Studi Trent. Sci. Nat., Acta Geol., 80 (2003): 169-173 ISSN 0392-0534 © Museo Tridentino di Scienze Naturali, Trento 2005 High-resolution luminescence speleothem records from Savi Cave, Trieste, NE Italy Diana STOYKOVA 1 , Yavor SHOPOV 1* , Ugo SAURO 2 , Andrea BORSATO 3 , Franco CUCCHI 4 & Paolo FORTI 5 1 University Center for Space Research, Faculty of Physics, University of Sofia, 1164 Sofia (Bulgaria) 2 Dipartimento di Geografia, Università di Padova, Via del Santo 26, I-35123 Padova 3 Museo Tridentino di Scienze Naturali, Via Calepina 14, I-38100 Trento 4 Dipartimento di Scienze Geologiche, Ambientali e Marine, Università di Trieste, Via Weiss 2, I-34127 Trieste 5 Dipartimento di Scienze della Terra e Geologico-Ambientali, Università di Bologna * Corresponding author e-mail: YYShopov@Phys.Uni-Sofia.BG SUMMARY - High-resolution luminescence speleothem records from Savi Cave, Trieste, NE Italy - We measured three luminescent records from the sample SV1, a stalagmite from Savi Cave (Trieste karst, Italy). The longest panoramic record (having the lowest resolution from the records) is a proxy of the solar influence on the climatic system and covers last 14430±176 years. The step of the record varies from 1.1 to 12.7 years. First composite record, which consists of 81000 data points, is compiled of 39 overlapping scans. It covers the last 5005±140 years. The time step of the record varies from 9.9 days to 33.9 days. The highest resolution record covers last 2028±100 years and allows precise determination of growth rate of the stalagmite. It consists of 40106 data points compiled of 16 overlapping scans. Its time step varies from 15.6 days to 19.9 days. We made a reconstruction of the annual growth rate variations for the last 2028 years, which represents annual precipitation for this region. RIASSUNTO - Record di luminescenza ad alta risoluzione di uno speleotema della Grotta Savi, Trieste, Italia - Si presentano tre record di luminescenza della stalagmite SV1 proveniente dalla Grotta Savi nel Carso di Trieste. Il record panoramico più lungo (e con la risoluzione più bassa) è un dato proxy dell’influenza solare sul clima locale, e copre gli ultimi 14430±176 anni, con una risoluzione che varia da 1,1 a 12,7 anni. Il primo record composito, costituito da 81000 dati assemblati da 39 scansioni sovrapposte, copre gli ultimi 5005±140 anni con una risoluzione che varia da 9,9 a 33,9 giorni. Il record a maggior risoluzione, costituito da 40106 dati assemblati da 16 scansioni sovrapposte, copre gli ultimi 2028±100 anni con una risoluzione che varia da 15,6 a 19,9 giorni, e consente di determinare con precisione il tasso di crescita annuale della stalagmite. In base a questo record si è ricostruito il tasso di crescita annuale della stalagmite che rappresenta il valore di precipitazione media annuale per l’area in esame. Key words: luminescence, speleothems, solar insolation, paleoclimate, Trieste Karst Parole chiave: luminescenza, speleotemi, insolazione, paleoclima, Carso Triestino 1. INTRODUCTION Calcite speleothems usually display lumines- cence produced by calcium salts of humic and ful- vic acids derived from soils above the cave (Shopov 1989; White & Brennan 1989). These acids are released by the roots of living plants and by the decomposition of dead vegetative matter. Root re- lease is modulated by the visible solar radiation via photosintesis, while rates of decomposition depend exponentially on soil temperature. Soil tempera- ture depends mainly on solar infrared and visible radiation in the case that the cave is covered only by grass or upon temperature in the case that the cave is covered by forest or bush (Shopov et al. 1994). In the first case the zonality of luminescence can be used as a proxy of solar insolation (Shopov & Dermendjiev 1990) and in the second case it can be used as a paleotemperature proxy. The luminescent index has high resolution as in the case when the step of a record is less than one month the signal contains mainly climatic modula- tion. But in the case of the step bigger than one year, the climatic modulation of signal is in the range of the experimental error. And the luminescent record turns to proxy of solar insolation.