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[1] Previous studies have demonstrated the potential for the Li content of coral aragonite to record information about environmental conditions, but no detailed study of tropical corals exists. Here we present the Li and Mg to Ca ratios at a bimonthly to monthly resolution over 25 years in two modern Porites corals, the genus most often used for paleoclimate reconstructions in the tropical Indo-Pacific. A strong relationship exists between coral Li/Ca and locally measured SST, indicating that coral Li/Ca can be used to reconstruct tropical SST variations. However, Li/Ca ratios of the skeleton deposited during 1979-1980 do not track local SST well and are anomalously high in places. The Mg/Ca ratios of this interval are also anomalously high, and we suggest Li/Ca can be used to reconstruct tropical SST only when Mg/Ca data are used to carefully screen for relatively rare biological effects. Mg/Li or Li/Mg ratios provide little advantage over Li/Ca ratios, except that the slope of the Li/Mg temperature relationship is more similar between the two corals. The Mg/Li temperature relationship for the coral that experienced a large temperature range is similar to that found for cold water corals and aragonitic benthic foraminifera in previous studies. The comparison with data from other biogenic aragonites suggests the relationship between Li/Mg and water temperature can be described by a single exponential relationship. Despite this hint at an overarching control, it is clear that biological processes strongly influence coral Li/Ca, and more calibration work is required before widely applying the proxy.
(Table 2) Original depths, offsets, composite depths and core overlaps for cores at DSDP Site 86-577
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La presente tesis doctoral, El brazo mayor de la catedral de Cuenca. Configuración original y alteraciones posteriores, pretende verificar tres hipótesis y alcanzar otros tantos objetivos principales, los cuales se presentan en este primer capítulo, que también incluye una justificación de la elección del tema de investigación. La catedral de Cuenca es, posiblemente, la más antigua de las grandes iglesias propiamente góticas de Castilla1 y, sin duda, una pieza clave en la expansión del opus francigenum en aquel reino2. Sin embargo, a un edificio de tal relevancia sólo se le ha dedicado una monografía de carácter científico centrada en aspectos documentales y estilísticos3. En el resto de la bibliografía especializada sólo encontramos apurados análisis insertos en los repertorios clásicos de arquitectura gótica, breves artículos que describen las tareas de conservación, o bien estudios carentes de metodología definida, la mayoría con una voluntad estrictamente divulgativa.
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Estrenado en el Teatro de la Princesa el 6 de abril de 1878
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Port. con grab. xil
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Sign.: A<16>
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Huella de sello de placa (30 x 30 mm.) recortado en las dos hojas