Geothermal resources within carbonate reservoirs in western Sicily (Italy): A review

Abstract Low-to-medium temperature fluid reservoirs hosted in carbonate rocks are some of the most promising and unknown geothermal systems. Western Sicily is considered a key exploration area. This paper illustrate a multidisciplinary and integrated review of the existing geological, geochemical and geophysical data, mainly acquired during oil and gas explorations since the 1950s, specifically re-analyzed for geothermal purposes, has led to understanding the western Sicily geothermal system as a whole, and to reconstructing the modalities and particular features of the deep fluid circulation within the regional reservoir. The data review suggests the presence of wide groundwater flow systems in the reservoir beneath impervious cap rocks. We identified the main recharge areas, reconstructed the temperature distribution at depth, recognized zones of convective geothermal flow, and depicted the main geothermal fluid flow paths within the reservoir. We believe that our reconstruction of geothermal fluid circulation is an example of the general behavior of low-to-medium enthalpy geothermal systems hosted in carbonate units on a regional scale. Due to the recent technological developments of binary plants, these systems have become more profitable, not only for geothermal direct uses but also for power production

Towards a checklist of the Italian gypsophilous vascular flora.

The strict relationship between plants and particular types of substrate has long been known to botanists and plant ecologists who have dealt with this issue. The peculiar flora growing on Italian gypsum substrates has been underlined since the nineteenth century (1, 2, 3). The concept of plant gypsophily can be defined as the exclusiveness or marked preference for living on gypsum outcropping rocks. Thus, only those plant species which show preference, or even exclusivity, for gypsum substrates, should be classified as gypsophilous (4). The main aim of this research has been to provide a checklist of the Italian gypsophilous flora. The study was made possible through international collaboration between the “Mediterranea” University of Reggio Calabria (Italy) and the University of Almería (Spain). During this first step, an extensive literature review has been carried out in order to collect all available information about Italian gypsophilous flora and to compile a preliminary list. Afterwards 18 regional botanists expert on Italian gypsum flora have been asked to rank the gypsum preference of the species from this preliminary list. Following the methodology proposed by Mota et al. (5), the degree of gypsophily was ranked on a scale from 1 to 5 (corresponding to low and total dependence on gypsum substrates, respectively). The species list was subsequently amended and improved twice on the basis of peer opinions to obtain a final evaluation. More than 360 species have been taken into account. According to the obtained values, all the plant species, ranking between absolute or preferential gypsophytes (with median values between 5 and 3), will figure in the final checklist of the Italian gypsophytes. A more detailed study on the gypsophilous flora and plant communities would be required to support an effective conservation action for the Italian gypsum areas and their natural heritage

Checklist of gypsophilous vascular flora in Italy

Our understanding of the richness and uniqueness of the flora growing on gypsum substrates in Italy has grown significantly since the 19th century and, even today, new plant species are still being discovered. However, the plants and plant communities, growing on gypsum substrates in Italy, are still a relatively unknown subject. The main aim of this paper was to elaborate a checklist of the Italian gypsophilous flora, to increase knowledge about this peculiar flora and for which conservation efforts need to be addressed. Through a structured group communication process of experts (application of the Delphi technique), a remarkable number of experienced Italian botanists have joined together to select focal plant species linked to gypsum substrates. From the results obtained, 31 plant species behave as absolute or preferent taxa (gypsophytes and gypsoclines) and form the ‘core’ Italian gypsophilous flora. The most abundant life forms were chamaephytes and hemicryptophytes, belonging to Poaceae and Brassicaceae; as for chorotypes, the most represented are Mediterranean and narrow endemics. By improving on previously available information about the flora with a clear preference for gypsum in Italy, this undertaking represents an important contribution to the knowledge of a habitat which is today considered a priority for conservation