Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

450 PATA Days 2024 Ancient neolithic earthquakes The Neolithic records are located around drainage- divide of the Central Betic Cordillera between the Granada andMálaga provinces (South Spain). These ancient records are related to speleoseismological anomalies such as roof collapses, orientedfalls, tiltingreorientations andanomalous growths of stalagmites and stalagmites, normally indicative of underground seismic actions (Becker et al., 2006). These are found in three main cave systems separated by a lineal distance of c. 50-70 km in an area of 145 km2: El Aguadero, Las Tres Vasijas y El Toro. In the last two caves, karstic collapses sealed their original entrances, triggering their abandonment by the first Neolithic settlers. The pottery, bones and other artifacts preserved in these caves that date their eventual depopulation and causative earthquakes to around 5,000 BP (Martín Socas et al., 2014; Bradley & García Sanjuan; 2017). El Aguadero sinkhole record a wide variety of speleoseismological anomalies including the rotation of the entire cave for about 10º and reoriented overgrowths of stalagmites. 14C ages indicate that these anomalies date for 5110 ± 70 cal yr BP (Bradley & García Sanjuan, 2017). This Cave also record important karstic failures triggered by the 1884 ADArenas del Rey Earthquake (17 km away), the strongest historical earthquake occurred in the Iberian Peninsula with Intensity IX-X (MSK/ESI07) and estimatedmagnitude 6.7 – 6.9Mw (Silva et al., 2019). Data compiled in the Spanish EEE Catalogue (Silva et al., 2019) indicate that the Ventas de Zafarraya Fault was the responsible for both the 1884 AD and the Neolithic events (Fig. 1). All the caves are located within gigantic Jurassic olistoliths (< 500m3) floating in the Basal Triassic evaporites of the Betics (Keuper), consequently increasing their susceptibility to record earthquake underground effects. Following the guidelines for classical macroseismic scales (e.g. MSK, MCS) moderate intensity levels ≥ VIII (Becker et al., 2006). Pre-roman earthquakes (< 2nd Century BCE) There are only three antique events occurred before the onset of the Roman Period in the Iberian Peninsula (Late 3th century BCE). The older one is the already mentioned Late Bronze Age event affecting to “La Tira del Lienzo site” (Totana, Murcia) and linked to a strike- slip surface faulting event in the Lorca-Alhama de Murcia fault zone, responsible for important historical and instrumental events ≥ 5.0 Mw (Silva et al., 2015). Masonry walls at this site are left-laterally displaced several centimetres along the fault recording the occurrence of a surface faulting event >6.5 Mw soon after the year 1550 BCE (Ferrater et al., 2015). The following earthquake is a late 8th Century BCE event, affecting to the ancient Phoenician coastal site of “Cabezo Pequeño del Estaño” placed near Guardamar del Segura in Alicante (Silva & Prados, 2024). This site was also settled onto a fault zone, the Lower Segura Fault a major reverse blind-fault of the Eastern Betic Cordillera responsible for several strong historical events (VIII-IX MSK/ESI07) as is the case of the 1829 AD Torrevieja event with a magnitude estimated in 6.6 Mw (Silva et al, 2019). These two ancient events in Murcia and Alicante, affected to poorly founded dry- masonry constructions, built in relatively hard surfaces (thick Pleistocene calcretes). This fact favoured deformation in the fabric of the built structures, causing displacements, titling and oriented collapses of house and city walls. In both cases, oriented damage is congruent with fault kinematics and/or theoretical ground motion caused by surface wave propagation (seismic shacking). The Phoenician site additionally display numerous signals of postseismic reparations (Wall buttress) archaeological and isotopically (14C) dated in the 720 BCE (Silva & Prados, 2024). The last earthquake of this group is the Lacus Ligustinus Earthquake-Tsunami event occurred around Fig. 2: Speleoseismological damage recorded in the Neolithic site of Las 3 Tinajas Cave (Alozaima, Málaga).