The Colider and Roosevelt olcanic rocks (sw amazonian craton):geochemistry and sm-nd isotope characteristics of a silicic large igneous province

Bruna Saar de Almeida • Mauro Ce´sar Geraldes • Carlos Augusto Sommer •Felipe Corrales • Antonio Joa˜o Paes de Barros

Abstract The volcanic rocks of the Colı´der and Roosevelt formations are extensively exposed in the south-central portion of the Amazonian Craton where effusive and pyroclastic rocks have been mapped. Both units, topped by chemical sediments and oceanic facies as rhyolite and andesite lavas, rhyodacite, and porphyritic dacite, with frequent intercalations of pyroclastic and epiclastic deposits. Whole-rock geochemistry for 55 samples of rhyolitic to andesitic composition suggests the involvement of fertile mantle-derived components with E-MORB to OIB compositions. The analyzed rocks display calc-alkaline to shoshonitic affinity consistent with generation related to an active continental margin. The whole-rock Sm-Nd isotope data from selected felsic volcanic rocks of the Colı´der and Roosevelt formations yield negative initial εNd values between –3 and –9, indicating the predominantly crustal nature of the parental magmas with early Archean to late Paleoproterozoic (ca. 2.5–2.0 Ga) depleted mantle model ages.

Keywords Amazonian craton ∙Geochemistry ∙Sm-Nd isotopes ∙Paleoproterozoic ∙Volcanism

1 Introduction

The 1.85–1.75 Ga volcanic-plutonic rocks of central Amazonia, Brazil, exhibit a plethora of different names and unit classifications that result in inconsistent and often confusing literature. For example, the same volcanic rocks are grouped as Juruena Supersuite, Teles Pires Suite, and Colı´der Group (Santos et al. 2014, 2017; Duarte et al.,2012); Rizzotto et al. (2019) proposed the Western Amazonia Igneous Belt and Neder et al. (2002) and Pinho et al.(2003) proposed the Roosevelt Group for the volcanic rocks and associated granites. The felsic volcanic and subvolcanic rocks of the Colı´der and Roosevelt formations presently crop out across some 85,000 km2with a general NW-N structural trend. The outcrop area occurs in three states of central Brazil, namely, northern Mato Grosso,southern Para´, and northeastern Rondoˆnia (Leal et al.,1978; Pinho et al., 2003; Leite et al., 2005). These Paleoproterozoic rocks of predominantly ＞80% rhyolitic and dacitic composition occur among several granitic intrusions of the Rio Negro-Juruena Province in the Amazonian Craton (Fig. 1a) (Tassinari and Macambira, 1999). In general, one of the main features of the Rio Negro-Juruena Province and the Amazonian Craton is the widespread occurrence of acid volcanic rocks (Fig. 1b), which cover approximately 3,500,000 km2of the craton (Trompette,1994). The Paleoproterozoic acid volcanic rocks and associated intrusions of the Amazonian Craton can be observed in two areas based on their U–Pb ages: (1) the 2000–1880 Ma Uatuma˜SLIP, which is restricted to the Tapajo´s and Central Amazonian provinces (Lamara˜o et al.,2002; Juliani et al., 2005); and (2) the proposed Colı´der silicic large igneous province (SLIP), proposed here, which has ages of 1800–1755 Ma (Santos et al., 2019) within the Rio Negro-Juruena Province (Fig. 1a).

Fig. 1 a The provinces of the Amazon Craton according to Tassinari (1996) and Tassinari and Macanbira (1999) with the study area indicated;b Geological map of the Rio Negro-Juruena Province modified from published geology (Souza et al., 2005) and with detailed legend summarizing published U–Pb and Pb–Pb ages (in zircon) and Sm–Nd (whole rock) results

One of the challenges of working in this region is that access is often limited, and many areas are heavily forested. Previous work in the area has largely been restricted to regional mapping projects undertaken by the Brazilian Geological Survey (CPRM) and the Mato Grosso State Geological Survey and unpublished work by mineral exploration and mining companies. The 1800–1770 Ma Colı´der Formation was defined by Souza et al. (2005)during the CPRM’s mapping of the Alta Floresta gold province. These authors proposed that the rocks of the Colı´der Formation represent volcanic and subvolcanic expressions of the Juruena magmatic arc. Santos et al.(2004) and Ribeiro and Duarte (2010) correlated the volcanic Roosevelt Formation with the Colı´der Formation,suggesting that the former was deposited in back-arc basins of the Juruena magmatic arc. Neder et al. (2002) and Pinho et al. (2003) obtained U–Pb ages between 1750 and 1769 Ma for volcanic rocks of the Roosevelt Formation and associated granites, with Pinho et al. (2003) proposing that these rocks formed during the collision of the Juruena magmatic arc. Later work reported by Duarte et al. (2012)proposed that these rocks were formed in a back-arc tectonic setting. Ribeiro and Duarte (2010) reported U–Pb crystallization ages from 1772–1748 Ma for the volcanic rocks of the Roosevelt Formation, slightly younger than the published ages for the Colı´der Formation. In addition, the volcanoclastic rocks of the Roosevelt Formation area were affected by deformation and metamorphism ca. 1650 Ma,related to the Juruena orogeny (Santos et al., 2004). An important contribution to Colider volcanic rocks geochronology was reported by Silva et al. (2014) with U–Pb dating (SHRIMP) on monzogranite rock yielding an age of 1869 ± 10 Ma, and granodiorite yielding an age of 1781 ± 10 Ma. Duarte et al. (2019) recently reported U–Pb ages (1.8 Ga) for an association of volcanic rocks and related epizonal granitic plutons (interpreted as a volcanic belt with more than 600 km long), ascribed to Colider Formation. Rizzoto et al. (2019) reported new U–Pb ages of the assemblage of silicic and basic rocks of the Western Amazonia Igneous Belt was formed between 1825 and 1757 Ma.

This study proposes that the Roosevelt Formation and Colı´der Formation together form the Colı´der SLIP (Silicic Large Igneous Province) of the Paleoproterozoic age. This proposition is based on similar ages, common geochemical characteristics, and comparable lithological associations,including large volumes of rhyolitic material. Both the Colı´der Formation and the Roosevelt Formation display great lithologic diversity with a predominance of pyroclastic rocks in the Roosevelt Formation and subvolcanic intrusions in the Colı´der Formation sharing general characteristics of SLIP around the world. Previous literature about this subject is comprised of Antonio et al. (2021)focusing on the Uatuma˜event interpreted as a silicic large igneous province (SLIP) covering an area of 1,500,000 km2of the Amazonia craton at ca. 1890–1850 Ma (Klein et al.2013).

Effusive rocks are less common and vary from vitric rhyolitic, rhyodacitic, and dacitic lavas to microporphyritic andesites. Basaltic rocks occur as small bodies composing less than 5% of the estimated volume of the igneous province and some large igneous provinces have large volumes of silicic igneous rock without associated with large volumes of mafic rock (Twist and French 1983; Allen and McPhie 2002). Such provinces have been referred to as Silicic Large Igneous Provinces (SLIPs). Only a few examples of SLIPs have been documented worldwide(Table 1), three of which are of Proterozoic age and formed during supercontinent assembly: (1) ～2100 Ma rhyolites and dacites of the Rooiberg Felsite, South Africa, (Lenhardt and Eriksson 2012; Lenhardt, et al. 2017); (2)1592 Ma Gawler Range Volcanics, South Australia,(Agangi et al. 2011, 2012); and (3) the 1100 Ma rhyolites of the North Shore Volcanic Group in Minnesota, United States of America (Green and Fitz 1993). Silicic igneous provinces are often dominated by pyroclastic deposits(ignimbrites) and vary in composition from intermediate to acidic with calc-alkaline to I-type magmatic affinities.They may occur associated with intraplate extension or along continental margins, but unlike basalt-dominated LIPs or subduction-related magmatism, geochemical trends are not easily discernable on most tectonic discrimination diagrams.

Table 1 Major Silicic Large Igneous Provinces

Bryan et al. (2002a, b) suggested that the term silicic large igneous province (SLIP) may be used to describe volcanic-plutonic provinces with the following characteristics: (i) extrusive volumes of ≥105 km3; (ii) compositions ≥75 vol% of dacitic-rhyolitic compositions; and (iii)rhyodacite-rhyolite compositions near the hydrous granite minimum. The same authors observed that SLIPs can occur in both intraplate environments (associated with the continental breakup), and active convergent margins undergoing extension e.g. back-arc extension or intra-arc rifting.The latter examples tend to demonstrate close spatial–temporal relationships with subduction-related magmatism(Ward et al. 1995).

This work considers a description and comparison of the volcanic rocks from Colı´der and Roosevelt areas using Sm–Nd isotope geochronology together with whole-rock geochemistry. These data emphasize some features that can characterize both succession and associate intrusions as representatives of a large magmatic event with similar geochemical and isotopic characteristics.

The great extents and the features of the Colı´der and Roosevelt volcanic rocks have been reported in the literature (Leite et al. 2005; Neder et al. 2002; Santos et al.2019), and the rocks studied here could represent a preserved Paleoproterozoic SLIP in the southeastern part of the Amazonian Craton (Tassinari and Macambira, 2000).This working hypothesis is the focus of this investigation.

1.1 Geological setting

The Amazonian Craton was defined by Almeida et al.(1981) as a continental shield with an Archean nucleus reworked by the Paleoproterozoic Trans-Amazonian Cycle of Amaral (1974). Geochronologic studies indicate that its evolution began in the Archean and the spatial variations in ages suggest that the craton grew through the progressive accretion of magmatic arcs, micro-continent accretions,mobile belts, and magmatic arcs followed by anorogenic magmatism (Cordani and Brito Neves 1982, Cordani et al.1979, Teixeira et al. 1989, Tassinari and Macambira 1999,Santos et al. 2000, Geraldes et al. 2001, Vasquez et al.2008). The Amazonian Craton is bordered by Neoproterozoic to Cambrian mobile belts that formed during the Brazilian cycle, which also resulted in the reworking of the cratonic margins (Braun 1974, Almeida et al. 1976,Almeida 1978, Tassinari et al. 2000). However, while the tectonic evolution of the Sa˜o Francisco Craton is relatively well understood (Teixeira et al. 2000), several different models have been proposed for the Paleoproterozoic tectonic evolution of the Amazonian Craton; hence, it is still controversial.

The Amazonian Craton was divided into six provinces by Tassinari (1996) based on regional mapping and geochronological data: (1) Central Amazonia: (＞2.3 Ga)characterized by Archean granite-greenstone and granitegneiss terranes; (2) Maroni-Itacaiunas: (2.2-1.95 Ga),which includes granite-greenstone terranes and Trans-Amazonian mobile belts; (3) Ventuari-Tapajo´s:(1.95-1.8 Ga) consisting of granite-gneiss terranes of predominantly quartz dioritic and granodioritic compositions; (4) Rio Negro-Juruena: (1.8-1.55 Ga), characterized by A-type granitic-granodioritic intrusive rocks; 5) the 1.5-1.3 Ga Rondonia-San Igna´cio mobile belt; and (6) the Sunsa´s (1.25-1.0 Ga) Province related to thinned-skinned tectonics along the southwestern margin of the Amazonian Craton. This division was modified by Santos et al.(2000, 2001), who proposed the following geological provinces: Caraja´s-Imataca (3.1–2.53 Ga), Transamazonica (2.2-2.0 Ga), Tapajo´s-Parima (2.1-1.87 Ga), Rio Negro (1.86–1.52 Ga), Rondoˆnia-Juruena (1.75-1.47 Ga),and Sunsa´s (1.33-0.99 Ga) (Fig. 1a).

According to Tassinari and Macambira (1999), the rocks of the Colı´der Suite crop out along the limit between the 1.95-1.8 Ga Ventuari—Tapajo´s (VTP) and 1.8–1.55 Ga Rio Negro-Juruena (RNJP) provinces, both of which are characterized by granite-gneiss terranes of dioritic to granodioritic composition, intruded by A-type granites, and covered by Proterozoic and Phanerozoic sedimentary rocks.

1.2 Regional setting

The RNJP is located to the west of the Ventuari-Tapajo´s Province (Fig. 1b), and its exposures form an approximately 2000 km-long and 600 km-wide, NW–SE trending belts within the western portion of the Amazonian Craton,with outcrops in Brazil, Venezuela, and Colombia (Tassinari and Macambira 1999). The rocks in this province present zircon U–Pb crystallization ages between 1.85 and 1.75 Ga and Sm–Nd model ages as old as 2.24 Ga (Pimente 2001; Lacerda Filho et al. 2004). The former ages are related to the development of the Juruena magmatic arc and subsequent collision of the Juruena arc with the older(2.1–1.95 Ga) Cuiu´-Cuiu´ magmatic arc (Vasquez et al.2002) in the Late Paleoproterozoic (Souza et al. 2005). The Cuiu´-Cuiu´ magmatic arc occurs along the southwestern margin of the Ventuari-Tapajos Province (Souza et al.2005, Tassinari 1996). Detailed mapping of the Alta Floresta region, located along the southeastern boundary of the RNJP, defines three different crustal domains: a relatively undeformed volcanic-plutonic domain; an accretionary domain of medium- to high-grade metamorphic rocks; and a metavolcanic-sedimentary domain (Oliveira and Albuquerque 2005, Souza et al. 2005).

The rocks of the Colı´der Formation occur in a WNWESE belt within the volcanic-plutonic domain, which also includes calc-alkaline granites related to the development of the Juruena magmatic arc (Souza et al. 2005). Juliani et al. (2005) suggested that the felsic to intermediate volcanic and subvolcanic to plutonic rocks of the Colı´der Formation represent the first phase of the Uatuma˜magmatic event associated with an intra-arc or back-arc tectonic setting. Fernandes et al. (2008) argued that contemporaneous anorogenic (A-type) granitoids were emplaced in adjacent stable cratonic domains. On the other hand, the tectonic evolution of the Juruena magmatic arc can be described by four tectonic stages (Oliveira and Albuquerque 2005, Souza et al. 2005): (1) a pre-arc stage(2.2 to 1.9 Ga), (2) inversion/subduction (1.9-1.85 Ga),(3) collision (1.85-1.75 Ga) and (4) a postorogenic stage(1.70-1.60 Ga). The first stage is related to the opening of a restricted ocean basin with incipient seafloor spreading(the amphibolite Bacaeri-Mogno Complex) between older continental blocks, including older granites and gneisses to the west/southwest related to the development of the 2.1 to 1.95 Ga Cuiu´-Cuiu´ magmatic arc (Vasquez et al. 2002,Oliveira and Albuquerque 2005, Braga et al. 2019). This oceanic basin was inverted during the second stage due to initial NW–SE-directed convergence and the subduction of oceanic crust, leading to the development of the Juruena magmatic arc from 1.9-1.8 Ga (Souza et al. 2005). This was followed by the oblique collision of the Juruena magmatic arc with the older Cuiu´-Cuiu´ Magmatic arc at approximately 1.85 Ma, which resulted in voluminous calc-alkaline, high-K and metaluminous magmatism with ages between 1.85 and 1.75 Ga (Lie´geois 1998, Souza et al. 2005).

The Colider magmatism encompasses the granites and monzogranites of the Juruena Suite (U–Pb:1817 ± 12 Ma) and the Paranaı´ta Suite (U–Pb:1,796 ± 17 Ma; Ribeiro and Duarte 2010), as well as the monzogranites, syenogranites, and associated subvolcanic rhyodacites, quartz syenites and granophyres of ‘‘Nhandu Granite’’ (Souza et al. 2005). These latter igneous rocks have a calc-alkaline, high-K character with shoshonitic tendencies indicating a late orogenic/post-collisional tectonic context (Souza et al. 2005). The volcanic rocks of the Colı´der Formation (1774-1809 Ma, Pinho et al. 2003;Santos et al. 2019) also present similar geochemistry, and their temporal and spatial proximity suggests a genetic association with the plutonic to subvolcanic rocks of the Juruena and Paranaı´ta Intrusive suites and the Nhandu Granite (Duarte et al. 2012; Souza et al. 2005). The oblique collision of the Juruena magmatic arc resulted in the development of crustal-scale transpressive (ductile) shear zones with predominant sinistral movement along E-W- to WNW-ESE-oriented shear zones and dextral movement along secondary NW–SE-oriented shear zones.

However, ductile deformation was largely restricted to the accretionary domain of medium- to high-grade metamorphic rocks. During orogenesis, this domain was placed at middle to lower crustal levels (Souza et al. 2005). In contrast, the rocks of the Colı´der Formation and associated plutonic rocks of the volcanic-plutonic domain were located at higher crustal levels under brittle-ductile to brittle conditions. Within this domain, the N55°E direction of maximum compression controlled the development of quartz veins and associated gold mineralization within the Alta Floresta gold province (Souza et al. 2005).

The Teles Pires Granite has been dated at 1778 ± 6 Ma(U–Pb age; Santos et al. 2004, Souza et al. 2005); however,these porphyritic granites, syenogranites, and associated subvolcanic biotite granophyres and microgranites intrude the volcanic rocks of the Colı´der Formation in the form of undeformed, subcircular to stocks and batholiths. These characteristics and the fact that some of the porphyritic granites display rapakivi and anti-rapakivi textures suggest a postorogenic to anorogenic context for the Teles Pires Granite (Souza et al., 2005). A final postorogenic phase for the tectonic evolution of the Juruena magmatic arc was proposed by Oliveira and Albuquerque (2005) and Souza et al. (2005). This phase occurred between 1.70 and 1.60 Ga and was characterized by the brittle reactivation of older structures as strike-slip and normal faults to form pull-apart basins with continental to shallow marine sedimentation (Souza et al., 2005). Leite and Saes (2003)presented Pb-Pb ages of detrital zircons from the basal conglomerate of the Beneficiente Formation, which Gave a maximum age of 1.7 Ga for the deposition of these sediments in one such pull-apart basin, the Cachimbo Basin.

The Rio Negro-Juruena Province also includes rare amphibolite within the Bacaeri-Mogno Complex, interpreted as a basement unit composed of metavolcanic-sedimentary rocks (Lacerda Filho et al., 2014). The rare Earth element geochemistry of mafic rocks indicates a tholeiitic nature with MORB-like characteristics for these amphibolites, and as such, they are interpreted to represent remnants of the oceanic crust, which was subducted and consumed to generate the granitic rocks of the Juruena magmatic arc (Souza et al. 2005). Another unit is interpreted as basement rocks of the Colı´der unit by the Cuiu´-Cuiu´ magmatic arc formed from 2.1 to 1.95 Ga (Vasquez et al. 2002).

2 Materials and methods

In total, 55 samples of Colı´der and Roosevelt rocks were considered for geochemical studies. The results of the whole-rock and trace element analyses are given in Table 1. Colı´der rocks (36 samples) were crushed and analyzed for major, trace, and rare Earth element contents by Activation Laboratories Ltd., Ontario, Canada. A database (19 samples) of Roosevelt rocks was integrated to make a geochemical comparison between these Paleoproterozoic volcanic rocks. Samples of Roosevelt rocks were analyzed by Chemex, Lima, Peru. Major elements were analyzed using lithium metaborate and tetraborate fusion by ICP for major elements and ICP-MS for trace and rare Earth elements.

Radiogenic isotope ratios of Nd (143Nd/144Nd) were measured by isotopic solution at the Department of Earth Sciences (University of Geneva, Switzerland) using ICPMS. Whole-rock powder (100 mg) was dissolved for 7 days in SavillexⓇ. Samples were ultrasonicated in Teflon vials using 4 mL of concentrated HF and 1 mL of 14 M HNO3, at a temperature of 140 °C, for 30 min (twice a day). Later, samples were dried and redissolved for 3 days(also with 30 min of ultrasonication twice a day) in 3 mL of 14 M HNO3and dried again. Nd was then separated using cascade columns with Sr-Spec, TRU-Spec, and Ln-Spec resins according to a protocol reported by Pin et al(1994). The material was dissolved in 2% HNO3solutions,and ratios were measured using a Thermo Neptune PLUS multicoletors ICP-MS in static mode. The ratio used to monitor internal fractionation was146Nd/144Nd = 0.7219 for143Nd/144Nd. The external standard used was JNdi-1(143Nd/144Nd = 0.512115), with a long-term external reproducibility of 10 ppm.143Nd/144Nd isotope ratios were further corrected for external fractionation (due to a systematic difference between measured and accepted standard ratios) by a value of + 0.047% amu. Interference of mass144Sm on144Nd was monitored by the mass of147Sm and corrected using a144Sm/147Sm value of 0.206700. TDMvalues were calculated using the De Paolo (1980) one model ages.

3 Local Geology

3.1 The lower units of the Colı´der Formation

The basal units are composed of volcanic rocks characterized by deposition on a continental substrate with little or no influence of overlying water comprised of ignimbrites, lavas, and lapilli tuffs and are widespread. In the northernmost region, the volcanic rocks are located at the Cachimbo Graben border on national road BR-163. Lapilli tuffs and rhyolitic lavas form a topographically distinct bench up to 20 m in height (Fig. 2a).

The ignimbrite, covering an area of approximately 10,000 km2(Fig. 1), is well exposed in road cuts along BR-163 on the border between Mato Grosso and Para´ states and directly overlying the basement rocks. Rhyolitic lavas and ignimbrites are intercalated, showing different degrees of welding and compaction causing folds (Fig. 2b). Ignimbrite lithofacies ranging from low-grade welded to highgrade, display alkali feldspar and quartz phenocrysts(0.5–2 mm) with commonly flow texture as flow-banding or alignment of crystals. Groundmass is dominated by flattened vitric shards showing moderately to strongly fiammes that form discontinuous layering, varying from millimetric to 2-5 cm in size, welding lineation, or eutaxitic texture. Massive, pale, felsic ash layers occur within the pumiceous lapilli stone. It is largely composed of ash tuffs with a thickness of 1 m, interspersed with lapilli tuffs, which suggest that they are associated deposits.

The ignimbritic rocks exhibit well-preserved WNWESE flow structures with flow textures and are classified as crystal and lapilli tuffs (Fig. 2c). These rocks show fragments of moderately to strongly flattened glass (fiamme)that form discontinuous layers at outcrop scale, varying from millimeter size to 2-5 cm (Fig. 2d) and defining a lineation where microscopic cooling textures locally show Gas escape structures.

Fig. 2 a Outcrop morphology of ignimbrite rocks.; b The layers can be folded as a result of flux; c Rhyolitic features at outcrop scale;d Fragments of moderately to strongly flattened glass (fiamme) that form discontinuous layers

The southeastern domain consists mainly of lavas associated with epiclastic rocks. The porphyritic rhyolite lavas are interspersed with a sequence of gray feldspar and consist of phenocrysts of quartz (15%) and alkali feldspar(1-3 %) within an aphanitic groundmass. The groundmass is usually a devitrified assemblage of quartz and feldspar,but in some samples, it is cryptocrystalline or glassy. The rocks generally exhibit flow texture, including flow bands or phenocryst alignment. The feldspars are almost fresh,and the development of pale beige clay in the groundmass is the main sign of change.

Volcanic rocks have been described and dated by Neder(2002), as volcanic sucession dominated by felsic volcanic sequence formed between 1762 ± 32 Ma and 1755 ± 18 Ma intruded by epizonal granitoid rocks. The studied samples from the Roosevelt Formation have similar characteristics and present phases of alkali feldspar and quartz phenocrysts (1-2 mm) in an aphanitic to microcrystalline, seriticized, and recrystallized groundmass.Quartz crystals show partial resorption and rounded surfaces. Biotite and chlorite are the dominant mafic phases,common in all analyzed rocks.

3.2 The intermediate units of the Colı´der Formation

The intermediate units of the Colı´der Formation show an environmental evolution with a greater marine influence and are intercalated with rock packages having continental characteristics. The outcrops (Fig. 3a) are composed of devitrified lavas, porphyritic lavas, tuff lavas, and volcanic ash. The rhyolitic samples collected from the central region commonly display flow textures (Fig. 3b), including flow banding and alignment of phenocrysts. Hand samples consist of quartz (15 %) and alkali feldspar (3 %) phenocrysts (1-3 mm) within a fine-grained to aphanitic groundmass. Microscopy studies indicate that the groundmass is comprised of quartz and alkali feldspar (Fig. 3c).The lava flows are classified according to their silica contents greater than 55 % (andesites lavas; Fig. 3d). The volumes of individual lava flows vary widely from small reservoirs to extensive bodies that reach 1 km3in volume.

3.3 The upper units of the Colı´der Formation

The upper units of the Colı´der Formation are represented by volcaniclastic deposits related to eruptions with marine influence on deposition as suggested by the layers of sediments interspersed with volcanic ash. In addition, the associated lava flows (Fig. 4a) differ from the lower layers in their geometry, extent, and volume, characterized by large amounts of slag, pumices, vitroclasts, and crystal fragments (Fig. 4b). In this extreme eastern portion of the Colı´der Formation, a sedimentary layer (Fig. 4c) crops out as boulders and small cliffs along WNW-ESE-aligned ridges. The observed rocks are mostly comprised of centimetric brown and yellow layers, composed of fine angular grains of quartz, feldspar (rarely biotite, chlorite, and sulfides). The white layer is composed of quartz, orthoclase,and plagioclase interpreted as formed in continental to shallow marine sedimentation.

The pyroclastic deposits are dominated by a dark orange to light brown porphyritic rhyodacite with feldspar(0.5-3 mm), quartz (0.5-2 mm), and biotite(0.2-0.6 mm) dispersed in a hypocrystalline to a holocrystalline quartz-feldspathic matrix (Fig. 4d). This porphyritic rhyodacite crops out as blocks, boulders, and large exposed surfaces along E-W-aligned ridges. In the studied pyroclastic deposits, the welding process is characterized by the presence offiammeand the consequent eutaxitic and parataxitic structures.

Fig. 3 a The subvolcanic rocks outcrop as layers defining characteristics morphology features in the field; b Rhyodacite lava flow structures with a large granulometric range. c Porphyritic andesite lava alkali feldspar with phenocrysts (1-3 mm) within a fine-grained to aphanitic groundmass; d Thin section of the porphyritic andesitic lava shows groundmass originally completely glassy before it underwent devitrification

4 Analytical results

4.1 Geochemistry

Major and minor elements from the Colı´der and Roosevelt rocks are presented in (Table 2). Volcanic rocks from Colı´der and Roosevelt span a compositional range from andesite (57% SiO2) to rhyolite (81% SiO2), and the other components gradually increase or decrease systematically with SiO2variation. The Harker major oxide variation diagrams for the studied rocks are presented in Fig. 5 and increasing contents of TiO2and Al2O3are observed with decreasing SiO2contents, consistent with fractionation or accumulation of titanite and feldspar. The MgO contents decrease systematically with SiO2contents. The contents of CaO and Al2O3increase and the Fe2O3contents decrease with decreasing MgO contents, which is consistent with the fractionation/accumulation of amphibole and plagioclase. Rocks form a continuous chemical trend with typical alkaline rocks having higher SiO2contents.

The studied Colı´der rocks plot in the rhyolite, rhyodacite, dacite, and andesite fields (Fig. 6a) on the Zr/TiO2versusNb/Y diagram Pearce (2008). Using geotectonic classification diagrams, all samples are distributed in the active continental margin setting. Th-Yb-Nb classification diagram (Fig. 6b) shows a volcanic arc tectonic setting. In this diagram, the E-MORB composition represents a subordinate component of global MORB and is 5–10 times more enriched in incompatible elements than the more common ‘‘normal-type’’ MORB, or N-MORB (Arevalo and Mcdonough, 2009), while OIB represents intracontinental magma composition, Fig. 6b present the tectonic setting discriminant diagrams (Nb/Nb versus Th/Yb)according to Pearce (2008) and the plot suggests a volcanic arc tectonic setting. The magma formed in arc-basin systems is typically enriched relative to an N-MORB mantle source but would become depleted during flow as an effect of preconditioning by the loss of small melt fractions(Pearce 2006). The transition from E-MORB to OIB composition in Colı´der and Roosevelt rocks represents an important component in the magma generation and the evolution of the rocks here studied. In the same way, diagrams Th/TiO2versus Ta/Yb (Fig. 7a); Th versus Ta(Fig. 7b); and Th/Hf versus Ta/Hf (Fig. 7c; and Th/Ta versus Yb (Fig. 7d), suggest the rocks here studied were originated in an active continental margin.

The Colı´der and Roosevelt rocks show low fractionation of REEs and moderate negative Eu anomalies when observed altogether (Fig. 8a). When observed separated,North Colider andesitic rocks present similar REE patterns(Fig. 8b and c). Chondrite-normalized REE patterns of Roosevelt rocks show slight LREE depletion (Fig. 8d), and the subparallel REE patterns may be interpreted as fractional crystallization process. Apart from three andesite samples, all analyzed rocks show weak negative Eu anomalies.

Spider diagram (compared to chondrite according to Thompson 1982) shows incompatible elements Sm, Zr, Hf,Tb, Y, Tm, Yb flat to slightly to highly enriched patterns.Normalized multi-element diagrams indicate that they are generally much more depleted in HFS and enriched in some of LFS elements (Rb, K). High charge atoms as Ti and P are highly depleted. All samples behave coherently in spider diagrams (Fig. 9) forming a pattern that peaks Rb,Th, K, with moderately to highly enriched content and strongly depleted in incompatible elements, particularly Sr and P. High and flat La, Ce, Nd, Sm, Zr and Hf patterns are consistent with the evolved silicic magmas, suggesting that old crust can be considered as magma sources. The chondrite-normalized ratio of ‘‘paired elements’’ (i.e. elements with similar geochemical behavior) such as Zr(N)/Hf(N) show little variation.

Fig. 4 a Amygdaloidal rhyodacite lava; b Porphyritic rhyodacite showing chlorite and biotite from metamorphic alteration; c Sediments comprised of centimetric layers of brown to yellow, composed of fine angular grains of quartz, feldspar (rarely biotite, chlorite, and sulfides in dark layers); d Subvolcanic rhyodacite with rounded quartz grains

4.2 Sm–Nd isotope results

The results of the Sm-Nd isotope analyses and geographic information are listed in Table 3 and Table 1 of supplementary material and are plotted in Fig. 10. Sm-Nd results of the samples from the Eastern area show TDMage of 2.17 Ga for rhyodacite rocks and more negative εNd(1787Ma)value (-5.48) than rhyolites from the North area. Whole-rock Sm–Nd analyses from sample 24 show a143Nd/144Nd(1800Ma)ratio of ≈0.50946, a143Nd/144Nd(1800Ma)ratioof ≈0.510292, and a TDMmodel age of 2.07 Ga. The negative εNdvalue (-3.90 Ga) calculated at a crystallization age of 1.8 Ga indicates a crustal source for the formation of northern Colı´der rocks involving partial melting of Paleoproterozoic crust. A similar source is observed for sample 35. In sample 02, the analysis yields a 147Sm/144Nd ratio of ≈0.0918 and a143Nd/144Nd(1792 Ma)ratio of 0.510299; this sample also shows an Sm–Nd TDM model age of 2.40 Ga and a negative εNd(1792 Ma) value(–4.09), comparable to those of recycled crustal sources.

Table 3 Sm–Nd analytical data for Colı´der and Roosevelt volcanic rocks

Fig. 5 Harker major oxides variation diagrams for the Colı´der and Roosevelt rocks

-37 BSA-36 BSA-35 BSA-34 BSA-33 BSA-32 BSA-31 BSA-26 BSA-24 BSA.0.7 69 13 73 3.09 0.89 0.85 1.99 3.37 4.49 0.19 0.78 0..6.1 69 14 72 3.08 0.58 1.97 0.21 2.44 6.48 0.21 0.64 2..3.7 67 14 96 3.09 0.98 0.10 2.29 4.42 4.53 0.22 0.86 0..1.6 68 14 82 3.08 0.58 1.98 0.20 4.84 4.50 0.21 0.42 1..4.9 76 11 23 2.02 0.29 0.26 0.90 2.43 5.19 0.01 0.72 0..7.5 67 14 92 3.09 0.93 0.17 2.13 4.37 4.51 0.19 0.6 0..0.1 68 15 76 3.09 0.93 0.24 2.27 4.38 4.52 0.20 0.78 0..5.9 76 11 65 1.02 0.13 0.04 0.08 3.24 5.19 0.01 0.71 0..5.3 77 12 83 1.04 0.17 0.05 0.33 1.91 6.31 0.02 0.25 1..3.3.7.2.7 98 008 1.05 6.03 4.41 1081 342 31 216.4.0.9.7.2 99 027 1.14 5.05 2.38 5882 221 27 195.6.4.3.3.9 98 009 1.06 7.03 3.47 1121 375 32 220.9.7.2.5.1 98 015 1.09 6.04 3.46 1341 225 31 218.6.5.4 99 007 1.02 3.04 5.0 5.88 1 7.66 337.6.3.5.2.3 98 006 1.04 6.02 3.42 1222 415 28 218.6.4.1.3.6 99 008 1.05 6.03 4.46 1175 400 32 208.7.1.3.4 98 007 1.01 2.02 3.1 7.196 14 40 192.5.2 100 013.1.1.8 1.05 4.04 3.10 56 10 67 340.2.2.1.5.1 20 04 5.20 10 60 18 01 1..5.5.3.9.4 20 16 6.20 10 71 15 03 1..2.2.1.5.2 20 05 6.20 10 60 18 01 1..3.3.1.0.3 20 09 6.20 10 71 19 01 1..1.1.1.2.2 20 01 1.20 10 30 21 01 2..1.1.1.3.1 20 03 5.20 10 50 18 01 1..2.2.1.4.1 20 04 5.20 10 50 18 01 1..1.1.1.2.1 20 01 1.20 10 30 18 01 1..3.3.1.8.3 20 01 1.20 10 60 20 03 2.04 5.155 1 9.02 2.50 0.20 0.01 1.50 0.91 0.14.3 5.181 10 05 2.51 0.21 0.03 1.03 1.60 3.04.1 5.145 11 02 2.50 0.20 0.02 2.50 0.91 0.07.2 5.153 12 03 2.51 0.20 0.03 2.51 0.01 1.04.1 5.222 20 01 2.71 0.20 0.04 5.50 0.71 0.03.1 5.138 11 02 3.50 0.20 0.01 2.50 0.01 1.04.1 5.142 10 02 2.50 0.20 0.02 2.50 0.11 1.04.1 5.139 13 01 2.50 0.20 0.02 3.50 0.50 0.06.2 5.220 13 03 2.51 0.20 0.04 3.51 0.82 1.ks roc-23 BSA .4.8 76 11 58 1.03 0.22 0.10 0.13 0.98 7.29 0.02 0.43 1..6.1.7.0 98 015 1.04 3.03 2.1 6.67 10 49 273.3.3.1.6.3 20 01 1.20 10 40 19 03 2.07.3 5.200 17 03 2.61 0.20 0.04 3.51 0.22 1.l t eve Roos and-22 BSA .2.0 78 11 90 1.04 0.17 0.05 0.58 0.84 7.25 0.01 0.92 0..1.4 100 009.5 1.03 3.03 3.0 5.68 1 8.57 257.2.2.1.3.1 20 01 1.20 10 30 16 01 1.05.1 5.222 12 02 2.61 0.20 0.02 2.50 0.01 1.r´de ı Col om fr s nt eme e l nor m i a nd jor-04 BSA-03 BSA-02 BSA.0.4 73 12 17 3.08 0.21 0.55 0.61 3.37 5.30 0.03 0.84 0..9.3 70 13 81 3.10 0.43 0.25 1.67 3.22 5.53 0.11 0.54 0..0.8 76 12 42 2.02 0.34 0.16 0.72 2.70 5.34 0.05 0.3 1..7.7.4.4 98 009 1.04 5.03 4.1 7.399 81 50 396.3.1.9.2.7 99 005 1.04 8.02 3.19 793 170 45 489.5.1 100 013.1.4.0 1.05 4.04 3.11 540 29 75 314.2.2.1.9.2 20 01 1.20 10 100 20 02 2..1.1.1.5.1 20 01 2.20 10 90 20 01 1..3.3.1.5.2 20 01 1.20 10 40 17 01 1.04.1 5.188 14 02 2.71 0.20 0.03 3.50 0.31 1.03.1 5.156 11 01 2.11 1.20 0.01 2.50 0.41 1.07.2.2 5.171 13 03 2.51 0.20 0.03 2.51 0.42 1.2 Ma e Tabl e mpl Sa O2%2O3%2O3%O%2O%I Si A l Fe MnO%MgO%Ca Na K2O%O2%T i P2O5%LO us )))))))a l ul(ppm(ppm Tot lc (ppm(ppm(ppm Ca (ppm(ppm Sc Be V Ba Sr Y Zr))))))))))))))(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm ))(ppm(ppm(ppm(ppm Cr Co N i Cu Zn Ga Ge As Rb Nb Mo Ag In Sn Sb Cs

-37 BSA-36 BSA-35 BSA-34 BSA-33 BSA-32 BSA-31 BSA-26 BSA-24 BSA-23 BSA-22 BSA-04 BSA-03 BSA.0.9.6 52 101 10 37 8 6.06 1.44 5.91 0..1.2 41 80 1 9.32 3 5.93 0.21 4.62 0..7.0.0 54 106 12 42 328 7.1.14 5.81 0..7.6.0 52 103 11 41 928 6.1.97 4.81 0..7 102 178.4.3.1.18 21 73 13 44 0.11 71 1..9.7.8 46 93 10 36 229 6.1.83 4.70 0..3.2.2 51 99 11 39 727 6.1.94 4.81 0..1.2 14 64 9 4.16 5 4.32 0.13 4.81 0..3 102 149.1.8.2.75 21 74 13 87 0.11 52 1..5.6.7 47 235 12 42 658 8.0.60 6.22 1..1 116 133.4.6.7 23 80 13 82 0.79 9.61 1..6.4.4.4 85 165 18 63 10 90 0.77 8.31 1..3.6.0.1 88 170 18 67 11 32 1.45 8.41 1.84.2.2 4.01 1.02 3.49 0.43 3.52 0.94 4.01 1.01 1.30 0.23 40 0.21 95 5.01.4.7 4.82 0.57 2.39 0.67 2.42 0.03 5.92 0.03 1.62 0.16 41 0.16 90 3.84.3.5 4.01 1.03 3.46 0.23 3.49 0.45 5.01 1.03 3.61 0.29 40 0.18 35 5.67.3.4 4.01 1.84 2.45 0.15 3.49 0.78 5.01 1.01 1.61 0.23 41 0.19 58 5..48.1 10 22 2.45 6.00 1.55 6.04 1.37 9.01 2.01 2.81 0.1 9.40 0.27 96 8.33.1.8 4.91 0.82 2.42 0.72 2.44 0.43 5.01 1.01 1.50 0.22 40 0.17 63 4.64.2.4 4.91 0.82 2.44 0.02 3.45 0.24 5.01 1.02 2.50 0.24 40 0.18 24 5.54.1.9 5.21 1.93 3.63 0.33 4.73 0.94 5.31 1.01 1.50 0.11 40 0.19 94 4.01.2.8 9.72 1.67 5.81 0.27 5.76 0.39 7.11 1.06 5.41 0.17 41 0.23 04 3.91.2.5 7.62 1.18 5.81 0.48 5.81 0.91 7.52 1.03 2.51 0.12 41 0.27 35 3.39.1.3 9.92 1.65 5.89 0.75 5.82 0.46 6.31 1.01 1.40 0.11 40 0.25 84 4.67.3.9 7.61 1.84 4.73 0.94 4.72 0.57 8.31 1.01 1.50 0.31 40 0.19 04 5.24.1.2 8.71 1.83 4.73 0.93 4.75 0.35 9.11 1.01 1.30 0.23 40 0.18 42 4.-75 BSA-74 BSA-73 BSA-71 BSA-69 BSA-68 BSA-67 BSA-66 BSA-65 BSA-62 BSA-43 BSA-42 BSA-41 BSA.6.3 71 13 07 4.12 0.50 0.26 1.76 3..7.9 75 11 45 2.06 0.21 0.32 0.85 2..1.2 72 16 97 3.02 0.07 1.03 0.03 0..2.6 74 12 06 2.08 0.13 0.04 0.70 3..2.9 70 14 57 3.08 0.83 0.03 2.96 3..9.2 74 13 20 2.06 0.22 0.63 0.91 3..1.1 62 16 44 6.14 0.65 1.78 3.53 4..5.8 74 12 85 2.11 0.35 0.75 0.74 2..5.3 69 14 79 3.08 0.81 0.98 1.85 3..5.2 72 13 18 3.09 0.47 0.31 1.79 3..6.2 58 16 52 7.13 0.98 2.32 6.39 3..5.3 58 15 05 8.14 0.67 3.18 6.19 3..9.0 58 17 09 9.09 0.06 3.90 2.73 2.13.4 5.55 0.11 0.47 0.100 03.9 6.27 0.02 0.54 0.99 53.7 5.62 0.05 0.23 3.99 51.6 5.32 0.01 0.48 0.98 47.6 4.48 0.15 0.53 0.100 68.2 4.26 0.04 0.48 0.100 11.2 4.95 0.39 0.68 0.100 77.3 4.36 0.06 0.99 2.99 22.2 4.49 0.19 0.67 0.99 70.8 4.37 0.10 0.72 0.99 39.8 3.93 0.37 0.2 1.99 78.7 2.72 0.24 0.06 1.98 50.6 4.01 1.28 0.69 1.99 d inue ont 2 c e Tabl-02 BSA e mpl Sa.1.2.8 160 247.7.5.02.60.1 38 140 21 59 2.17 03 2.73 9.82 1.37 5.76 0.07 5.72 0.98 5.22 1.05 4.20 0.46 41 0.20 66 4.))))))))))))))))))(ppm(ppm )))(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm )(ppm La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu H f Ta W T l Pb B i Th U-38 BSA e mpl Sa.4.8 69 14 06 4.09 0.96 0.24 2.07 4.O2%2O3%2O3%O%2O%Si A l Fe MnO%MgO%Ca Na 34.7 4.53 0.23 0.54 0.100 K2O%O2%I a l T i P2O5%LO Tot

-75 BSA-74 BSA-73 BSA-71 BSA-69 BSA-68 005.1 1.04 9.01 3.21 846 005 1.02 4.02 4.0 6.326 033.33.5 1.10 17 5.15 408 005 1.02 5.01 3.0 7.43 005.2 1.03 6.02 3.39 1281 005.1 1.01 3.01 3.11 621.8.3.7 172.2.1.1.0.1.1 45 482 20 01 3.20 10 140 21 01 2.02 5.167 14 01 2.80 0.20 0..3.3.0.1.1.1.4.1.1 48 59 373 20 01 1.20 10 80 21 01 2.03 5.201 15 02 3.50 0.20 0..0.4.0.7.7.3.3.8.4 31 42 339 20 07 2.20 10 72 23 07 2.17 5.334 12 07 2.52 0.21 0..3.8 0.1.1.0.3.1.1 7.57 361 20 00 1.20 10 70 23 00 1.02 5.191 16 01 2.60 0.20 0..1.1 398.2.1.1.1.4.1.1 32 216 20 03 5.20 10 70 20 01 1.03 5.168 12 01 2.50 0.20 0..5.2.9.1.1.0.2.1.1 94 34 178 20 00 1.20 10 40 18 01 2.02 5.187 13 01 2.50 0.20 0.01.3.3.0.1 2.50 0.91 2.87 171 19 70 12 56 1.04 9.41 1.94 7.61 1.62 4.02.6.9.3.3 3.50 0.01 1.105 174 21 75 12 86 0.55 9.41 1.05 9.81 1.53 5.07.7.3.4.9 2.03 1.44 4.92 147 19 66 10 02 2.96 7.24 1.13 7.34 1.82 3.01.5.6.2.6.85 3.50 0.80 0.105 160 24 86 15 92 0.10 61 1.35 9.81 1.43 5.01.5.8.5 2.50 0.41 1.54 108 11 41 2 7.34 1.63 5.80 0.13 5.01 1.02 3.01.4.8.4 3.50 0.61 1.48 99 10 37 686 6.0.12 5.80 0.92 4.00 1.22 3.BSA-67 007.09.5 1.13 02 3.69 1445.6.3.0 384.3.1.11.1.1.1.1 49 334 20 16 20 10 141 21 01 1.03 5.103 13 01 2.60 0.20 0.01.8.2.8.0 2.50 0.11 1.80 161 18 68 12 40 2.77 9.31 1.85 7.51 1.53 4.BSA-66 031.5 1.16 5.12 4.16 522.8.1 126.5.6.6.3.2.7.4 48 367 20 06 2.20 10 72 21 03 1.16 5.178 12 06 2.62 0.21 0.09.6.4.8.4 3.52 0.33 4.72 148 16 56 10 24 1.35 8.34 1.04 8.55 1.85 4.BSA-65 007.3 1.04 6.02 3.38 1121.5.5 372.2.1.1.1.3.1.1 28 222 20 03 5.20 10 50 19 01 2.03 5.165 13 01 2.50 0.20 0.01.5.8 2.50 0.01 1.45 89 9 9.34 3 6.25 1.93 4.81 0.63 4.91 0.62 2.BSA-62 007.2 1.04 5.04 5.25 839.3.0 175.3.1.1.1.7.1.1 38 277 20 02 3.20 10 90 20 01 1.04 5.204 15 01 2.50 0.20 0.02.9.1.5 3.50 0.81 1.72 141 15 52 5 8.19 1.14 6.01 1.04 6.21 1.63 3.BSA-43 012.22.8 1.18 02 2.151 1333.8.2 816.3.2.22.2.7.9.2 21 183 20 18 20 60 70 20 01 1.06 5.85 1 9.02 2.51 0.20 0.02.6.3.1 2.51 0.13 2.40 84 10 39 0 7.81 1.26 5.71 0.15 4.81 0.13 2.BSA-42 011.21.8 1.19 02 2.164 856.4.7 599.2.8.25.4.7.8.2 21 154 70 23 40 60 70 17 01 1.05 5.93 102 5.2.51 0.20 0.01.3.8 1.51 0.46 5.35 70 1 8.29 025 6.1.55 4.71 0.04 4.81 0.22 2.BSA-41 017.35.1 1.20 05 3.185 860.4.3 377.4.3.36.3.2.4.4 21 197 20 21 20 10 81 22 02 1.09 5.171 203 9.2.51 0.20 0.03.3.1.5 2.51 0.12 7.43 90 11 42 490 7.1.49 5.71 0.07 4.81 0.24 2.BSA d inue ont 2 c e Tabl-38 BSA e mpl Sa 005.3.2.1.2.1.1.1.3.1.1.5.3.9 1.04 7.02 4.51 1180 403 27 226 20 03 6.20 10 50 18 01 1.03 5.144 12 01 2.50 0.20 0.01 2.50 0.61 1.45 92 10 34 118 6.1.62 4.70 0.22 4.90 0.61 2.))))))))))))))us )))(ppm ))(ppm ))))(ppm(ppm(ppm ul(ppm(ppm(ppm ))))(ppm(ppm(ppm(ppm(ppm(ppm ))(ppm ))(ppm(ppm(ppm ))(ppm lc (ppm(ppm(ppm(ppm(ppm )(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm Ca Be (ppm Sc V Ba Sr Y Zr Cr Co N i Cu Zn Ga Ge As Rb Nb Mo Ag In Sn Sb Cs La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er

-75 BSA-74 BSA-73 BSA 69.05 0.62 4.74 0.10 11 1.83 0.63 5.86 0.24 8.51 1.59 0.24 4.66 0.65 7.93 0.00.2.4 1.70 0.41 40 0.16 52 3.01.2.4 1.70 0.35 40 0.22 83 5.07.9.0 2.72 0.27 41 0.14 65 4.-16 VTM-15 VTM-13 VTM.7.9 76 10.9.3 71 12.1.7 83 10 06 4.08 0.47 6.01 0.01 0.08 2.08 0.19 3.18 0.67 2.50 2.57 0.83 4.20 0.66 1.01 0.82 0.01 0.01 0.59 3.08 0.02.4 0.25 3.100 033 1.00 0.00 0.3 8.152 2 1.09.5.4.3 0.64 2.98 028 1.00 0.00 0.14 549 25 01.0.2 0.9 1.100 019 1.00 0.00 0.11 242 2 2..1.5.7 74 139 20.3.7.6 39 173 20.9.3.4 33 122 20-71 BSA-69 BSA 82 0.63 5.91 0.54 8.61 1.46 0.12 3.51 0.43 5.11 1.00.1.7 1.60 0.29 40 0.26 53 5.01.1.6 1.60 0.28 40 0.18 23 5.-11 VTM-8 VTM.6.6 75 13.2.1 77 12 02 2.05 0.01 1.12 0.53 5.78 1.17 0.25 5.06 0.59 1.21 0.02 0.56 3.15 0.04.0.1.6 0.87 0.100 009 1.00 0.00 0.11 446 12 03.1.3 0.99 1.100 020 1.00 0.00 0.13 191 8 3..9.7.2 30 190 20.1.9.4 62 143 20-68 50 0.42 3.55 0.52 4.11 1.00.1.3 1.60 0.25 40 0.17 02 4.BSA-67 BSA-66 BSA-65 BSA-62 BSA-43 BSA-42 BSA-41 BSA 65 0.43 4.69 0.05 7.91 0.76 0.95 4.80 0.87 8.03 1.40 0.72 2.47 0.54 5.21 1.56 0.93 3.64 0.95 6.41 1.31 0.02 2.31 0.66 4.61 0.33 0.22 2.33 0.54 3.51 0.31 0.03 2.31 0.29 5.61 0.01.2.3 1.30 0.24 40 0.12 02 3.06.9.4 2.52 0.28 41 0.17 20 3.01.2.5 1.60 0.26 40 0.18 83 3.01.2.9 1.81 0.31 40 0.26 45 6.01.2 1.30 0.13 40 0.0 9.02 2.01.1 1.20 0.10 40 0.612 8.2.02.2 1.61 0.13 41 0.864 9.2.-5 VTM-91 BSA-88 BSA-87 BSA-83 BSA-82 BSA-80 BSA-78 BSA.1.7 78 12.0.6 70 15.1.0 71 13.7.3 67 14.0.5 70 13.6.8 65 14.2.5 70 14.3.9 71 13 95 2.07 0.38 2.02 0.01 0.91 3.18 0.03 4.02 0.83 0.03 0.12 0.61 7.75 0.19 3.11 0.62 0.27 3.39 2.80 4.69 0.67 5.12 0.21 1.09 3.19 2.42 4.83 0.18 3.10 0.67 0.85 2.17 2.32 5.69 0.45 5.12 0.18 1.92 1.07 4.42 5.85 0.27 3.08 0.44 0.62 1.59 4.36 4.42 0.78 3.10 0.51 0.19 1.67 3.22 5.52 0.02.4.3 0.28 2.100 023 1.00 0.00 0.12 443 4 3.13.2.28.3.7 0.46 2.99 025 1.11 10 4.12 2572 69 11.2.38.8.9 0.6 3.99 038 1.10 11 3.20 2312 79 29.9.4.1 0.03 4.99 042 1.38 9.13 3.34 1121 175 11.6.36.7.8 0.47 3.98 036 1.10 11 3.19 2662 78 32.7.18.7.7 0.81 1.99 018 1.10 06 3.38 1389 149 08.6.3.9 0.08 2.99 021 1.17 8.04 2.16 1740 186 10.4.1.4 0.83 0.100 008 1.07 8.03 3.17 870 174.0.1.2 44 268 10.7.2 110 411.5 20.6.2.8 43 335 20.7.7.8 41 388 20.5.5.7 42 327 20.8.3.4 43 402 20.6.2.6 28 250 30.4.1.2 45 501 20 d inue ont 2 c e Tabl-38 BSA e mpl Sa 39.1.7 0.82 2.45 0.03 6.11 1.01 2.60 0.22 40 0.18 83 5.))(ppm(ppm ))(ppm ))))(ppm(ppm ))(ppm(ppm )Tm (ppm(ppm(ppm Yb Lu (ppm H f Ta W T l Pb B i Th U-77 BSA e mpl Sa.9.5 70 13 O2%2O3%Si A l 03 4.08 0.91 0.52 0.65 2.94 5.53 0.2O3%O%2O%Fe MnO%MgO%Ca Na K2O%O2%T i 10.2.3.5 0.48 1.99 015 1.14 9.05 3.19 615 33 us ))))P2O5%ul(ppm a l I (ppm )LO Tot lc (ppm(ppm Ca (ppm Sc Be V Ba Sr.7.3.3 47 487 20)))(ppm(ppm(ppm Y Zr Cr

-16 VTM 03.7 1.2 5.00 0.00 0.14 58 2.00 0.69.6.5.0.7.1.01.33 13 10 3.00 0.04 0.07 2.18 0.52 0.81 157 17 61 11 99 0.11 75 1.10 25 2.19 7.95 0.77 6.92 0.86 4.93 0.23 7.16 0.0 0.-15 VTM 11.9 4.100 5.0.00 0.14 57 2.00 0.153.1.0.2.4.5.69 15 51 0.00 0.35 0.22 8.94 5.48 2.186 323 34 126 19 15 5.12 42 1.76 6.46 1.50 4.65 0.72 4.61 0.75 5.92 0.14 5.74 0.0 0.-13 VTM 04.6 2.0 1.00 0.00 0.13 55 2.00 0.114.5.9.2 11 12 6.00 0.90 0.06 3.19 0.69 0.40 86 6 9.35 1 6.38 0.79 5.98 0.70 5.25 1.49 4.62 0.68 4.73 0.79 4.82 0.12 6.04 0.0 0.-11 VTM 04.9 5.0 3.00 0.00 0.11 52 2.00 0.57.5.1.2.5 13 02 2.00 0.05 0.02 2.53 0.95 0.57 112 12 44 2 8.00 1.02 7.04 1.61 5.21 1.55 4.64 0.57 4.71 0.36 6.01 1.04 4.16 0.0 0.-8 VTM 12.3 6.1 6.00 0.00 0.17 55 2.00 0.129.4.0.1.9.0.37.36 11 02 1.00 0.16 0.10 5.24 0.90 0.100 191 21 79 14 78 1.13 96 1.10 92 1.19 6.78 0.38 5.72 0.80 4.82 0.10 5.19 0.0 0.-5 VTM-91 BSA 51.3 0.0 2.00 0.00 0.17 56 2.00 0.126 05.5.3.8.5 2.20 10 30 21 03 1.13 5.205.9.9.4.5 14 02 1.00 0.03 0.07 3.53 0.94 0.41 87 10 40 6 7.07 1.08 7.06 1.94 6..4.7.5.7.3.74.20 15 05 2.51 0.21 0.05 2.82 0.95 1.108 164 27 107 19 68 4.17 77 2.16 48 1.84 4.82 0.08 5.69 0.08 8.02 1.14 6.14 0.0 0.18 3.33 9.27 1.20 8.24 1.51 8.13 1.05 2.51 0.1 5.-88 BSA-87 BSA 08.8.4.1.6 2.20 10 31 16 04 1.19 5.131.50.8.4.8.8 12 20 10 93 20 04 1.21 5.141.5.0.8.2 13 08 2.52 0.21 0.08 2.52 0.35 1.55 110 12 49 4 9.52 2.51 8.35 1.47 7..5.0.7.5.6 12 34 8.52 0.21 0.08 2.52 0.56 1.76 149 16 62 10 25 2.92 7.15 1.77 6.35 1.05 4.58 0.84 3.59 0.16 7.04 1.04 1.31 0.3 9.35.5 1.17 4.59 0.17 4.66 0.02 8.94 0.08 2.52 0.11-83 BSA-82 BSA 07.7.4.1.6 2.20 10 31 16 07 2.18 5.137 13.4.2.0.4 7.20 10 112 21 04 2.09 5.136.4.3.5.6 11 07 2.52 0.21 0.07 2.52 0.55 1.54 109 12 47 935 8.2.08 8.14 1.74 6..2.3.2.3.3 13 04 2.61 0.20 0.04 2.51 0.81 0.73 145 16 60 10 17 2.15 8.22 1.44 7.24.4 1.84 3.56 0.84 3.58 0.63 6.93 0.04 1.41 0.10 53.2 1.28 4.63 0.28 4.68 0.84 7.92 0.02 1.41 0.12-80 BSA-78 BSA 04.4.2.9.4 2.20 10 40 18 02 1.11 5.121 03.2.1.8.2 3.20 10 90 22 02 2.04 5.164 204.9.4.5 9.2.51 0.20 0.04 2.51 0.82 0.64 118 13 48 269 8.1.82 5.82 0.80 4..1.0.1.5.8 15 02 2.91 0.20 0.02 2.50 0.31 1.87 170 19 68 11 57 1.77 8.31 1.07 8.92.3 0.66 2.41 0.86 2.46 0.41 5.82 0.04 2.51 0.13 61.69.2 1.84 4.69 0.64 4.75 0.10 21 1.02 2.61 0.29 d inue ont 2 c e Tabl-77 BSA e mpl Sa 05.3.2.6.3 3.20 10 40 21 02 1.08 5.188))))))))(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm Co N i Cu Zn Ga Ge As Rb.2.0.5.2.8 15 03 2.81 0.20 0.05 3.51 0.73 1.86 160 18 68 11 46 1.44 9.42 1.63 8.)))))))))(ppm(ppm(ppm ))))))(ppm(ppm(ppm(ppm(ppm )(ppm(ppm(ppm(ppm(ppm(ppm(ppm Nb Mo Ag (ppm In Sn Sb Cs La Ce Pr Nd Sm Eu Gd Tb Dy 73.46 1.87 4.71 0.87 4.81 0.10 22 1.03 2.61 0.1 8.)))(ppm )))))))(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm Ho Er Tm Yb Lu H f Ta W T l Pb

-16-40 VTM-15 VTM-13 VTM-11 VTM-8 VTM 45.8 0.14 80 4.67.5 9.13 61 4.90.8 1.14 73 3.77.5 3.17 69 5.49.3 4.14 43 4.VTM-39 VTM-38 VTM-36 VTM-35 VTM.8.0 69 16 80 3.04 0..8.4 72 15 83 3.02 0..9.2 76 13 65 2.03 0..4.8 71 13 36 3.09 0..3.9 75 10 32 2.10 0.86.9.9.1.0.5.0.3 4.25 0.10 0.62 4.36 0.08 0.32 4.99 045 1.00 0.00 0.19 517 8 3.42 232 10 23 5.2 4.00 0.00 0.20 61 2.00 0.112 15 18.1.8.4.1.2.5.6.7 2.14 0.11 0.13 5.45 0.09 0.83 3.100 040 1.00 0.00 0.47 571 6 3.47 263 31 28 7.13 00 0.00 0.21 60 2.00 0.126 16 05.3.5.6.1.3.4.2 3.08 0.09 0.01 4.23 0.05 0.18 3.100 033 1.00 0.00 0.14 456 0 3.38 193 10 10 3.000 1.0.00 0.15 58 2.00 0.96 11 19.4.3.7.9.6.9.8 5.73 1.16 0.32 4.26 0.05 0.77 2.100 028 1.00 0.00 0.2 8.688 19 37 212 20 09 3.0 1.00 0.00 0.17 57 2.00 0.119 10 33.9.5.4.2.3.7.8.7 5.40 2.23 0.09 3.23 0.07 0.28 2.99 023 1.00 0.00 0.23 399 24 33 187 30 12 5.100 3.0.00 0.13 56 2.00 0.88 14-5 VTM 21.8 0.14 05 4.-34 VTM .7.4 75 14 39 3.03 0.64.2.3.4.3.5.8.2 1.01 0.12 0.73 4.13 0.03 0.23 2.100 023 1.00 0.00 0.11 326 2 3.49 192 20 07 3.0 2.00 0.00 0.18 56 2.00 0.164 18-91 BSA 41.5 0.13 05 2.-32-88 VTM .8.0 66 14 51 6.35 0.95.3.7.8.8.4.4.9.6 6.33 1.08 0.78 3.36 0.09 0.42 3.100 035 1.00 0.00 0.48 610 4 6.24 228 41 14 4.12 00 0.00 0.16 59 2.00 0.125 13 BSA 42.7 0.11 05 4.-30-87 VTM .6.3 72 13 61 6.04 0.26.5.9.2.8.2.8.9 2.22 0.11 0.86 4.41 0.09 0.99 3.100 041 1.00 0.00 0.46 656 4 5.35 221 31 25 6.2 6.00 0.00 0.16 60 2.00 0.157 12 BSA 42.3 0.14 54 3.-24-83 VTM .8.3 78 12 39 1.05 0.99.9.6.0.8.2.2.8 0.50 0.10 6.53 0.25 0.04 0.72 0.100 007 1.00 0.00 0.1 9.104 12 39 256 30 01 2.000 2.0.00 0.12 52 2.00 0.13 13 BSA 41.3 0.11 63 3.-23-82 BSA 41.3 0.14 36 3.VTM .1.0 80 11 42 3.03 0.30.5.3.4.0.3.4.9 1.15 0.03 0.03 4.34 0.11 0.5 1.100 015 1.00 0.00 0.20 199 4 3.27 201 20 05 3.1 7.00 0.00 0.28 54 2.00 0.149 11-21-80 BSA-78 BSA 41.9 0.13 17 3.40.5 0.16 53 3.VTM-19 VTM.0.5 74 13 14 7.07 0..8.5 73 14 59 5.03 0.54.2.3.5.2.0.33.8.1 1.02 0.02 0.66 3.21 0.02 0.48 2.100 025 1.00 0.00 0.11 225 6 2.45 289 41 13 100 5.0.00 0.19 56 2.00 0.122 15 15.6.9.3.9.8.31.9.8.8 1.14 0.07 0.58 4.49 0.11 0.51 2.100 026 1.00 0.00 0.37 227 0 5.47 276 30 12 36 00 0.00 0.25 56 2.00 0.151 15 d inue ont 2 c e Tabl-77 BSA e mpl Sa 41.2 0.17 76 3.))(ppm(ppm )(ppm B i Th U-17 VTM e mpl Sa.1.6 77 12 59 2.05 0.%%%O2 2O3 Si A l2O3 Fe MnO%15.0.3.2.6.6.3.4 4.01 0.09 0.32 3.08 0.02 0.85 2.100 029 1.00 0.00 0.11 254 1 2.60 162 20 06 2.100 2.0.00 0.17 57 2.00 0.101 15))))))))))O%))MgO%us O2)ul 2O%))P 2O5 I a l lc (ppm(ppm(ppm(ppm(ppm(ppm ))(ppm(ppm(ppm(ppm(ppm K2O%%%(ppm(ppm(ppm(ppm(ppm(ppm Ca Na T i LO Tot Ca Sc Be V Ba Sr Y Zr Cr Co N i Cu Zn Ga Ge As Rb Nb

-40 VTM 05.59.3 1.00 0.04 0.13 96 3.06 1.55 111.0.9 12 45 5 8.41 1.69 7.33 1.53 7.48 1.77 4.75 0.47 5.76 0.53 7.94 0.14 3.16 0.0.8 0.13 4.14 92 3.-39 VTM 08.48.80.0 2.00 0.07 0.12 20 27 1.58 119.6.7 12 48 5 8.56 1.45 9.64 1.44 8.72 1.64 5.79 0.68 4.73 0.69 7.04 1.16 4.29 0.0.5 0.13 6.16 49 5.-38 VTM 03.5 1.00 0.14 0.10 3.43 1.81 0.39 79 3.2 8.31 700 5.1.35 6.00 1.45 6.39 1.35 4.66 0.64 4.69 0.58 5.83 0.07 2.13 0.073.0 0.0.14 12 4.-36 VTM 03.2 1.00 0.06 0.17 6.58 0.35 2.40 78 1.1 8.31 7 5.80 0.02 6.93 0.06 6.23 1.98 3.61 0.93 3.60 0.96 5.72 0.09 3.85 0.0.3 0.63 0.12 61 3.-35 VTM 02.5 1.00 0.08 0.09 4.42 0.95 1.39 79 5.7 8.31 795 5.0.69 5.96 0.22 5.18 1.66 3.60 0.12 4.51 0.73 5.02 1.14 6.79 0.095.4 0.1.12 52 3.-34 VTM 05.7 2.00 0.14 0.09 4.86 0.27 2.22 47 6.9.25 5.21 8 4.54 0.83 6.33 1.42 8.87 1.42 6.88 0.06 6.79 0.16 7.13 1.11 11 0.0.6 0.33 0.17 77 4.-32 VTM 04.29.3 1.00 0.01 0.11 3.42 0.20 46 90 6.2 9.36 527 5.1.35 4.72 0.71 3.96 0.19 3.50 0.89 3.61 0.04 7.93 0.32 9.79 0.002.1 0.0.14 44 5.-30 VTM 12.9 3.00 0.05 0.25 6.35 3.20 1.53 107.8.8 11 43 9 7.10 1.12 6.93 0.32 5.17 1.04 4.58 0.92 3.54 0.35 6.83 0.29 7.04 1.0.2 0.00 5.12 66 3.-24 VTM 01.8 2.00 0.01 0.01 2.15 0.14 0.42 87 2.6 9.35 883 5.0.49 5.99 0.92 5.33 1.33 4.60 0.47 4.61 0.55 7.01 1.04 5.02 0.079.5 0.0.14 54 4.-23 VTM 02.89.7 1.00 0.09 0.59 05 0.32 1.24 53 2.3 6.23 8 4.83 0.51 4.79 0.65 4.98 0.92 2.46 0.40 3.55 0.99 5.71 0.08 5.50 0.0.1 0.03 3.11 64 3.-21 VTM 03.7 1.00 0.19 0.15 6.07 0.82 0.18 38 2.4 4.16 065 3.0.27 4.90 0.48 6.57 1.43 5.85 0.98 5.82 0.41 8.92 0.15 6.05 0.058.9 0.2.15 54 4.-19 VTM 13.56.0 5.00 0.28 0.22 29 0.94 0.80 160.5.3.5 17 67 11 48 1.56 9.50 1.39 8.75 1.84 4.75 0.68 4.74 0.49 7.92 0.20 8.08 0.0.82.4 0.52 17 89 5.-17 d inue VTM 51.6 0.00 0.04 0.09 3.11 0.83 0.39 90.4.8 10 38 247 8.0.00 9.48 1.63 9.19 2.88 6.01 1.95 6.96 0.66 5.93 0.18 6.06 0.007.2 0.0.17 92 4.ont 2 c e Tabl e mpl Sa))(ppm(ppm ))))))(ppm(ppm(ppm(ppm(ppm Mo Ag (ppm In Sn Sb Cs La Ce)))))))))))))))))))(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm(ppm )(ppm Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu H f Ta W T l Pb B i Th U

In the southern Colı´der area, isotope studies on sample 76 yield a147Sm/144Nd ratio of≈0.1068 and a143Nd/144Nd(1776Ma)ratio of ≈0.510166 and include an Sm–Nd TDMage of 2.28 Ga and a negative εNd(1776Ma)value of -6.96. Similar results can be observed for samples 42 and 88. These samples yield147Sm/144Nd ratios of ≈0.1204 and 0.1156 and143Nd/144Nd(1780Ma)ratios of 0.510149 and 0.510113, respectively, with all rocks having a range of Sm–Nd TDMmodel ages from 2.37 Ga to 2.40 Ga and negative εNd(1780Ma*)values from -7.27 to -7.98. The εNdvalues are calculated using volcanic rock ages(1792 Ma). Four samples from the Roosevelt area (samples 101, 102, 103, and 104) were analyzed and exhibit similar results. The Nd isotope data exhibit a narrow range of values (εNdTvalues between –8.29 and –9.99) that indicate largely crustal source material, although depleted mantle model ages between 2.40 and 2.53 Ga suggest some input from slightly older sources than those of northern Colı´der rocks, showing characteristics similar to those of southern Colı´der rocks, as observed in the Nd isotopic evolution diagram in Fig. 10.

Fig. 6 Geochemistry diagrams from Colı´der and Roosevelt rocks. a) Nb/Yb versus Zr/TiO2 from Winchester and Floyd (1977) classificatory diagram; b) Nb/Nb versus Th/Yb (Pearce 2008) geotectonic environment

Fig. 7 (A) Th/TiO2 versus Ta/Yb; (B) Th versus Ta; (C) Th/Hf versus Ta/Hf; and (D) Th/Ta versus Yb; Geotectonic classification showing clear active continental margin origin for all analyzed samples

Fig. 8 Rare Earth elements diagram normalized by chondrite, according to the values of Boyton (1984). a REE diagram from all 55 samples;b REE diagram from North-east Colı´der; c REE diagram from South Colı´der; D) REE diagram from Roosevelt rocks

Fig. 9 Spider-diagram normalized by chondrite,according to the values of Thompson, 1982)

Fig. 10 Nd isotopic evolution diagram for the rocks of Colider and Roosevelt formations

5 Discussion

New data here reported allowing to compare the Colider-Roosevelt LISP characteristics with other provinces and contribute with the geological knowledge on several fronts,as well as answering questions related to the origin of these provinces characterized by the huge volume of volcanic material. Among these questions, it is possible to suggest:(i) which characteristics of a province allow the correlation with SLIP rocks, such as petrographic, geochemical, isotopic aspects, among others. (ii) What is the timing of volcanic activity in the area, or how long did it last ? (iii)What is the source of magma and the magmatic processes involved for the production of LISP: (iv) What are the tectonic environments where these magmatic processes occur and; (v) cyclicity in geological time and correlation with supercontinents.

(i) Characterization of the Colider-Roosevelt Large Igneous Silicious Province.

The Colider-Rossevelt SLIP here proposed is the largest silicic igneous province in South America and is characterized by a continuous silicic volcanism composed mainly of ignimbrites. The region of occurrence of this SLIP forms a prominent high plateau, and sections of flat volcanic rocks, with packages of expressive thickness as observed in the south sector (Colider), to the north (Unia˜o do Norte city), and the extreme west (Roosevelt). Typically thick,high-silica rhyolites were formed as numerous lava domes located along fault lines or aligned structures characterizing explosive fissure eruptions. In this sense, the welded pyroclastic dykes demonstrate that the faults were used by silicic magmas flow.

This preliminary study suggests that the Colider and Roosevelt volcanic rocks were generated in complex magmatic systems during different pulses. These magmas probably ascended through large fissures, which generate a series of extensive lavas, pyroclastic flows, and volcanic domes. The interpretation of these large fissures is based on linear features showing the general WNW-ESE direction,and which are filled with rocks of andesitic to rhyodacitic compositions.

Rocks previously denominated as Roosevelt Formation present geochemical characteristics like those of the described rocks of the Colı´der Formation. Considering only the Colider rocks, there is a slight tendency for the rocks to the south and southwest to have andesitic and dacitic compositions, while the rocks to the north, east, and northeast are dacitic to rhyolitic. Volcaniclastic and epiclastic rocks occur in several successions and appear to represent inter eruptive sedimentations. In the Colı´der rocks located in the extreme northern part of the area, near the edge of the Cachimbo graben, pyroclastic rocks predominate, composed of quartz-feldspar tuffs, and may be interpreted as distal deposits.

Regarding lithogeochemistry, the studied rocks present great homogeneity despite the extensive area. Colider and Roosevelt samples indicate a calcium-alkaline composition with magmatic fractionation features. In this sense, Harker diagrams of major elements showed compositional variations that may be related to fractional crystallization with a change in the fractional assemblage. Tectonic setting discriminant diagrams (Nb/Y versus Th/Yb; Pearce 2008)suggest a volcanic arc tectonic setting. In the same way,diagrams (Th/TiO2versus Ta/Yb; Th versus Ta; Th/Hf versus Ta/Hf; and Th/Ta versus Yb), indicate an active continental margin origin for all analyzed samples. Colider and Roosevelt rocks also present similar REE patterns (and spider multi-element diagram) which may be interpreted as a result of the fractional crystallization process.

(ii) What is the timing of volcanic activity in the area, or how long did it last?

An important aspect in the formation of a LISP is related to the global impact of an expressive volume of magma intruded and released during geologically brief events.LISP, therefore, represents important, albeit episodic,periods of addition of new crust. The epoch of magmatism of a SLIP investigated of U–Pb ages in zircon delineated the main silicic igneous events in Paleoproterozoic ca.2.7 Ga and 1.9 Ga (Campbell and Hill 1988, Condie 1998;Condie et al. 2009, 2011).

A minimum volume of 400,000 km3 of predominantly rhyolithic ignimbrite erupted between 1800-1776 Ma for Colider rocks, and 1760–1755 Ma for Roosevelt rocks(Neder et al 2002, Santos et al. 2019). This proposed event lasted approximately 45 Myr and began in the north with the formation of volcanic systems and related intrusions and migrated to the South as the magmatic process and the sources evolved (TDMat 2.2–2.3 Ga and 2.4–2.5 Ga,respectively). The studied rocks in the South area show greater crustal contribution (εNdfrom –6 to –9) than those in the Northern and Eastern Colider areas (–3 to –5). These data here reported suggesting that Colider and Roosevelt volcanic rocks may have generated related to a possible back-arc setting (as proposed in Fig. 11).(iii) What are the magmatic processes involved to produce this expressive volume of magma:

Fig. 11 Schematic representation of the geotectonic setting for the volcanic deposits here studied. The formation of back-arc assemblages that host the felsic-dominated deposits

The importance of partial melting of the Earth’s crust to generate the observed volcanic rock volumes and the geochemical characteristics of a LISP are addressed by many studies (Riley et al. 2001; Ferrari et al. 2007; Bryan 2007; Bryan et al. 2008). These studies have shown that these igneous rocks have been fundamental for the development of plume models and mantle convection models(Campbell and Griffiths 1990; Campbell 2005, 2007).

In this context, some studies attempt to investigate how explosive eruptions of silicon-rich magmas that occur in brief events result in significant volumes of volcanic deposits (Ross et al. 2005; White et al., 2009). In these cases, the Plinian type of explosive is responsible for the largest LISP volcanic eruptions in continental areas. In these terms, the rocks described in the Colider-Roosevelt LISP present continental features evolution characteristics that evolve into the marine environment, similar to several studies where continental LISPs are later broken up to produce new oceanic basins and coincide with periods of lithospheric extension. Thus, crustal extension is generally considered important for generating large volumes of silica magma (Hanson and Glazner 1995; Gans and Bohrson 1998), and petrogenetic studies have demonstrated the substantial contribution of partial crustal melting to LISPgenerating magmatism (Riley et al. 2001; Bryan et al.2002a, b, 2008).

(iv) What are the tectonic environments where these magmatic processes occur.

LISP is currently defined as magmatic provinces with area extensions ＞0.1 M km2, volumes ＞0.1 M km3, and a maximum formation period of 50 Ma originated in an intraplate, magmatic arc and associated with magmatic plume environments. In this sense, LISPs need not be related to a single tectonic environment to explain the voluminous magmatism, and such large LISP-forming events in igneous provinces are not only related to oceanic crust subduction zones.

Many authors propose alternative models, including decompression and fusion in deep fault zones (White and McKenzie 1989, 1995), extensional processes (Carlson and Hart 1987, Rivers and Corrigan 2000; Long et al. 2012);and lithospheric mantle melting in response to plume impact (Sengo¨r 2001). Thus, LISP may be interpreted as the result of decompression and fusion of a mantle plume,probably originating from the core-mantle boundary(Richards et al. 1989; Campbell and Griffiths 1990). The suggestion of the existence of plumes for the generation of LISP stems from the record of magma formation at the core-mantle boundary, triggering an increase in convection in the outer core (Larson 1991; Ernst and Buchan, 2002).

On the other hand, advances in the recognition of LISP,including the understanding of tectonic environments, main petrological and geochemical characteristics, and magma sources, allow considering silicic magmatism as generated in a continental magmatic arc, represented by an active subduction zone (Cameron et al. 1980; Jones and Veevers,1983; Wark et al. 1990; Wark 1991). Such a hypothesis results from the interpretation of the calcium-alkaline affinity and juvenile isotopic signatures (Bryan et al. 2013).Following this hypothesis, it can be identified that LISP formation events along the geological record can occur in a wide range of environments in the Earth’s crust such as cratonic areas, continental margins, and ocean basins(Bryan and Ernst 2008; Coffin and Eldholm 1992, 1994). In the studied area, NWN-ESSE truncated with NWW-SE and EW lineaments are potential structures for volcanic extrusion and could occur along with terrane limits (deep structures) as indicated in Fig. 12.(v) Cyclicity in geological time and correlation with supercontinents.

Fig. 12 Landsat Image (TM-5 bands 4, 3, 2 (RGB), showing structures (lineaments)

The cyclicity of LISP-forming events is consistent with episodic lithospheric growth events representing important epochs of lithosphere construction, detected in Earth crust growth models (Condie 2001, van Hunen et al. 2002,Hawkesworth and Kemp 2006, Liu et al. 2010). Even if a large proportion of the igneous volume generated during a LISP-forming event does not reach the surface and remains stored deep in the lithosphere. LISPs have therefore become important to our understanding of mantle dynamics and provide samples and windows to the lower mantle.LISP almost became synonymous with mantle plumes and the proposal that large igneous provinces record large mantle melting events and therefore require large amounts of thermal energy expended in a geologically short period(Bryan and Ferrari 2007, Saunders 2005). Because of the vast spatial dimensions of large igneous provinces, understanding why such magmatism occurs could potentially provide information about mantle dynamics, particularly mantle-core boundary instability and the efficiency of convective mixing (Richards et al. 1989, Larson 1991, Hill et al. 1992, Takahahshi et al. 1998, Korenaga 2004, 2011).

Thus, the main igneous age peaks result from events at the core-mantle interface and their reflections on the instability of the crust such as extension, and may be linked to periods of supercontinent amalgamation (Condie and Aster, 2010, Cawood et al. 2013). The global spatial and temporal distribution of LISP generates a clustering of events at times of supercontinent breakup and therefore are an integral part of the Wilson cycle and are becoming an increasingly important tool in constraints continental fragments amalgamation over time. In this way, LISP is playing a key role in the reconstructions of the supercontinent where the ages of large igneous provinces present in different terrains are compared and the age correspondences in a given interval are established and are then used as supporting evidence for paleo-continental reconstructions during this period (Bleeker and Ernst 2006,Ernst 2007).

About the studied case, geological and geochronological similarities in the Mesoproterozoic evolution of Laurentia and Baltica with that of Amazonian craton led several authors to propose a possible correlation between the northeastern Amazonian craton and southwestern Baltica(Zhao et al., 2004, 2006; Hou et al. 2008; Johansson 2009).Those cratons show subduction-related accretion belts that evolved along the Paleoproterozoic margin as mobile belts.However, paleogeographic Paleoproterozoic reconstruction(Pesonen et al., 2003; Bispo-Santos et al., 2008) indicates that these cratons were not linked. Instead, the age of 1789 ± 7 Ma (Neder et al., 2002; Pinho et al., 2003)obtained for the volcanic rocks of the Colider suite suggested that the space between the Amazonic craton and the Laurentia-Baltica block could have been occupied by the Northern Craton China (D’Agrella-Filho et al., 2006;Bispo-Santos et al., 2008). In this sense, these continental masses could be united in the formation of the supercontinent Columbia.

6 Conclusions

Geochemical, petrographic, and isotopic information for the Paleoproterozoic Colı´der and Roosevelt volcanism in the Amazonian Craton reveals an extensive, heterogeneous, and complex configuration of the volcanic products with rhyolite to andesite compositions aligned in several E-W and WNW-ESE structures. Whole-rock element geochemistry shows that the volcanic complex and the subvolcanic rocks formed in anorogenic continental setting.

In conclusion, the data here reported strongly suggest a common origin for the Roosevelt and Colı´der rocks in a unique silicic LIP. The estimated area covers 55 × 103km2,and the volume is 27 × 106km3and volcaniclastic rocks dominate. The U–Pb crystallization ages are between 1800 and 1755 Ma, and the TDMages range from 2.0 to 2.5 Ga.The Colı´der SLIP consists of 80% rhyolites and rhyodacites,10% andesites, and 5% basalts representing 70% volcaniclastic features according to their structural positions.Important magmatic arcs took place on the Paleoproterozoic terranes in Amazonia craton and magma injection originated voluminous volcanic and plutonic orogenic activity generating large belts of igneous rocks by additions of magma to the continental crust resulting in the silicous Colider-Roosevelt Large Igneous Provinces.

Supplementary InformationThe online version contains supplementary material available at https://doi.org/10.1007/s11631-021-00490-2.

AcknowledgementsThis paper is the result of a doctoral project by the first author, financed by the Rio de Janeiro Research Council(FAPERJ # 100.173/2014) and CAPES Brazilian Council (Sandwich fellowship No. 99999.006532/2015–02). The present research was performed under the field trips support of Geociam (Instituto Nacional de Cieˆncia e Tecnologia de Geocieˆncias da Amazoˆnia) and Metamat(Companhia Matogrossense de Minerac¸a˜o). We thank the staff of the Universidade do Estado do Rio de Janeiro (including the tin section laboratory) and the University of Geneva for sample preparation and isotopic analysis. We are also grateful to Votorantin Metais and CPRM for geochemical data from the Roosevelt Formation rocks.The manuscript text was strongly improved by anonymous reviewers’polishing works.

Availability of data and materialAll data generated and analyzed during this study are included in this published article and its supplementary information files.

Declarations

Conflict of interestOn behalf of all authors, the corresponding author states that there is no conflict of interest.