María Cruz Zuluaga

MICROTEXTURES AND THE ORIGIN OF MUSCOVITE-KAOLINITE INTERGROWTHS IN SANDSTONES OF THE UTRILLAS FORMATION, BASQUE CANTABRIAN BASIN, SPAIN

Muscovite-kaolinite intergrowths found in Albian sandstones of the Basque Cantabrian basin (northern Spain) were studied by optical, scanning and electron microscopy and electron microprobe analysis. Kaolinitization begins at grain edges, forming the characteristic fanned-out textures, and propagates toward the interior along the cleavages of muscovite. Kaolinite and muscovite occur as thick packets, being free of interlayering. Phase boundaries between both minerals show bidimensional crystallographic continuity, and no intermediate phases have been identified. The data obtained suggest that muscovite only supplied a template suitable for the epitactic crystallization of kaolinite, while Al was available in sufficient amounts due to the dissolution of detrital K-feldspar. Very small packets of magnetite or maghemite showing a coherent orientation with the kaolinite crystals have been recognized, and could be responsible for the small Fe contents usually detected in electron microprobe analyses of kaolinite.Textural relationships between authigenic kaolinite and deformation microstructures in the intergrowths, combined with previous information about burial conditions, show that alteration proceeded during a late stage of the diagenetic history, related to the uplift of the studied materials as a result of the Alpine orogeny.

Combining Small-Vertebrate, Marine and Stable-Isotope Data to Reconstruct Past Environments

Three very different records are combined here to reconstruct the evolution of environments in the Cantabrian Region during the Upper Pleistocene, covering ~35.000 years. Two of these records come from Antoliñako Koba (Bizkaia, Spain), an exceptional prehistoric deposit comprising 9 chrono-cultural units (Aurignacian to Epipaleolithic). The palaeoecological signal of small-vertebrate communities and red deer stable-isotope data (δ13C and δ15N) from this mainland site are contrasted to marine microfaunal evidence (planktonic and benthic foraminifers, ostracods and δ18O data) gathered at the southern Bay of Biscay. Many radiocarbon dates for the Antoliña’s sequence, made it possible to compare the different proxies among them and with other well-known North-Atlantic records. Cooling and warming events regionally recorded, mostly coincide with the climatic evolution of the Upper Pleistocene in the north hemisphere.

Isotope analyses to explore diet and mobility in a medieval Muslim population at Tauste (NE Spain)

The Islamic necropolis discovered in Tauste (Zaragoza, Spain) is the only evidence that a large Muslim community lived in the area between the 8th and 10th centuries. A multi-isotope approach has been used to investigate the mobility and diet of this medieval Muslim population living in a shifting frontier region. Thirty-one individuals were analyzed to determine δ15N, δ13C, δ18O and 87Sr/86Sr composition. A combination of strontium and oxygen isotope analysis indicated that most individuals were of local origin although three females and two males were non-local. The non-local males would be from a warmer zone whereas two of the females would be from a more mountainous geographical region and the third from a geologically-different area. The extremely high δ15N baseline at Tauste was due to bedrock composition (gypsum and salt). High individual δ15N values were related to the manuring effect and consumption of fish. Adult males were the most privileged members of society in the medieval Muslim world and, as isotope data reflected, consumed more animal proteins than females and young males.

Isotopic evidence for the reconstruction of diet and mobility during village formation in the Early Middle Ages: Las Gobas (Burgos, northern Spain)

Strontium, carbon, and nitrogen isotopes of human bone and tooth remains have been used to reconstruct residential mobility and diet of early medieval populations at Las Gobas from the sixth to eleventh centuries. Most non-local individuals correspond to the tenth to eleventh centuries and were mostly women and infants. This residential mobility coincided with the formation of Laño village and the abandonment of artificial cave settlement. Carbon and nitrogen isotope ratios of bone collagen indicate an omnivorous homogenous diet based on terrestrial plant resources, with few animal-derived proteins from livestock. Millet consumption was restricted to an earlier period of time (seventh to ninth centuries); and in later periods (tenth to eleventh centuries), mainly C3 plants such as wheat and barley were consumed. In general, there were no dietary differences between individuals according to sex or age. Sex-related dietary differences have only been observed in the tenth to eleventh centuries, when females consumed a more vegetarian diet and less animal protein. The higher δ15N values in infants reflect the weaning effect, while the differences in δ15N values between young adult men and young adult women can be explained as a physiological factor related to pregnancy or different origins. In a comparison with contemporaneous medieval populations in the northern Iberian Peninsula, both δ13C and δ15N values suggest similar foodstuff resources and diet among Christian and Muslim populations.

KIPUTZ IX: UN CONJUNTO SINGULAR DE CIERVO ROJO (CERVUS ELAPHUS LINNAEUS, 1758) DEL PLEISTOCENO SUPERIOR DE LA PENÍNSULA IBÉRICA

Abstract. KIPUTZ IX: A UNIQUE ENSAMBLE OF RED DEER (CERVUS ELAPHUS LINNAEUS, 1738) FROM THE UPPER PLEISTOCENE OF THE IBERIAN PENINSULA. Kiputz IX is an upper Pleistocene site that has provided the richest set of Cervus elaphus complete remains in the Iberian Peninsula. This paper provides a metric and isotopic study of the postcranial skeleton of the 43 individuals that conform this tafocenosis. The robustness of the distal metacarpus evidences the existence of a clear sexual dimorphism and a small predominance of females respect to males. The stage of dental substitution makes evident that the sample is dominated by sub-adult and juvenile specimens, with a low proportion of juvenile and adult individuals. Application of a variability size index on a group of samples from the middle and upper Paleolithic in the Cantabrian Region do not allow establishing any osteometric relation with geographic and chronological factors. Variations in &dgr;13C values among red deer and reindeer are related to the specialized consumption of different plant types. However, the gradual decline in red deer &dgr;13C values over time may reflect the so-called ‘canopy effect’ impacting the floristic composition. Variations in the &dgr;13C and &dgr;15N values, studied together in red deer show that when climatic conditions were more temperate, humidity was higher in this environment than in de northern Pyrenees. The red deer sample from Kiputz IX constitutes a good basis for comparative studies of red deer populations from the Middle and Upper Pleistocene of Europe.