J. L. 2010. Identification of arid phases during the last 50 cal. ka BP from the Fuentillejo maar-lacustrine record (Campo de Calatrava Volcanic Field, Spain).ABSTRACT: Geochemical (element analysis, molecular analysis of organic compounds), physical, palynological, mineralogical and sedimentary facies analysis were performed to characterise the sedimentary record in Fuentillejo maar-lake in the Central Spanish Volcanic Field of Campo de Calatrava, in order to reconstruct the palaeoenvironmental and palaeoclimatic processes which controlled vegetation patterns and deposition of different sedimentary facies. The upper 20 m of core FUENT-1 show variations in clastic input, water chemistry, vegetation and organic fraction sources in the lake throughout the Late Pleistocene and Holocene. The temporal framework provided by 14 C accelerator mass spectrometry dating allows assigning the sequence to the last 50 cal. ka BP. Arid phases identified in the FUENT-1 sequence are correlated to Heinrich events (HE) and to stadials of the Dansgaard/Oeschger (D/O) cycles. Siliciclastic facies with high magnetic susceptibility values, high Juniperus pollen content, a low Paq index (aquatic macrophysics proxy index), a decrease in the relative percentage of the n-C 27 and an increase in the n-C 31 alkanes are indicative of arid and colder climatic events related to HE 2, HE 1 and the Younger Dryas (YD). Similar short cold and arid phases during the Holocene were identified at 9.2-8.6, 7.5-7 and 5.5-5 cal. ka BP. In dolomite-mud facies, the pollen data show an increase in the herbs component, mainly -Chenopodiaceae, Artemisia and Ephedra -steppe taxa; a low Paq index, a decrease in the relative percentage of the n-C 27 alkane and an increase in the n-C 31 alkane are also observed. This facies was probably the result of lower lake levels and more saline-alkaline conditions, which can be interpreted as linked to arid-warm periods. These warm and arid phases were more frequent during Marine Isotope Stage (MIS) 3 and the interstadials of MIS 2. HE 4, HE 2, HE 1 and the YD in core FUENT-1 were immediately followed by increases of warm steppe pollen assemblages that document rapid warming similar to the D/O cycles but do not imply increasing humidity in the area. Fuentillejo hydrology is controlled by changes in the atmospheric and oceanic systems that operated on the North Atlantic region at millennial scale during the last 50 cal. ka BP.

Geoconservation in Spain dates back to the beginning of the twentieth century. During the first decades, the protection of biotic and geological heritage developed together, and geologists played an important role, but the conservation of geological values was overlooked during the second half of the twentieth century. As a general rule, the protection of geological heritage was limited to scenic elements of a great value in the landscape but did not pay attention to their scientific interest and representativeness or to geological exclusiveness criteria. On the other hand, the beginnings of the study of geological heritage in Spain date back to the 1970s. Although the methodological bases were defined at that time, the work done on research, promotion, and conservation of the geological heritage has been mainly developed in the last 15 years. The increasing presence of geological heritage in the Spanish scientific and social fields has been completed with Law 42/2007 on Natural Heritage and Biodiversity, which mentions the conservation of geodiversity and geological heritage as one of its sources of inspiration. This Law replaces the Law 4/1989 on the Conservation of Wild Flora and Fauna that was the main legal framework for nature conservation in Spain during three decades. The purpose of this paper is to analyzefrom a historical perspective-the evolution of the study and protection of the geological heritage in Spain since the beginning of the twentieth century, both referring to the legal framework and the studies required. Finally, an estimate is presented of challenges to be faced by geoconservation in Spain in the next decades.

Abstract-This paper deals with a model adjustment for the estimation of age by means of amino acid racemization analysis. Two model families were obtained on the basis of the different genera of mol luscs analysed, and were applied to a palaeontological site located in the Cullar-Baza basin: "Venta Micena" (Orce, Granada). The analytical results obtained from the study of fossil gastropods have pro vided a very coherent average dating of 983 ± 58 Ky, this coinciding to a large extent with the most widespread palaeontological, geological and stratigraphical datings for the site. There is, however, no agreement with certain recent theories that situate Venta Micena chronologically at the PliocenePleistocene boundary (ca.

a b s t r a c t a r t i c l e i n f oIn the Campo de Calatrava Volcanic Field (CCVF, Central Spain), the eruption of Pliocene-Pleistocene maar craters into two clearly distinct types of pre-volcanic rocks allows the observation and comparison of hardsubstrate and soft-substrate maar lakes. Hard-substrate maars formed when phreatomagmatic processes affected the jointed, Paleozoic igneous and metamorphic rocks (hard substrate), giving rise to funnel-like maar lake basins. Soft-substrate maars resulted from phreatomagmatic volcanic processes affecting poorlyconsolidated Pliocene sediments, forming bowl-like maar lake basins. Pre-volcanic bedrock determined the post-eruptive lacustrine architecture in the craters and favored a higher preservation of hard-substrate maars in comparison to soft-substrate maars. This is because the hard-substrate maars, surrounded by a deep stable crater wall, are more capable of collecting sediments in their basins. These sediments could be preserved for longer than similar deposits in broad, shallow maars with a soft substrate. Ancient soft-substrate maars do not usually preserve their original morphology well and can be identified only by their lacustrine deposits. Carbonate lacustrine/palustrine deposits surrounding a bowl-like depression are the remnants of this second type of maar lake, and allow reconstruction of the original morphology of ancient soft-substrate maar craters. Geophysical (electrical tomography ground surveys) and geomorphologic-geologic mapping techniques were combined with fieldwork and facies analysis in order to locate and accurately characterize the PliocenePleistocene soft-substrate maar volcanic structures of the CCVF.

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