This brief note presents geochemical data from rock samples from the Cabo Ortegal Complex (NW Spain). The samples belong to acid lithologies within the mainly basic to intermediate granulite unit that have been poorly investigated so far. For this communication, five samples of the migmatites and an amphibolitic enclave within them have been analysed. The whole-rock major and trace-element analyses were accomplished by means of Q-ICPMS. The dataset provides new and useful information relevant to the origin of the acid migmatites and can be used in addition to information from neighbouring lithologies to enhance understanding of the geological evolution of the Western Variscan Belt

Abalos Villaro, Benito

Beranoaguirre de Miguel, Aratz

García de Madinabeitia Martínez de Lizarduy, Sonia

Gil Ibarguchi, José Ignacio

Puelles Olarte, Pablo

Sánchez Lorda, María Eugenia

Data in Brief

English

PubMed

Archivo Digital para la Docencia y la Investigación

Data in Brief 40 (2022) 107823 Contents lists available at ScienceDirect Data in Brief journal homepage: www.elsevier.com/locate/dib Data Article Geochemical dataset of high-pressure acid migmatites from the Cabo Ortegal Complex (NW Spain) Aratz Beranoaguirre a , b , ∗, Sonia Garcia de Madinabeitia b , Maria Eugenia Sanchez-Lorda c , Pablo Puelles b , Benito Abalos b , Jose Ignacio Gil-Ibarguchi b a Institut für Geowissenschaften, Goethe-Universität, Altenhöferallee 1, Frankfurt am Main 60438, Germany b Geologia Saila, Euskal Herriko Unibertsitatea UPV/EHU, PO Box 644, Bilbao 48080, Spain c Geokronologia eta Geokimika Isotopikoaren Zerbitzua – SGIker-IBERCRON, Euskal Herriko Unibertsitatea UPV/EHU, PO Box 644, Bilbao 48080, Spain a r t i c l e i n f o Article history: Received 29 October 2021 Revised 23 December 2021 Accepted 7 January 2022 Available online 10 January 2022 Keywords: Whole-rock geochemistry Cabo Ortegal Complex NW Iberia Migmatite Variscan a b s t r a c t This brief note presents geochemical data from rock samples from the Cabo Ortegal Complex (NW Spain). The samples be- long to acid lithologies within the mainly basic to interme- diate granulite unit that have been poorly investigated so far. For this communication, five samples of the migmatites and an amphibolitic enclave within them have been anal- ysed. The whole-rock major and trace-element analyses were accomplished by means of Q-ICPMS. The dataset provides new and useful information relevant to the origin of the acid migmatites and can be used in addition to information from neighbouring lithologies to enhance understanding of the ge- ological evolution of the Western Variscan Belt. © 2022 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ) ∗ Corresponding author at: Geologia Saila, Euskal Herriko Unibertsitatea UPV/EHU, PO Box 644, Bilbao 48080, Spain. E-mail address: aratz.beranoaguirre@ehu.eus (A. Beranoaguirre). https://doi.org/10.1016/j.dib.2022.107823 2352-3409/© 2022 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ) 2 A. Beranoaguirre, S. Garcia de Madinabeitia and M.E. Sanchez-Lorda et al. / Data in Brief 40 (2022) 107823 Specifications Table V    1 (  o  e  s  t  u  t  fi  c  (  c  e  a s  p  Subject Earth Sciences Specific subject area Geochemistry and Petrology Type of data Table Figure How data were acquired Analysis of whole-rock composition (major and trace elements) using quadrupole ICPMS (Thermo Fisher XSeries II) Data format Raw and Analyzed Parameters for data collection The samples were collected from the poorly studied acid lithologies within the extensively investigated, mainly basic to intermediate in composition, granulite unit of the Cabo Ortegal Complex. Description of data collection The description of the data collection is presented in the Experimental Design, Materials, and Methods section. Data source location Samples storage at: University of the Basque Country UPV/EHU, Science and Technology Faculty, SGIker research facility, Leioa (Spain) Samples collected at the Cabo Ortegal Complex, Bacariza Formation (NW Iberia). See coordinates in [1] . Data accessibility With the article Related research article A. Beranoaguirre, S. Garcia de Madinabeitia, M. E. Sanchez-Lorda, P. Puelles, B. Abalos, J. I. Gil Ibarguchi, U-Pb, Hf isotope and REE constraints on high-pressure acid migmatites from the Cabo Ortegal Complex (NW Spain): New evidence of short-duration metamorphism in a Variscan subduction channel, Lithos 372-373 (2020) 105,660. doi: 10.1016/j.lithos.2020.105660 alue of the Data • The data provide geochemical information to classify and characterize the acid migmatites ofthe granulite unit at Cabo Ortegal. • The data can be used to better understand the petrogenesis of the rocks. • The data can be re-used, together with additional information, to gain further insights re-garding the origin and subsequent evolution of the high-pressure metamorphic nappes ofthe Cabo Ortegal Complex. • The data presented in this article complement the data obtained from the previous study [1] .. Data Description Geochemical data from poorly known acid migmatites exposed in the Cabo Ortegal ComplexWestern Variscides, NW Spain) are presented here. The migmatites, previously called granuliticrthogneisses [2] , are part of the high-pressure granulite unit, tectonically placed between theclogite and ultramafic (peridotite-pyroxenite) units [3] . Except for the so-called felsic gneissample and the amphibolitic enclave, all the other samples bear evidence of partial melting. De-ailed petrographic information of those migmatites can be found elsewhere [1 , 2] . Due to thebiquity of the mafic granulites, earlier geochemical works in the area have been focused onhose lithotypes [e.g. 4 ], leaving aside the scarce acid migmatite outcrops. This paper intends toll this gap on geochemical data and for that purpose, six samples from the biotite-absent mus-ovite bearing migmatites (samples T-4 and CO-35a), muscovite- and biotite-bearing migmatitesCO-55a), biotite-bearing migmatites lacking muscovite (CO-5b, including an amphibolitic en-lave), and mica-lacking felsic gneisses (CO-49) have been studied. Accompanying frequent min-rals include garnet, quartz, feldspars and rutile, and, in some cases zoisite/clinozoisite, kyanitend antiperthitic plagioclase. Table 1 shows the results of the whole rock major and trace element analyses of the selectedamples, together with two samples from the literature [4] used in Fig. 1 (see below) for com-arative purposes. All samples analysed are quite evolved, with SiO 2 contents varying from 50.2%A. Beranoaguirre, S. Garcia de Madinabeitia and M.E. Sanchez-Lorda et al. / Data in Brief 40 (2022) 107823 3 Table 1 Major and trace element analyses of acid migmatites from the Cabo Ortegal Complex. ∗ from [4] . Sample CO-08-5b CO-08-5b Enc CO-35a CO-49 CO-55a T-4 AMP-463 ∗ AMP-466 ∗Major elements (%) SiO 2 58.06 52.17 56.22 59.68 50.21 71.83 43.60 46.10 TiO 2 1.31 1.26 1.02 0.58 1.69 0.48 1.96 3.90 Al 2 O 3 17.72 16.88 18.67 15.93 20.19 13.12 15.20 13.80 Fe 2 O 3 9.18 10.98 9.73 9.50 12.86 5.12 18.20 15.80 MnO 0.17 0.12 0.16 0.19 0.24 0.11 0.24 0.28 MgO 3.78 6.67 3.08 2.34 4.57 1.10 6.5 6.22 CaO 3.56 6.56 4.47 7.81 4.46 2.57 10.9 10.8 Na 2 O 3.15 2.34 3.04 3.28 3.66 1.99 1.23 0.99 K 2 O 1.85 1.46 3.11 3.28 3.66 2.52 0.18 0.34 P 2 O 5 0.21 0.13 0.11 0.10 0.12 0.12 0.05 0.47 LOI 0.58 0.98 0.66 0.11 0.76 0.82 0.00 0.50 Total 99.57 99.55 100.27 102.79 102.41 99.78 98.06 99.20 Trace elements (ppm) Sc 23.5 25.9 4.53 4.84 4.15 24.9 - - V 139.1 228.1 171.6 124.5 268.9 35 - - Cr 85.3 280.0 158.6 204.9 211.9 54.3 200 300 Co 19.0 96.1 34.77 19.61 70.61 75.2 55 36 Ni 47.0 82.4 46.97 b.d.l. 218.2 6.1 b.d.l. 55 Cu 45.1 46.2 21.9 15.64 21.01 b.d.l. - - Zn 54.6 125.4 56.92 55.92 91.11 38.1 - - Rb 54.0 32.9 109.8 7.782 69.42 54.4 4 7 Sr 197.9 120.6 201.7 280.1 265.9 151 153 62 Y 35.1 35.8 35.08 19.77 68.37 100 b.d.l. 46 Zr 194.1 124.4 231.3 57.58 380.9 401.2 37 235 Nb 9.2 6.1 13.23 b.d.l. 25.29 10 5 7 Ba 488.7 258.7 780.3 75.72 491.8 915 167 252 La 20.5 15.0 38.07 9.229 86.56 111 2 10.7 Ce 55.6 33.7 95.3 17.43 176.5 229 5 28 Pr 5.9 4.2 11.46 2.631 23.65 29.4 - - Nd 22.5 18.0 44.11 11.61 93.56 114 4 21 Sm 5.2 5.4 9.179 3.059 18.8 23.3 1.17 6.61 Eu 1.2 1.5 2.157 1.316 3.473 2.7 0.69 2.66 Gd 5.2 6.4 11.28 3.668 23.34 19.5 - - Tb 0.9 1.1 1.372 0.605 2.727 3.03 0.3 1.7 Dy 6.1 6.6 7.525 3.636 14.79 18.5 1.9 10 Ho 1.0 1.1 1.498 0.779 3.041 3.11 - - Er 3.4 3.5 4.465 2.322 9.17 10.3 - - Tm 0.6 0.6 0.652 0.366 1.367 1.71 - - Yb 3.6 3.5 4.428 2.535 9.031 10.1 1.24 5.75 Lu 0.6 0.6 0.628 0.388 1.24 1.79 0.19 0.86 Hf 5.7 3.9 6.574 1.699 10.76 12.75 1 7 Ta 0.8 1.0 1.001 0.194 1.962 1.25 b.d.l. b.d.l. Th 9.1 3.9 8.723 1.405 18.15 28.3 b.d.l. b.d.l. U 1.3 1.0 2.16 1.181 2.242 2.4 0.2 0.4           up to 71.8% and MgO < 5%, except for the amphibolite nodule in sample CO-5b. Their freshnessis confirmed by the < 1% values for loss on ignition. Harker diagrams for major element oxides are presented in Fig. 1 . As a comparison, we alsoplotted the geochemical data of two already published data of mafic and rare ultramafic (pyri-garnite) granulites within the same unit (from [4] ). All major elements except K 2 O exhibit acoherent decreasing linear trend with respect to increasing SiO 2 , above all observable in MgOand Fe 2 O 3 diagrams. This is consistent with a differentiation process for magmatic protoliths ofthe granulite unit. The main difference between mafic and acid rocks is related to the higheralkali (Na 2 O and K 2 O) contents as well as distinctively lower Fe 2 O 3 and CaO components in thelatter. Indeed, the amount of K 2 O in acid lithotypes is responsible for the characteristic whitemica growth in the migmatites. Regarding the trace elements, the most significant feature is the4 A. Beranoaguirre, S. Garcia de Madinabeitia and M.E. Sanchez-Lorda et al. / Data in Brief 40 (2022) 107823 Fig. 1. Plots of SiO 2 content against different major elements oxide (Harker diagram) of the samples. Black dots corre- spond to the samples analysed here, white dots are from [4] . See text for further explanations. i  o  L  o  5 c  p  b  p  t  t e  p  m  P  E  S  d  ncreasing of U content increasing SiO 2 . It is also worth mentioning the low Zr and Hf contentn the mica-lacking gneisses (sample CO-49), where lower amount of zircon was also observed.ikewise, the gneisses have a distinctive lower content of REE in comparison to the amountbserved in the white mica rich lithotypes ( REE < 60 μg/g in the gneisses against REE >50 μg/g in the biotite-absent muscovite bearing migmatite, sample T-4). According to the classification of [5] ( Fig. 2 a), the migmatite samples are peraluminous, ex-ept for the amphibolite enclave in sample CO-5b that plots in the metaluminous field. Whenlotting in the ternary AFM diagram of [6] ( Fig. 2 b) the samples show a calc-alkaline affinityut close to the boundary with the tholeiitic series. The rocks studied here do not plot in anyarticular field of the ones proposed by [7] ( Fig. 2 c), pointing to a progressive trend. Similarly,he tectonic discrimination diagrams of [8] are also inconclusive ( Fig. 2 d), with cases straddlinghe boundaries between volcanic-arc and within-plate granites. Trace element concentrations ( Table 1 ) are reported in primitive mantle-normalized multi-lement diagrams and chondrite-normalized REE patterns ( Fig. 3 , normalized to [9] ). They dis-lay patterns typical for volcanic-arc scenarios, with enrichments in large-ion lithophile ele-ents (Rb, Ba) and depletion in Nb and Ta ( Fig. 3 a), as well as enrichment in LREE (La, Ce,r) over HREE ( Fig. 3 b). A notable feature of these patterns is their negative anomaly in Sr andu in the partially melted samples, i.e. all except the felsic gneiss, which is slightly enriched inr and Eu. This reflects the more evolved nature of the samples because Sr becomes relativelyepleted with respect to its neighbouring elements during plagioclase fractionation. Indeed, theA. Beranoaguirre, S. Garcia de Madinabeitia and M.E. Sanchez-Lorda et al. / Data in Brief 40 (2022) 107823 5 Fig. 2. Samples of the acid migmatites plotted in classification diagrams proposed by (a) [5] , (b) [6] , (c) [7] , and (d) [8] .              positive anomaly in Sr and Eu observed in the felsic gneisses may indicate the cumulative natureof this lithology. 2. Experimental Design, Materials and Methods The sample processing was accomplished at the sample preparation laboratories of the Ge-ology Department at the University of the Basque Country UPV/EHU. 5 to 10 kgs of the sample(depending on grain size) were ground using first a jaw crusher (Retsch bb200 Wolframcarbid)and subsequently a Retsch RS1 type ring-mill with widia rings. The measurement protocol was mostly based on the procedures of [10] , and it was as fol-lows: 250 mg of sample and 500 mg of LiBO 2 were put into the Pt(Au) crucible with three tofour drops of LiBr solution as a non-wetting agent. The mixture was fused and poured ontoa polypropylene beaker containing 100 ml of diluted HNO3:HF acid mixture. The solution wasstirred ca. 10 min to ensure total dissolution. The samples were consequently analysed using aThermo Fisher XSeriesII quadrupole ICPMS at the SGIker Research Facilities of the University ofthe Basque Country UPV/EHU. The precision for all analytes is in general < 2%. The LOI was de-termined by heating the samples using a muffle furnace with a temperature of 10 0 0 °C. Beforeand after heating the samples, their masses were measured using a balance weighing with theaccuracy ±0.0 0 02 g so the weight loss was used to calculate the LOI. 6 A. Beranoaguirre, S. Garcia de Madinabeitia and M.E. Sanchez-Lorda et al. / Data in Brief 40 (2022) 107823 Fig. 3. Multi-element and REE patterns of the studied samples. Normalization values are the ‘pyrolite silicate Earth’ for the primitive mantle, and C1 chondrites [9] . ED t  C S  So  Dthics Statement Not applicable. eclaration of Competing Interest The authors declare that they have no known competing financial interests or personal rela-ionships which have, or could be perceived to have, influenced the work reported in this article.RediT Author Statement Aratz Beranoaguirre: Investigation, Formal analysis, Data curation, Writing – original draft;onia Garcia de Madinabeitia: Formal analysis, Writing – original draft; Maria Eugeniaanchez-Lorda: Formal analysis, Writing – original draft; Pablo Puelles: Data curation, Writing –riginal draft; Benito Abalos: Data curation, Writing – original draft; Jose Ignacio Gil-Ibarguchi:ata curation, Writing – original draft. A. Beranoaguirre, S. Garcia de Madinabeitia and M.E. Sanchez-Lorda et al. / Data in Brief 40 (2022) 107823 7                      Acknowledgments Financial support was provided by the Basque Country University UPV/EHU (ProjectGIU20/10 ). Technical and human support provided by the Geochronology and Isotope Geo-chemistry and the Electronic Microscopy and Material Microanalysis SGIker facilities (UPV/EHU,MINECO, GV/EJ, ERDF and ESF) is acknowledged. References [1] A. Beranoaguirre, S. Garcia de Madinabeitia, M.E. Sanchez-Lorda, P. Puelles, B. Abalos, J.I. Gil Ibarguchi, U-Pb, Hfisotope and REE constraints on high-pressure acid migmatites from the Cabo Ortegal Complex (NW Spain): newevidence of short-duration metamorphism in a Variscan subduction channel, Lithos 372-373 (2020) 105660, doi: 10.1016/j.lithos.2020.105660 . [2] P. Puelles, B. Ábalos, J.I. Gil Ibarguchi, Metamorphic evolution and thermobaric structure of the subduction-relatedBacariza high-pressure granulite formation (Cabo Ortegal Complex, NW Spain), Lithos 84 (2005) 125–149, doi: 10.1016/j.lithos.2005.01.009 . [3] J.R. Martínez Catalán, J. Gómez Barreiro, I. Dias da Silva, M. Chichorro, A. López-Carmona, P. Castiñeiras, J. Abati,P. Andonaegui, J. Fernández-Suárez, P. González Cuadra, J.M. Benítez-Pérez, C. Quesada, J.T. Oliveira, Variscan suturezone and suspect terranes in the NW Iberian massif: allochthonous complexes of the Galicia-Trás os Montes Zone(NW Iberia), in: The Geology of Iberia: A Geodynamic Approach. Volume 2: The Variscan Cycle. Regional GeologyReviews, Springer, 2019, pp. 99–130, doi: 10.1007/978- 3- 030- 10519- 8 _ 4 . [4] G. Galan, A. Marcos, Geochemical evolution of high-pressure mafic granulites from the Bacariza formation (CaboOrtegal Complex, NW Spain): an example of a heterogeneous lower crust, Geol. Rundsch. 86 (1997) 539–555, doi: 10.10 07/s0 05310 050162 . [5] P.D. Maniar, P.M. Piccoli, Tectonic discrimination of granitoids, Geol. Soc. Am. Bull. 101 (1989) 635–643, doi: 10.1130/0016-7606(1989)101 〈 0635:TDOG 〉 2.3.CO;2 . [6] T.N. Irvine, W.R.A. Baragar, A guide to the chemical classification of the common volcanic rocks, Can. J. Earth Sci. 8(1971) 523–548, doi: 10.1139/e71-055 . [7] B.R. Frost, C.G. Barnes, W.J. Collins, R.J. Arculus, D.J. Ellis, C.D. Frost, A geochemical classification for granitic rocks, J.Petrol. 42 (2001) 2033–2048, doi: 10.1093/petrology/42.11.2033 . [8] J.A . Pearce, N.B.W. Harris, A .G. Tindle, Trace element discrimination diagrams for the tectonic interpretation ofgranitic rocks, J. Petrol. 25 (1984) 956–983, doi: 10.1093/petrology/25.4.956 . [9] W.F. McDonough, S.S. Sun, The composition of the earth, Chem. Geol. 120 (1995) 223–253, doi: 10.1016/0 0 09-2541(94)0 0140-4 . [10] S. Garcia de Madinabeitia, M.E. Sanchez-Lorda, J.I. Gil Ibarguchi, Simultaneous determination of major to ultratraceelements in geological samples by fusion-dissolution and inductively coupled plasma mass spectrometry techniques,Anal. Chim. Acta 625 (2008) 117–130, doi: 10.1016/j.aca.2008.07.024 . 

Geochemical dataset of high-pressure acid migmatites from the Cabo Ortegal Complex (NW Spain)

http://dx.doi.org/10.1016/j.dib.2022.107823

Geochemical dataset of high-pressure acid migmatites from the Cabo Ortegal Complex (NW Spain)

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