-2.1 CHY31-3.1 CHY31-4.1 CHY31-5.1 CHY31-6.1 CHY31-7.1 CHY31-8.1 CHY31-9.1 CHY31-10.1 CHY31-11.1 CHY31-12.1 Sample CHY-33 CHY33-1.1 CHY33-2.1 CHY33-3.1 CHY33-4.1 CHY33-5.1 CHY33-6.1 CHY33-7.1 CHY33-8.1 CHY33-9.1 CHY33-10.1 488 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... 8.5 6.3 4.9 9.4 4.3* 4.8* 7.4 5.6 4.1 3.3* 6.0 5.7 ±1σ 11.2 11.1 11.6 11.6 11.5 11.2 11.1 11.4 13.7 12.5 10.6 12.4 error U 238 Pb/ 296.0 281.7 282.9 321.7 308.0 316.6 316.6 313.9 280.4 282.5 322.2 292.4 268.8 267.1 284.5 267.5 257.8* 296.9* 277.4 274.6 275.8 297.2* 284.7 273.2 Age Ma 206 Pb corrected 204 % 5.84 8.63 2.69 8.73 2.74 8.16 7.75 error 11.06 15.10 23.45 34.30 14.19 10.27 17.52 32.10 31.23 27.22 19.51 14.80 13.61 20.24 20.51 17.56 21.22 Pb 206 Pb/ 0.04950 0.05242 0.06904 0.05089 0.05297 0.05194 0.05212 0.05207 0.05205 0.05728 0.05005 0.05046 0.05152 0.05276 0.05039 0.05425 0.05194 0.05261 0.05248 0.05190 0.05699 0.05216 0.05897 0.05490 207 Radiogenic % 3.87 4.02 4.93 3.68 3.85 3.73 3.62 4.09 3.87 4.03 3.61 4.34 3.23 2.42 1.77 3.57 1.71 1.66 2.74 2.07 1.53 1.15 2.14 2.14 error Pb 206 U/ 21.27 22.37 22.24 19.53 20.42 19.85 19.86 20.03 22.49 22.31 19.51 21.52 23.46 23.61 22.15 23.58 24.50 21.20 22.73 22.96 22.87 21.19 22.13 23.08 238 Radiogenic % 3.02 9.18 6.60 1.79 5.60 4.22 1.26 4.10 2.32 6.40 1.20 6.13 6.69 7.78 4.05 3.93 3.38 3.44 4.91 4.92 3.19 2.71 4.02 3.77 error Pb 206 Total CHY-18 Dark green, rhyolitic tuff, La Tabla Formation; Concordia U-Pb age = 276.6±2.0 Ma Tabla rhyolitic tuff, La Dark green, CHY-18 Pb/ 0.070758 0.083100 0.136134 0.061796 0.075690 0.064427 0.055752 0.067687 0.064521 0.077632 0.054500 0.102148 0.087245 0.089644 0.070675 0.082335 0.073984 0.070820 0.072312 0.072952 0.070838 0.062205 0.079908 0.075274 207 % 3.78 3.87 4.27 3.67 3.79 3.71 3.61 4.06 3.83 3.90 3.61 4.02 2.71 1.96 1.76 3.37 1.49 1.46 2.46 1.69 1.36 1.07 1.79 1.64 error CHY-14 Dark purple, rhyolitic tuff, La Tabla Formation; Concordia U-Pb ages = 311.3±4.1 and 282.0±5.7 Ma Formation; Concordia U-Pb ages = 311.3±4.1 Tabla Dark purple, rhyolitic tuff, La CHY-14 Pb 206 U/ Total 20.71 21.51 20.34 19.27 19.84 19.55 19.78 19.64 22.14 21.74 19.40 20.13 22.42 22.52 21.59 22.75 23.82 20.72 22.17 22.36 22.47 20.93 21.55 22.50 238 Pb 206 Pb/ 0.001446 0.002095 0.004677 0.000743 0.001552 0.000852 0.000248 0.001066 0.000851 0.001398 0.000303 0.003520 0.002436 0.002519 0.001381 0.001922 0.001504 0.001243 0.001354 0.001436 0.000951 0.000686 0.001441 0.001395 204 Pb 8.43 5.45 2.29 9.07 9.16 4.79 3.67 3.62 3.00 5.70 3.64 5.16 6.21 4.21 4.44 6.45 3.80 4.23 ppm 206 22.79 12.38 46.81 12.27 54.00 12.51 Radiogenic U 238 0.95 1.21 0.77 1.01 0.89 0.75 1.31 0.84 0.70 1.10 1.15 1.29 0.63 0.57 0.59 0.90 0.68 1.08 0.63 0.79 0.60 0.73 0.60 0.62 Th/ 232 Th 40.15 57.22 43.20 81.57 83.88 94.65 66.69 88.42 97.30 54.91 66.63 ppm 187.15 159.65 497.27 181.43 204.69 169.37 212.82 128.50 107.61 156.21 214.44 1,368.89 1,354.19 U ppm 54.20 86.09 94.36 78.74 96.37 95.34 511.04 115.56 110.80 203.31 136.39 209.54 281.62 209.42 316.22 121.19 143.35 143.04 149.78 108.75 168.71 304.74 1,077.47 1,219.29 Pb % 2.64 3.83 8.54 1.35 2.83 1.55 0.45 1.94 1.55 2.55 0.55 6.42 4.45 4.61 2.52 3.51 2.75 2.27 2.47 2.63 1.74 1.25 2.63 2.55 206 Common Grain Spot appendix 2 continued. Sample CHY-14 CHY14-1.1 CHY14-2.1 CHY14-3.1 CHY14-4.1 CHY14-5.1 CHY14-6.1 CHY14-7.1 CHY14-8.1 CHY14-9.1 CHY14-10.1 CHY14-11.1 CHY14-12.1 Sample CHY-18 CHY18-1.1 CHY18-2.1 CHY18-3.1 CHY18-4.1 CHY18-5.1 CHY18-6.1 CHY18-7.1 CHY18-8.1 CHY18-9.1 CHY18-10.1 CHY18-11.1 CHY18-12.1 Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 489 9.8 9.8 9.9 ±1σ 11.7* 11.6 11.7 11.9* 10.0 10.9 10.5 10.0 10.1 10.8 10.6 10.6 14.0 13.1 10.6 10.1 10.2 10.2 10.7 error U 238 Pb/ 272.2 273.8 319.9* 267.4 268.5 278.5 276.6 266.2 264.7 323.7* 272.2 291.5 279.8 257.8 279.2 270.4 264.0 267.7 269.3 272.3 276.3 281.5 Age Ma 206 Pb corrected 204 % 8.16 2.58 8.07 9.56 9.82 9.42 8.23 4.48 5.47 error 25.16 31.79 26.50 14.22 19.41 17.30 45.35 38.60 14.76 17.15 15.83 13.04 14.28 Pb 206 Pb/ 0.05277 0.05460 0.05162 0.05285 0.05236 0.06074 0.05194 0.05210 0.05018 0.05152 0.05661 0.05077 0.05071 0.05456 0.07063 0.05190 0.05089 0.05887 0.05095 0.05171 0.05132 0.05058 207 Radiogenic % 3.73 3.65 3.74 4.17 4.42 4.30 3.88 3.85 3.89 3.75 4.04 3.72 3.88 5.52 4.80 3.99 3.92 3.89 3.88 3.66 3.65 3.89 error Pb 206 U/ 23.18 23.05 19.65 23.58 23.48 22.63 22.80 23.71 23.85 19.41 23.17 21.61 22.52 24.46 22.54 23.32 23.90 23.56 23.43 23.17 22.83 22.39 238 Radiogenic % 2.32 1.82 3.23 3.31 5.68 2.50 4.90 3.26 3.02 7.22 2.19 2.88 5.45 3.12 4.56 2.39 3.06 1.31 3.16 3.08 error 11.98 10.76 Pb 206 CHY-17 Dark green rhyolitic tuff, La Tabla Formation; Concordia U-Pb age = 273.9±3.3 Ma Tabla rhyolitic tuff, La Dark green CHY-17 Total CHY-15 Dark green, rhyolitic tuff, La Tabla Formation; Concordia U-Pb age = 272.6±3.4 Ma Tabla rhyolitic tuff, La Dark green, CHY-15 Pb/ 0.064015 0.057090 0.059613 0.097361 0.099556 0.094346 0.064672 0.065652 0.067992 0.067333 0.085921 0.061827 0.084799 0.130619 0.136515 0.074758 0.078859 0.094346 0.074749 0.061801 0.056703 0.072750 207 % 3.70 3.65 3.71 3.92 4.05 4.06 3.84 3.83 3.81 3.72 3.92 3.69 3.78 4.85 4.18 3.91 3.82 3.76 3.82 3.66 3.64 3.82 error Pb 206 U/ Total 22.85 22.97 19.45 22.27 22.09 21.67 22.44 23.31 23.32 19.03 22.31 21.32 21.56 22.13 20.65 22.66 23.07 22.51 22.73 22.88 22.68 21.77 238 Pb 206 Pb/ 0.000768 0.000171 0.000545 0.003040 0.003222 0.002318 0.000869 0.000925 0.001212 0.001078 0.002011 0.000753 0.002322 0.005206 0.004602 0.001559 0.001905 0.002442 0.001622 0.000688 0.000367 0.001510 204 Pb 3.88 2.74 2.76 9.23 9.69 5.55 4.14 7.61 2.05 2.22 4.90 5.42 7.17 6.56 5.81 ppm 206 11.40 10.86 19.93 10.04 13.06 35.55 21.22 Radiogenic U 238 1.58 1.75 0.73 0.78 1.18 0.91 1.38 0.91 0.66 0.57 0.67 0.91 0.55 0.87 0.67 0.63 0.66 1.14 1.35 1.42 1.42 0.86 Th/ 232 Th 76.28 80.46 61.04 95.55 70.12 44.29 34.42 78.48 92.40 ppm 440.78 900.96 181.51 321.07 231.51 121.96 285.05 101.52 206.53 226.51 770.55 121.90 1,299.53 U ppm 70.42 69.60 52.71 53.29 288.98 532.98 258.08 100.55 241.06 262.85 150.62 222.34 107.59 323.96 191.01 129.22 145.40 187.72 173.46 946.76 560.17 147.19 Pb % 206 1.40 0.31 0.99 5.56 5.89 4.24 1.59 1.69 2.22 1.96 3.68 1.37 4.24 9.53 8.41 2.85 3.49 4.47 2.97 1.26 0.67 2.76 Common Grain Spot appendix 2 continued. Sample CHY-17 CHY17-1.1 CHY17-2.1 CHY17-3.1 CHY17-4.1 CHY17-5.1 CHY17-6.1 CHY17-7.1 CHY17-8.1 CHY17-9.1 CHY17-10.1 CHY17-11.1 CHY17-12.1 Sample CHY-15 CHY15-1.1 CHY15-2.1 CHY15-3.1 CHY15-4.1 CHY15-5.1 CHY15-6.1 CHY15-7.1 CHY15-8.1 CHY15-9.1 CHY15-10.1 490 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... 6.2 5.9 4.5* 6.2 5.9 6.8 8.1* 8.4 7.1 7.0 7.5 7.1 6.7 7.4 7.7 7.4 7.6 6.0 6.3 8.2 5.9 8.9* ±1σ 11.0* error 14.4* U 238 Pb/ 689.7* 262.9 269.1 210.0* 272.9 276.1 262.8 285.7* 308.8* 276.5 279.0 268.8 281.1 269.3 266.5 256.3 259.6 277.4 262.4 278.2 271.8 272.8 265.6 339.4* Age Ma 206 Pb corrected 204 % 5.77 9.75 2.46 8.96 2.92 8.72 8.27 9.18 9.26 9.15 5.97 7.76 5.76 4.09 8.08 error 14.34 15.99 20.25 10.13 26.26 12.08 19.57 16.11 19.77 Pb 206 Pb/ 0.07279 0.05037 0.05173 0.05314 0.05178 0.05095 0.05425 0.05576 0.05514 0.05296 0.05113 0.05099 0.05212 0.05136 0.05221 0.05092 0.05172 0.05360 0.05308 0.05764 0.05235 0.04894 0.05300 0.05387 207 Radiogenic % 2.40 2.24 2.20 2.30 2.19 2.66 2.20 2.90 3.63 3.10 2.61 2.68 2.73 2.68 2.57 2.95 3.02 2.71 2.94 2.20 2.35 3.07 2.25 2.69 error Pb 206 8.85 U/ 24.02 23.46 30.19 23.13 22.84 24.02 22.06 20.36 22.79 22.60 23.48 22.43 23.43 23.69 24.64 24.32 22.74 24.05 22.68 23.22 23.12 23.77 18.48 238 Radiogenic % 3.57 1.81 2.07 2.30 4.12 7.09 3.56 2.60 5.60 4.88 3.09 4.02 2.83 2.32 3.03 3.03 7.49 4.07 1.98 6.07 5.18 3.36 2.52 error 13.42 Pb CHY-25 Pinkish gray, dacite, Pantanoso Formation; Concordia U-Pb age = 270.3±2.1 Ma Pinkish gray, CHY-25 206 CHY-22 Purple, banded rhyolite, La Tabla Formation; Concordia U-Pb age = 270.4±2.3 Ma Tabla Purple, banded rhyolite, La CHY-22 Total Pb/ 0.063397 0.055472 0.068363 0.053833 0.061342 0.072821 0.066617 0.088233 0.081928 0.062097 0.066392 0.060664 0.064212 0.061805 0.076918 0.074004 0.064104 0.074841 0.059000 0.056234 0.065425 0.063856 0.080115 0.083766 207 % 2.34 2.24 2.14 2.30 2.15 2.58 2.86 3.51 2.90 2.57 2.64 2.67 2.63 2.55 2.81 2.96 2.67 2.75 2.18 2.34 2.97 2.23 2.40 2.17 error Pb 206 8.73 U/ Total 23.63 23.35 29.62 23.07 22.55 23.47 21.76 19.52 21.97 22.29 23.03 22.19 23.06 23.40 23.84 23.64 22.44 23.40 22.64 23.11 22.65 23.45 17.88 238 Pb 206 Pb/ 0.000887 0.000255 0.001040 0.000140 0.000708 0.001271 0.000744 0.002267 0.001979 0.000747 0.001049 0.000583 0.000876 0.000655 0.001771 0.001520 0.000718 0.001487 0.000093 0.000265 0.001120 0.000742 0.001795 0.000769 204 Pb 3.56 7.02 6.64 3.55 6.07 2.58 8.23 5.20 4.64 5.59 8.88 3.77 7.05 5.45 4.34 7.09 4.01 5.86 3.17 ppm 206 16.12 14.38 10.34 13.23 15.44 Radiogenic U 238 0.66 0.56 0.75 0.52 0.76 0.45 0.56 0.62 0.59 0.66 0.65 0.61 0.88 0.88 0.55 0.94 1.01 0.58 0.50 0.53 0.61 0.42 0.53 0.39 Th/ 232 Th 62.68 78.98 48.59 82.60 37.85 88.28 70.52 55.33 66.84 90.20 62.69 65.27 34.04 58.92 ppm 236.21 358.84 140.14 134.84 135.82 127.22 206.14 176.11 138.86 184.10 U ppm 97.84 89.88 65.91 65.96 119.91 118.12 438.21 495.71 277.76 184.35 181.41 137.81 213.45 139.39 150.06 241.90 104.73 193.86 142.35 186.74 355.80 105.79 159.81 156.83 Pb % 1.62 0.47 1.91 0.26 1.29 2.33 1.36 4.13 3.62 1.37 1.92 1.07 1.60 1.20 3.24 2.78 1.31 2.72 0.17 0.48 2.05 1.36 3.26 1.35 206 Common Grain Spot CHY25-7.1 CHY25-8.1 CHY25-9.1 CHY25-10.1 CHY25-11.1 CHY25-12.1 appendix 2 continued. Sample CHY-22 CHY22-1.1 CHY22-2.1 CHY22-3.1 CHY22-4.1 CHY22-5.1 CHY22-6.1 CHY22-7.1 CHY22-8.1 CHY22-9.1 CHY22-10.1 CHY22-11.1 CHY22-12.1 Sample CHY-25 CHY25-1.1 CHY25-2.1 CHY25-3.1 CHY25-4.1 CHY25-5.1 CHY25-6.1 Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 491 ±1σ 7.1* 6.3 8.1 6.1 6.5 6.0* 6.7 6.6 6.8 6.4 6.5 6.6 6.2 7.3 6.4 8.2 6.2 6.5 6.4 6.6 7.1 6.4 7.7 error 11.3 27.2* 36.3* U 238 Pb/ 297.0* 265.9 285.4 256.5 272.6 241.7* 276.6 262.3 266.2 265.3 268.8 265.5 262.9 482.6 270.7 273.1 270.8 270.6 269.2 265.2 265.6 266.8 273.4 266.5 Age Ma 1162.0* 1650.8* 206 Pb corrected 204 % 1.78 7.95 6.97 0.86 6.50 3.00 6.32 6.16 4.83 6.24 9.69 error 11.40 10.87 15.12 45.91 20.24 4.10 8.61 9.24 5.45 6.99 9.12 7.34 4.19 6.24 4.49 Pb 206 Pb/ 0.07751 0.05273 0.05150 0.05183 0.10438 0.06141 0.06123 0.05298 0.05521 0.05119 0.05231 0.05115 0.05567 0.05438 0.05252 0.05300 207 Radiogenic 0.05149 0.05175 0.04999 0.05163 0.05339 0.04989 0.05135 0.05273 0.05202 0.05151 % 2.45 2.41 2.91 2.56 2.49 2.42 2.76 2.41 3.07 2.36 2.48 2.46 2.55 2.72 2.41 2.96 error 2.43 2.42 2.53 2.47 2.57 2.62 2.45 2.48 2.52 2.41 Pb 206 5.06 3.42 U/ 21.21 23.74 22.08 12.86 23.30 23.10 23.25 23.33 23.44 23.81 23.77 23.64 23.08 23.68 238 24.63 23.14 26.17 22.80 24.07 23.71 23.80 23.48 23.78 24.02 Radiogenic % 2.25 2.55 2.95 0.72 7.95 4.81 1.81 1.65 2.43 1.98 2.69 7.52 1.97 2.61 0.57 error 13.08 1.19 4.66 1.90 1.82 3.59 3.08 3.66 2.61 3.07 2.70 CHY-27 Purple rhyolite, Pantanoso Formation; Concordia U-Pb age = 269.9±2.0 Ma CHY-27 Pb 206 Total Pb/ 207 0.059984 0.062873 0.071248 0.083052 0.072883 0.078842 0.059328 0.127000 0.054702 0.058763 0.058762 0.060990 0.081687 0.060552 0.065562 0.106599 0.057983 0.061637 0.068765 0.059089 0.061920 0.064488 0.058119 0.055111 0.059986 0.057905 CHY-26 Purple, rhyolitic ignimbrite, Pantanoso Formation; Concordia U-Pb age = 266.1±2.2 Ma CHY-26 % 2.40 2.38 2.84 2.56 2.40 2.57 2.38 2.47 2.35 2.45 2.43 2.54 2.51 2.38 2.90 2.49 error 2.42 2.39 2.49 2.46 2.55 2.58 2.43 2.48 2.50 2.40 Pb 206 5.03 3.42 U/ Total 21.01 23.40 21.55 12.67 22.78 22.92 21.16 23.22 23.25 23.58 23.62 22.84 22.85 23.31 24.43 22.86 25.55 22.59 23.82 23.28 23.60 23.41 23.54 23.83 238 Pb 206 Pb/ 0.000495 0.000775 0.001325 0.000391 0.000792 0.001215 0.000434 0.004918 0.000239 0.000440 0.000519 0.000364 0.001869 0.000548 0.000858 0.000162 204 0.000443 0.000674 0.001277 0.000509 0.000583 0.000994 0.000461 0.000163 0.000543 0.000436 Pb 5.78 5.08 6.86 5.23 8.81 11.73 13.85 89.48 19.04 18.91 22.85 19.68 14.82 18.08 15.32 ppm 206 120.57 43.55 16.12 26.71 18.53 16.31 10.67 19.09 18.22 18.14 20.56 Radiogenic U 238 0.67 0.87 1.11 0.61 0.63 0.73 1.20 0.58 0.93 0.91 0.55 1.08 0.68 0.90 0.96 0.11 Th/ 1.28 0.53 1.16 0.67 0.47 0.67 0.56 0.49 0.60 0.68 232 94.54 95.25 91.91 50.75 Th 187.23 316.00 155.95 220.13 893.76 318.37 205.07 186.98 286.44 233.93 289.31 376.60 307.71 171.51 585.09 555.55 470.34 218.24 518.49 356.53 222.63 ppm 1,539.65 U ppm 286.87 377.15 144.86 428.99 794.46 487.37 452.10 289.26 524.38 496.49 497.07 570.35 523.50 280.86 134.69 504.52 168.95 617.70 532.64 406.74 497.01 138.96 407.40 239.07 479.43 1,238.36 Pb % 0.90 1.42 2.42 0.81 1.23 2.34 0.93 1.07 1.82 0.84 0.30 0.99 0.80 0.66 1.42 2.22 0.79 8.99 0.44 0.81 0.95 0.67 3.42 1.00 1.57 0.26 206 Common Grain Spot CHY27-14.1 CHY27-15.1 CHY27-16.1 Sample CHY-26 CHY26-1.1 CHY26-2.1 CHY26-3.1 CHY26-4.1 CHY26-5.1 CHY26-6.1 CHY26-7.1 CHY26-8.1 CHY26-9.1 CHY26-10.1 CHY27-13.1 appendix 2 continued. Sample CHY-27 CHY27-1.1 CHY27-2.1 CHY27-3.1 CHY27-4.1 CHY27-5.1 CHY27-6.1 CHY27-7.1 CHY27-8.1 CHY27-9.1 CHY27-10.1 CHY27-11.1 CHY27-12.1 492 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... 5.2 5.4 5.5 5.2 5.2 5.6 5.3 7.1* 5.3 5.3 5.3 5.2 5.1 5.1 5.2 ±1σ 11.4 error 10.4 10.7 10.6 10.6 10.8 10.8 10.9 10.7 10.9 10.4 10.9 U 238 Pb/ 261.6 271.0 262.3 259.5 259.9 255.7 267.3 301.6* 260.7 260.7 258.0 266.6 260.4 260.9 263.8 245.9 255.0 264.6 256.1 255.2 260.6 251.0 264.7 258.5 258.2 244.2 260.3 Age Ma 206 Pb corrected 204 % 3.65 3.95 7.85 4.12 4.40 5.52 2.42 2.74 4.51 3.29 2.94 2.77 3.63 3.13 2.50 4.80 4.51 4.55 3.07 2.54 3.05 3.46 2.57 2.80 5.19 3.49 5.17 error Pb 206 Pb/ 0.05093 0.05297 0.05147 0.05199 0.05147 0.05062 0.05142 0.05182 0.05153 0.05163 0.05155 0.05122 0.05162 0.05182 0.05164 0.05496 0.04966 0.05203 0.05169 0.05144 0.05169 0.05133 0.05132 0.04993 0.05167 0.05356 0.05217 207 Radiogenic % 2.01 2.05 2.14 2.03 2.05 2.23 2.04 2.41 2.08 2.08 2.08 2.01 2.02 2.01 2.01 4.32 4.28 4.40 4.20 4.22 4.22 4.40 4.21 4.22 4.29 4.32 4.29 error Pb 206 U/ 24.14 23.29 24.08 24.35 24.30 24.72 23.62 20.87 24.23 24.23 24.49 23.69 24.26 24.21 23.94 25.72 24.78 23.86 24.67 24.77 24.24 25.19 23.86 24.44 24.47 25.91 24.27 238 Radiogenic % 1.41 1.81 2.11 1.61 1.87 2.64 1.81 1.86 1.75 1.62 1.66 1.86 1.53 1.49 1.42 3.38 3.26 2.22 1.91 2.27 2.26 2.58 2.00 2.01 3.06 3.49 3.10 error Pb 206 Total Pb/ 0.055113 0.056110 0.056208 0.054291 0.055220 0.056085 0.056469 0.056825 0.055238 0.054003 0.054271 0.053566 0.054379 0.054402 0.055344 0.057567 0.058036 0.056653 0.054483 0.053670 0.053872 0.054809 0.053034 0.052112 0.056061 0.053556 0.054950 207 CHY-36 Dark purple, fluidal Formation; Concordia U-Pb age = 262.0±1.4 Ma CHY-36 Tabla rhyolite, La FO-11-27 Pink rhyolitic ignimbrite, Cas Formation, Peine Group; Concordia U-Pb age = 255.9±3.1 Ma Pink rhyolitic ignimbrite, Cas Formation, Peine Group; FO-11-27 % 2.00 2.04 2.09 2.01 2.04 2.21 2.04 2.41 2.06 2.07 2.08 2.01 2.01 2.01 2.00 4.31 4.28 4.39 4.20 4.22 4.22 4.40 4.21 4.22 4.28 4.32 4.28 error Pb 206 U/ Total 24.02 23.20 23.93 24.28 24.19 24.55 23.47 20.74 24.12 24.16 24.40 23.62 24.17 24.13 23.83 25.64 24.52 23.73 24.58 24.70 24.17 25.08 23.81 24.37 24.34 25.91 24.19 238 Pb 206 Pb/ 0.000285 0.000215 0.000323 0.000157 0.000256 0.000372 0.000344 0.000341 0.000253 0.000162 0.000186 0.000160 0.000188 0.000176 0.000252 0.000179 0.000570 0.000316 0.000190 0.000152 0.000149 0.000237 0.000117 0.000148 0.000300 0.000000 0.000190 204 Pb 7.39 9.74 9.42 8.68 9.35 ppm 206 32.34 19.85 14.55 24.82 19.35 17.80 19.36 17.98 32.97 29.59 23.70 46.94 29.29 28.61 37.30 25.24 23.60 17.75 18.27 13.42 22.63 23.40 Radiogenic U 238 0.80 0.44 0.64 0.83 0.57 1.13 0.77 0.67 1.23 0.63 0.82 0.66 0.77 0.60 0.72 0.53 0.67 0.72 0.91 0.74 0.78 0.82 0.74 0.71 0.48 0.72 0.55 Th/ 232 Th ppm 113.18 699.08 230.79 250.09 563.28 303.06 556.23 393.06 281.63 508.18 533.75 819.16 615.58 466.09 718.77 179.12 482.98 594.47 366.54 387.35 310.79 447.31 457.23 123.30 183.36 140.00 1101.19 U ppm 904.23 536.04 405.23 701.42 544.82 508.61 528.89 434.19 925.51 832.22 673.10 824.12 803.69 220.56 278.11 697.03 675.21 510.14 513.94 391.89 627.08 663.85 266.92 261.67 263.28 1034.36 1,290.46 Pb % 206 0.52 0.39 0.59 0.29 0.47 0.68 0.63 0.62 0.46 0.30 0.34 0.29 0.34 0.32 0.46 0.33 1.04 0.58 0.35 0.28 0.27 0.43 0.21 0.27 0.55 0.00 0.35 Common Grain Spot appendix 2 continued. Sample CHY-36 CHY36-1.1 CHY36-2.1 CHY36-3.1 CHY36-4.1 CHY36-5.1 CHY36-6.1 CHY36-7.1 CHY36-8.1 CHY36-9.1 CHY36-10.1 CHY36-11.1 CHY36-12.1 CHY36-13.1 CHY36-14.1 CHY36-15.1 Sample FO-11-27 FO11-27-1.1 FO11-27-2.1 FO11-27-3.1 FO11-27-4.1 FO11-27-5.1 FO11-27-6.1 FO11-27-7.1 FO11-27-8.1 FO11-27-9.1 FO11-27-10.1 FO11-27-11.1 FO11-27-12.1 Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 493 5.0 4.9 5.0 6.4* 6.3* 6.3* 6.6* 4.9 4.9 4.7 6.6* 4.8 9.8 ±1σ error 10.0 10.3 10.2 10.6 10.2 10.1 10.2 10.2 10.2 10.0 10.0 U 238 Pb/ 252.5 256.1 253.2 330.1* 314.7* 325.1* 313.6* 240.8 252.7 246.4 334.5* 247.5 239.7 246.8 233.1 244.5 244.5 244.5 246.6 244.4 247.5 244.5 242.4 238.2 Age Ma 206 Pb corrected 204 % 2.63 1.48 3.63 3.07 2.62 3.26 8.21 5.07 2.84 1.63 2.48 3.65 4.24 2.76 5.57 5.22 6.37 3.89 1.56 3.80 3.28 3.50 2.68 3.98 error Pb 206 Pb/ 0.051593 0.051407 0.052567 0.053233 0.052501 0.051483 0.054259 0.050051 0.051524 0.049920 0.054556 0.053677 0.05222 0.05267 0.04870 0.05089 0.04975 0.04765 0.05104 0.05008 0.05138 0.05082 0.05352 0.05078 207 Radiogenic % 2.03 1.95 2.03 2.00 2.06 2.00 2.16 2.09 1.99 1.96 2.02 1.98 4.26 4.25 4.28 4.26 4.41 4.25 4.18 4.25 4.22 4.23 4.22 4.29 error Pb 206 U/ 25.03 24.67 24.96 19.03 19.99 19.33 20.05 26.28 25.01 25.67 18.78 25.54 26.40 25.63 27.15 25.87 25.86 25.87 25.65 25.88 25.55 25.87 26.10 26.56 238 Radiogenic % 1.41 0.96 1.86 1.67 1.58 1.66 1.80 2.87 1.63 1.02 1.91 1.37 2.66 2.76 2.70 2.76 2.49 2.70 1.56 2.41 2.00 2.46 2.29 1.90 error Pb 206 Total FO-11-26 Redish rhyolite, Cas Formation, Peine Group; Concordia U-Pb age = 242.7±2.9 Ma Redish rhyolite, Cas Formation, Peine Group; FO-11-26 Pb/ 207 0.053824 0.052579 0.056736 0.055662 0.056471 0.055786 0.069732 0.053720 0.055668 0.051563 0.056559 0.059870 0.054280 0.052670 0.055675 0.054140 0.055790 0.052309 0.051038 0.053494 0.053635 0.052456 0.055143 0.053293 CHY-56 Dark greenish, basaltic tuff, La Totora Formation; Concordia U-Pb age = 249.7±1.9 Ma Totora basaltic tuff, La Dark greenish, CHY-56 % 2.02 1.95 2.02 2.00 2.06 1.99 2.11 2.07 1.99 1.96 2.01 1.97 4.25 4.25 4.27 4.25 4.39 4.25 4.18 4.25 4.22 4.23 4.22 4.29 error Pb 206 U/ Total 24.96 24.64 24.83 18.97 19.89 19.22 19.66 26.16 24.88 25.62 18.73 25.35 26.33 25.63 26.91 25.77 25.67 25.72 25.65 25.77 25.48 25.82 26.05 26.48 238 Pb 206 Pb/ 0.000152 0.000080 0.000285 0.000166 0.000271 0.000293 0.001059 0.000250 0.000283 0.000112 0.000137 0.000423 0.000141 0.000000 0.000474 0.000221 0.000411 0.000316 0.000000 0.000233 0.000154 0.000112 0.000111 0.000171 204 Pb 8.32 ppm 206 11.88 11.34 28.96 68.27 15.56 20.65 22.47 21.21 13.62 20.58 55.69 15.45 29.57 14.88 12.05 13.66 12.28 36.87 15.13 21.79 14.83 15.92 25.36 Radiogenic U 238 0.04 0.04 0.05 0.40 0.51 0.74 0.75 0.72 0.07 0.11 0.52 0.06 0.79 0.66 0.76 0.84 0.60 0.63 0.64 0.59 0.53 0.81 0.94 0.83 Th/ 232 Th ppm 28.82 78.38 22.30 42.48 49.35 177.40 259.24 340.95 227.29 176.39 172.64 170.58 348.08 225.72 260.23 293.25 237.91 225.97 683.98 259.77 333.26 347.78 438.19 626.91 U ppm 311.76 841.19 449.81 456.08 520.15 474.69 253.40 595.95 336.83 872.26 456.09 354.50 355.32 361.48 407.99 367.76 453.81 646.04 445.77 482.74 781.84 1,957.98 1,660.55 1,100.86 Pb % 0.28 0.15 0.52 0.30 0.49 0.53 1.93 0.46 0.52 0.20 0.25 0.78 0.26 0.00 0.87 0.41 0.75 0.58 0.00 0.43 0.28 0.20 0.20 0.31 206 Common Grain Spot appendix 2 continued. Sample CHY-56 CHY56-1.1 CHY56-2.1 CHY56-3.1 CHY56-4.1 CHY56-5.1 CHY56-6.1 CHY56-7.1 CHY56-8.1 CHY56-9.1 CHY56-10.1 CHY56-11.1 CHY56-12.1 Sample FO-11-26 FO11-26-1.1 FO11-26-2.1 FO11-26-3.1 FO11-26-4.1 FO11-26-5.1 FO11-26-6.1 FO11-26-7.1 FO11-26-8.1 FO11-26-9.1 FO11-26-10.1 FO11-26-11.1 FO11-26-12.1 494 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... 8.2 7.8 7.1 8.2 8.0 7.9 7.0 7.5 7.3 7.2 6.8 5.7 6.3 5.5 5.7 5.7 5.6 5.5 5.3 5.7 5.9 5.4 ±1σ error U 238 Pb/ 211.3 232.2 228.0 233.8 234.5 238.1 234.8 237.8 230.1 226.2 232.0 224.3 227.6 228.0 226.0 234.5 226.9 227.1 216.6 220.6 228.3 214.3 Age Ma 206 Pb corrected 204 % 8.18 6.85 3.52 6.30 3.98 2.54 4.91 4.48 7.40 5.91 9.77 4.04 4.56 error 28.19 27.45 13.71 26.30 15.08 22.28 22.81 16.53 13.77 Pb 206 Pb/ 0.04772 0.05207 0.05254 0.05366 0.05022 0.05030 0.05153 0.05170 0.05472 0.05316 0.04993 0.04980 0.05165 0.05085 0.05109 0.05204 0.05200 0.05092 0.04971 0.04981 0.05070 0.05135 207 Radiogenic % 3.59 3.48 3.10 3.55 3.41 3.42 2.98 3.30 3.29 3.14 3.10 2.56 2.80 2.49 2.46 2.54 2.52 2.57 2.56 2.63 2.64 2.54 error Pb 206 27.24 27.75 27.06 26.96 26.56 26.94 26.60 27.49 27.98 27.28 28.23 27.83 27.78 28.03 26.99 27.90 27.89 29.25 30.01 28.71 27.74 29.58 U/ 238 Radiogenic % 4.89 6.80 4.81 5.98 5.09 4.12 2.95 7.69 4.50 2.13 5.41 1.39 1.92 2.09 1.26 1.99 2.37 2.21 1.73 2.55 2.57 1.91 error Pb 206 Total Pb/ 0.083220 0.099324 0.073604 0.095967 0.069019 0.084973 0.066104 0.085024 0.082031 0.062125 0.069834 0.053401 0.057965 0.055225 0.054378 0.058822 0.054733 0.060712 0.057132 0.062567 0.054973 0.057797 207 % 3.27 3.21 3.02 3.25 3.32 3.21 2.96 3.12 3.15 3.12 3.04 2.55 2.78 2.48 2.45 2.53 2.51 2.54 2.53 2.58 2.63 2.53 error Pb 206 U/ Total 26.04 26.11 26.35 25.53 25.94 25.77 26.12 26.35 27.02 26.98 27.53 27.70 27.56 27.87 26.88 27.67 27.79 28.90 29.73 28.25 27.59 29.34 238 CHY-10 Redish brown, banded rhyolite, Los Tilos Sequence, Pastos Blancos Group; Concordia U-Pb age = 232.1±2.3 Ma Sequence, Pastos Blancos Group; Tilos banded rhyolite, Los Redish brown, CHY-10 Concordia U-Pb age = 224.0±1.7 Ma Sequence, Pastos Blancos Group; Tilos banded rhyolite, Los Redish brown, CHY-01 Pb 206 Pb/ 0.002409 0.003225 0.001438 0.002892 0.001280 0.002361 0.000994 0.002273 0.001870 0.000613 0.001354 0.000245 0.000431 0.000298 0.000224 0.000463 0.000186 0.000667 0.000505 0.000868 0.000291 0.000439 204 Pb 4.46 5.45 4.84 5.66 7.09 6.38 9.68 8.25 7.24 7.63 5.92 ppm 206 11.24 11.62 11.92 17.59 17.16 17.32 12.21 22.74 10.87 12.23 10.07 Radiogenic U 238 0.53 0.62 0.75 0.55 0.76 0.80 0.90 0.75 0.53 0.86 0.73 0.85 0.73 0.95 1.33 0.81 0.64 0.63 0.91 0.42 0.83 0.79 Th/ 232 Th ppm 70.00 99.01 76.75 78.88 251.30 259.02 131.41 465.22 157.93 102.62 450.89 219.98 461.67 186.25 364.90 915.67 183.39 219.36 156.72 374.17 306.86 263.46 U ppm 711.31 135.22 165.62 344.80 143.86 350.76 169.93 534.61 217.43 200.78 538.74 310.29 558.61 264.74 396.18 233.03 351.68 256.72 423.45 194.56 382.83 343.94 Pb % 3.32 4.91 2.32 5.26 1.99 3.53 1.39 4.18 3.25 1.06 1.40 0.32 0.03 0.67 0.22 0.00 0.33 1.36 206 -0.05 -0.36 -0.15 -0.14 Common Grain Spot appendix 2 continued. Sample CHY-10 CHY10-1.1 CHY10-2.1 CHY10-3.1 CHY10-4.1 CHY10-5.1 CHY10-6.1 CHY10-7.1 CHY10-8.1 CHY10-9.1 CHY10-10.1 CHY10-11.1 Sample CHY-01 CHY1-1.1 CHY1-2.1 CHY1-3.1 CHY1-4.1 CHY1-5.1 CHY1-6.1 CHY1-7.1 CHY1-8.1 CHY1-9.1 CHY1-10.1 CHY1-11.1 Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 495 5.4 5.9 5.9 5.6 5.5 5.5 5.4 5.8 5.5 5.3 6.0 4.9 4.8 4.5 4.6 4.5 5.0 5.3 5.5 5.0 4.7 4.5 4.6 6.6* 5.7* 5.2 6.1* ±1σ error U 238 Pb/ 211.4 218.9 226.2 220.9 225.6 223.3 222.2 216.9 217.5 217.2 220.6 227.2 221.6 221.8 218.9 221.8 222.7 227.3 225.3 219.3 217.1 219.2 221.4 241.8* 261.0* 225.2 248.2* Age Ma 206 Pb corrected 204 % 4.42 3.37 3.99 4.60 6.55 6.72 4.03 7.26 3.77 8.73 9.17 8.70 6.84 6.85 9.85 4.99 9.14 error 11.72 10.97 14.64 18.21 15.15 12.18 27.88 10.97 16.62 27.56 Pb 206 Pb/ 0.04988 0.05157 0.05082 0.05111 0.05078 0.05410 0.05093 0.05107 0.04974 0.05002 0.05468 0.05128 0.05000 0.05389 0.05148 0.05090 0.04982 0.05186 0.04992 0.05109 0.04958 0.05324 0.05038 0.05522 0.05093 0.05058 0.05112 207 Radiogenic % 2.49 2.66 2.71 2.50 2.51 2.50 2.55 2.71 2.56 2.46 2.69 2.23 2.22 2.10 2.09 2.05 2.24 2.57 2.47 2.31 2.20 2.09 2.09 2.79 2.24 2.34 2.51 error Pb 206 28.94 28.00 28.68 28.07 28.36 28.50 29.22 29.14 29.18 28.72 27.87 28.58 28.56 28.95 28.56 28.44 27.85 29.99 28.10 28.88 29.18 28.90 28.61 26.14 24.20 28.11 25.45 U/ 238 Radiogenic % 1.50 2.04 3.97 1.67 1.69 2.18 3.23 2.01 2.28 1.61 3.00 2.51 3.71 3.86 3.07 2.24 4.22 5.66 2.01 3.25 3.39 2.78 3.39 6.83 5.57 4.40 8.69 error Pb 206 Total Pb/ 0.054718 0.055215 0.062207 0.055644 0.056974 0.067904 0.059638 0.055341 0.056661 0.055193 0.063611 0.065904 0.061775 0.066294 0.060378 0.059293 0.070679 0.078392 0.073061 0.063353 0.063743 0.058951 0.063643 0.087375 0.064030 0.074017 0.093070 207 % 2.48 2.65 2.63 2.49 2.50 2.47 2.53 2.70 2.53 2.46 2.63 2.14 2.17 2.05 2.06 2.02 2.11 2.39 2.32 2.24 2.09 2.08 2.04 2.22 2.18 2.17 2.19 error CHY-57 Dark redish brown, porphyritic basalt, La Totora Formation; Concordia U-Pb age = 221.0±1.3 Ma Totora porphyritic basalt, La brown, Dark redish CHY-57 CHY-02 Pink rhyolitic tuff, Los Tilos Sequence, Pastos Blancos Group; Concordia U-Pb age = 221.6±1.7 Ma Sequence, Pastos Blancos Group; Tilos Pink rhyolitic tuff, Los CHY-02 Pb 206 U/ Total 28.77 27.87 28.27 27.91 28.15 28.01 28.90 28.99 28.93 28.53 27.56 28.05 28.14 28.49 28.24 28.14 27.12 28.99 27.29 28.44 28.67 28.70 28.14 25.08 23.80 27.29 24.12 238 Pb 206 Pb/ 0.000329 0.000249 0.000776 0.000309 0.000422 0.000945 0.000594 0.000291 0.000471 0.000352 0.000612 0.000997 0.000801 0.000848 0.000607 0.000572 0.001419 0.001810 0.001575 0.000836 0.000963 0.000391 0.000903 0.002203 0.000893 0.001596 0.002859 204 Pb ppm 206 7.99 5.17 9.46 9.65 5.23 8.31 8.33 7.12 7.89 11.97 14.03 15.02 14.04 18.10 17.25 20.48 14.09 15.58 17.26 24.14 10.48 18.90 13.66 20.32 18.28 14.81 10.09 Radiogenic U 238 0.76 0.87 0.56 0.76 0.85 0.89 0.64 0.99 0.73 1.17 0.56 0.75 0.89 0.93 1.46 1.52 0.58 0.77 1.28 1.20 0.95 1.42 1.60 0.96 0.69 0.71 1.36 Th/ 232 Th ppm 91.57 91.38 347.62 218.18 358.83 379.74 507.79 196.08 556.52 229.28 773.56 196.96 399.45 463.96 803.17 185.33 210.12 471.74 728.15 418.03 932.38 924.60 192.36 274.60 220.31 292.32 1162.20 U ppm 469.83 259.20 169.98 487.86 459.86 589.94 318.34 582.11 324.82 680.36 167.78 271.41 461.64 516.66 567.34 790.78 330.97 281.07 380.23 625.61 455.81 678.93 598.58 207.92 410.34 320.48 221.58 Pb % 0.10 0.72 1.71 0.43 0.28 1.31 1.83 1.47 1.56 1.11 1.05 2.60 3.33 2.89 1.54 1.77 0.72 1.66 4.04 1.63 2.93 5.24 206 -0.10 -0.26 -0.37 -0.05 -0.03 Common Grain Spot appendix 2 continued. Sample CHY-02 CHY2-1.1 CHY2-2.1 CHY2-3.1 CHY2-4.1 CHY2-5.1 CHY2-6.1 CHY2-7.1 CHY2-8.1 CHY2-9.1 CHY2-10.1 CHY2-11.1 Sample CHY-57 CHY57-1.1 CHY57-2.1 CHY57-3.1 CHY57-4.1 CHY57-5.1 CHY57-6.1 CHY57-7.1 CHY57-8.1 CHY57-9.1 CHY57-10.1 CHY57-11.1 CHY57-12.1 CHY57-13.1 CHY57-14.1 CHY57-15.1 CHY57-16.1 496 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... 5.3 5.5 5.5 5.9 5.0 8.2 8.8 7.8 7.8 8.2 7.7 8.1 8.0 7.8 8.0 8.2 7.9 6.0 5.3 5.0 ±1σ error 29.4* U 238 Pb/ 311.5 311.0 153.8 143.2 156.8 156.5 161.6 315.6 309.6 310.2 322.0 303.9 313.7 319.7 315.6 323.1 327.1 153.9 150.7 153.2 1102.5* Age Ma 206 Pb corrected 204 % 1.25 8.92 6.04 5.34 5.33 6.57 3.91 5.72 4.96 6.28 9.09 2.60 error 30.32 40.48 26.43 35.26 16.68 10.08 39.51 31.26 20.91 Pb 206 Pb/ 0.07539 0.05140 0.04934 0.05097 0.04960 0.04779 0.05238 0.05404 0.05293 0.05135 0.05352 0.05234 0.05312 0.05133 0.05661 0.04936 0.05320 0.05339 0.05143 0.05036 0.04897 207 Radiogenic % 3.48 3.89 3.52 3.83 3.14 2.65 2.90 2.58 2.56 2.61 2.61 2.65 2.56 2.53 2.54 2.71 2.49 3.92 3.57 3.29 2.90 error Pb 206 5.36 41.38 44.47 40.58 40.64 39.37 19.92 20.32 20.28 20.20 19.52 20.71 20.05 19.66 19.93 19.45 20.22 19.21 41.36 42.25 41.55 U/ 238 Radiogenic % 8.58 6.06 5.01 5.58 3.49 2.94 2.30 2.23 3.39 3.06 2.99 2.18 3.46 2.09 2.78 1.57 7.12 6.53 4.96 0.86 error 10.22 Pb 206 Total Pb/ 0.091561 0.108891 0.091338 0.103714 0.068933 0.064518 0.063700 0.060811 0.058288 0.058235 0.059791 0.058509 0.059207 0.061382 0.058728 0.065420 0.056337 0.112271 0.099050 0.082336 0.077940 207 CHY-08 Reddish brown, porphyritic andesite, Picudo Formation; Concordia U-Pb age = 154.3±1.9 Ma Reddish brown, CHY-08 % 3.20 3.39 3.24 3.35 3.04 2.61 2.83 2.56 2.54 2.60 2.58 2.64 2.54 2.52 2.52 2.66 2.48 3.33 3.20 3.12 2.90 error Pb 206 CHY-05 Light gray, coarse-grained, biotite monzogranite; Guachicay pluton; Concordia U-Pb age = 315.7±2.3 Ma Light gray, CHY-05 5.34 U/ Total 39.29 41.14 38.52 37.88 38.33 19.62 20.08 20.08 20.02 19.41 20.52 19.92 19.47 19.81 19.23 19.91 19.14 38.19 39.67 39.81 238 Pb 206 Pb/ 0.002738 0.004050 0.002751 0.003681 0.001435 0.000829 0.000661 0.000539 0.000473 0.000323 0.000508 0.000368 0.000537 0.000327 0.000637 0.000835 0.000201 0.004148 0.003315 0.002268 0.000179 204 Pb ppm 206 4.59 3.41 4.35 3.42 9.79 7.30 5.63 9.75 9.51 9.68 6.01 3.51 4.59 5.99 11.75 10.90 13.41 16.73 13.12 29.54 88.01 Radiogenic U 238 0.93 0.86 0.88 0.77 1.47 0.68 0.67 0.49 0.39 0.72 0.64 0.86 0.71 0.49 0.49 0.67 0.52 0.89 1.04 0.82 0.26 Th/ 232 Th ppm 84.89 95.40 90.62 112.04 110.31 188.35 136.28 165.74 621.44 109.03 149.16 144.16 259.81 183.94 182.52 138.11 333.23 135.08 214.02 218.89 135.25 U ppm 211.77 209.98 163.36 194.96 150.90 436.61 166.83 131.50 228.01 253.95 214.81 231.16 310.84 266.21 385.73 293.61 139.39 658.03 156.08 277.41 547.40 Pb % 5.81 7.35 4.95 6.27 1.59 1.06 1.45 0.49 0.35 0.64 0.85 0.37 0.54 1.20 0.19 7.85 4.38 3.24 0.09 206 -0.52 -0.09 Common Grain Spot CHY8-6.1 CHY8-7.1 CHY8-8.1 CHY8-9.1 CHY8-10.1 Sample CHY-05 CHY5-1.1 CHY5-2.1 CHY5-2.2 CHY5-3.1 CHY5-4.1 CHY5-5.1 CHY5-6.1 CHY5-7.1 CHY5-8.1 CHY5-9.1 CHY5-10.1 CHY5-11.1 appendix 2 continued. Sample CHY-08 CHY8-1.1 CHY8-3.1 CHY8-4.1 CHY8-5.1 Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 497 8.0 7.2 8.1* 9.0 7.4 9.2 7.4 7.5 7.5 7.4 9.2 9.7 9.1 9.1 9.2 9.8 9.5 9.0 9.8 7.5 9.0* ±1σ error 11.2* 11.7 27.0* 25.9* U 238 Pb/ 311.6 311.2 307.9 303.8 283.8* 310.7 309.1 301.9 312.7 309.3 469.4* 305.2 312.6 306.2 317.7 322.0 309.0 310.1 306.4 314.5 308.6 297.2 358.9* 1103.1* 1142.2* Age Ma 206 Pb corrected 204 % 2.70 8.70 2.40 8.26 1.21 2.05 8.42 1.17 3.06 3.33 4.07 1.56 6.79 3.40 7.49 8.04 9.50 4.86 5.60 1.54 error 11.44 11.93 31.07 14.98 10.32 Pb 206 Pb/ 0.07488 0.05417 0.05228 0.05129 0.05089 0.07256 0.05262 0.05487 0.05207 0.05168 0.05544 0.05179 0.05202 0.05412 0.05265 0.05274 0.05348 0.05406 0.05242 0.05582 0.04987 0.05404 0.05524 0.05417 0.05278 207 Radiogenic % 2.65 2.44 2.91 2.98 2.45 3.13 2.42 2.47 2.46 2.51 2.43 2.66 2.48 3.08 3.77 3.18 2.91 3.02 3.04 3.26 3.14 2.94 3.24 2.57 2.58 error Pb 206 5.35 5.16 20.44 20.72 22.21 20.25 20.36 20.85 20.12 20.34 13.24 20.62 20.12 20.55 19.76 20.19 19.52 20.36 20.29 20.53 20.21 20.00 20.39 21.19 17.47 U/ 238 Radiogenic % 3.69 1.27 2.33 3.26 1.41 4.04 0.86 1.58 2.51 2.11 1.18 1.52 2.23 6.44 2.37 1.55 3.42 2.61 7.08 3.13 1.75 4.74 3.28 1.42 0.84 error Pb 206 Total Pb/ 0.062762 0.054981 0.064261 0.064616 0.054067 0.065034 0.052486 0.055611 0.059168 0.056570 0.053297 0.079568 0.074889 0.099852 0.060614 0.057828 0.064486 0.064691 0.073225 0.064925 0.062516 0.070230 0.059576 0.053162 0.074754 207 % 2.61 2.44 2.88 2.91 2.44 3.09 2.41 2.46 2.46 2.50 2.43 2.65 3.00 3.38 3.15 2.90 3.00 3.01 3.17 3.10 2.93 3.19 2.55 2.58 2.47 CHY-09 Pink, coarse-grained, biotite syenogranite; Guanta pluton; Concordia U-Pb age = 311.9±3.0 Ma Pink, coarse-grained, biotite syenogranite; Guanta pluton; Concordia U-Pb age = 311.9±3.0 CHY-09 error Pb 206 5.33 5.14 CHY-06 Coarse-grained, foliated, biotite-hornblende tonalite; Guanta pluton; Concordia U-Pb age = 307.1±2.4 Ma CHY-06 U/ Total 20.22 20.65 21.85 19.90 20.32 20.58 20.11 20.24 13.18 20.50 20.09 20.01 18.60 19.99 19.42 20.09 19.98 20.09 19.83 19.79 20.00 21.05 17.46 238 Pb 206 Pb/ 0.000587 0.000184 0.000884 0.000935 0.000099 0.000696 0.000029 0.000268 0.000255 0.000326 0.000087 0.000329 0.001421 0.003223 0.000537 0.000297 0.000713 0.000838 0.001194 0.001025 0.000580 0.001027 0.000370 0.000026 0.000154 204 Pb ppm 206 7.17 9.40 7.74 7.04 4.24 7.20 9.38 41.49 38.14 99.32 27.72 37.02 17.22 51.71 23.94 12.87 15.77 34.67 13.94 12.86 18.09 23.77 12.06 67.12 59.70 Radiogenic U 238 0.71 0.39 0.82 0.85 0.41 0.65 0.49 0.41 0.64 0.52 0.46 0.48 0.57 0.73 0.43 0.63 0.54 0.80 0.33 0.47 0.62 0.66 0.56 0.12 0.50 Th/ 232 Th 68.61 64.63 53.19 ppm 115.74 373.40 189.29 146.98 360.40 105.44 257.52 349.40 206.10 542.66 166.30 151.83 478.60 169.47 231.53 188.98 329.80 180.74 124.76 164.64 171.50 1,094.68 U ppm 91.83 168.78 997.49 238.93 179.38 902.07 168.66 653.08 567.72 410.94 148.40 299.74 366.96 783.55 325.92 299.00 168.43 417.74 547.35 280.89 229.70 357.42 2,324.88 1,209.40 1,363.90 Pb % 0.91 0.61 0.75 0.68 0.04 0.03 1.77 5.77 0.76 0.32 0.89 1.15 2.69 1.04 0.17 1.97 0.39 206 -0.10 -0.07 -0.16 -0.44 -0.23 -0.06 -0.03 -0.24 Common Grain Spot CHY6-11.1 CHY6-12.1 CHY6-13.1 CHY6-7.2 CHY6-4.1 CHY6-5.1 CHY6-6.1 CHY6-7.1 CHY6-8.1 CHY6-8.2 CHY6-9.1 CHY6-10.1 appendix 2 continued. Sample CHY-09 CHY9-1.1 CHY9-2.1 CHY9-3.1 CHY9-4.1 CHY9-5.1 CHY9-6.1 CHY9-7.1 CHY9-8.1 CHY9-9.1 CHY9-10.1 Sample CHY-06 CHY6-1.1 CHY6-2.1 CHY6-3.1 498 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... 7.9 6.9 7.3 7.5 7.5 7.1 8.0 7.3 7.0 8.5 7.1 7.3 8.2 8.8 8.2 8.8 8.2 8.6 7.9 9.3 9.9* ±1σ error 13.0* U 238 Pb/ 289.2 284.7 293.6 288.9 284.9 290.2 297.5 291.7 285.6 275.4 281.9 273.1 291.7 284.8 289.6 275.9 462.9* 292.0 286.1 281.8 315.2 350.6* Age Ma 206 Pb corrected 204 % 3.06 6.14 7.78 9.99 5.21 7.38 5.26 4.37 6.66 3.13 2.94 9.51 2.76 2.32 2.08 2.61 4.49 error 14.42 12.35 10.33 15.60 10.86 Pb 206 Pb/ 0.05170 0.05215 0.05332 0.05317 0.05431 0.05306 0.06141 0.05364 0.05191 0.05181 0.05356 0.05107 0.05157 0.05150 0.05138 0.05070 0.05700 0.05196 0.05235 0.05196 0.05275 0.05377 207 Radiogenic % 2.80 2.48 2.55 2.64 2.71 2.51 2.74 2.57 2.50 3.16 2.57 2.74 2.88 3.16 2.88 3.26 2.91 2.87 3.08 2.87 3.03 2.91 error Pb 206 21.78 22.14 21.45 21.81 22.13 21.71 21.17 21.60 22.07 22.90 22.36 23.10 21.60 22.12 21.76 22.86 13.43 21.58 22.03 22.38 19.96 17.89 U/ 238 Radiogenic % 5.26 2.31 3.44 2.66 5.57 1.89 3.45 2.29 1.86 4.26 2.22 2.95 1.29 6.24 1.33 3.76 1.94 1.12 5.31 1.09 1.32 2.70 error Pb 206 Total Pb/ 0.072813 0.054418 0.060241 0.062243 0.064821 0.060051 0.069512 0.060680 0.058297 0.071788 0.062610 0.066082 0.056650 0.074898 0.055825 0.065816 0.060541 0.056280 0.064295 0.055475 0.056857 0.059809 207 % 2.71 2.47 2.53 2.61 2.66 2.49 2.70 2.55 2.48 3.09 2.54 2.68 2.88 3.08 2.88 3.23 2.91 2.87 3.03 2.87 3.02 2.90 error Pb 206 U/ Total 21.20 22.08 21.27 21.56 21.84 21.52 20.95 21.41 21.90 22.33 22.11 22.67 21.47 21.48 21.64 22.43 13.37 21.46 21.70 22.28 19.85 17.75 238 Pb 206 CHY-24 Coarse-grained, hornblende-biotite quartz monzodiorite; Pedernales Batholith; Concordia U-Pb age = 287.0±2.1 Ma CHY-24 Pb/ 0.001440 0.000155 0.000473 0.000620 0.000720 0.000478 0.000560 0.000481 0.000436 0.001363 0.000618 0.001023 0.000346 0.001595 0.000303 0.001030 0.000243 0.000295 0.000815 0.000240 0.000280 0.000413 204 CHY-07 Light gray, coarse-grained, muscovite-biotite granite; Burro Muerto pluton; Cochiguaz Unit; Concordia U-Pb age = 286.3±3.1 Ma coarse-grained, muscovite-biotite granite; Burro Light gray, CHY-07 Pb ppm 206 5.76 8.10 6.42 5.66 7.57 6.57 8.33 11.15 19.66 12.36 16.43 17.65 12.52 49.92 46.67 13.02 38.70 63.68 10.84 67.64 52.44 37.12 Radiogenic U 238 0.59 0.64 1.03 1.08 0.79 1.02 1.05 0.66 0.51 0.66 1.08 0.70 0.04 0.36 0.08 1.10 0.37 0.05 0.99 0.05 0.54 0.73 Th/ 232 Th ppm 81.70 52.98 72.66 92.83 82.23 92.43 117.62 310.78 304.78 213.25 125.37 404.48 139.82 178.07 220.09 125.44 336.66 362.83 213.43 262.22 630.25 538.80 U ppm 411.54 142.29 505.20 305.97 203.39 163.23 138.11 277.83 449.80 196.73 322.09 173.23 208.31 339.97 602.35 273.78 766.96 1,211.96 1,247.44 1,175.42 1,590.96 1,754.39 Pb % 2.63 0.28 0.86 1.13 1.31 0.87 1.02 0.88 0.80 2.49 1.13 1.87 0.16 2.63 0.36 0.39 0.41 1.89 0.06 0.25 206 -0.09 -0.07 Common Grain Spot appendix 2 continued. Sample CHY-24 CHY24-1.1 CHY24-2.1 CHY24-3.1 CHY24-4.1 CHY24-5.1 CHY24-6.1 CHY24-7.1 CHY24-8.1 CHY24-9.1 CHY24-10.1 CHY24-11.1 CHY24-12.1 Sample CHY-07 CHY7-1.1 CHY7-2.1 CHY7-3.1 CHY7-4.1 CHY7-5.1 CHY7-6.1 CHY7-7.1 CHY7-8.1 CHY7-9.1 CHY7-10.1 Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 499 7.1 6.9 7.1 6.8* 7.7 9.3 6.8 7.4 6.8 ±1σ 11.8 11.8 11.3 11.4 13.7 12.5 12.9 23.0 12.3 12.3 12.3 12.1 12.2 14.1 25.2* 40.8* 40.0* error U 238 Pb/ 294.7 292.8 276.2 282.1 297.7 283.9 292.7 292.8 282.6 288.0 294.0 276.8 276.8 269.3 287.6 279.1 272.7 263.1* 285.7 294.7 288.6 278.7 271.9 1070.5* 1825.7* 1860.5* Age Ma 206 Pb corrected 204 % 3.36 1.23 2.78 1.78 2.26 1.43 3.34 6.90 0.80 3.75 1.68 2.08 1.93 7.47 3.08 9.72 7.21 2.00 1.26 3.85 2.52 0.85 error 16.09 13.87 10.52 24.26 Pb 206 Pb/ 0.05257 0.05589 0.05053 0.05037 0.05267 0.05426 0.05216 0.05289 0.05173 0.05233 0.05212 0.05161 0.05202 0.05165 0.07451 0.05159 0.05128 0.05194 0.05086 0.05184 0.05263 0.05193 0.13579 0.05289 0.05196 0.11052 207 Radiogenic % 4.75 4.37 4.75 8.34 4.22 4.44 4.29 4.23 4.28 4.19 4.24 4.19 4.20 5.34 2.55 2.53 2.52 2.67 2.63 2.77 3.24 2.42 2.56 2.71 2.56 2.48 error Pb 206 5.53 3.05 2.99 21.38 21.51 22.84 22.35 21.15 22.21 21.53 21.52 22.31 21.89 21.43 22.79 22.79 23.43 21.91 22.60 23.13 23.99 22.06 21.36 21.84 22.63 23.21 U/ 238 Radiogenic % 2.34 6.10 1.19 1.73 1.77 1.84 1.16 2.78 2.40 0.80 2.15 1.59 1.41 2.09 1.08 3.41 1.65 2.79 4.32 4.13 6.36 1.27 0.93 2.80 1.49 0.70 error Pb 206 Total Pb/ 0.056364 0.072065 0.051257 0.053948 0.052540 0.054340 0.053051 0.055675 0.056154 0.052062 0.055656 0.052207 0.053643 0.069662 0.077804 0.059725 0.053481 0.066795 0.065961 0.058061 0.089490 0.054039 0.139095 0.056944 0.055499 0.112030 207 % 4.75 4.27 4.75 8.34 4.22 4.44 4.29 4.23 4.26 4.19 4.24 4.19 4.20 5.27 2.55 2.51 2.52 2.62 2.58 2.75 2.98 2.42 2.56 2.71 2.56 2.48 error Pb 206 5.51 3.04 2.98 U/ Total 21.28 21.08 22.82 22.25 21.16 22.21 21.50 21.44 22.19 21.89 21.33 22.78 22.74 22.90 21.69 22.54 22.70 23.54 21.89 20.37 21.78 22.52 23.11 238 Pb CHY-19a Foliated, dark green, biotite-hornblende tonalite; Sierra Castillo batholith; Concordia U-Pb age = 285.3±3.2 Ma Foliated, dark green, CHY-19a 206 Pb/ 0.000259 0.001109 0.000049 0.000243 0.000005 0.000061 0.000190 0.000301 0.000241 0.000041 0.000110 0.001228 0.000231 0.000555 0.000150 0.001013 0.001029 0.000425 0.002517 0.000144 0.000251 0.000277 0.000241 0.000112 204 -0.000009 -0.000019 Pb ppm 206 9.97 9.94 7.46 7.61 3.61 11.16 55.01 23.33 21.87 17.78 49.14 14.58 98.89 16.04 37.02 30.28 10.46 41.82 13.63 23.40 10.70 41.85 36.00 26.46 28.00 74.44 Radiogenic U 238 0.81 0.23 0.02 0.07 1.21 0.58 0.27 0.85 0.52 0.18 0.63 0.03 0.04 0.69 0.39 0.52 0.44 1.25 0.54 0.30 0.69 0.14 0.36 0.26 0.18 1.01 Th/ 232 Th ppm 54.50 21.54 42.02 31.23 27.43 78.72 56.88 43.78 215.44 628.46 258.62 315.62 300.98 128.25 451.11 244.23 185.59 102.02 173.60 258.82 238.41 108.62 146.91 174.79 134.02 251.68 U 85.57 ppm 276.45 244.59 604.21 538.56 459.58 364.00 256.71 398.18 981.44 801.68 278.91 343.99 613.93 197.11 208.52 272.63 127.40 693.65 753.28 258.43 268.30 1,461.19 1,230.06 2,520.25 1,060.99 Pb % 0.47 2.02 0.09 0.44 0.01 0.11 0.35 0.55 0.44 0.07 0.20 2.25 1.01 0.27 1.85 1.88 0.78 4.59 0.26 0.39 0.51 0.44 0.17 0.39 206 -0.02 -0.03 Common Grain Spot Sample CHY-19a CHY19A-1.1 CHY19A-2.1 CHY19A-3.1 CHY19A-4.1 CHY19A-5.1 CHY19A-6.1 CHY19A-7.1 CHY19A-8.1 CHY19A-9.1 CHY19A-10.1 CHY19A-11.1 CHY19A-12.1 CHY19A-13.1 CHY19A-14.1 Sample CHY-23 CHY23-1.1 CHY23-2.1 CHY23-3.1 CHY23-4.1 CHY23-5.1 CHY23-6.1 CHY23-7.1 CHY23-8.1 CHY23-9.1 CHY23-9.2 CHY23-10.1 CHY23-11.1 appendix 2 continued. 500 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... 7.2 5.4 6.7 7.1 6.4 5.7 4.7* 5.8 8.6* 5.6 5.3 5.5 5.5 6.0 6.8 5.4 7.9* 7.5 6.8 6.9 7.1 ±1σ 11.1* 20.8* 14.3* error U 238 Pb/ 954.7* 722.6* 283.8 272.5 479.2* 266.5 285.2 259.4 280.1 230.5* 275.4 429.2* 275.6 260.0 277.8 274.8 274.7 283.2 273.2 390.1* 284.8 283.3 270.3 280.6 Age Ma 206 Pb corrected 204 % 1.60 3.24 2.62 3.90 8.14 3.08 9.42 2.18 7.94 4.39 6.39 6.28 2.09 3.05 6.65 3.64 2.29 9.28 2.68 6.20 error 20.16 10.66 14.28 10.34 Pb 206 Pb/ 0.07282 0.06856 0.05318 0.05133 0.05716 0.05192 0.05146 0.05072 0.05274 0.05127 0.05170 0.06055 0.05191 0.05013 0.05184 0.05147 0.05120 0.05183 0.05204 0.05502 0.05326 0.05261 0.05269 0.05177 207 Radiogenic % 2.34 2.60 2.02 2.40 2.55 2.56 2.50 2.09 2.07 2.08 2.14 2.08 2.07 2.08 2.02 2.03 2.23 2.45 2.04 2.08 2.69 2.46 2.59 2.59 error Pb 206 6.26 8.43 22.20 23.16 12.95 23.69 22.11 24.34 22.52 27.46 22.91 14.52 22.89 24.29 22.71 22.96 22.97 22.26 23.10 16.03 22.13 22.26 23.35 22.47 U/ 238 Radiogenic % 2.55 2.08 1.76 5.26 1.19 2.77 1.35 1.75 1.56 2.22 1.90 2.45 3.08 2.09 2.16 2.22 4.58 2.77 1.43 1.99 2.72 1.68 2.15 3.14 error Pb 206 Total Pb/ 0.079521 0.053623 0.063730 0.059604 0.056471 0.062857 0.074380 0.053348 0.074668 0.062279 0.063587 0.056360 0.058056 0.051840 0.055904 0.055879 0.056526 0.055098 0.056540 0.073856 0.067738 0.055393 0.062463 0.064385 207 % 2.34 2.28 2.02 2.39 2.53 2.56 2.45 2.07 2.01 2.10 2.06 2.04 2.06 2.02 2.03 2.19 2.29 2.03 2.07 2.08 2.64 2.46 2.57 2.52 error Pb 206 CHY-23 Pink medium-grained, biotite monzogranite; Pedernales batholith; Concordia U-Pb age = 280.6±2.1 Ma CHY-23 6.25 8.37 U/ Total 21.47 23.09 12.85 23.46 21.97 23.98 22.50 26.66 22.61 14.47 22.77 24.05 22.71 22.83 22.84 22.13 23.01 16.00 21.73 22.18 23.06 22.12 238 CHY-48 Light pink, coarse-grained, biotite, monzogranite; Pan de Azúcar pluton; Concordia U-Pb age = 276.6±1.8 Ma Azúcar Light pink, coarse-grained, biotite, monzogranite; Pan de CHY-48 Pb 206 Pb/ 0.001800 0.000156 0.000451 0.000525 0.000342 0.000827 0.000110 0.000042 0.001595 0.000721 0.000210 0.000303 0.000540 0.000000 0.000302 0.000319 0.000320 0.000209 0.000104 0.000369 0.000990 0.000190 0.000668 0.000860 204 Pb ppm 206 7.72 6.52 7.71 11.03 11.87 11.82 11.97 15.32 19.22 14.89 76.38 14.32 17.98 18.95 12.52 10.60 10.82 12.11 28.13 15.07 25.34 14.97 13.35 112.30 Radiogenic U 238 0.68 0.07 0.13 0.12 0.02 0.41 0.26 0.12 1.65 0.23 0.52 0.21 0.18 0.21 0.11 0.16 0.35 0.48 0.59 0.48 0.88 0.52 0.21 0.64 Th/ 232 Th ppm 29.79 37.21 46.15 42.85 56.00 64.03 57.08 53.52 64.39 34.44 49.46 57.22 68.32 80.09 126.32 157.54 203.76 938.36 106.44 150.23 297.74 166.53 328.95 214.30 U ppm 411.69 192.87 287.47 406.52 399.78 817.23 470.95 587.90 290.28 210.88 280.87 302.85 313.72 321.91 314.13 168.02 320.52 523.88 146.88 194.91 654.08 401.79 343.81 1953.02 Pb % 3.29 0.29 0.81 0.96 0.62 1.51 0.19 0.08 2.93 1.32 0.38 0.55 0.99 0.00 0.55 0.58 0.58 0.38 0.19 0.65 1.81 0.35 1.22 1.57 206 Common Grain Spot CHY48-14.1 CHY48-15.1 Sample CHY-47 CHY47-1.1 CHY47-1.2 CHY47-2.1 CHY47-3.1 CHY47-4.1 appendix 2 continued. CHY23-12.1 CHY23-13.1 CHY23-14.1 CHY23-15.1 Sample CHY-48 CHY48-1.1 CHY48-2.1 CHY48-3.1 CHY48-4.1 CHY48-5.1 CHY48-6.1 CHY48-7.1 CHY48-8.1 CHY48-9.1 CHY48-10.1 CHY48-11.1 CHY48-12.1 CHY48-13.1 Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 501 6.3 6.9 7.9 5.9 6.5 5.5 5.8 5.8 6.0 6.1* 5.8 5.5 5.8 5.6 6.3* 6.3 6.9* 6.1 6.9 6.2 6.5 ±1σ 15.1* 25.5* error U 238 Pb/ 657.4* 272.7 265.7 269.9 268.8 271.7 262.0 274.5 274.0 276.1 296.5* 264.9 263.4 270.1 262.7 291.8* 272.9 297.6* 261.5 274.2 264.9 276.5 1151.6* Age Ma 206 Pb corrected 204 % 3.97 3.12 2.83 6.25 6.04 3.26 5.91 5.44 5.22 5.96 5.35 9.78 4.72 2.15 2.48 4.30 6.30 6.71 2.92 error 17.95 40.99 10.49 18.52 Pb 206 Pb/ 0.06424 0.05162 0.04857 0.03529 0.05182 0.05166 0.05285 0.05623 0.05374 0.05152 0.05380 0.05158 0.05403 0.05111 0.05258 0.05224 0.07760 0.05116 0.05465 0.05158 0.04635 0.05206 0.05274 207 Radiogenic % 2.35 2.66 3.00 2.25 2.43 2.14 2.15 2.16 2.21 2.10 2.24 2.15 2.20 2.19 2.22 2.37 2.42 2.38 2.38 2.58 2.41 2.39 2.42 error Pb 206 9.31 5.11 23.14 23.75 23.36 23.48 23.23 24.10 22.98 23.02 22.85 21.24 23.83 23.97 23.37 24.04 21.59 23.13 21.16 24.15 23.01 23.83 22.81 U/ 238 Radiogenic % 2.14 3.89 8.92 1.97 2.98 2.59 2.31 3.03 3.29 1.90 2.90 3.28 2.05 5.28 2.69 1.97 2.63 1.85 3.67 7.43 1.99 1.13 1.54 error Pb 206 Total Pb/ 0.054068 0.072670 0.078760 0.057901 0.056809 0.060806 0.061643 0.061138 0.056674 0.059201 0.065968 0.062330 0.056364 0.062363 0.056466 0.053781 0.070145 0.063974 0.058550 0.063359 0.059079 0.055960 0.081307 207 % 2.34 2.49 2.68 2.25 2.41 2.11 2.15 2.14 2.20 2.08 2.16 2.13 2.18 2.14 2.21 2.37 2.41 2.37 2.37 2.44 2.37 2.38 2.42 error CHY-35 Pink, coarse-grained, biotite monzogranite; El Hielo batholith; Concordia U-Pb age = 267.9±1.9 Ma CHY-35 CHY-47 Pink, coarse-grained, leucocratic granite; Pan de Azúcar pluton; Concordia U-Pb age = 269.5±2.0 Ma Azúcar Pink, coarse-grained, leucocratic granite; Pan de CHY-47 Pb 206 9.24 5.09 U/ Total 23.07 23.04 22.12 23.30 23.08 23.86 22.83 22.81 22.70 21.10 23.40 23.73 23.21 23.74 21.48 23.05 20.91 23.94 22.52 23.62 22.72 238 Pb 206 Pb/ 0.000167 0.001638 0.002905 0.000415 0.000351 0.000543 0.000371 0.000506 0.000351 0.000370 0.000981 0.000568 0.000358 0.000668 0.000288 0.000179 0.000409 0.000638 0.000476 0.001152 0.000479 0.000220 0.000261 204 Pb ppm 206 7.62 6.48 8.51 8.97 9.77 9.36 11.35 11.81 11.10 37.95 12.42 10.88 13.56 13.67 28.17 25.15 18.43 18.54 23.25 21.65 23.65 61.29 31.43 Radiogenic U 238 0.05 0.12 0.27 0.62 0.40 0.68 0.54 0.55 0.40 0.48 0.64 0.71 0.58 0.72 0.68 0.11 0.61 0.18 0.23 0.13 0.14 0.02 1.30 Th/ 232 Th ppm 49.74 23.35 43.35 52.25 99.39 35.52 88.74 38.52 117.53 116.79 186.00 130.49 198.17 190.59 139.34 322.83 150.71 185.81 178.54 180.06 412.00 133.19 233.63 U ppm 204.38 166.94 307.95 333.56 302.27 226.21 359.90 361.18 691.76 244.21 269.79 319.21 258.58 628.80 494.57 199.46 565.85 603.40 291.08 650.32 186.15 1,019.09 1,620.80 Pb % 0.30 3.00 5.31 0.76 0.64 0.99 0.68 0.92 0.64 0.67 1.80 1.04 0.65 1.22 0.53 0.33 0.72 1.16 0.87 2.11 0.88 0.40 0.44 206 Common Grain Spot CHY47-11.2 CHY47-12.1 CHY47-13.1 Sample CHY-35 CHY35-1.1 CHY35-2.1 CHY35-3.1 CHY35-4.1 CHY35-5.1 CHY35-6.1 CHY35-7.1 CHY35-8.1 CHY35-9.1 CHY35-10.1 CHY35-11.1 CHY35-12.1 CHY47-10.2 CHY47-11.1 appendix 2 continued. CHY47-5.1 CHY47-6.1 CHY47-7.1 CHY47-8.1 CHY47-9.1 CHY47-10.1 502 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... 4.5* 9.9 9.8 9.2 9.7 9.8 9.9 9.7 ±1σ 11.0 11.9 11.0 11.4 10.5 10.6 10.0 12.2* 10.6 13.3 10.9 10.7 10.3 10.4 error U 238 111.7* Pb/ 266.3 261.4 273.6 260.9 255.1 272.7 267.1 234.1 260.5 262.3 315.8* 267.1 267.6 271.7 264.1 261.7 262.7 264.0 263.0 268.7 260.9 Age Ma 206 Pb corrected 204 % 9.13 error 29.32 32.25 19.77 17.83 24.74 28.38 12.43 10.10 16.65 21.86 24.38 17.49 10.20 40.55 33.75 30.84 32.55 24.96 22.40 10.70 10.63 Pb 206 Pb/ 0.04969 0.05055 0.04720 0.05251 0.05139 0.05917 0.05117 0.05302 0.05589 0.04258 0.05538 0.06012 0.05003 0.05141 0.06072 0.05493 0.05247 0.05821 0.04748 0.05180 0.05037 0.05245 207 Radiogenic % 4.21 4.05 3.87 3.90 4.65 4.41 3.97 3.75 3.99 3.93 3.76 3.96 4.04 3.75 4.99 4.41 4.24 4.16 3.97 4.05 3.76 3.79 error Pb 206 23.68 57.15 24.15 23.05 24.18 24.74 23.13 23.62 27.02 24.23 24.07 19.87 23.62 23.58 23.17 23.87 24.10 24.00 23.90 23.99 23.48 24.20 U/ 238 Radiogenic % 6.77 3.95 6.11 7.06 5.51 6.56 2.78 4.10 2.18 5.73 4.56 2.02 7.93 3.44 6.45 7.89 5.82 7.63 4.87 4.95 2.50 3.25 error Pb 206 Total Pb/ CHY-16 Andesite dike that crosscut La Tabla Formation; Concordia U-Pb age = 264.6±3.5 Ma Tabla La Andesite dike that crosscut CHY-16 0.095167 0.118905 0.075467 0.077812 0.090116 0.108344 0.070235 0.069220 0.093255 0.070762 0.066821 0.129700 0.071719 0.065167 0.132968 0.107767 0.103026 0.125606 0.081467 0.083298 0.069653 0.069031 207 % 3.96 3.75 3.77 3.81 4.47 4.07 3.91 3.72 3.87 3.82 3.73 3.73 3.97 3.71 4.28 4.02 3.91 3.84 3.77 3.85 3.71 3.75 error Pb 206 U/ Total 22.34 52.22 23.30 22.32 23.01 23.21 22.58 23.15 25.75 23.39 23.72 18.13 22.98 23.18 21.06 22.29 22.58 21.96 22.89 23.05 22.92 23.70 238 Pb CHY-12 Pink, coarse-grained, biotite-hornblende monzogranite; Pedernales batholith; Concordia U-Pb age = 264.9±3.5 Ma CHY-12 206 Pb/ 0.003094 0.004655 0.001917 0.001728 0.002640 0.003385 0.001299 0.001107 0.002562 0.001901 0.000784 0.004796 0.001476 0.000938 0.004984 0.003618 0.003452 0.004635 0.002306 0.002148 0.001313 0.001132 204 Pb ppm 206 3.80 7.75 8.02 6.57 4.37 2.73 7.59 6.26 8.58 6.61 1.98 3.03 4.26 5.47 7.59 5.22 8.78 10.37 10.39 16.64 10.58 16.78 Radiogenic U 238 0.63 2.12 0.60 0.55 0.87 0.68 0.78 0.67 0.54 0.75 0.71 1.59 0.99 1.39 1.10 1.17 1.24 1.24 0.61 0.69 1.00 1.06 Th/ 232 Th ppm 60.63 90.65 99.01 48.31 51.66 88.74 93.29 968.90 127.08 151.28 180.69 163.96 123.40 163.11 541.79 169.25 384.41 134.58 168.07 120.39 434.81 247.85 U ppm 98.87 73.86 48.55 78.68 116.98 311.26 112.05 471.36 217.42 170.61 199.48 279.43 170.36 236.83 351.17 176.78 285.36 139.84 202.34 140.06 447.76 242.16 Pb % 5.66 8.63 3.51 3.16 4.83 6.20 2.38 2.02 4.70 3.48 1.43 8.74 2.70 1.72 9.11 6.62 6.32 8.48 4.22 3.93 2.40 2.07 206 Common Grain Spot appendix 2 continued. Sample CHY-12 CHY12-1.1 CHY12-2.1 CHY12-3.1 CHY12-4.1 CHY12-5.1 CHY12-6.1 CHY12-7.1 CHY12-8.1 CHY12-9.1 CHY12-10.1 CHY12-11.1 CHY12-12.1 CHY16-2.1 CHY16-3.1 CHY16-4.1 CHY16-5.1 CHY16-6.1 CHY16-7.1 CHY16-8.1 CHY16-9.1 CHY16-10.1 Sample CHY-16 CHY16-1.1 Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 503 5.5 7.3* 5.4 6.4* 6.2 8.5 7.8 9.6 7.6 5.7 5.6 8.0 5.9 7.2 5.6 5.4 7.5 6.4 6.4 6.1 6.7* 6.2* 5.5 ±1σ error 19.5* U 238 Pb/ 311.4* 264.3 323.9* 254.7 297.4* 262.7 265.6 266.3 261.8 265.3 269.5 263.3 261.7 264.9 263.0 260.4 262.5 262.7 258.5 263.7 264.9 278.4* 253.8 Age Ma 1,011.9* 206 Pb corrected 204 % 0.69 4.52 1.69 2.12 2.91 9.45 5.42 3.62 2.57 2.90 2.09 error 20.19 40.23 32.95 43.13 28.22 10.84 39.82 15.90 33.65 15.54 15.45 28.69 13.87 Pb 206 Pb/ 0.07344 0.05149 0.05345 0.05235 0.05346 0.05062 0.04940 0.04940 0.05476 0.05429 0.05075 0.05263 0.05026 0.05157 0.05158 0.05319 0.05172 0.05411 0.05380 0.05111 0.05769 0.05195 0.05241 0.05157 207 Radiogenic % 2.11 2.32 2.16 2.19 2.08 2.42 3.26 3.01 3.75 2.93 2.16 2.18 3.12 2.26 2.79 2.21 2.09 2.92 2.52 2.49 2.36 2.21 2.28 2.21 error Pb 206 5.88 U/ 23.89 19.41 24.81 21.18 24.02 23.75 23.69 24.08 23.78 23.41 23.98 24.10 23.83 23.98 24.26 24.06 24.03 24.44 23.92 23.83 20.20 22.65 24.90 238 Radiogenic % 3.24 0.96 1.02 1.91 4.09 2.57 4.07 9.00 2.50 3.96 7.90 5.85 2.22 2.20 3.71 3.49 8.16 5.05 1.26 1.43 1.54 0.58 error 10.81 10.11 Pb 206 Total Pb/ 0.055709 0.055732 0.053922 0.056066 0.082216 0.091692 0.089883 0.115722 0.083042 0.066204 0.067482 0.105745 0.068340 0.094728 0.054797 0.057883 0.074786 0.067585 0.093388 0.074855 0.053701 0.053472 0.053835 0.074071 207 % 2.11 2.32 2.16 2.18 2.17 2.26 2.37 3.04 2.46 2.10 2.10 2.37 2.10 2.28 2.18 2.08 2.77 2.33 2.08 2.21 2.21 2.27 2.21 2.08 error CHY-38 Pink, medium-grained, biotite granite; Caballo Muerto pluton; Concordia U-Pb age = 263.5±1.7 Ma CHY-38 Pb 206 5.88 U/ Total 23.77 19.35 24.77 21.11 23.07 22.50 22.49 22.24 22.92 22.96 23.53 22.43 23.33 22.69 24.21 23.87 23.41 24.01 22.66 23.31 20.16 22.62 24.83 238 Pb 206 Pb/ 0.000288 0.000156 0.000108 0.000178 0.002152 0.002876 0.002753 0.004174 0.001967 0.001053 0.001014 0.003778 0.001144 0.002943 0.000110 0.000420 0.001415 0.000943 0.002881 0.001180 0.000120 0.000073 0.000155 0.000044 204 Pb ppm 206 8.91 6.13 4.69 4.32 6.92 4.79 6.23 3.50 4.66 4.79 26.54 52.72 58.38 25.97 20.69 14.13 13.60 16.91 12.34 13.51 33.20 26.48 42.62 120.10 Radiogenic U 238 0.03 0.22 0.02 0.38 0.79 1.00 1.35 1.38 0.58 0.82 0.78 1.28 0.76 1.70 0.70 0.38 1.15 1.11 0.68 0.59 0.14 0.05 0.04 0.04 Th/ 232 Th ppm 24.10 35.08 74.05 34.39 50.62 29.12 251.67 236.89 183.87 154.61 160.40 149.42 103.55 436.38 292.07 155.49 272.77 271.07 324.22 126.88 106.29 140.41 234.25 106.01 U ppm 95.33 111.75 734.20 638.16 239.34 160.56 122.78 184.77 552.85 387.08 125.04 369.35 164.68 476.65 342.86 130.18 356.38 130.07 779.02 697.30 821.81 1,187.61 1,683.06 1,231.81 Pb % 0.53 0.28 0.20 0.33 3.94 5.26 5.04 7.64 3.60 1.93 1.86 6.91 2.09 5.38 0.20 0.77 2.59 1.73 5.27 2.16 0.22 0.13 0.28 0.08 206 Common Grain Spot CHY58-5.2 CHY58-6.1 CHY58-7.1 CHY58-8.1 appendix 2 continued. Sample CHY-38 CHY38-1.1 CHY38-2.1 CHY38-3.1 CHY38-4.1 CHY38-5.1 CHY38-6.1 CHY38-7.1 CHY38-8.1 CHY38-9.1 CHY38-10.1 CHY38-11.1 CHY38-12.1 CHY38-13.1 CHY38-14.1 CHY38-15.1 Sample CHY-58 CHY58-1.1 CHY58-2.1 chy58-3.1 CHY58-4.1 CHY58-5.1 504 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... 5.8 5.9 5.8 5.1 5.0 5.0 6.1 4.8 5.6 8.5 5.5 5.9 5.2 5.3 6.1 5.8 6.1 5.9 7.8 6.0 5.6* ±1σ error 11.1* 27.9* 13.5* U 238 244.5 242.0 249.6 247.3 246.3 246.9 244.9 237.3 247.3 253.1 237.8 240.2 244.4 668.6* 257.8 251.8 242.2 240.8 416.8* 255.7 240.4 249.2 275.6* Pb/ Age Ma 1,331.9* 206 Pb corrected 204 % 0.64 7.46 3.89 7.41 2.88 5.44 5.21 6.55 2.70 5.49 4.60 3.85 4.97 1.94 error 11.53 12.98 17.94 14.16 15.39 22.51 10.56 10.78 14.03 14.24 Pb 206 Pb/ 0.08979 0.05140 0.05311 0.05110 0.05135 0.05110 0.05149 0.05195 0.05042 0.05255 0.05162 0.05035 0.05515 0.05279 0.06547 0.05196 0.05092 0.05133 0.05279 0.05580 0.05053 0.05160 0.04341 0.05206 207 Radiogenic % 2.41 2.48 2.36 2.09 2.05 2.06 2.52 2.05 2.30 3.42 2.35 2.52 2.18 2.08 2.45 2.43 2.60 2.76 2.37 3.32 2.45 2.32 2.09 2.13 error Pb 206 4.36 9.14 U/ 25.86 26.14 25.33 25.56 25.67 25.61 25.82 26.66 25.56 24.97 26.60 26.32 25.88 24.51 25.10 26.12 26.26 14.97 24.71 26.31 25.36 22.89 238 Radiogenic % 3.37 5.76 1.62 3.97 2.28 5.39 3.33 1.71 4.60 4.36 4.34 6.92 3.64 1.63 3.93 1.91 6.06 2.30 2.08 2.92 5.64 0.50 1.66 0.85 error CHY-58 Quebrada Pintado Tonalite mylonitized; Concordia U-Pb age = 258.9±2.5 Ma Tonalite Quebrada Pintado CHY-58 Pb 206 Total Pb/ 0.060461 0.067357 0.055139 0.056160 0.053358 0.050493 0.068183 0.056619 0.068887 0.065350 0.063107 0.087269 0.063132 0.056386 0.063618 0.058748 0.065919 0.064095 0.056315 0.057885 0.060920 0.090999 0.053602 0.074967 207 % 2.38 2.38 2.35 2.05 2.05 2.05 2.26 2.03 2.16 3.30 2.28 2.20 2.09 2.08 2.38 2.42 2.49 2.75 2.37 3.31 2.38 2.32 2.09 2.07 error CHY-46 Leucocratic, coarse-grained granite; Cerros del Vetado pluton; Concordia U-Pb age = 246.5±2.0 Ma Vetado del Leucocratic, coarse-grained granite; Cerros CHY-46 Pb 206 4.35 9.04 U/ Total 25.56 25.67 25.20 25.41 25.60 25.64 25.29 26.46 25.04 24.54 26.18 25.26 25.54 24.38 24.70 25.87 25.83 14.81 24.53 26.10 24.81 22.85 238 Pb 206 Pb/ 0.000618 0.000974 0.000275 0.000328 0.000154 0.001107 0.000422 0.001115 0.000936 0.000869 0.002200 0.000706 0.000302 0.000865 0.000506 0.000897 0.000569 0.000394 0.000429 0.001182 0.000087 0.000105 0.000659 204 -0.000068 Pb ppm 206 9.22 4.04 5.80 6.29 5.64 11.74 11.02 11.03 17.55 13.56 32.93 16.28 26.12 18.32 23.42 14.34 20.88 20.74 21.13 28.78 15.55 32.79 52.63 220.13 Radiogenic U 238 0.20 0.13 0.71 0.68 0.77 0.78 1.13 1.70 0.96 1.27 1.13 1.27 0.66 0.04 0.20 0.17 0.22 0.26 0.11 0.18 0.18 0.96 0.11 0.27 Th/ 232 Th ppm 49.81 25.27 78.81 69.56 88.83 65.64 77.48 97.01 102.66 661.44 179.40 363.60 587.88 129.61 930.23 157.52 220.97 389.73 204.00 209.76 102.85 155.67 145.45 1,033.46 U ppm 118.95 522.39 405.32 965.85 272.71 485.26 779.68 564.07 168.93 179.53 357.77 165.77 327.50 664.46 412.25 628.87 331.73 357.65 603.30 874.44 449.02 871.98 553.56 1,114.63 Pb % 1.13 1.78 0.50 0.60 0.28 2.03 0.77 2.04 1.71 1.59 4.03 1.29 0.55 1.58 0.93 1.64 1.03 0.72 0.79 2.17 0.14 0.19 1.16 206 -0.12 Common Grain Spot CHY46-9.1 CHY46-10.1 CHY46-11.1 Sample CHY-60 CHY60-1.1 CHY60-2.1 CHY60-3.1 CHY60-4.1 CHY60-5.1 CHY60-6.1 CHY60-7.1 CHY60-8.1 CHY60-9.1 CHY60-10.1 CHY58-10.2 Sample CHY-46 CHY46-1.1 CHY46-2.1 CHY46-3.1 CHY46-4.1 CHY46-5.1 CHY46-6.1 CHY46-7.1 CHY46-8.1 appendix 2 continued. CHY58-9.1 CHY58-10.1 Maksaev et al. / Andean Geology 41 (3): 447-506, 2014 505 5.3 6.0 5.2 5.2 9.2* 4.4* 4.9 5.8 5.5 5.0 7.1* 4.8 9.6* 5.6 5.0 ±1σ error 15.3* 10.4* 13.5* U 238 Pb/ 783.8* 234.2 235.6 237.8 236.2 410.3* 459.1* 195.6* 647.9* 235.7 245.8 245.9 244.0 317.8* 241.2 448.4* 236.0 242.7 Age Ma 206 Pb corrected 204 % 1.00 5.48 5.11 8.45 1.54 3.04 2.61 3.88 8.93 4.82 5.85 2.18 4.06 error 11.78 12.76 14.08 17.54 14.55 Pb 206 Pb/ 0.07667 0.05079 0.05224 0.05353 0.05017 0.05552 0.05681 0.05031 0.06979 0.05135 0.05129 0.05211 0.04988 0.05333 0.05127 0.05746 0.05514 0.05043 207 Radiogenic % 2.31 2.59 2.23 2.26 2.62 2.08 2.26 2.10 2.08 2.19 2.42 2.28 2.10 2.29 2.02 2.22 2.42 2.10 error Pb 206 7.74 9.46 U/ 27.02 26.86 26.61 26.80 15.22 13.54 32.45 26.85 25.72 25.71 25.91 19.79 26.22 13.88 26.81 26.06 238 Radiogenic % 3.93 3.46 5.55 3.10 1.04 1.82 4.44 1.76 1.00 2.59 5.01 2.68 3.21 2.81 1.77 5.17 1.62 2.09 error Pb 206 Total Pb/ 0.057555 0.056006 0.066092 0.055175 0.056929 0.060337 0.071201 0.056956 0.076165 0.071249 0.069409 0.059532 0.059278 0.057384 0.056452 0.066727 0.056120 0.073684 207 % 2.30 2.58 2.12 2.21 2.62 2.07 2.14 2.09 2.08 2.18 2.14 2.04 2.28 2.00 2.22 2.33 2.09 2.19 error CHY-60 Pink, coarse-grained, biotite monzogranite; Chollay batholith; Concordia U-Pb age = 244.0±1.4 Ma CHY-60 CHY-45 Coarse-grained, biotite monzogranite; Cerros del Vetado pluton; Concordia U-Pb age = 237.0±2.0 Ma Vetado del Coarse-grained, biotite monzogranite; Cerros CHY-45 Pb 206 7.74 9.41 U/ Total 26.79 26.74 26.19 26.63 15.19 13.49 31.60 26.66 25.08 25.15 25.60 19.64 26.02 13.90 26.42 25.88 238 Pb 206 Pb/ 0.000461 0.000257 0.000859 0.000341 0.000097 0.000242 0.001422 0.000382 0.001360 0.001180 0.000657 0.000407 0.000417 0.000794 0.000388 0.000271 204 -0.000036 -0.000069 Pb ppm 206 6.74 7.71 15.78 21.32 13.32 32.74 60.88 47.22 12.04 19.24 59.98 16.32 27.72 31.24 21.97 10.38 22.73 32.39 Radiogenic U 238 0.57 0.44 0.39 0.60 0.16 0.51 0.23 0.38 0.23 0.88 0.86 0.76 0.44 1.96 0.11 0.34 0.08 0.24 Th/ 232 Th ppm 99.00 39.27 53.06 81.79 272.27 282.38 154.25 588.24 163.52 365.92 222.11 120.97 168.35 188.55 355.60 266.91 105.55 1,793.87 U ppm 492.09 663.50 406.14 741.27 442.99 597.10 540.44 196.63 225.68 486.21 633.75 946.20 355.48 319.05 684.53 354.79 1,014.67 1,076.33 Pb % 0.85 0.47 1.58 0.63 0.17 0.43 2.62 0.70 2.49 2.16 1.20 0.74 0.76 1.46 0.71 0.48 206 -0.06 -0.12 Common Grain Spot CHY45-7.1 CHY45-8.1 CHY45-9.1 CHY45-10.1 CHY45-11.1 CHY45-12.1 CHY45-13.1 CHY45-5.1 CHY45-6.1 appendix 2 continued. CHY60-11.1 CHY60-12.1 CHY60-13.1 CHY60-14.1 CHY60-15.1 Sample CHY-45 CHY45-1.1 CHY45-2.1 CHY45-3.1 CHY45-4.1 506 Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology... 6.9 6.3 5.9 6.2 5.7 7.4 7.2* ±1σ error U 238 Pb/ 232.9 232.9 226.9 233.6 223.1 228.9 282.2* Age Ma 206 Pb corrected 204 % 7.77 5.07 error 11.69 11.56 20.02 10.44 13.90 Pb 206 Pb/ 0.04991 0.05046 0.05148 0.04941 0.05053 0.05032 0.05217 207 Radiogenic % 3.01 2.75 2.66 2.69 2.59 3.27 2.62 error Pb 206 U/ 27.16 27.17 27.90 27.09 28.40 27.65 22.34 238 Radiogenic indicate excluded spot analyses from age calculation. * ) % 4.69 3.57 4.94 4.61 3.72 3.20 2.50 3 error Pb 206 Total Pb/ 0.076956 0.061409 0.061199 0.061703 0.060095 0.065674 0.058505 207 % 2.82 2.67 2.60 2.58 2.56 3.21 2.61 error Pb 206 U/ Total 26.24 26.80 27.56 26.67 28.06 27.12 22.16 238 CHY-03 Brick-red, fine-grained, Brick-red, CHY-03 syenogranite; La Coneja pluton; Colorado Unit; Concordia U-Pb age = 229.6±2.6 Ma Pb 206 Pb/ 0.001840 0.000746 0.000662 0.000836 0.000652 0.001045 0.000432 204 Pb ppm 206 2.92 7.91 5.83 6.77 7.59 6.49 12.64 Radiogenic U 238 0.72 1.08 0.89 0.85 1.11 0.67 0.71 Th/ 232 Th ppm 61.93 257.36 160.56 173.48 266.93 132.88 225.48 U ppm 89.20 246.61 186.92 210.32 247.78 204.91 326.10 ) Uncertainties are given at the one σ level for individual spo t analyses and calculated concordia ages; ( 2 Pb % 2.99 0.85 0.23 0.91 1.17 1.39 0.55 206 Common High U, Th and commom Pb High U, Th and commom Pb High U, Pb corrected ages; ( 204 ) 1 : ( Grain Spot appendix 2 continued. Sample CHY-03 CHY3-1.1 CHY3-2.1 CHY3-3.1 CHY3-4.1 CHY3-5.1 CHY3-6.1 CHY3-7.1 CHY3-8.1 CHY3-9.1 Notes