Juan Ramón Vidal Romaní

A population study on the cave bear (Ursus spelaeus Ros.-Hein.)) from Cova Eirós (Triacastela, Galicia, Spain)

Abstract The Cova Eiros site is at present the most western euroasiatic limit of the distribution of this species. To date, close to 4,000 bones, mainly Ursus spelaeus,, have been found. Absolute dating (U/Th) carried out on the stalagmaitic flows below the fertile levels give an age between 117,000 and 28,000 years BP 14CC, whilst dating of a bone has given an age of 24,090 years BP. The taphonomic study discounts the existence of post mortem selective processes in the formation of the deposit. The population study indicates occupation of the site by bears of both sexes, being used during hibernation by both adult males and adult females, pregnant and/or with cubs. Distribution by age of the population has been possible by carrying out a study on the wear stages of the cheek teeth. The distribution by age shows a low mortality rate for adult bears (7%) whilst the mortality rate for neonates and yearlings was high (73%). The disappearence of this population can therefore be attributed to the aforementioned high mortality rate aswell as the isolation of the population during the development of glaciers during the last glacial period.

Paleogenomic Evidence for Multi-generational Mixing between Neolithic Farmers and Mesolithic Hunter-Gatherers in the Lower Danube Basin

Summary The transition from hunting and gathering to farming involved profound cultural and technological changes. In Western and Central Europe, these changes occurred rapidly and synchronously after the arrival of early farmers of Anatolian origin [1, 2, 3], who largely replaced the local Mesolithic hunter-gatherers [1, 4, 5, 6]. Further east, in the Baltic region, the transition was gradual, with little or no genetic input from incoming farmers [7]. Here we use ancient DNA to investigate the relationship between hunter-gatherers and farmers in the Lower Danube basin, a geographically intermediate area that is characterized by a rapid Neolithic transition but also by the presence of archaeological evidence that points to cultural exchange, and thus possible admixture, between hunter-gatherers and farmers. We recovered four human paleogenomes (1.1× to 4.1× coverage) from Romania spanning a time transect between 8.8 thousand years ago (kya) and 5.4 kya and supplemented them with two Mesolithic genomes (1.7× and 5.3×) from Spain to provide further context on the genetic background of Mesolithic Europe. Our results show major Western hunter-gatherer (WHG) ancestry in a Romanian Eneolithic sample with a minor, but sizeable, contribution from Anatolian farmers, suggesting multiple admixture events between hunter-gatherers and farmers. Dietary stable-isotope analysis of this sample suggests a mixed terrestrial/aquatic diet. Our results provide support for complex interactions among hunter-gatherers and farmers in the Danube basin, demonstrating that in some regions, demic and cultural diffusion were not mutually exclusive, but merely the ends of a continuum for the process of Neolithization.

Luminescence Dating of Pseudokarst Speleothems: A First Approach

ABSTRACT Water trickling through the discontinuities of granitic massifs causes slow rock weathering, resulting in mineral deposits within rock fissures (speleothems). Geochemical studies have shown different types regarding the mineral composition: evansite, opal-A, and Al-bearing organic compounds. They grow by accretion of concentric layers, and they are a suitable microenvironment for the settlement of organisms, spores, and pollen grains, which could be used as paleoclimatic records if the speleothems were dated. Among speleothem types, opal-A and evansite usually contain quartz- and feldspar-rich detrital grains. Thus, Optically Stimulated Luminescence (OSL) could be used to date them if detrital grains were sufficiently exposed to daylight (bleaching) before burial within the speleothems. The OSL of such grains was investigated to estimate ages of samples from Northwest Spain. Post-IR OSL (Post-Infrared Optically Stimulated Luminescence) has been used on coarse grains due to the high feldspar content. Results are indicative of complete bleaching of residual geological signals and ages between 0.5 and 3 ka BP.

Autochthonous and Allochthonous Micro and Nanoparticles in Deteriorated Lime Mortars of Historical Buildings

Lime mortars have been commonly used in historical buildings since ancient times. The progressive deterioration of these mortars by air pollution and other environmental causes hinders the assessment of the original composition. The weakening of the mortar structure is due to dissolution and formation of calcium sulphate layers because of the interaction with SOx gaseous pollutants. Also, pollution particles can be incorporated to the mortar because of dissolution by rainwater or runoff. Scanning Electron Microscopy (SEM) studies allow us to distinguish allochthonous and autochthonous micro- and nanoparticles in order to identify original intact plasters. By comparing these intact to deteriorated mortars from both air polluted and non-polluted areas it is possible to indentify and preserve the original mortar composition as a key step to project future façade cleaning and restorations.