102,486 research outputs found
Buccione, R., Mameli, P., Mongelli, G., Oggiano, G. 2024. First row transition metals deportment in Cretaceous karst bauxite: the case of the southern Italy and Sardinia Island deposits. 37th International Geological Congress 2024, Busan (Korea).
No full textMongelli, G., Boni, M., Buccione, R., Mameli, P., Mondillo, N., Oggiano, G., Sinisi, R., 2016 Critical metals distribution in Tethyan karst bauxite: the Cretaceous Italian example. Rend. Online Soc. Geol. It., Suppl. n. 1 al Vol. 40. September Napoli, 7-9, 2016.
No full textNematoplana hamata Curini-Galletti & Oggiano & Casu 2002, sp. nov.
No full textNematoplana hamata sp. nov. (gures 5, 8C) Material examined HOLOTYPE: Australia, New South Wales, Byron Bay, town beach, lower intertidal in medium sand (July 1993), whole mount (lactophenol): G21826. Other material. One immature from the type locality studied karyologically (July 1993). Etymology Named after the characteristically hooked shape (lat: hamatus) of the stylet. Description The holotype is about 5 mm long, colourless, entirely ciliated. With two pigmented eye-spots located within the brain capsule. The short, collar-shaped pharynx is located in the posterior fth of the body. Male genital organs. Numerous testes arranged in two irregular rows between vitellaria in front of the pharynx. The copulatory organ consists of an ovoid muscular bulb (about 85 Mm high and 40 Mm wide), provided with a thick outer coating of circular and inner longitudinal musculature, connected basally to a single seminal vesicle. No sperm were seen within the vesicle. Distally, the bulb is provided with a copulatory stylet. The stylet is tubular, and about 110 Mm long. The proximal end is slightly swollen, with a markedly oblique opening. The tube has a constant width (about 9– 10 Mm) for all of its length. The distal fourth of the stylet is bent at nearly 45ss. The distal opening is about 9 Mm in diameter, and is provided with a slit about 20 Mm long. Female genital organs. With two rows of three isolated oocytes each, laterally in front of the pharynx. Vitellaria stretch from behind the brain at the level of the seminal vesicle. Female pore behind the male pore. Karyotype. With n 58. Plates were unsuitable for a karyometrical analysis. Discussion The very long, narrowly cylindrical, distally angled stylet of the new species is unique in the genus. Nematoplan a hamata shares with N. martensi and N. pullolineata the absence of an apophysis. The stylet of N. martensi is, however, straight, distally denticulate, and with a distal spike (see above); that of N. pullolineata is smaller (about 30 Mm), and diOEerently shaped (with a proportionally much smaller distal angled part, and a nearly straight ventral side) (cf. Tajika, 1979).Published as part of Curini-Galletti, M., Oggiano, G. & Casu, M., 2002, The genus Nematoplana Meixner, 1938 (Platyhelminthes: Unguiphora) in eastern Australia, pp. 1023-1046 in Journal of Natural History 36 (9) on pages 1036-1037, DOI: 10.1080/00222930110039585, http://zenodo.org/record/534082
The genus Nematoplana Meixner, 1938 (Platyhelminthes: Unguiphora) in eastern Australia
No full textCurini-Galletti, M., Oggiano, G., Casu, M. (2002): The genus Nematoplana Meixner, 1938 (Platyhelminthes: Unguiphora) in eastern Australia. Journal of Natural History 36 (9): 1023-1046, DOI: 10.1080/00222930110039585, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293011003958
Terranes in the variscan segment of Sardinia: a tentative approach. Annales geologiques des pays helleniques
No full textThe variscan basement and the post - collisional evolution. Late paleozoic continental basin of Sardinia
No full textPost-collisional late Variscan granites of southern Sardinia: evidences of contrasting suites
No full textThe Sardinia portion of the Sardinia-Corsica batholith emplaced mostly during the post collisional
evolution of the Variscan chain. The majority of plutons emplaced in about 40 Ma during two phases, the
older of which clustered at about 310 Ma, whereas the younger, clustered in the range of 290 Ma.The former is dominated by monzogranitic and granodioritic calc-alkaline plutons, while the latter mostly consists of leucogranites; minor mafic intrusions are more spread in northern Sardinia and preferentially associated to the latter phase. In southern Sardinia, in the frontal part of the orogenic wedge (nappe zone), the younger phase consists of two main rock-suites. The prevalent suite dissects porphyritic granodiorites, is dominated by syderophyllite monzogranites and leucogranites (SGS, syderophyllite granite suite) and, in turn, is crosscut with sharp vertical contacts by Fe-hastingsite granites (HGS, Fe-hastingsite granite suite). Both series are classified as ferroan, F-bearing granites, showing an alkali-calcic character; near liquidus temperatures indicate values in excess of 850°C. Siderophyllitic mica contains ilmenite inclusions and shows in the whole SGS a continuous trend in the Mg-Al plot. Conversely, in the HGS Fe-hastingsite amphibole occurs as early phase hosting magnetite and allanite inclusions.
Magnetic susceptivity data indicate that SGS shows values typical of an ilmenite series in the range 20 to
60.10-6 SI unit, whereas HGS plots on the ilmenite/magnetite series boundary with values in the range 1.7-
2.8.10-3 SI unit. Different trends displayed by variation diagrams confirm the contrasting behavior between the HGS leucogranites and the SGS monzogranites-leucogranites, the chemical variations of which can be
accounted for with crystal/liquid fractionation processes dominated by plagioclase + biotite ± minor amounts of accessory phases. Field occurrences and petrochemistry indicate a dominant crustal origin for both suites, according to εNd290 (–7.47) from Conte et al. (2015) and δ18OS.M.O.W. values (10.5±0.2 – 12.1±0.3) from Boni et al. (1992). A Proterozoic age of the involved crustal source may be inferred from the distribution of studied suites in the frontal part of the chain. Constraints on source materials are offered by chemical compositions of our rocks, which meet the liquids experimentally obtained by low degrees of partial melting of a meta-igneous source (Conrad et al., 1988). Mass balance calculations indicate for SGS a low degree of partial melting of about 25%. Conversely, the whole data set indicate a different path for the HGS, possibly due to inhomogeneities in the crustal source. The younger phase of magmatism marks the transition from late- to post-collisional Variscan events in southern Sardinia. Further questions arise from the thermal regimes, which triggered the partial melting, as far modelled by adiabatic decompression during the exhumation of the chain and shear heating (Casini et al.,
2015). Boni, M., Iannace, A., Köppel, V., Früh-Green, G., Hansmann, W. (1992): Late to post-hercynian hydrothermal activity and mineralization in south-west Sardinia (Italy). Econ. Geol., 87, 2113-2137.
Casini, L., Cuccuru, S., Puccini, A., Oggiano, G., Rossi, P. (2015): Evolution of the Corsica–Sardinia Batholith and lateorogenic shearing of the Variscides. Tectonophys., 646, 65-78.
Conrad, W.K., Nichols, I.A., Wall, V.J. (1988): Water saturated and undersaturated melting of metaluminous and peraluminous crustal compositions at 10 kbar: evidence for the origin of silicic magmas in the Taupo Volcanic Zone, New Zealand and other occurrences. J. Petrol., 29, 765-803. Conte, A.M., Cuccuru, S., Oggiano, G., Naitza, S., Secchi, F., Tecce, F. (2015): Cassiterite veins deposits related to latevariscan
ilmenite series in south western Sardinia (Italy): insights for a new tin province. Proc.13th SGA Meeting, 1,
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The geological map of Sardinia (Italy) at 1:250,000 scale
No full textOver the last 25 years the Italian national geological mapping program of the Italian Geological Survey (CARG Project, italian: Progetto Carta Geologica) at 1:50,000 scale has led to significant improvements in the geological knowledge for the Island of Sardinia (Italy). As a result, about one half of the island now is covered by new geological maps with 1:10,000–1:25,000 accuracy and geological maps at the 1:50,000 scale whose explanatory notes are available electronically. At the beginning of the CARG Project a geological map for Sardinia Island at 1:200,000 scale was published [Carmignani, L. (1996). Carta Geologica della Sardegna (1:200.000). Servizio Geologico Nazionale, Regione Autonoma della Sardegna], summarizing all the geological information available at that time, and a book with explanatory notes for the map was later published [Carmignani, L., Oggiano, G., Barca, S., Conti, P., Salvadori, I., Eltrudis, ... Pasci, S. (2001). Geologia della Sardegna: Note Illustrative della Carta Geologica della Sardegna in scala 1:200.000, Memorie Descrittive della Carta Geologica d'Italia (Vol. 60). Roma: Servizio Geologico d'Italia, 283 pp]. The enclosed Geological map of Sardinia at 1:250,000 scale incorporates all maps of the CARG Project, unpublished author studies and recently published maps and represents the most updated synthesis of an area characterised by a complex geological evolution that, with few exceptions, can be considered continuous during the last 540 Ma. The main events that influenced the geology of the island are the Variscan orogen that deeply involved the passive margin of North Gondwana and then the complex episodes that occurred in the present-day Mediterranean area after the accretion of Pangea up to the opening of the Tyrrhenian basin
Regional contribute to Terrane Map of the Mediterranean area (Western and Eastern Part) 1:2.500.000
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