Papers by giacomo oggiano
Nell’ambito dei programmi di valorizzazione dei Beni Culturali, entro le priorità di recupero e m... more Nell’ambito dei programmi di valorizzazione dei Beni Culturali, entro le priorità di recupero e manutenzione del Patrimonio conosciuto, il Comune di Oschiri, in collaborazione con la Soprintendenza per i Beni Archeologici delle province di Sassari e Nuoro, ha realizzato un progetto per l’intervento di conservazione e restauro su una parte della struttura di fortificazione di un Castrum bizantino, ancora in fase di indagine e di studio
Journal of Metamorphic Geology
Journal of Maps, 2015
This paper presents the geological, structural and metallogenic map of the Arbus Pluton, a late V... more This paper presents the geological, structural and metallogenic map of the Arbus Pluton, a late Variscan composite intrusion belonging to the Corsica-Sardinia Batholith. The pluton is surrounded and crosscut by a wide variety of vein ore deposits. The Arbus Pluton was emplaced at shallow crustal levels at the end of the Variscan Orogeny, along an E-W trending shear zone located in the low-grade external nappe pile of the Sardinian basement. The architecture of the pluton is roughly concentric with a core of cordierite-bearing leucogranites and an outer shell composed of pyroxene-bearing and hornblende granodiorites. New U/Pb dating on zircons of granodiorite yields an emplacement age of 303.7 ± 1.1 which improves previous Rb/Sr and Ar/Ar dating. The map has been compiled on the basis of new geological/structural surveys and petrographical studies coupled with in situ gamma ray spectrometry. All the data-sets have been processed using a geographical information system.
Geological Field Trips, 2012
Editor in Chief Secondo giorno-Successione meso-cenozoica e zona a falde del basamento varisico d... more Editor in Chief Secondo giorno-Successione meso-cenozoica e zona a falde del basamento varisico della Sardegna sud-orientale Sguardo geologico d'insieme ..
Nell’ambito dei programmi di valorizzazione dei Beni Culturali, entro le priorita di recupero e m... more Nell’ambito dei programmi di valorizzazione dei Beni Culturali, entro le priorita di recupero e manutenzione del Patrimonio conosciuto, il Comune di Oschiri, in collaborazione con la Soprintendenza per i Beni Archeologici delle province di Sassari e Nuoro, ha realizzato un progetto per l’intervento di conservazione e restauro su una parte della struttura di fortificazione di un Castrum bizantino, ancora in fase di indagine e di studio.
This volume summarizes the state of the art of Variscan geology from Iberia to the Bohemian Massi... more This volume summarizes the state of the art of Variscan geology from Iberia to the Bohemian Massif. The European Variscan belt consists of two orogens: the older, northern and the younger, southern. The northern Variscan realm was dominated by Late Devonian–Carboniferous rifting, subduction and collisional events as defined by sedimentary records, crustal growth, recycling of continental crust and large-scale deformations. In contrast, the southern European crust was reworked by major Late Carboniferous collision followed by Permian wrenching. The Late Carboniferous–Permian orogeny overprinted the previously accreted system in the north, but with much lower intensity, resulting in magmatic recycling and extensional tectonics. These two main orogenic cycles do not reflect episodic evolution of a single orogenic system but a complete change in orientation of stress field, thermal regime, degree of reworking and recycling of European crust, reflecting a major switch in plate configurat...
Seismological Research Letters, 2020
The recent discovery of gravitational waves (GWs) and their potential for cosmic observations pro... more The recent discovery of gravitational waves (GWs) and their potential for cosmic observations prompted the design of the future third-generation GW interferometers, able to extend the observation distance for sources up to the frontier of the Universe. In particular, the European detector Einstein Telescope (ET) has been proposed to reach peak strain sensitivities of about 3×10−25 Hz−1/2 in the 100 Hz frequency region and to extend the detection band down to 1 Hz. In the bandwidth [1,10] Hz, the seismic ambient noise is expected to represent the major perturbation to interferometric measurements, and the site that will host the future detectors must fulfill stringent requirements on seismic disturbances. In this article, we conduct a seismological study at the Italian ET candidate site, the dismissed mine of Sos Enattos in Sardinia. In the range between few mHz to hundreds of mHz, out of the detection bandwidth for ET, the seismic noise is compatible with the new low-noise model (P...
Bulletin of Engineering Geology and the Environment, 2018
Textural, physical-mechanical, and mineralogical-chemical properties influence the degradation of... more Textural, physical-mechanical, and mineralogical-chemical properties influence the degradation of building stone. These properties also control the efficacy of different preventative treatments to inhibit degradation. In this study, several historic buildings in northern Sardinia, Italy, constructed with a wide variety of building stones were examined in order to contrast degradation effects with and without frontal polymerization. Different types of degradation were observed in carbonate and volcanic lithologies, which compromise their durability and toughness. Among the different lithotypes tested, four revealed a good response to the polymerization treatment. Textural and physical-mechanical evidences show that open porosity and capillary absorption control the suitability of this treatment. Laboratory tests on both untreated and treated specimens revealed a strong reduction of parameters directly related to decay (e.g., open porosity and water absorption), as well as an improvement on crush strength. Moreover, the polymerization treatment retains a residual porosity sufficient to enable the rock to equilibrate with the ambient environmental humidity.
Journal of Iberian Geology, 2018
The Variscan Palaeozoic successions exposed in Sardinia show clear evidences of tectonic instabil... more The Variscan Palaeozoic successions exposed in Sardinia show clear evidences of tectonic instability during Ordovician times. In the Foreland zone (SW Sardinia), the Cambrian to lower Ordovician strata are folded giving way to an angular unconformity sealed by a Middle-Upper Ordovician syn-tectonic succession, characterized at the base by a thick conglomeratic deposit. This is indicative of a tectonic-driven uplift, followed by intensive erosion. A time-equivalent angular unconformity, sealed by Middle Ordovician volcano-sedimentary complexes, is also recorded in the External nappe zone (central-southern Sardinia). These volcanic products became rare toward NE and approaching the Inner zone, where few remnants of Ordovician magmatic rocks consist of the protoliths of small bodies of calc-alkaline orthogneisses and metabasites. Paleogeographic reconstructions generally assume that Sardinia formed a coherent crustal block since the late Cambrian; therefore, the SW-NE trend of magmatic and sedimentary features observed in the Ordovician successions has been interpreted as sequential snapshots captured along an Ordovician volcanic arc. Stratigraphic and paleontological data, sediment provenance and petro-chronology of magmatic products indicate that the Ordovician successions could have belonged to different, and possibly far paleogeographic domains. These data suggest that the actual zonation of the Palaeozoic basement of Sardinia is a puzzle resulting from extensive crustal reworking and amalgamation in Variscan times. Hence it cannot be directly referred to an Ordovician paleogeography. Keywords Gondwana • Palaeozoic paleogeography • Geodynamic models • Qaidam ocean • Rheic ocean • Sardic phase Resumen La serie Varisca expuesta en Sardinia muestra claras evidencias de instabilidad tectonica durante el Ordovícico. En el antepaís (SW Cerdeña), las capas del Cambrico y Ordovícico estan deformadas y producen una discordancia angular sellada por una serie sin-tectónica del Ordovícico Medio-Superior que se caracteriza por una potente capa de conglomerados a su base. Esto indica un levantamiento tectonico seguido por intensa erosión. Otra discordancia angular de la misma edad que está sellada por una serie volcano-sedimentaria del Ordovícico Medio se encuentra en la zona de los cabalgamientos externos (la parte central y sur de Sardinia). Estos productos volcanicos son menos frequentes en las zonas mas internas hacia el NE donde los pocos restos magmaticos del Ordovícico estan representados por los protolitos de pequeños cuerpos de orthogneiss calc-alkalino y de metabasitas. Las reconstrucciones paleogeográfico normalmente asumen que Sardinia constituía un bloque de corteza coherente desde el Cámbrico superior, por lo tanto, el trend de cuerpos magmaticos y sedimentarios que se observan dentro del la serie del Ordovícico desde el SW hacia el NE se ha interpretado como una secuencia de instantaneas tomadas a lo largo de un arco volcanico Ordovícico. Los datos sedimentarios y paleontológico, la origen de los sedimentos y la cronología petrologica de los productos magmaticos indican que la serie del Ordovícico puede haber pertenecido a dominios paleontológico distintos y posiblemente lejanos. Estos datos sugieren que la Zonación del basamiento Paleozoico en Cerdeña es un puzzle que resulta de una amalgamación y reelaboración extensiva durante el Varisco y que por lo tanto no puede directamente relacionarse con una paleontológico del Ordovícico. Palabras clave Gondwana • paleogeografía del Palaeozoico • modelos geodinámicos • océano de Qaidam • oceano Reico • fase Sarda Extended author information available on the last page of the article
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Papers by giacomo oggiano