http://hdl.handle.net/10366/79682 Thu, 23 Apr 2026 01:56:13 GMT 2026-04-23T01:56:13Z http://hdl.handle.net/10366/79876 Many Renaissance and Baroque monuments of the city of Salamanca (“Mankind Heritage”) were built between the sixteenth and nineteenth centuries using vaugneritic stone. Recognition of the stone itself in monuments together with historic documentation led to two quarries to be proposed as the original sites of provenance. One of them might be located close to the village of La Magdalena, about 70 km south of the city of Salamanca, close to the locality of Barco de Ávila, in the Spanish Central System; the rocks from this quarry being Variscan coarse-grained diorites and quartzdiorites. The second quarry is located at Calzadilla del Campo, close to Ledesma, 34 km west of Salamanca. The rocks from this quarry include Variscan monzo-diorites and quartz-monzodiorites showing a conspicuous vaugneritic texture consisting of large decussate biotite and amphibole crystals. For this latter quarry, an almost continuous production during a time-span of 300 years has been inferred, although the varying rhythms of production appear to have depended on historic, economic and social circumstances. An initial period of prosperity can be dated to the end of the sixteenth century and the beginning of the seventeenth century, while a second one seems to have developed during the second half of the eighteenth century as can be deduced not only from certain relevant monuments to be found in the city of Salamanca but also from many ancestral homes from the town of Ledesma made of vaugneritic stones. The weathering of the typical sandstone (“golden stone”) from Salamanca used close to the base of the monuments seems to have been an increasingly important problem in construction in medieval times. This problem was partially solved using Cainozoic microconglomerate and mainly by the use of vaugneritic stones and other plutonic rocks (granitoids), which also were used to definitively reinforce the Roman Bridge and the Cathedrals. The vaugnerite stone also provided an interesting chromatic effect on some Baroque monuments, such as that of la Clerecía, resulting in a good combination of black vaugneritic stones and white or golden Cainozoic sandstones. Finally, the presence of many shields, lintels and monolithic shafts made of vaugneritic stone underscores its versatility and a appropriateness for sculpture work. Technical tests applied to the stone of the monuments and to the stone from the quarries are currently in progress with a view to completing the necessary groundwork for future restorations.; Muchos monumentos renacentistas y barrocos de Salamanca fueron construidos con piedra vaugnerítica durante los siglos XVI al XIX. El reconocimiento de la piedra de dichos monumentos así como la documentación histórica permite proponer la localización de dos canteras originarias. Una de ellas, situada en La Magdalena, Sistema Central, muestra rocas de composición diorítica y cuarzodiorítica, mientras que la otra, situada al O de Salamanca, presenta rocas monzodioríticas y cuarzomondioríticas, y además, con textura vaugnerítica, consistente en grandes cristales entrecruzados de biotita y/o anfíbol. Esta última fue explotada durante unos 300 años con una intensidad variable según los momentos socio-económicos. El empleo de la vaugnerita en el basamento de los monumentos contribuyó a solucionar el problema de la alterabilidad de la “piedra dorada” de Salamanca (arenisca de Villamayor), y además, sirvió para reforzar definitivamente algunos monumentos, como el Puente Romano y las Catedrales. También significó una aportación estética interesante por su tonalidad oscura. Finalmente, su utilización en escudos y en numerosos fustes monolíticos demuestra una buena aptitud para ser esculpida. Su estudio tanto en los monumentos como en las canteras permite sentar unas bases de experimentación para actuaciones futuras de restauración. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/10366/79876 2007-01-01T00:00:00Z http://hdl.handle.net/10366/79875 It has been studied the stratigraphy, sedimentology and isotopical geochemistry of the Podolskian-Myachkovian interval in the Lois-Ciguera sector (Central Coal Basin, Cantabrian Zone), formed by Bachende limestones (late Kashirian-late Podolskian/Myachkovian), Dueñas sandstones, shales and limestones (Myachkovian) and Ciguera limestones (Myachkovian), that had been correlated with Lena Group. The main mineralized level of the Salamón gold deposit is near the boundary between the units of Bachende and Dueñas, and consists in black silicificated and laminated shales, that are sometimes brecciated. There have been realized 72 analyses of stable isotopes (13C and 18O), 68 in micrite and 4 in cements. The Podolskian-Myachkovian boundary could be reflected in the isotopical sign. This succession was deposited in a carbonate ramp, that was occasionally invaded by terrigenous materials which disabled, totally or partially, the production of carbonate, giving place to the development of a siliciclastic-mixed shelf. The main production of carbonate was focused in the mid- and outer-ramp and was controlled by calcareous algae buildups and mud mounds.; En este trabajo se estudia la estratigrafía, sedimentología y geoquímica isotópica del tránsito Podolskiense-Myachkoviense en el sector Lois- Ciguera (Cuenca Carbonífera Central, Zona Cantábrica), representado por las unidades de las Calizas de Bachende (Kashiriense sup.-Podolskiense sup./ Myachkoviense inf.), Areniscas, lutitas y calizas de Dueñas (Myachkoviense) y Calizas de Ciguera (Myachkoviense), atribuidas al Grupo Lena. El nivel mineralizado fundamental del yacimiento de oro de Salamón está localizado próximo al límite entre las unidades de Bachende y Dueñas, y consiste en unas lutitas negras silicificadas, laminadas, y en ocasiones brechificadas. Se han realizado 72 análisis de isótopos estables (13C y 18O), 68 en micrita y 4 en cementos, pudiendo estar el límite Podolskiense-Myachkoviense reflejado en la señal isotópica. Esta sucesión fue sedimentada en una rampa carbonatada, que ocasionalmente era invadida por materiales terrígenos que inhibían, total o parcialmente, la producción de carbonato, dando lugar al desarrollo de una plataforma terrígena-mixta. La principal producción de carbonato se centraba en las partes medias y distales de la rampa carbonatada, estando controlada por las construcciones de algas calcáreas y los montículos de fango o mud mounds. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/10366/79875 2007-01-01T00:00:00Z http://hdl.handle.net/10366/79874 The fossil turtles and crocodiles from the marine Early Oligocene of the Weisselster Basin are described and compared with related species of the same stratigraphical age. Additionally, an overview is given on the history of research, the palaeogeographic and stratigraphic situation as well as on the relationships of the species mentioned. Beside the known representatives of the Trionychidae, Testudinidae, Cheloniidae and Psephophorus, the turtles include also a new species of Allopleuron. The crocodile remains are poorly preserved and therefore only tentatively assigned to Diplocynodon sp.; Se describen tortugas del Oligoceno inferior marino de la cuenca de Weisselster, comparándolas con especies vivientes y relacionadas de la misma edad. Se presenta la historia de las investigaciones, paleogeografía y situación estratigráfica así como las relaciones paleontológicas con otras especies de Trionychidae, Testudinidae, Cheloniidae y Psephophorus. Se presenta una nueva especie de Allopleuron. Se conservan escasos restos de cocodrilos, determinados a priori como Diplocynodon sp. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/10366/79874 2007-01-01T00:00:00Z http://hdl.handle.net/10366/79873 From the South Island of New Zealand a new Eocene genus of a sea turtle "Maorichelys wiffeni" n. gen. n. sp., is erected. The holotype, a fragment of a humerus, is described and compared in its features to the known species of the same age.; Se describe como "Maorichelys wiffeni" n. gen. n. sp., una nueva tortuga marina, procedente del Eoceno de la Isla del Sur de Nueva Zelanda. El holotipo, consistente en un húmero, es descrito y comparado con los húmeros de las especies conocidas de la misma edad. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/10366/79873 2007-01-01T00:00:00Z http://hdl.handle.net/10366/79872 Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/10366/79872 2007-01-01T00:00:00Z http://hdl.handle.net/10366/79871 Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/10366/79871 2007-01-01T00:00:00Z