Tuscan Archipelago Research Articles

Geochemistry of Tuscan Archipelago Granitoids, Central Italy: The Role of Hybridization Processes in Their Genesis

This paper reports major, trace, and rare-earth-element data for selected samples from the Elba, Giglio, and Monte-cristo plutons, which lie in the Tuscan Archipelago (Italy). On the basis of field and petrologic constraints, all the rocks can be divided into five facies and range in composition from granodioritic to alkali-granitic, with a strong predominance of monzogranites. Tuscan Archipelago granitoids are clearly collision-related rocks, and they straddle the I and S types of Chappell and White. However, mineralogical and chemical characteristics indicate that the more basic rocks are broadly I type, while the high-silica rocks are S type. Genetic models that relate these magmas through the segregation of their major and accessory mineral phases are inconsistent with major, trace, and REE element abundant data. Geological, petrographical, and geochemical constraints show that the microgranular mafic enclaves found within the rocks are blobs of mafic, high-temperature magma chilled within a cooler, more silicic host, but a simple two-end-member mixing process fails to explain the geochemical characteristics of the plutons, either as a group or singly. A two-stage petrogenetic model explains all the geological, petrographical, and geochemical features shown by these intrusive rocks: first, a Mixing plus Crystal Fractionation (MFC) process involving a crustal peralumi-nous magma and a basic magma of probable subcrustal origin, and second, a simple mixing process between the same crustal peraluminous magma and different evolved magmas derived from the basic magma during the first stage. The second stage can be complicated by possible superimposed processes. The acid end-member could be the Leucocratic Facies found in the Giglio pluton, while the basic end-member should be similar to the Capraia rocks on the basis of age and geochemical characteristics. The model proposed is also able to explain the dichotomy between S and I granite characteristics. Trace element data support aplites genesis by a crystal fractionation process starting from the most evolved monzogranites and crystallizing an assemblage consisting of plagioclase, K-feldspar, quartz, monazite, and zircon.

Morphological observations on some fleshy crustose algae of the Island of Gorgona (Tuscan Archipelago)

Abstract Morphological and ecological observations on four fleshy crustose algae collected in the eulittoral and upper sublittoral zone of the Island of Gorgona: Myrionema liechtenstenii Hauck, Hildenbrandia canariensis B⊘rgesen, Peyssonnelia armorica (P. et H. Crouan) Weber-van Bosse in B⊘rgesen and Cruoria cruoriaeformis (P. et H. Crouan) Denizot are reported. For each species, information on some aspects of their ecology, geographical distribution and notes on their vegetative and reproductive morphology are given.

Marine gastrotrichs from the Tuscan archipelago (Tyrrhenian Sea): I. macrodasyida, with description of three new species

Abstract The sediments from 16 localities (8 from the Island of Elba, 3 from the Island of Giglio, and 5 from the Island of Capraia) yielded several hundreds of specimens, all identified. They belong to 28 species in 13 genera in 5 families. Of the three island, Elba, with 25 species, proved to be the richest, followed by Capraia, with 18 species, and finally by Giglio with only 8 species. Diplodasys meloriae, Tetranchyroderma quadritentaculatum, and T. sanctaecaterinae are new to science. Tetranchyroderma cirrophora is new for the Italian fauna.

Benthic marine flora in the Tuscan Archipelago. A first contribution: Isles of Capraia, Elba, Formiche di Grosseto, Giglio, Scoglio d'Africa, Montecristo and Giannutri

Abstract Benthic marine flora of Tuscan Archipelago has been studied. Several samples were collected along five islands and some rocks. This paper is a compendium of new and already published data, in which 267 species, varieties, forms and stadia of algae and seagrasses are listed: 5 Bangiophyceae, 182 Florideophyceae, 45 Phaeophyceae, 6 Chlorophyceae, 28 Bryopsidophyceae, 1 Angiospermae.

Marine gastrotrichs from the Tuscan achipelago (Tyrrhenian Sea): II. Chaetonotida, with description of three new species

Abstract Twenty‐three species of chetonotid gastrotrichs are reported from three islands of the Tuscan Archipelago (Tyrrhenian Sea, Italy). The island of Elba is the largest in the archipelago and has the most sand beaches. It possesses the greatest diversity of gastrotrich fauna, with 17 known species. The island of Capraia ranks second with 12 species, and the island of Giglio is third with 8 species. Chaetonotus napoleonicus from the island of Elba and Chaetonotus aegilonensis together with Halichaetonotus marivagus, both from the island of Capraia, are described as new species. A clarification of the diagnostic characters of C. atrox, C. dispar and C. neptuni is given. Xenotrichula carolinensis is synonymized with X. intermedia.

Redescription ofFeiderzetes latus(Schweizer, 1956) with redefinition ofFeiderzetes(Acarida, Oribatida, Mycobatidae)

Abstract The oribatid mite Punctoribates (Minunthozetes) latus Schweizer, 1956 is redescribed on the basis of the holotypus from the Swiss Alps and specimens newly collected from Spain and the Tuscan Archipelago (Italy). The redescription enables the authors to redefine the genus Feiderzetes and discuss its relationships in the framework of the Mycobatidae.

An assessment of pollutants in eggs of audouin's gull ( Larus audouinii), a rare species of the Mediterranean sea

Audouin's gull ( Larus audouinii) is a very rare species endemic to the Mediterranean basin. A sub-population of an estimated 130 pairs is breeding in the Tuscan Archipelago, an area heavily polluted by mercury and chlorinated hydrocarbons. Here we present the data from 5 years spent monitoring the contaminant levels in the eggs of this species. Mercury, selenium, polychlorobiphenyls (PCBs) and DDE concentrations are two to five times higher than in similar species, such as the yellow-legged herring gull, nesting in the same area. The annual trends in these contaminant levels are discussed. In view of the endangered status of Audouin's gull, there is a need to observe closely the developing trend of contamination in this species.

Long term monitoring of pollutants in eggs of Yellow-legged Herring Gull from Capraia island (Tuscan Archipelago)

Chlorinated hydrocarbons (hexachlorobenzene, lindane, pp'DDE, polychlorinated biphenyls) and trace elements (Hg, Se, Cd, Pb) were determined in eggs of Yellow-legged Herring Gull (Larus cachinnans) collected in an island of the Tyrrhenian Sea during the period 1981-1986. PCBs levels vary on the average between 30.4μg g(-1) d.w. in 1981 to 56.1 μg g(-1) d.w. in 1983. The capillary chromatograms revealed the presence of about 30 somers of PCBs without significant variations in the eggs of the same year; more than 50% of the residues is made up only three isomers: the 22'44'55', the 22'344'5' and the 22'344'55'. Average DDE residues were 7-8 times lower than those of PCBs and declined during the period (from 9.2 μg g(-1) d.w. in 1981 to 4.5 μg g(-1) d.w. in 1986). Cadmium and lead are present in low concentrations. The average levels of mercury and selenium are around 2-2.5 μg g(-1) d.w., and a cumulative correlation, on a molar basis, exists between these two elements.

The genus «Aristolochia» L. (Aristolochiaceae) in Italy

Abstract A taxonomic revision of the Italian species of Aristolochia L. has been carried out. Evidence and information were drawn from the study of living plants and herbarium exsiccata, including type material. The attention was focused on the flower morphological characters, frequently disregarded, and on the chromosome numbers. This resulted in the systematic, nomenclatural and chorological rearrangement of the genus with special regard to Italy. Ten taxa were recognized to grow in Italy against the seven or eight entities listed in recent Floras: A. altissima Desf. (Sicily); A. clematitis L. (continental Italy, Sicily); A, rotunda L. (mainland Italy, Tuscan Archipelago, Ischia, Sicily); A. insularis Nardi et Arrigoni (Sardinia); A. clusii Lojacono (S-Italy, Sicily); A. navicularis Nardi, sp. nov. (Sardinia, Egadi Is.); A. pallida Willd. (continental Italy); A. lutea Desf. (mainland Italy, Tuscan Archipelago, Sicily); A. tyrrhena Nardi et Arrigoni (Sardinia); A. sicula Tineo (Sicily). A. pistobchia L. ...

La flora vascolare dell′Isola d′Elba (Arcipelago Toscano). Parte prima

The Island of Elba is by far the largest of the islands of the Tuscan Archipelago (High Thyrrhenian Sea). It lies about 5 miles west of Promontory of Piombino on the Tuscan coast and extends from approximately 10°6′ to 10°26′ east longitude and from 42°42′ to 42°52′ north latitude. The land area of the island is 223,50 km2 and the lenght of coasts is about 147 km. The Island is mountainous with four groups of mounts; M. Capanne, that is located in the west part of the island, attains the extreme elevation of 1018 m above sea level. The rocks are igneous (mostly intrusive), sedimentary and metamorphic; they are the result of the Apennines orogenesis, of age between the Carboniferous and the Eocene. Four pedological associations are recognized on the Elba. The associations are: N. 1, 17, 21, 22, according to MANCINI et al. (1966). The Island is characterized by a mesomediterranean climate. The present work is a revision of the vascular flora: bibliographical data, since 1583, and specimens, since 1827, were...

Notulae orthopterologicae XXI - Le Dolichopoda della Francia e della Spagna

The revision of French-Iberian Dolichopoda has led to the identification of four different species of Dolichopoda s. str. One of these (D. azami) seems to have a large geonomy in the French Alps and it had already been noticed in Italy, too. A second species (D. chopardi m.), still new to science, seems to be restricted to the Maritime Alps; the third and the fourth (D. linderi and D. bolivari), already well known, seem to be localized in the Pyrenees and the Cevennes. Owing to their morphological characters Dolichopoda azami and chopardi constitute a very homogeneous group, comprising also D. ligustica, and which could be defined alpine; on the contrary, D. linderi and bolivari are very different from said group and are very similar between them. Such similarity partly emerged from the citological observations of Saltet (1959-1960). We could then set an Alpine group against a Pyrenean one. It is then possible to state that the geographic isolation has a basic importance for the specific differentiation of the French-Pyrenean Dolichopoda, which appears to have descended from a unique, very old, common stock. The elaboration of the analytical key closing the work, shows proof of such affinity and reveals a more complex situation in Italy and Greece where two successive, different immigrations may have taken place. Such theory is fully confirmed by the presence of two subgenera in both peninsulas, that is Dolichopoda and Chopardina (the second having preceded the first: Baccetti 1960). On the whole four Chopardina are known (one in Macedonia, one in Tuscany, two in Corsica) and nineteen Dolichopoda, one of which is caucasian, one anatolian, four distributed among Attica, Peloponnesus and minor islands of Greece, one in Macedonia, three are localized in the coast between Dalmatia and Epirus, three in the Apennines, one practically restricted to the Tuscan Archipelago, three in the Alps and two in the Pyrenees. We could state that the elements of each group have close affinity and that the phenomena of morphological parallelism at great distance are but apparent exceptions: for instance Dolichopoda baccettii and Dolichopoda graeca. As — when there are no conditions of insularity causing a particularly remarkable differentiation specific to many entities — the geographic barriers among the elements of each group are often very scanty, we can consider possible that after the two great immigrations from the East, by which two suhgenera, one after the other, were imported during the Tertiary period (Baccetti, 1960), the phenomena of speciation were largely favoured, in the Quaternary, by the acquisition of troglophilia which has greatly hindered any possible migration.

Confirmation of the Absolute Age of the Granodiorite Outcrop in Elba Island with Potassium/Argon Measurements

SOME of the islands of the Tuscan Archipelago are formed by outcrops of granitic intrusions which also outcrop along the coast. According to the general scheme of the Apennine orogenesis the age of these intrusions is believed to become progressively younger proceeding from south-west to north-east. This fact is in agreement with pleochroic halo measurements1.

FALCO ELEONORAE

SummaryThe approximate totals for each part of the range may now be tabulated(a) Northwest Africa 250 pairs(b) Western Mediterranean 130(c) Central Mediterranean 150(d) Eastern Mediterranean(i) Aegean Crete 850‐1,150 pairs(ii) Cyprus 150–300This gives a grand total of 1,550‐2,000 breeding pairs. Owing to the probable existence of undiscovered colonies not allowed for in the individual estimates, this total may be too small; on the other hand, many of the estimates for Aegean colonies were made fifty or more years ago, since when, on the analogy of the only two colonies in that area about whose history anything is known, there has probably been a decline in numbers. It should be remembered, too, that the size of many colonies has only been guessed. In spite of these uncertainties, however, I would suggest that the total world population of Eleonora's Falcons is under 4,000 birds, about half of which breed in the Aegean and Crete.The most important areas where large colonies perhaps remain to be discovered are the Dodecanese and Algeria. Birds have been recorded in summer from the Tuscan Archipelago (Arrigoni degli Oddi & Damiani 1911, Moltoni 1954), the Ligurian Sea (Giglioli 1889), Pantelleria (Moltoni 1957 a), the Adriatic (Moltoni 1957 b), the Ionian Islands (Reiser 1905) and elsewhere (e.g. Provence, Leveque & Vuilleumier 1958, and even Central Spain, Lilford 1866), and, though most of these records are from the early part of the summer, it is possible that some of them represent hitherto undiscovered breeding populations. There was once a colony at Gibraltar, but this has long since ceased to exist (Bate 1928, on palaeolithic cave remains). Irby (1895) points out that the Rev. John White's “Hobbies”, which he says bred on the Rock, must have been Eleonora's Falcons and in the seventeenth century Eleonora's Falcon bred on the lies ?Hyeres (?Arcussia 1644: 60).SummaryThe known facts about Eleonora's Falcon are brought together, and contributions to existing knowledge made, under the headings Characters, General Habits, Food, Breeding, Breeding Distribution and Numbers, Migration, and Predation. It is shown that the breeding season is from mid‐July to October, that Eleonora's Falcon is a largely crepuscular feeder, that it is a summer visitor to its breeding haunts, and that it is dimorphic. The total world population is estimated to be rather less than 4,000 birds.

IX.—Note on the Tuscan Archipelago

In the course of a recent prolonged residence in Tuscany and the Carrara Marble District, I had occasion to become well-acquainted with the Maremma hills and the islands composing the Tuscan Archipelago; and as I propose to revisit those islands at an early date with a view to more closely examine certain phenomena relating to the eruptive and metamorphic series more especially of Elba, it may not be out of place if, in the meantime, I give a rapid preliminary sketch of the leading geological and petrological features of that archipelago as a whole.

The Petrography of the Island of Capraja

1. Topography Of The Island The Island of Capraja, situated 43° 2′ 35″ lat. N. and 9° 50′ 45″ long. E. of Greenwich, according to the Admiralty chart, constitutes one of the northernmost members of the Tuscan Archipelago. From it on a clear day the observer can easily see the Island of Elba to the south-east, Monte Cristo and Pianosa to the south, Corsica to the south-west, and Gorgona to the north, besides a long stretch of Apennines ranging east and north-east. The island is roughly oval; its longest axis, lying almost north and south, measures, according to the Italian Ordnance Map, 8 kilometres (5 miles); and from east to west nearly 4 kilometres (2½ miles) in the broadest parts. A chain of hills, ranging in height from 350 to 450 metres (1150 to 1475 feet), traverses its entire length; the eastern slopes of these hills fall away gradually, while the western plunge abruptly to the sea, often in precipitous cliffs, or deep ravines, exposing the structure of the island remarkably well. The east coast also is bounded by a line of cliffs; and these, though generally much lower than the western cliffs, offer equal facilities for study. 0nly at one point on this side of the island do they reach a height comparable with the cliffs on the west, i. e. beneath the twin hills of Monte Campanile and Monte Majone. Inland, the slopes are everywhere cut into by little valleys, which present a chequered