Search results for "Island"

A LA-ICP-MS STUDY OF CARBONATITES FROM FUERTEVENTURA, CANARY ISLAND

Carbonatites complexes are very rare in oceanic environments and in the Atlantic Ocean they can be only found at Cape Verde islands and Fuerteventura. Fuerteventura is the second largest island in the Canary Archipelago and is located on a transitional, continental to oceanic, crust. It consists essentially of Mesozoic sediments, submarine volcanic rocks, subaerial basaltic and trachytic series, ultramafic, mafic to felsic intrusives (clinopyroxenites, melteijites-ijolites, nepheline-monzogabbros, nepheline-sienites) and carbonatitic dike swarms (age 25 Ma). Carbonatite dike (Ca-carbonatites) mineralogy consists of calcite, aegirine-augite, albite, K-feldspar, biotite, apatite, Fe-Ti oxides…

Ecotoxicity assessment of natural attenuation effects at a historical dumping site in the western Baltic Sea.

2005

During the late 1950s and early 1960s of the past century, industrial waste material highly enriched in various contaminants (heavy metals, PAHs) was dumped in the inner Mecklenburg Bay, western Baltic Sea. Large-scale shifts in the spatial distribution of heavy metals in surface sediments were mapped by geochemical monitoring in the mid-1980s and 12 years later in 1997. A further study in 2001 was designed to investigate the small-scale spatial distribution of contaminants inside, on top of, and around the historical dumping ground and to examine possible effects to benthic organisms (Arctica islandica, microbiological toxicity tests). The site is located within an area characterized by a …

Concept of Biogenic Ferromanganese Crust Formation: Coccoliths as Bio-seeds in Crusts from Central Atlantic Ocean (Senghor Seamount/Cape Verde)

2011

At depths of 2,000 to 3,000 m, seamounts from the Cape Verde archipelago (Central Atlantic Ocean) are largely covered with ferromanganese crusts. Here we studied 60 to 150 mm thick crusts from the Senghor Seamount (depth: 2257.4 m). The crusts have a non lamellated texture and are covered with spherical nodules. The chemical composition shows a dominance of MnO2 (26.1%) and Fe2O3 (38.8%) with considerable amounts of Co (0.74%) and TiO2 (2.1%). Analysis by scanning electron probe microanalyzer (EPMA) revealed a well defined compositional zonation of micro-layers; the distribution pattern of Mn does not match that of Fe. Analysis by high resolution scanning electron microscopy (SEM) revealed…

Environmental Gamma Radiation Measurements on the Island of Pantelleria

1992

The population exposure to those living on the island of Pantelleria, Italy, was estimated by measuring the natural gamma background. Gamma spectra of natural rocks and measurements of absorbed dose in air were taken. A correlation was found between the mean gamma exposure rate and the mean values of natural radionuclide concentrations in the investigated rocks.

Temporal evolution of the Fogo Volcano magma storage system (Cape Verde Archipelago): a fluid inclusions perspective

2023

The architecture of the magma storage system underneath Fogo Volcano (Cape Verde Archipelago) is characterised using novel fluid inclusion results from fifteen basanites, spanning the last 120 thousand years of volcanic activity, and encompassing a major flank collapse event at -73 ka. Fluid inclusions, hosted in olivine and clinopyroxene, are made of pure CO2, and based on their textural characteristics, are distinguished in early (Type I) and late (Type II) stage. Inclusions homogenize to a liquid phase in the 2.8 to 30.8 degrees C temperature range. Densities values, recalculated assuming an original 10% H2O content at the time of trapping, range from 543 to 952 kg center dot m(-3), and …

A tool for evaluating geothermal power exploitability and its application to Ischia, Southern Italy

2015

Abstract The paper proposes a method to evaluate the potential for electric power production at any site of possible geothermal interest. Accounting for geological data of the reservoirs, the method allows the computation of the available electrical power of the investigated site. Electrical energy production from geothermal sources is realized through different techniques, such as single flash and double flash, dry steam, and binary ORC plants. The technique chosen to be the most productive is determined by analyzing a specific range of geofluid properties, mainly temperature and pressure. Moreover, each plant typology has a global efficiency that may be correlated to geofluid enthalpy by …

Review of the genus Prolactistes (Heteroptera: Cydnidae), with two new combinations, first Indonesian records and a key to species of the genus

2020

Two species of the genus ParaethusJ. A. Lis, 1994 (Hemiptera: Heteroptera: Cydnidae: Cydninae: Geotomini) are transferred to ProlactistesJ. A. Lis, 2001, resulting in the following new combinations: Prolactistes jani(J. A. Lis, 1995), comb. nov., and Prolactistes lisi(Magnien, 2014), comb. nov. Diagnostic characters for Prolactistes, and a key for its three species are provided. The present note also reports the first Indonesian record for Prolactistes australisJ. A. Lis, 2001 (Ambon Island, Timor) and P. lisi(Ambon Island), both known previously only from Australia.

Potential and limitation of combining terrestrial and marine growth records from Iceland

2017

Abstract Seasonally formed, perennial growth increments of various organisms may possibly contain information about past environmental changes, well before instrumental measurements occurred. Such annually resolved proxy records have been mainly obtained from terrestrial archives, with a paucity of similar data originating from marine habitats. Iceland represents ideal conditions to develop both, tree ring (dendro) and bivalve shell (sclero) chronologies from adjacent sites. Here we introduce the first network of Icelandic birch (Betula pubescens Ehrh.) and rowan (Sorbus aucuparia) dendrochronologies, as well as ocean quahog (Arctica islandica L.) sclerochronologies. In order to identify th…

Considerazioni biogeografiche sulla presenza di specie aliene nella flora vascolare del Mediterraneo

2011

Biogeographia vol. XXX - 2011 (Pubblicato il 23 dicembre 2011) La Biogeografia della Sicilia Considerazioni biogeografiche sulla presenza di specie aliene nella flora Vascolare del Mediterraneo GIANNIANTONIO DOMINA, PIETRO MAZZOLA Dipartimento di Biologia Ameientale e Biodiversita, Universita a’egli Studi di Palermo, via Arc/airafi 38, 90123 Palermo (Italy) Key words: alien vascular flora, islands, Mediterranean, statistics. SUMMARY Relations between the occurrence of aliens and biogeographic Features of some territories in the Mediterranean are analysed. Mediterranean islands host a higher percentage of aliens in comparison with the mainland. The most ‘ important relations have been observed be…

Shallow Sea Gas Manifestations in the Aegean Sea (Greece) as Natural Analogs to Study Ocean Acidification: First Catalog and Geochemical Characteriza…

2022

The concepts of CO2 emission, global warming, climate change, and their environmental impacts are of utmost importance for the understanding and protection of the ecosystems. Among the natural sources of gases into the atmosphere, the contribution of geogenic sources plays a crucial role. However, while subaerial emissions are widely studied, submarine outgassing is not yet well understood. In this study, we review and catalog 122 literature and unpublished data of submarine emissions distributed in ten coastal areas of the Aegean Sea. This catalog includes descriptions of the degassing vents through in situ observations, their chemical and isotopic compositions, and flux estimations. Tempe…