THE NATURAL RADIOACTIVITY MAP OF UMBRIA (ITALY): A MULTIPURPOSE TOOL FOR ENVIRONMENTAL UNDERSTANDING Matteo Albéri1,2,*, Marica Baldoncini1,2, Stefano Bisogno3, Carlo Bottardi2,4, Ivan Callegari5, Enrico Chiarelli1,2, Giovanni Fiorentini2,4, Fabio Mantovani2,4, Andrea Motti3, Norman Natali3, Marco Ogna3, Kassandra Giulia Cristina Raptis1,2, Andrea Serafini2,4, Gianluigi Simone3, Virginia Strati2,4 1INFN, Legnaro National Laboratories, Legnaro, Padua, Italy, 2Department of Physics and Earth Sciences, University of Ferrara, Ferrara, Italy, 3Servizio Geologico, Regione Umbria, Perugia, Italy, 4INFN, Ferrara Section, Ferrara, Italy, 5German University of Technology, Department of Applied Geosciences AGEO, Muscat, Oman *Corresponding author: [email protected] (Matteo Albéri) 1:150000 scale This map presents the distribution of the terrestrial natural radioactivity of the 02.5 5 10 15 40 232 km Umbria region (Italy). The total specific activity due to the presence of K, Th and 238U in the environment is given in Bq/kg. Natural radioactivity was 30 30 characterized by means of gamma spectroscopy measurements performed by 20 adopting complementary survey methodologies, namely rock and soil San Giustino sampling, together with airborne gamma ray surveys. Referring to the Geological Database provided by the Geological Regional Service and based 50 on a 1:10000 scale survey, the 214 Cartographic Units (CUs) were divided into two groups: Deposits sensu lato (s.l.), comprising the 118 CUs corresponding i 2 0 3 20 0 Vasch to quaternary deposits and loose geological formations, and Rocks s.l., 30 20 consisting of 96 CUs of rocky geological formations. The Rocks s.l. group (50% 20 of the regional surface) was investigated via a rock sampling campaign (one 2 0 50 2 Città di Castello sample per 15 km ). The natural radionuclides content of the 283 rock 60 samples (from representative outcrops) and 14 soil samples was 30 ara So Pietralunga characterized through high-resolution gamma spectroscopy measurements 20 30 80 Normalized estimation errors (%) o Monte Santa Maria Tiberina n ra u 6 carried out in laboratory with the MCA_Rad, a High-Pure Germanium detector B 0 70 3 0 Scheggia e Pascelupo that can automatically measure 24 samples without human intervention. The 0 Tevere 2 4 0 50 Total specific activity 30 3 radioactivity of the Deposits s.l. group (50% of the regional surface) was 0 20 Percentile Bq/kg 0 3 investigated through airborne gamma ray spectroscopy measurements, 5 100 1553 20 0 performed at a nominal 100 m altitude with a 16L volume sodium iodide (NaI) 20 Costacciaro 40 5 na 0 6 detector mounted on the Radgyro, an experimental aircraft devoted to a 0 L Montone Gubbio 2 97 538 0 30 40 multiparametric surveys. This thematic map represents one of the final products Sigillo of the Umbria-Rad project, realized thanks to the support of the Italian 80 361 30 30 National Institute of Nuclear Physics (INFN) and the Geological Service of 30 3 ne 0 cco the Umbria Region. Ni 0 60 314 2 Fossato di Vico 20 Umbertide 50 288 20 40 248 20 40 Sampling points 2 0 25 0 8 156 Rock samples io c s ia 20 h C Soil samples 10 95 Gualdo Tadino 8 Lisciano Niccone R 0 a si Airborne survey n a 0 0 36 2 60 50 Rocks s.l. 2 Deposits s.l. Tuoro sul Trasimeno 0 0 70 0 3 3 5 0 0 2 0 5 30 Passignano sul Trasimeno 20 2 0 2 60 0 Valfabbrica 0 40 5 30 0 40 3 0 0 2 3 C Magione a l Trasimeno Lake Corciano 40 d o Nocera Umbra g Castiglione del Lago 30 n o l PERUGIA a 40 3 0 80 50 0 3 20 re Assisi 2 e Bastia Umbra 0 v 0 e 7 Valtopina T 0 30 6 50 5 20 0 3 20 0 30 20 2 Torgiano 0 0 0 4 Panicale 3 T Paciano Bettona op in o 3 05 10 20 30 0 50 km 0 20 3 Cannara 0 Nestore Spello 5 20 M e 0 n 2 o t Deruta re T e 0 v 2 2 0 e r 20 o n Piegaro e 40 Foligno 0 Città della Pieve 2 2 0 Bevagna 30 30 4 0 30 Fersi non P Gualdo Cattaneo e u 3 Montegabbione 3 0 g 0 70 0 2 li a 0 Ch 8 Sellano ia Monteleone d'Orvieto Collazzone ni Marsciano Montefalco Preci 30 60 30 40 Trevi 3 0 6 6 0 0 70 30 20 0 5 4 Fabro San Venanzo 0 40 20 0 Parrano 3 Fratta Todina 4 0 0 2 8 0 30 50 Monte Castello di Vibio Giano dell'Umbria Campello sul Clitunno Cerreto di Spoleto 80 70 0 Castel Ritaldi 0 2 0 2 Ficulle 7 0 3 5 0 Norcia 60 4 R 0 i Allerona to 8 3 0 0 r to 30 4 0 Todi Massa Martana 0 Vallo di Nera 5 3 0 30 Spoleto 0 20 7 0 8 60 0 50 50 70 8 Castel Viscardo Sant'Anatolia di Narco Cascia 3 7 0 0 Scheggino Poggiodomo 0 5 80 70 60 10 Orvieto 60 70 2 P Corbara Lake 0 agl Acquasparta Castel Giorgio i 0 10 1 a 7 0 0 0 6 3 40 0 a 5 i T 0 a 4 e 80 5 N v 0 0 Porano e 7 0 r 60 4 7 e Baschi 0 Monteleone di Spoleto 5 0 Montecchio 8 C 0 o Avigliano Umbro r Montecastrilli n 0 4 o 1 0 30 70 80 0 8 Ferentillo 0 60 6 0 60 50 Guardea 7 70 40 8 5 San Gemini 0 0 Montefranco 40 0 4 0 K ABUNDANCES Mean and 1σ uncertainty (symmetric or 8 Polino 3 Arrone 0 70 50 80 40 asymmetric) of K (%), Th (µg/g) e U (µg/g) Alviano Percentile % 0 7 San Giustino 100 3.6 8 0 0 70 5 0 TERNI 0 6 abundances for the 29 CUs characterized by 3 Lugnano in Teverina 60 8 Città di Castello 97 1.5 ra e 2 N 80 1.0 0 or more samples and covering 92% of the 30 0 3 Gubbio 60 0.8 Amelia 80 Umbertide Rocks s.l. group surface. The distribution 40 0.6 Piediluco Lake Gualdo Tadino 30 25 0.4 function for each dataset was graphically F 60 o 0 s 6 10 0.2 s Magione o G PERUGIA studied using univariate statistics to gain an 0 0.1 Narni Corciano Assisi r Castiglione del Lago 0 a 4 n Bastia Umbra 2 0 0 d insight into the data structure and to 0 6 50 e 7 Stroncone Attigliano Giove discriminate the normal and lognormal eTh ABUNDANCES Foligno 40 Marsciano 0 Penna in Teverina 3 distributions. Percentile µg/g San Giustino 100 75.9 Todi Spoleto 97 14.5 MONTI VULSINI SUPERSYNTHEM (middle Pleistocene) [Volcanic rocks] Città di Castello Orvieto # samples K ± σ [%] Th ± σ [µg/g] U ± σ [µg/g] 80 8.0 Gubbio ORV1 Orvieto Synthem, Canonica-Torre San Severo Subsynthem 3 1.54 ± 0.42 82.1 ± 16.7 8.6 ± 1.7 60 6.8 TERNI Umbertide Amelia 40 5.8 TUSCAN UNITS (lower Eocene to lower Miocene) [Terrigenous and carbona!c sedimentary rocks] 3 Narni 0 0 Gualdo Tadino 4 25 4.3 # samples K ± σ [%] Th ± σ [µg/g] U ± σ [µg/g] 50 MAC3 Macigno, Lippiano Member 7 1.88 ± 0.55 9.4 ± 1.3 2.6 ± 0.6 Magione 10 2.0 3 0 +0.43 +2.2 +0.4 0 7 PERUGIA MAC2 Macigno, Poggio Belvedere Member 11 1.89 -0.35 10.2 -1.8 2.8 -0.3 Otricoli 0 0.5 Castiglione del Lago Corciano Assisi MAC1 Macigno, Molin Nuovo Member 6 2.03 ± 0.20 10.7 ± 3.1 2.2 ± 0.8 Bastia Umbra 05 10 20 30 km STO4b Scaglia Toscana, Calcareni! di Dudda Member (litofacies di Poggioni) 3 0.70 ± 1.13 5.0 ± 7.5 1.3 ± 0.4 3 0 Calvi dell'Umbria Foligno MONTE RENTELLA SUCCESSION (lower Miocene) [Terrigenous sedimentary rocks] Marsciano # samples K ± σ [%] Th ± σ [µg/g] U ± σ [µg/g] +0.77 +3.5 +0.7 REN Montagnaccia Fm. 15 1.43 -0.50 7.6 -2.4 2.4 -0.5 Todi FMR Monte Rentella Fm. 3 1.86 ± 0.17 10.4 ± 2.1 3.3 ± 0.5 Spoleto eU ABUNDANCES Orvieto UMBRO-ROMAGNA SUCCESSION (lower to middle Miocene) [Marls and sandstones] # samples K ± σ [%] Th ± σ [µg/g] U ± σ [µg/g] Percentile µg/g TERNI San Giustino Amelia SMT3 Monte S. Maria Tiberina Fm., Poggio Strada Member 3 1.59 ± 0.27 8.5 ± 1.0 2.8 ± 0.2 100 12.4 Narni FMA9a Marnoso-Arenacea Romagnola Fm., Civitella Member 5 1.63 ± 0.23 8.1 ± 0.9 3.0 ± 0.3 Città di Castello 97 3.9 FMA4a Marnoso-Arenacea Romagnola Fm., Galeata Member (lower litofacies) 3 1.43 ± 0.13 6.1 ± 1.2 2.5 ± 0.5 80 2.6 +1.26 +5.3 +1.1 FMA4b Marnoso-Arenacea Romagnola Fm., Galeata Member (litofacies superiore) 31 0.98 -0.55 4.9 -2.5 2.0 -0.7 Gubbio 60 2.2 FMA4b-OLI Marnoso-Arenacea Romagnola Fm., Galeata Member (olistostrome) 3 0.94 ± 0.67 5.3 ± 2.7 1.9 ± 0.8 Umbertide 05 10 20 30 A multivariate geostatistical method (Collocated CoKriging) was 40 1.8 km MUM4b Marnoso-Arenacea Umbra Fm., Be"ona Member (sandy lithofacies) 3 1.98 ± 0.07 6.3 ± 1.3 1.2 ± 0.2 Gualdo Tadino MUM3 Marnoso-Arenacea Umbra Fm., Vesina Member 4 1.06 ± 0.62 5.0 ± 3.1 1.9 ± 0.7 applied for interpolating sparse gamma-ray data by taking into 25 1.4 MUM2 Marnoso-Arenacea Umbra Fm., Monte Casale Member 3 2.07 ± 0.49 5.9 ± 2.8 1.9 ± 1.4 Magione 10 0.7 PERUGIA MUM1 Marnoso-Arenacea Umbra Fm., Casa Spertaglia Member 8 1.61 ± 0.38 7.8 ± 2.1 2.5 ± 0.6 account the well-known geological information as ancillary variable.