Characterisation of Kalalikhera Felsic Volcanics, Pur-Banera Belt, Rajasthan: Insights from Monazite–Xenotime Geochemistry and Chemical Ages

J. Earth Syst. Sci. (2021) 130:84 Ó Indian Academy of Sciences

https://doi.org/10.1007/s12040-021-01572-8 (0123456789().,-volV)(0123456789().,-volV)

Characterisation of Kalalikhera felsic volcanics, Pur-Banera belt, Rajasthan: Insights from monazite–xenotime geochemistry and chemical ages

1, 2 1 SURESH CHANDER * ,SANTANU BHATTACHARJEE ,MANIDEEPA ROY CHOUDHURY 1 and NIKHIL AGARWAL 1Geological Survey of India, Western Region, 15-16 Jhalana Dungri, Jaipur 302 004, India. 2Geological Survey of India, Training Institute, Bandlaguda, Hyderabad 500 068, India. *Corresponding author. e-mail: [email protected]

MS received 15 October 2020; revised 5 January 2021; accepted 6 January 2021

Geological and geochemical characteristics of the litho units exposed in and around Kalalikhera area of Pur-Banera belt have conBrmed the presence of felsic volcanic rock unit named Kalalikhera felsic volcanic, with characteristic features such as (i) abundance of lapilli composed of polygonal quartz and feldspar and (ii) presence of relict bipyramidal quartz. These volcanics are associated with thin bands of chert. Geo- chemically, the volcanics are found to be of rhyolitic composition. Development of garnet porphyroblasts along with preferred orientation of the silicate minerals of rhyolite indicates a low to medium grade metamorphism and deformation of the units. Monazite geochemistry of the volcanics indicated towards the metamorphic origin of monazites, with REE pattern show steep fractionation trend from La to Lu. The in- situ chemical age of 2192 ± 57 Ma recorded from xenotime is interpreted as indicative of the opening of the Aravalli basin with the onset of rifting leading to the formation of Kalalikhera volcanics. The estimated ages of 1784 ± 92, 1351 ± 45 and 1026 ± 57 Ma from monazite analyses are interpreted as different metamorphic events associated with (i) closure of the basin and the onset of Aravalli orogeny, (ii) further imprints of Delhi orogeny, and (iii) with late Grenvillian age imprints. Keywords. Pur-banera; Kalalikhera; monazite; xenotime; volcanics; REE.

1. Introduction from the Proterozoic cover sequence of the PBB was reported by Ozha et al.(2016) of mesoproterozoic The NNE–SSW trending Pur-Banera Belt (PBB) (*1.37–1.35 Ga) age. They also reported the constitutes an early Proterozoic cover sequence over preservation of Grenvillian ages of *1.05–0.99 Ga in Archaean Mangalwar Complex in south-central both the basement and supracrustal rocks. D’Souza Rajasthan. It is known to host several base metal et al.(2019) recorded monazite ages of 1.3–0.8 Ga prospects of sub-economic significance. Many and suggested multiple post-depositional workers have studied the metamorphic and struc- tectonothermal events in the PBB. tural evolution of the Pur-Banera Belt (PBB) of the The study of major oxides, trace elements south-central Rajasthan based on the monazite and including rare-earth elements (REE) and high Beld xenotime geochemistry and geochemical ages. The strength (HFS) elements can deBne the emplace- monazite geochronology of the metapelitic rocks ment of various felsic volcanic rocks in different 84 Page 2 of 14 J. Earth Syst. Sci. (2021) 130:84

Figure 1. (a) Geological map Pur-Banera Belt, Bhilwara District, Rajasthan (modiBed after Gupta et al. 1980). (b) Detailed geological map of Kalalikhera area. tectonic settings including the oceanic plateau, In the present work, the authors place the new subducted oceanic crust as well as in the spreading crystallization age of the felsic volcanic from the ridges (Andrehs and Heinrich 1998; Kerr et al. 2000; PPB by EPMA chemical dating of monazite and Hazarika et al. 2013; Ozha et al. 2016). REE-bearing xenotime and aim to geochemically characterize minerals such as monazite and xenotime are gener- felsic volcanics in the Pur-Banera basin. ally used as petrogenetic indicators which occur as accessory phases in felsic and alkaline magmatic rocks as well as in hydrothermal veins (Pearce et al. 2. Geology 1984; Ahmad and Tarney 1991; Ward and Miller 1993;Forster€ 1998b; Zhu et al. 1999; Spear and Pyle The NNE–SSW trending Pur-Banera Belt (PBB) 2002; Ondrejka et al. 2007; Ahmad et al. 2008a; (Bgure 1a) forms an isolated basin that rests over Berger et al. 2008; Singh and Singh 2012; Quach and the Archaean Gneissic Complex in south-central Hans 2015). Compositional variations in monazite Rajasthan. The belt extends from near Bhinder in and xenotime can provide valuable information on the south to Banera in the north. The geological fractionation, rock–Cuid interaction, and meta- framework of the PBB has been given by Gupta morphic overprint in host-rock. (1934) and Heron (1953) who considered the J. Earth Syst. Sci. (2021) 130:84 Page 3 of 14 84

Figure 2. Field photographs showing (a, b and c) lapilli bearing felsic volcanics in Kalalikhera area, (d) contact between felsic volcanics and mica-schist, (e and f) chert band intercalated with mica-schist. metasediments of the Pur-Banera basin to be The geochronological framework of Archaean equivalent of Aravalli rocks. Gupta et al.(1980) Gneissic Complex is fairly well understood. The have mapped the lithosequence of the PBB as Pur- oldest basement gneisses have yielded a whole rock Banera Group that forms part of the Archaean six-point isochron age of 3307 ± 33 Ma by Sm–Nd Bhilwara Supergroup. Sinha-Roy (1989), on the method (Gopalan et al. 1990). Rb–Sr whole-rock other hand, invoked the coevality of the PBB and isochron ages of the oldest granites of Untala area, the Proterozoic Aravalli basin. He suggested that intrusive into BGC, have been obtained as the intracratonic basins like that of Pur-Banera in 2900 ± 100 Ma (Sastry 1992). The potassic gran- the Archaean gneissic complex evolved as pull- ites exposed around Berach have been dated at apart basins that were contemporaneous with the 2533 Ma (Rb–Sr whole-rock isochron age) and opening of the Aravalli basin. The main rock types 2440 ± 8 Ma (ion microprobe study) by Crawford comprising the PBB include impure carbonates, (1970) and Wiedenbech et al. (1996); respectively. quartzites, calc-silicate rocks, garnetiferous quartz Radiometric dating of PBB and adjoining isolated mica schist, amphibolites and banded iron forma- basins of Rajpura–Dariba has been attempted by tions. The rocks of PBB are intensely deformed Deb et al. (1989). They determined Pb–Pb model into large scale folds that have NNE–SSW axial ages that hover around 1.8 Ga. The south-central trace. part of the PBB near Kalalikhera (KK) comprises 84 Page 4 of 14 J. Earth Syst. Sci. (2021) 130:84

Figure 3. Photomicrograph of the felsic volcanics showing (a) chloritisation of biotite grains, (b) post-tectonic garnet porphyroblast with orientation of inclusion trails (yellow dash line) parallel to outer schistosity orientation (red dash line), (c) relict bipyramydal quartz crystal rimmed by epidote, and (d) muscovite and biotite in quartzofeldspathic matrix. of multiple bands of garnetiferous quartzite, Chloritisation of biotite is observed at places quartzofeldspathic rocks, mica-schist and chert (Bgure 3a). Garnet porphyroblasts are post-tec- (Bgure 1b). The quartzofeldspathic rocks are Bne- tonic with inclusion rich core, with an orientation grained with aphyric texture and also consist of of internal inclusion trails matching with the lapillae that vary from 0.2 to about 0.5 cm in size external schistosity (Bgure 3b). The monazite (Bgure 2a–d). The width of these quartzofeld- grains are subhedral to euhedral while xenotime is spathic bands is about 30 m trending NNE–SSW. mostly euhedral. The quartzofeldspathic unit The lapillae bearing rocks contain pin-head size shows a relict bipyramidal shape of quartz at places garnets. Quartzite is a major lithounit exposed in rimmed by epidote (Bgure 3b). Bipyramidal quartz the area. In the northwestern part of the Kala- is indicative of its volcanic nature (Bgure 3d). likhera area, a well laminated thin band of chert is Biotite to chlorite alteration is noted at places present (Bgure 2e and f). (Bgure 3a). The presence of bipyramidal quartz and abundance of lapilli comprising of polygonal quartz and feldspar in felsic volcanic unit and 3. Petrology presence of associated chert band signiBes towards the felsic volcanic nature of the litho assemblage. Petrographically, the quartzofeldspathic rock dis- play microlites of quartz, k-felspar, biotite, muscovite, and garnet as the major mineral constituents; and sphene, epidote, monazite, etc., 4. Analytical methods as accessory phases (Bgure 3c). The rock displays evidence of deformation with well-developed The whole-rock (WR) analyses of six representa- foliation and lineation. Foliation is deBned by tive samples of felsic volcanics were carried out. biotite and recrystallized quartz and feldspar. Major oxides were analyzed by X-ray Cuorescence J. Earth Syst. Sci. (2021) 130:84 Page 5 of 14 84

Table 1. Major oxide (wt.%) and trace element (ppm) composition of representative samples of Kalalikhera felsic volcanics.

*SRM (JG-2) Sample KK-1 KK-2 KK-6 KK-7 KK-8 KK-9 CertiBed values Observed values (wt.%)

SiO2 82.11 83.15 82.97 82.13 80.15 82.95 76.83 75.73

Al2O3 8.41 7.47 8.14 8.39 8.5 8.16 12.47 12.05

Fe2O3 2.57 1.4 2.74 2.37 2.89 2.7 0.97 0.92 MgO 0.94 0.22 0.59 0.94 0.7 0.63 0.04 0.05 CaO 0.22 0.16 0.2 0.22 0.55 0.18 0.70 0.50

Na2O 2.3 4.95 4.12 2.3 3.8 4.14 3.54 3.21

K2O 1.58 1.62 0.05 1.78 1.26 0.08 4.71 4.48

TiO2 0.58 0.36 0.47 0.58 0.38 0.44 0.04 0.03

P2O5 0.08 0.06 0.07 0.08 0.07 0.68 0.00 0.02 Total 98.79 99.39 99.35 98.79 98.3 99.96 99.302 96.989 (ppm) V 182 142 166 180 140 164 3.78 3.79 Cr 92 63 113 94 65 115 6.37 6.31 Ni 13 4 22 11 3 25 4.35 4.31 Co215422 3.62 3.57 Cu 23 7 52 25 6 50 0.49 0.50 Pb 27 26 13 29 27 15 31.5 30.78 Zn 155 6 16 150 6 18 13.6 13.7 Ba 559 387 150 564 385 148 81 75 Sr 20 16 17 21 18 14 17.9 17.74 Rb 42 10 2 41 9 5 301 304 Zr 223 169 143 220 170 141 97.6 96.88 Y 11 2 2 13 3 5 86.5 85.64 Nb756647 14.7 14.63 La 17 2 4 18 1 2 19.9 19.6 Ce 22 1 1 23 2 2 48.3 47.56 Nd311211 26.4 26.2 *Imai et al. (1995) Geostandards Newsletter 19 135–213.

Figure 4. (a) TAS (total alkali-silica diagram, Middlemost 1994) classiBcation of Kalalikhera volcanics and (b) AFM diagram (Irvine and Baragar 1971) of Kalalikhera volcanics. 84 Page 6 of 14 J. Earth Syst. Sci. (2021) 130:84

Figure 5. (a) Primitive mantle normalized multi-element plot diagram of felsic volcanics. Normalizing factors from Sun and Mcdonough (1989); (b) tectonic discrimination diagram of felsic volcanics after Pearce et al. (1984), showing Rb vs. Y+Nb and Nb vs. Y plot.

(XRF) and trace elements were determined using P loss relative to REE. Therefore, 20 kV/100 nA inductively coupled plasma mass spectrometer was used with increased count time. Monazite (ICPMS) at Chemical Laboratory, Geological trace-element analysis requires the careful acqui- Survey of India, Jaipur using certiBed reference sition of counts using PbMa,UMb, and ThMa, the material (CRM) JG-2 of Geological Survey of intensity of YLc, interferes with PbMa and there- Japan. The electron probe microanalysis (EPMA) fore, this correction was used. Manual calculations studies were carried out at Geological Survey of were done as proposed by Suzuki and Adachi India, Southern Region, Hyderabad to analyze the (1991). The lines and standards used for monazite xenotime and monazite grains. The analyses were analyses and crystals used are: (i) YAG for Y La/ carried out using Cameca SX 100 microprobe TAP, (ii) apatite for P Ka/TAP, (iii) albite for Al having Bve spectrometers and LaB 6 source. Ka/TAP, (iv) orthoclase for Si Ka/TAP, (v) ap- A carbon coat (250 A thickness) is generally atite for Ca Ka/PET, (vi) La glass for La Lb/LIF, inadequate for the prevention of absorbed current (vii) Ce glass for Ce La/LIF, (viii) Pr glass for Pr Cuctuation and beam damage when using the high Lb/LIF, (ix) Nd glass for Nd La/LIF, (x) Sm glass current densities applied for high precision (e.g., for Sm Lb/LIF, (xi) Gd glass for Gd Lb/LIF, (xii) 200 nA, focused beam). Beam irradiation eAects Pyromorphite for Pb Ma/LPET, (xiii) U glass for include element mobility in monazite, resulting in U Mb/LPET, (xiv) Th glass for Th Ma/LPET, and .ErhSs.Sci. Syst. Earth J. Table 2. Representative EPMA analyses of xenotimes of Kalalikhera volcanics.

Point 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Wt.% SiO2 0.63 0.66 0.68 0.71 0.72 0.73 0.76 0.76 0.74 0.42 0.48 0.56 0.60 0.64 0.72 0.84 0.93 1.06 1.09 Al2O3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 P2O5 33.74 33.52 33.29 33.00 33.11 33.14 33.12 33.11 32.87 33.03 33.01 32.72 32.67 32.60 32.70 32.65 32.69 32.57 32.88

CaO 0.17 0.19 0.20 0.21 0.19 0.19 0.19 0.18 0.16 0.12 0.13 0.13 0.12 0.11 0.12 0.14 0.13 0.15 0.15 (2021) 130:84 FeO * * * * * * * * * 0.29 0.28 0.10 * * * * * * * Y2O3 40.80 40.76 40.66 40.56 40.46 40.55 40.56 40.68 40.63 41.11 40.92 40.36 40.35 40.13 40.21 39.98 39.97 40.03 40.20 La2O3 ******************* Ce2O3 0.06 0.04 0.01 0.02 0.02 0.05 0.04 * 0.03 0.00 0.01 0.02 0.00 0.02 0.01 0.03 0.04 0.02 0.03 Pr2O3 * 0.04 0.06 0.01 0.02 0.01 0.03 0.01 * 0.02 0.03 0.05 0.03 * 0.04 0.01 * * 0.06 Nd2O3 0.34 0.32 0.32 0.32 0.33 0.32 0.34 0.31 0.31 0.28 0.28 0.29 0.31 0.33 0.31 0.32 0.33 0.33 0.32 SmO 0.62 0.56 0.61 0.64 0.58 0.60 0.57 0.65 0.62 0.52 0.55 0.62 0.64 0.63 0.56 0.60 0.60 0.62 0.57 EuO 0.01 0.02 0.02 0.03 0.03 0.01 0.02 0.02 0.02 0.07 0.05 0.04 0.03 0.00 0.01 0.02 0.04 0.03 0.01 Gd2O3 2.44 2.48 2.52 2.54 2.45 2.53 2.53 2.53 2.48 2.32 2.33 2.35 2.42 2.44 2.52 2.44 2.44 2.46 2.50 Dy2O3 5.67 5.63 5.52 5.53 5.61 5.54 5.55 5.62 5.59 5.25 5.27 5.36 5.43 5.47 5.43 5.45 5.47 5.46 5.44 Ho2O3 2.24 2.23 2.20 2.21 2.17 2.23 2.21 2.22 2.21 2.12 2.14 2.15 2.16 2.21 2.19 2.18 2.26 2.15 2.25 PbO 0.52 0.52 0.52 0.52 0.52 0.52 0.52 0.51 0.51 0.40 0.43 0.49 0.52 0.54 0.54 0.54 0.53 0.52 0.48 ThO2 0.73 0.75 0.76 0.78 0.77 0.75 0.75 0.75 0.72 0.58 0.59 0.60 0.60 0.60 0.60 0.63 0.64 0.65 0.66 UO2 1.20 1.23 1.22 1.22 1.22 1.22 1.20 1.20 1.20 0.97 1.02 1.10 1.21 1.21 1.22 1.20 1.18 1.15 1.09 Er2O3 3.91 3.91 3.91 3.79 3.85 3.86 3.75 3.76 3.80 3.82 3.88 3.84 3.91 3.88 3.91 3.84 3.87 3.81 3.78 Yb2O3 2.44 2.45 2.44 2.46 2.49 2.48 2.42 2.46 2.50 2.64 2.66 2.73 2.69 2.62 2.64 2.60 2.59 2.54 2.55 Total 95.50 95.31 94.92 94.53 94.54 94.73 94.53 94.78 94.38 93.97 94.06 93.49 93.69 93.40 93.71 93.48 93.70 93.53 94.07 Cations per 4 oxygen atom Si 0.03 0.03 0.03 0.04 0.04 0.04 0.04 0.04 0.04 0.02 0.03 0.03 0.03 0.03 0.04 0.04 0.05 0.05 0.06 Al 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 P 0.72 0.72 0.72 0.71 0.72 0.72 0.72 0.71 0.71 0.72 0.72 0.72 0.71 0.72 0.71 0.71 0.71 0.71 0.71 Ca 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Fe * * * * * * * * * 0.03 0.02 0.01 * * * * * * * Y 1.10 1.10 1.10 1.10 1.10 1.10 1.10 1.10 1.11 1.12 1.12 1.11 1.11 1.11 1.10 1.10 1.09 1.09 1.09 La * * * * * * 0.00 * * * * * 0.00 * 0.00 0.00 * 0.00 0.00 ae7o 14 of 7 Page Ce 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Pr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Nd 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Sm 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 Eu 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Gd 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 84 84 Page 8 of 14 J. Earth Syst. Sci. (2021) 130:84

(xv) Hematite for Fe Ka/LIF with 0 beam size. Overlap corrections were performed wherever necessitated. Matrix eAects are eliminated using the X-Phi method. U–Pb systematics was used in determining the age. The inbuilt Age Quant software was used for determining the age which is cross-checked by manual calculation.

5. Results

5.1 Geochemistry of the felsic volcanic

The analyses of felsic volcanic rocks (table 1) from the study area show high SiO2 composition. All the samples plot in the rhyolite Beld of the TAS diagram (Bgure 4a) and shows a calc-alkaline trend (Bgure 4b). Trace element concentrations of the volcanic show a wide range of variation. Vanadium is fairly widespread and is present in a considerable concentration ranging from 140 to 182 ppm in the studied samples. In the multi-element spider diagram for the studied samples (Bgure 5a), large ion lithophile element (LILE) such as Ba and K show enriched characteristics with strong positive anomaly and Rb shows moderate negative anomaly which is also true for K in few samples due to random contamination of magma with crustal material (Condie 1994). The high Beld strength elements (HFSE) such as Nb and Ti show negative anomalies. A strong negative anomaly of Sr is also present. On Nb vs. Y and Rb vs. Y+Nb diagram (Pearce et al. 1984), all the samples of felsic volcanic plot within the volcanic arc granites (VAG) (Bgure 5b).

5.2 Monazite–xenotime mineral chemistry

The representative analyses of xenotime and monazites from felsic volcanics of the Kalalikhera area are given in tables 2 and 3; respectively. The analysis shows that the monazite compositions of

345678910111213141516171819 the majority of studied samples are Ce rich type than Th type (Bgure 6). In the molecular Ce–Ca–Th plot, the samples show the composition of typical monazite. Monazites have a range of ThO2 from 4.68 to 7.55 wt.%. Generally, in monazite, any observed variation in chemical composition takes place due to huttonite and cheralite

(Continued.) substitution (Zhu et al. 1999). The name ‘cheralite’ has priority over ‘brabanite’ and the nomenclature is as per the three-fold classiBcation of Interna- Point 1 2 Table 2. DyHoPbTh 0.09U 0.04Er 0.09 0.01Yb 0.04 0.09 0.01Age 0.01 (Ma) 0.04 0.01Age 0.09 0.01 err. 0.01 2110 0.06 0.04 0.01*bdl: 0.09 0.04 0.01 below 2131 detection 0.01 190 0.06 limit. 0.04 0.01 0.09 0.04 0.01 2135 0.01 0.06 187 0.04 0.01 0.09 0.04 0.01 2140 0.01 0.06 187 0.04 2141 0.01 0.09 0.04 0.01 0.01 0.06 0.04 187 2141 0.01 0.09 0.04 0.01 0.01 0.06 0.04 2152 0.01 187 0.09 0.04 0.01 0.01 0.06tional 2157 0.04 0.01 0.09 0.04 0.01 187 0.01 0.06 2169 0.04 0.01 0.09 0.04 0.01 188 0.01 2169 0.06 Mineralogical 0.04 0.01 0.09 0.04 0.01 2176 0.01 189 0.06 0.04 0.01 0.09 0.04 0.01 2218 0.01 0.06 190 0.04 0.01 0.09 0.04 0.01 2222 0.01 0.06 193 0.04 0.01 2260 0.09 0.04 0.01 0.01 0.06 0.04Association 189 2261 0.01 0.09 0.04 0.01 0.01 0.06 0.04 2266 195 0.01 0.09 0.04 0.01 0.01 0.06 2267 0.04 0.01 0.09 0.04 0.01 195 0.01 0.06 2268 0.04 0.01 0.04 0.01 197 (IMA) 0.01 2285 0.06 0.01 0.04 0.01 197 0.06 0.01 0.04 0.06 197rules, 0.04 198 198 198 J. Earth Syst. Sci. (2021) 130:84 Page 9 of 14 84

Table 3. Representative EPMA analyses of monazites of Kalalikhera volcanics.

Monazite Dataset/point 1/1 6/1 8/1 9/1 11/1 12/1 (wt.%)

SiO2 1.51 0.28 0.33 0.87 0.22 0.24 CaO 0.57 1.63 1.40 1.45 1.32 1.38 FeO À0.01 À0.03 0.04 0.06 À0.02 À0.04

Pr2O3 2.38 2.45 2.41 2.43 2.44 2.44

Nd2O3 8.97 10.44 10.54 10.98 10.99 10.98 SmO 1.20 1.84 1.78 2.08 2.07 2.18 EuO 0.45 0.83 0.83 0.60 0.93 0.93

Gd2O3 2.80 3.34 3.32 3.33 3.59 3.74

Tb2O3 0.08 0.08 0.11 0.08 0.12 0.17

Dy2O3 0.69 0.47 0.38 0.35 0.57 0.57

Ho2O3 0.53 0.63 0.50 0.59 0.76 0.79 Er2O3 0.17 0.12 0.09 0.02 0.17 0.10

Tm2O3 0.11 0.21 0.18 0.19 0.20 0.21

Yb2O3 0.03 * * * 0 0.02

Lu2O3 ****** PbO 0.73 0.42 0.36 0.58 0.44 0.45

ThO2 7.55 5.93 4.98 9.29 4.78 4.68

UO2 0.48 1.01 0.94 0.14 0.77 0.92

Ce2O3 28.24 27.15 28.34 26.42 27.23 27.29 P2O5 25.34 27.50 29.97 25.08 29.19 29.77

Y2O3 2.41 1.73 1.45 0.78 1.76 1.84

La2O3 14.26 12.85 13.57 12.40 12.64 12.62 Total 98.46 98.82 101.48 97.66 100.12 101.24 Cations per 4 oxygen atoms Si 0.09 0.02 0.02 0.05 0.01 0.01 Al 0.00 0.00 0.00 0.00 0.00 0.00 P 0.63 0.68 0.72 0.64 0.71 0.72 Ca 0.04 0.10 0.09 0.09 0.08 0.08 Fe * * 0.00 0.00 * * Y 0.08 0.05 0.04 0.03 0.05 0.06 La 0.31 0.28 0.28 0.28 0.27 0.26 Ce 0.61 0.58 0.59 0.58 0.57 0.57 Pr 0.05 0.05 0.05 0.05 0.05 0.05 Nd 0.19 0.22 0.21 0.24 0.23 0.22 Sm 0.03 0.04 0.04 0.05 0.04 0.05 Eu 0.01 0.02 0.02 0.01 0.02 0.02 Gd 0.05 0.07 0.06 0.07 0.07 0.07 Dy 0.01 0.01 0.01 0.01 0.01 0.01 Ho 0.01 0.01 0.01 0.01 0.02 0.02 Pb 0.01 0.01 0.01 0.01 0.01 0.01 Th 0.10 0.08 0.06 0.13 0.06 0.06 U 0.01 0.01 0.01 0.00 0.01 0.01 Age (Ma) 1784 1028 1023 1366 1336 1325 Age err. 92 78 82 60 97 100 *bdl: below detection limit. which has replaced the name ‘brabanite’ as per the tetrahedral site. Cheralite substitution is 2REE3+ early discredited six-fold classiBcation (Forster€ $ (Th, U)4++ Ca2+, with Ca replacing the addi- 1998a). The huttonite substitution is REE3++ P5+ tional REE in the 8-fold site. The plot (Th+U) vs. $ (Th, U)4++Si4+, with Si replacing P in the (Ca+Si) shows a linear trend (Bgure 7a) that is 84 Page 10 of 14 J. Earth Syst. Sci. (2021) 130:84

Figure 6. Ce–Ca–Th plot showing apatite (CaPO5) and huttonite (ThSiO4) and monazite composition Belds. inferred as the huttonite and cheralite exchange has taken place in monazites, which has accom- modated most of the (Th+U) in monazites. Fur- ther (Th+U) vs. Si plot illustrates that huttonite substitution is not dominant, showing a much- scattered pattern and non-linear distribution along the line of huttonite substitution (Bgure 7b). Whereas from (Th+U) vs. Ca plot, it is found that the cheralite substitution is dominant in the monazites, as the plot shows almost linear distribution along the line of cheralite substitution line (Bgure 7c). The major element compositional variation of xenotime-(Y) is limited with Y content ranging from 31.48 to 32.37 wt.% (table 2). Th+U contents in xenotime-(Y) are nearly similar for all the samples (ranging from 1.37 to 1.75 wt.%). Chondrite-normalized REE pattern in monazite show that a decreasing trend in LREE and zig-zag Figure 7. (a) Plot of monazite composition illustrating chem- pattern in HREE is due to tetrad eAect (Mclennan ical exchanges in (Th + U) vs. (Si + Ca), showing a linear 1994; Quach and Hans 2015)(Bgure 8). Eu anom- trend, (b) The plots illustrating the pattern of (a) huttonite aly pattern is negative to slightly positive. REE substitution showing a spread and scattered pattern along 1:1 patterns of xenotime show a positive slope through line of huttonite substitution, and (c) cheralite substitution the MREEs and Cat in the HREEs. A pronounced showing almost linear correlation along cheralite substitution negative Eu anomaly is present (Bgure 9). line.

biotite (Bgure 10a). The ages in monazite ranged in 5.3 Geochronology three clusters, 1026, 1351, and 1784 Ma (Bgure 11). In-situ chemical age determinations in six grains of monazite were carried out. The age is calculated 6. Conclusion using the software Age Quant of SX-Peak sight. The xenotime is Bne-grained and euhedral The felsic volcanics reported from the Kalalikhera (Bgure 10b). The ages calculated from xenotime area of the Pur-Banera basin are medium to Bne- grains ranged from 2110 to 2285 Ma, with a mean grained and contain abundant lapillae. Also, the of 2192 Ma. The monazites are subhedral to presence of relict bipyramidal quartz as seen under euhedral and are present within fabric deBning a microscope conBrms the volcanic nature of the J. Earth Syst. Sci. (2021) 130:84 Page 11 of 14 84

Figure 8. Chondrite-normalized REE pattern in monazites of the study area.

Figure 9. Chondrite-normalized REE pattern in xenotime of the study area. unit. Geochemically, the volcanics are of rhyolitic metamorphic monazite (Seydoux-Guillaume et al. composition. Geochemistry of monazites of the 2002). Chondrite normalized REE pattern in felsic volcanics indicated the metamorphic origin of monazite show steep fractionation trend from La to monazites with ThO2 ranging from 4.68 to 7.55 Lu. These monazites show negative Eu anomaly wt.%. Generally, for hydrothermal monazite, ThO2 which is typical for metamorphic monazite (Chen content is\1 wt.% and for igneous monazite, it is 3 et al. 2017; Ahmad et al. 2008b). Xenotime pref- to[5 wt.%, whereas metamorphic monazites show erentially accommodates HREE (Gd to Lu). A a wide variation in ThO2 content (Schandl and pronounced negative Eu anomaly indicates prefer- Gorton 2004). The substitution mechanism in ential partitioning of Eu in xenotime–chernovite monazite shows almost a linear trend in (Th+U) (Singh and Singh 2012). vs. Ca plot indicating dominance of ‘cheralite Trace element concentration of the volcanics substitution’, which also predominates in with a wide range of variation is indicative of 84 Page 12 of 14 J. Earth Syst. Sci. (2021) 130:84

Figure 10. BSE image of representative (a) monazite and (b) xenotime grains with spot ages.

Figure 11. Plot of relative probability and frequency of spot ages in monazite and xenotime, obtained using Isoplot/Ex (Ludwig 2003) software. variation in the degree of partial melting and/or (Pearce et al. 1984; Yousuf et al. 2019). Nb vs. Y crustal involvement (Condie 1994, 2000). A con- diagram and Rb vs. Y+Nb diagram of the samples siderable concentration of V is also present, which also indicate the dominance of an orogenic envi- may be considered as evidence of riftogenic setting ronment. The rifting and collisional orogenic for the studied samples, as a wide variety of V events are responsible for Kalalikhera felsic vol- mineralization is reported from several riftogenic canic in PBB. The ages in monazite ranged in three structures such as riftogenic Kola region of Russia clusters 1784, 1342 and 1025 Ma, which may cor- (Buck et al. 1999), Rampura-Agucha Pb–Zn respond to the time span of subsequent metamor- deposit which formed in intracratonic rifting, etc. phism. The chemical age of xenotime indicated (Forster€ 1998a; Uher et al. 2009). LILE elements 2110–2285 Ma age, with a mean of 2192 Ma. such as Ba and K show enriched characteristics From the overall studies, it can be inferred that with moderate negative anomaly for Rb and of K in the 2192 ± 57 Ma age recorded in xenotime may be few samples. HFSE elements such as Nb and Ti indicative of the opening of Aravalli basin with show a strong negative anomaly. Strong positive P onset of rifting, leading to formation of Kalalikhera anomaly, moderate positive Nb and Ti anomaly in volcanics and subsequent closure of the basin few samples are indicative of rare signatures of the leading to onset of Aravalli orogeny at 1784 ± 92 collisional environment, while negative Nb coupled Ma. Subsequent 1351 ± 45 Ma age recorded may with negative Ti in few samples is indicative of the be synchronous to Delhi orogeny, with late presence of collisional environmental component 1026 ± 57 Ma Grenvillian age imprints J. Earth Syst. Sci. (2021) 130:84 Page 13 of 14 84 corresponding to Bnal stage of closure of the Delhi Buck H M, Cooper M A, Cerny P, Grice J D and Hawthorne F Basin. C 1999 Xenotime-(Yb), YbPO4, a new mineral species from the Shatford Lake pegmatite group, southeastern Mani- toba, Canada; Can. Mineral. 37 1303–1306. Chen W, Honghui H, Bai T and Jiang S 2017 Geochemistry of Acknowledgements monazite within carbonatite related REE deposits; Re- sources 6 51. The authors are thankful to the Additional Direc- Condie K C 1994 Greenstones through Time; In: Archean tor General, Geological Survey of India, Western Crustal Evolution (ed.) Condie K C, Elsevier, Amsterdam. Region, Jaipur for support and encouragement. Condie K C 2000 Episodic continental growth models: The Brst author is thankful to Dr P R Golani, Afterthoughts and extension; Tectonophysics 322 153–162. Crawford A R 1970 The Precambrian geochronology of Deputy Director General (Retd.), Geological Sur- Rajasthan and Bundelkhand, Northern India; Canadian J. vey of India who inspired me to write this manu- Earth Sci. 125 91–110. script. The authors are thankful to Dr Ausaf Raza, Deb M, Thorpe R I, Cumming G L and Wagner P A 1989 Age Senior Geologist, and Ms Sonalika Joshi, Superin- source and stratigraphic implications of Pb isotope data for tending Geologist for their technical advice. We conformable, sediment-hosted, base metal deposits in the Proterozoic Aravalli–Delhi orogenic belt, northwestern acknowledge the oDcials of the Chemical Labora- India; Precamb. Res. 43 1–22. tory, GSI, Jaipur, and EPMA Laboratory, GSI, D’Souza J, Prabhakar N, Yigang Xu, Sharma K K and Sheth Hyderabad for analytical support. H 2019 Mesoarchaean to Neoproterozoic (3.2–0.8 Ga) crustal growth and reworking in the Aravalli Craton, northwestern India: Insights from the Pur-Banera supra- Author statement crustal belt; Precamb. Res. 332 105383, https://doi.org/10. 1016/j.precamres.2019.105383. Forster€ H J 1998a The chemical composition of REE–Y–Th– Suresh Chander: Conceptualisation, visualisation, U-rich accessory minerals in peraluminous granites of the methodology, Beld investigation collection of Beld Erzgebirge–Fichtelgebirge region, Germany; Part I: The data and writing of original draft. Santanu Bhat- monazite-(Ce)-brabantite solid solution series; Am. Min- tacharjee: Petrography, EPMA study with ana- eral. 83 259–272. lytical methods. Manideepa Roy Choudhury: Forster€ H J 1998b The chemical composition of REE–Y– Conceptualisation and incorporation of write up Th–U-rich accessory minerals in peraluminous granites of with additional ideas on geochemical data inter- the Erzgebirge–Fichtelgebirge region, Germany; Part II: Xenotime; Am. Mineral. 83 1302–1315. pretation. Nikhil Agarwal: Incorporation of write Gopalan K, Macdougall J D, Roy A B and Murali A B 1990 up with additional ideas. Sm–Nd evidence for 3.3 Ga old rocks in Rajasthan, northwestern India; Precamb. Res. 48 287–297. Gupta B C 1934 The geology of central Mewar; Geol. Soc. References India Memoir 65 107–168. Gupta S N, Arora Y K, Mathur R K, Iqballuddin, Prasad B, Ahmad T and Tarney J 1991 Geochemistry and petrogenesis Sahai T N and Sharma S B 1980 Lithostratigraphic map of of Garhwal volcanics: Implications for evolution of the Aravalli region; Geol. Surv. of India, Calcutta, Scale north Indian lithosphere; Precamb. Res. 50 69–88. 1:1,000,000. Ahmad T, Dragusanu C and Tanaka T 2008a Provenance of Hazarika P, Upadhyay D and Mishra B 2013 Contrasting Proterozoic Basal Aravalli maBc volcanics rocks from geochronological evolution of the Rajpura–Dariba and Rajasthan, northwestern India: Nd isotopes evidence for Rampura–Agucha metamorphosed Zn–Pb deposit, Araval- enriched mantle reservoirs; Precamb. Res. 162 150–159. li–Delhi Belt, India; J. Asian Earth Sci. 73 329–339. Ahmad T, Tanaka T, Sachan H K, Asahara Y, Islam R and Heron A M 1953 Geology of Central Rajasthan; Geol. Surv. Khanna P P 2008b Geochemical and isotopic constraints on India Memoir Kolkata 79 339. the age and origin of the Nidar Ophiolitic Complex, Imai N, Terashima S, Itoh S and Ando A 1995 Compilation of Ladakh, India: Implications for the Neo-Tethyan subduc- analytical data for minor and trace elements in seventeen tion along the Indus suture zone; Tectonophysics 451 GSJ geochemical reference samples, ‘Igneous rock series’; 206–224. Geostand. Newslett. 19 135–213. Andrehs G and Heinrich W 1998 Experimental determination Kerr A C, White R V and Saunders A D 2000 LIP Reading: of REE distributions between monazite and xenotime: Recognizing Oceanic Plateaux in the geological record; J. Potential for temperature-calibrated geochronology; Chem. Petrol. 41 1041–1056. Geol. 149 83. Ludwig K R 2003 Isoplot 3.00: A geochronological toolkit for Berger A, Gnos E, Janots E, Fernandez A and Giese J 2008 Microsoft Excel, Berkeley Geochronology Center, Berkeley, Formation and composition of rhabdophane, bastnasite€ and 70p. hydrated thorium minerals during alteration: Implications Mclennan S M 1994 Rare earth element geochemistry and the for geochronology and low-temperature processes; Chem. ‘tetrad’ eAect; Geochim. Cosmochim. Acta 58(9) Geol. 254 238–248. 2025–2033. 84 Page 14 of 14 J. Earth Syst. Sci. (2021) 130:84

Ozha M K, Mishra B, Hazarika P, Jeyagopal A V and Yadav Spear F S and Pyle J M 2002 Apatite, monazite, and xenotime G S 2016 EPMA monazite geochronology of the basement in metamorphic rocks; Rev. Mineral. Geochem. 48 and supracrustal rocks within the Pur-Banera basin, 293–335. Rajasthan: Evidence of Columbia breakup in northwestern Sun S S and McDonough W F 1989 Chemical and isotopic India; J. Asian Earth Sci. 117 284–303. systematics of ocean basalts: Implications for mantle Ondrejka M, Uher P, Prsek J and Daniel O 2007 Arsenian composition and processes, in Magmatism in the Ocean monazite-(Ce) and xenotime-(Y), REE arsenates and carbon- Basins, December 1989; Geol. Soc. London, Spec. Publ. 423 ates from the Tisovec–Rejkovo rhyolite, Western Carpathi- 13–345. ans, Slovakia: Composition and substitutions in the (REE, Y) Suzuki K and Adachi M 1991 Precambrian provenance and XO4 system (X = P, As, Si, Nb, S); Lithos 95 116–129. Silurian metamorphism of the Tsubonosawa paragneiss in Pearce J A, Harris N B and Tindle A G 1984 Trace element the South Kitakami terrane, Northeast Japan, revealed by discrimination diagrams for the tectonic interpretation of the chemical Th–U–total Pb isochron ages of monazite, granitic rocks; J. Petrol. 25 956–983. zircon, and xenotime; Geochem. J. 25 357–376. Quach D-T and Hans K 2015 Monazite and xenotime Uher P, Ondrejka M and Konecny P 2009 Magmatic and solubility in granitic melts and the origin of the lanthanide post-magmatic Y–REE–Th phosphate, silicate and tetrad eAect; Contrib. Mineral. Petrol. 169 8. Nb–Ta–Y–REE oxide minerals in A-type metagranite: An Sastry C A 1992 Geochronology of the Precambrian rocks example from the Turcok massif, the Western Carpathians, from Rajasthan and northeastern Gujarat; Geol. Surv. Slovakia; Mineral. Mag. 73 1009–1025. India Spec. Publ. 5 1–41. Ward D A and Miller C F 1993 Accessory mineral behavior Schandl E and Gorton M 2004 A textural and geochemical during differentiation of a granite suite: Monazite, xenotime guide to the identiBcation of hydrothermal monazite: and zircon in the Sweetwater Wash pluton, southeastern Criteria for selection of samples for dating epigenetic California, U.S.A; Chem. Geol. 110 49–67. hydrothermal ore deposits; Econ. Geol. 99 1027–1035. Wiedenbech M, Goswami J N and Roy A B 1996 Stabilization https://doi.org/10.2113/99.5.1027. of Aravalli Craton of northwestern India at 2.5 Ga: An ion Seydoux-Guillaume A M, Wirth R, Nasdala L, Gottschalk M, microprobe zircon study; Chem. Geol. 129 Montel J M and Heinrich W 2002 An XRD, TEM and 325–340. Raman study of experimentally annealed natural monazite; Yousuf I, Subba Rao D V, Balakrishnan S and Ahmad T 2019 Phys. Chem. Mineral. 29 240–253. Geochemistry and petrogenesis of acidic volcanics from Singh A K and Singh R K B 2012 Petrogenetic evolution of the Betul–Chhindwara Belt, Central Indian Tectonic Zone felsic and maBc volcanics suite in the Siang window of (CITZ), central India; J. Earth Syst. Sci., https://doi. Eastern Himalaya, North East India; Geosci. Front. 3(5) org/10.1007/s12040-019-1255-x. 613–634. Zhu X K, O’Nions R K, Zhu X and O’Nions R 1999 Monazite Sinha-Roy S 1989 Strike-slip fault and pull apart basins in chemical composition: Some implications for monazite Proterozoic fold belt developed in Rajasthan; Ind. Mineral geochronology; Contrib. Mineral. Petrol. 137 43(3&4) 226–240. 351–363.

Corresponding editor: N V CHALAPATHI RAO