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UDC 551. 435.4:551.435.8(460.13) Rosa Blanca González-Gutiérrez, Javier Santos-González, Amelia Gómez-Villar, Eduardo Alonso-Herrero, Alipio García-de Celis, Martín Cano & José María Redondo-Vega: Glaciokarst landforms in the Siera de los Grajos, Babia and Luna natural park (Cantabrian Mountains, NW Spain) Landforms resulting from the interaction between paleo-glaciers and karst are studied by using the Sierra de los Grajos (Cantabrian Mountains) as a model. This area contains glacial landforms that have not interested geomorphologists due to their low altitude (Peña Castillo is about 1857 m a.s.l.), the absence of glacial cirques and the scarcity of large moraines. However, the prevalence of groundwater flow and chemical dissolution has favoured the preservation of glacial landforms. Lateral and frontal moraines show three main glacial stages and other minor glacier stabilization phases, with the paleo-ELA oscillating between 1650 and 1760 m. Moraines are combined with depressions and sinks resulting from subglacial karstic drainage. This convergence of forms and processes is an exception in the Cantabrian Mountains, where postglacial erosion has usually eroded the frontal moraines and the proglacial sediments. In the case of the Sierra de los Grajos, despite the underground drainage and preservation of many glacial deposits on karstic landforms, an outwash-plain was formed. These proglacial sediments and others from non-karstified areas filled the depressions of the preglacial terrain located at their edges. The main glaciokarstic landforms have been mapped and a sedimentological analysis of the outwash plain was made in order to reconstruct the glacial dynamics of this area. Key words: glaciokarst landforms, glacial geomorphology, karst geomorphology, geomorphological mapping, Cantabrian Mountains. IzvlečekUDK 551.435.4:551.435.8(460.13) Rosa Blanca González-Gutiérrez, Javier Santos-González, Amelia Gómez-Villar, Eduardo Alonso-Herrero, Alipio García-de Celis, Martín Cano & José María Redondo-Vega: Glaciokraški relief na območju Sierra de los Grajos v parku Babia in luna (Kantabrijsko gorovje, SZ Španija) Na območju Sierra de los Grajos (Kantabrijsko gorovje) smo raziskovali relief, ki je v preteklosti nastal z medsebojnim vplivanjem kraških in ledeniških procesov. Zaradi nizke nadmorske višine (Peña Castillo je le 1857 m nad morjem) ter odsotnosti velikih moren in krnic to območje geomorfologov do sedaj ni posebej zanimalo. Prav kraški procesi in z njimi povezano podzemno odtekanje so tu omogočili ohranitev ledeniških oblik. Bočne in čelne morene kažejo na tri glavne faze poledenitev in več manjših faz stabilizacije ledenikov z ravnovesno mejo (ELA) med 1650 in 1760 m.n.m. Morene so pogosto vezane na kraške globeli. Glaciokraške pojave najdemo le na tem območju Kantabrijskega gorovja, kjer je sicer poledeniška erozija odstranila čelne morene in proglacialne sedimente. Kljub podzemnemu odtoku in ohranitvi številnih ledeniških sedimentov na kraškem reliefu se je na Sierra de los Grajos oblikoval predle...

Abstract:The so-called "Mucientes chert" is a variety that appears in the central area of the Iberian North Plateau, in the Duero Basin. It is widely known in the geological and archaeological literature and its use for knapping was especially important in Prehistory. From a macroscopic point of view it is a nodular chert, with white and very porous cortex, and brown to blackish or beige colour in the inner part.In this work we carried out a more accurate petrographic, mineralogical and chemical characterization of this lithology using SEM, XRD and XRF techniques in samples coming from "Las Canteras" (Mucientes village), a chert outcrop of the "Cuestas" Unit (Vallesian-Aragonian, Miocene Age). Also, we have made a review of its geological occurrence and archaeological distribution areas. It is intended to sketch the delimitation of the geographical area of occurrence taking into account the geological and archaeological references.

Abstract:A study of the chert nodules found in the Escalada Formation (Carboniferous, Ponga region, Cantabrian Zone) was carried out as a means to characterise a number of lithic raw materials found in several prehistoric sites of the Cantabrian Mountains (NW Spain). This study comprises fieldwork aimed at locating the outcrops and obtaining samples. Some selected samples from two localities were used for both petrological (macroscopic and microscopic analyses from thin sections) and geochemical (X-ray fluorescence and powder diffraction) analysis. The macroscopic study shows a rather homogeneus coloration and a conchoidal fracture although two extreme types of cherts with a variety of intermediate forms can be differentiated according to the matrix composition. The microscopic analysis shows a high heterogeneity in carbonate versus silica percentage and gentle differences in some other features such as type of silica, origin of carbonates, occurrence of organic matter and type of skeletal components. The results of several geochemical analysis suggest that there are not geochemical features neither in the major elements nor in the traces that allows us to clearly distinguish between the analysed samples. All these studies allow us to define the main features of these chert nodules and to establish several types and varieties among them. Those varieties with high percentage of silica and with a more homogeneous matrix are the most suitable samples for knapping. These results together with the study of the geological and geographical location of archaeological sites suggest that the nodules from the Escalada Formation likely were lithic material supply sources used in knapping activities When aiming to demonstrate the use of these materials at archaeological sites the sole macroscopic analysis of the pieces does not suffice; further analyses, such as those involving thin sections, are necessary. The absence of chert from Escalada Formation in some Mesolithic sites in the area was confirmed via these additional analyses.

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