Brushite, hydroxylapatite, and taranakite from Apulian caves (southern Italy); new mineralogical data, 1991, Fiore S, Laviano R,

Palaeoseismicity from karst sediments: the “Grotta del Cervo” cave case study (Central Italy), 1991, Postpischl D. , Agostini S. , Forti P. , Quinif Y. ,

Karst speleothems can be used for tectonic and palaeoseismic analyses; in particular, stalagmites can be treated as the records of a natural pendulum.Samples of stalagmites from the “Grotta del Cervo” and the “Grotta a Male” caves (Central Italy) have been dated using 14C and U/Th radiometric methods. The present paper shows the limits and validity of such methods for dating strong earthquakes of the past.In particular, radiometric 14C dating shows that the youngest general stalagmitic collapse observed inside the “Grotta del Cervo” cave must be related to the December 1456 earthquake of Central Italy

Les mouvements tectoniques récents dans les grottes du Monte Campo dei Fiori (Lombardie, Italie), 1992, Bini A. , Quinif Y. , Sules O. , Uggeri A.

Recent tectonic movements have been studied in the caves of Monte Campo dei Fiori in Lombardy (Italy). These develop in limestones and dolomites ranging from the Lower Trias to the Lower Lias. In the Frassino cave, movements can be observed along the layers (shifts in galleries) as well as speleothems that have been broken and displaced. U/Th datings of speleothems indicate ages of more 350.000 years. Karstification therefore preceded neotectonic movements. On the whole, observations point out an increasing folding of the syncline of the Varese Lake, together with an uplift of the neighbouring anticlines.

Late to post-Hercynian hydrothermal activity and mineralization in Southwest Sardinia (Italy), 1992, Boni M, Iannace A, Koeppel V, Fruehgreen Gl, Hansmann W,

LATE TO POSTHERCYNIAN HYDROTHERMAL ACTIVITY AND MINERALIZATION IN SOUTHWEST SARDINIA (ITALY), 1992, Boni M, Iannace A, Koppel V, Fruhgreen G, Hansmann W,

Several kinds of base metal deposits occur in the lower Paleozoic of southwest Sardinia (Iglesiente-Sulcis mineral district). This paper deals with those deposits which are generally referred to as Permo-Triassic, because they accompany and postdate the Hercynian orogeny and are related to magmatic activity. A large number of previously published geochemical data, integrated with additional new data (Sr, Pb, O, C, and S isotopes), are reviewed and discussed in the frame of the late to post-Hercynian geologic evolution of southwest Sardinia. According to geological and mineralogical characteristics, three types of deposits can be distinguished: (1) skarn ores related to late Hercynian leucogranitic intrusions, (2) high-temperature veins, and (3) low-temperature veins and karst filling. Pervasive epigenetic dolomitization phenomena are geochemically related to the low-temperature deposits. Sr and Pb isotopes of the first and second types (0.7097-0.7140 Sr-87/Sr-86; 17.97-18.29 Pb-206/Pb-204; 38.11-38.45 Pb-208/Pb-204) are distinctly more radiogenic than those of the third type (0.7094-0.7115 Sr-87/Sr-86; 17.86-18.05 Pb-206/Pb-204; 37.95-38.19 Pb-208/Pb-204) which, in turn, are closer to Paleozoic ores and carbonates. Fluid inclusion data indicate that the fluids responsible for mineralization of the first and second types of deposits were hot and dilute (T(h)= 370-degrees-140-degrees-C; <5 wt % NaCl equiv). In contrast, relatively colder and very saline fluids (T(h)= 140-degrees-70-degrees-C; >20 wt % NaCl equiv) were responsible for the third type of mineralization, as well for epigenetic dolomitization of the Cambrian host rocks. O isotopes measured in minerals from the first two types (deltaO-18SMOW = 12.8-18.9 parts per thousand) are O-18 depleted with respect to the third type (deltaO-18SMOW = 15.9-22.1 parts per thousand). These data, coupled with fluid inclusion formation temperatures, indicate that the fluids responsible for the first two types of mineralization were O-18 enriched with respect to those of the third type and related hydrothermal phenomena. The deltaS-34CDT in sulfides of the first two types vary between 3.7 and 10.73 per mil, whereas the values of the third type range from 12.0 to 17.9 per mil. Late to post-Hercynian mineralization is thus explained as the result of three distinct, though partly superimposed, hydrothermal systems. System 1 developed closer to the late Hercynian leucogranitic intrusions and led to the formation of the first and subsequently the second type of mineralization. The relatively hot and diluted fluids had a heated meteoric, or even partly magmatic, origin. Metals were leached from an external, radiogenic source, represented either by Hercynian leucogranites or by Paleozoic metasediments. Sulfur had a partly magmatic signature. System 2 was characterized by very saline, colder fluids which promoted dolomitization, silicification, and vein and karst mineralization. These fluids share the typical characteristics of formation waters, even though their origins remain highly speculative. The hydrothermal system was mainly rock dominated, with only a minor participation of the external radiogenic source of metals. Sulfur was derived by recirculation of pre-Hercynian strata-bound ores. System 3 records the invasion of fresh and cold meteoric waters which precipitated only minor ore and calcite gangue. It may represent the further evolution of system 2, possibly spanning a time well after the Permo-Triassic. The timing of all these phenomena is still questionable, due to the poor geologic record of the Permo-Triassic in southwest Sardinia. Nevertheless, the hypothesized scenario bears many similarities with hydrothermal processes documented throughout the Hercynian in Europe and spanning the same time interval. A comparison with the latter mineralization and hydrothermal activities leads to the hypothesis that the first two types of mineralization are linked to late Hercynian magmatic activity, whereas the third type may be related to either strike-slip or tensional tectonics which, throughout Europe mark the transition from the Hercynian orogeny to the Alpine cycle

Origin of sulphur in minerals and fluids from Latium (Italy); isotopic constraints, 1992, Cavarretta G, Lombardi G,

GEODYNAMICS OF THE SARDINIAN BAUXITES - TYPOLOGY, GENESIS AND PALEOTECTONIC CONTROL, 1993, Combes Pj, Oggiano G, Temussi I,

During the middle Cretaceous the karst bauxites of NW Sardinia are controlled by a favourable climate, an aluminous mother rock (Berriasian marls) and a significant tectonic instability which allows a morphostructural paleosurface to be constituted on the intracontinental areas, away from the eustatic changes of sea level. In connection with the uplift rate, the aluminous material is distributed into three types of deposit. Their genetic depositional system and main features are incorporated in a geodynamic model applicable to prospecting

Human impact on the karst of the Venetian Fore-Alps, Italy, 1993, Sauro U. ,

Continental deposits and archaeological data in the Trieste Karst area (north-east Italy: evidence of sea-level changes and possible tectonic activity in the Late Pleistocene and Early Holocene, 1993, Boschian G,

Rapports entre la karstification _périméditerranéenne et la crise de salinité messinienne, l’exemple du karst lombard (Italie), 1994, Bini, A.

The Mediterraean dessiccation theory suggests that during the Messinian the Mediterranean sea lad almost completely dried up did a thick succession of evaporites was laid down Due to dessiccation the erosional base level through the whole Mediterranean area was lowered, with the consequent development of long and deep fluviatile canyons (e.g. Nile, Rhône, Var, etc). This lowering strongly affected karst evolution This paper concerns the karst in Lombardy, around the southalpine lakes. The old evolutionary models, predating dessiccation theory, assume that the lacustine valleys were scoured by the quaternary glaciers. ln this case the karst should have been characterized by some features, like for example the altitudinal cave distribution as a consequence of the valley lowering after each glaciation. Seismic experiments through the lakes and their tributaries have shown that these valleys are deep fluviatile canyons. The study of caves has demonstrated that the caves themselves predate the entrenchment of the valleys and the glaciations. During the latter the caves were filled up and emptied several times, without any modifications of their inner morphology, including stalactites. Moreover the U/Th age determinations indicate that a great number of concretions are older than 350 ky, and that a few are older than 1.5 Ma. As a conse-quence, a general model of karst evolution can be proposed. The former karstic drainage system developed after the Oligo-Miocene emersion. Paleogeography obviously diffe-red from the present day landscape but the main valley had already been scoured. During the Messinian the dramatic lowering of base level determined major changes in karstic evolution and a reorganisation of the karst drainage system that was consequently lowered considerably. The Pliocene transgression determined a new karst evolution, after which a great number of caves were located well below the sea level base. This evolution occurred during hot and wet climate period, with seasonal high flows and relevant discharges of the karstic rivers The great caves of the Lombardian karst developed within the climatic stage.

Activity od the scientific commission of ''Grotta Grande del Vento'' (Genga, Ancona, Central Italy)., 1994, Bertolani Mario, Cigna Arrigo A.

The Grotta Grande del Vento (the Great Wind Cave) was discovered in 1971. An administrative body (the "Consorzio Frasassi") under the control of some local authorities took care of its development and the cave was opened to tourists in 1974. A Scientific Commission formed by some experts (choosen by the Consorzio Frasassi) of different disciplines was established in 1975. During these 15 years the Commission acted as an advisory committee for the Consorzio in order to guarantee the protection of the cave environment. In particular the Commission set up a monitoring network of the most important environmental parameters (air and water temperature. air currents, relative humidity and CO2 concentration) in some suitable locations and studied the best solutions to avoid algae and other plants proliferation in the vicinity of light sources. The Commission promoted and directed researches in the karst system under a strict co-operation with the Consorzio Frasassi which funded most of them. Some scientific papers resulted from these researches.

Faunistic study in the karst complex of Frasassi (Genga, Italy)., 1994, Bertolani Roberto, Manicardi Gian Carlo, Rebecchi Lorena

f the complex and they are the consequence of a relatively recent faunistic colonization.

Life cycle and population ecology of the cave cricket Dolichopoda geniculata (Costa) from Valmarino cave (Central Italy), 1994, Carchini Gianmaria, Rampini Mauro, Sbordoni Valerio

A D. geniculata population inhabiting a natural cave at low altitude near seashore was followed during two years. The population size, distribution in three age classes, spatial distribution, feeding habits were recorded. The life-cycle was found semivoltine, with overlaps between next choorts in each age class. A comparison to other Dolichopoda showed that the population of Valmarino cave is one of the best adapted to cave life, and this may be related with both historical and present geographical and ecological conditions of the cave.

Morphological description and environmental impact evaluation due to the development as a show cave of the ''Grotte di Is Zuddas'' (Cagliari. Sardinia, Italy), 1994, Curreli Roberto Nicolino Diana, Antonello Floris, Antonello Sulas.

After a short history of the discovery of the caves of "Is Zuddas" a geological description of the region and the geomorphological evolution of the cave are recorded. The results of a preliminary climatological research are reported and a rough evaluation of the visitors capacity is also given.

Tourist problems of Grotta Gigante in the Trieste karst, 1994, Forti Fabio

The paper reports the tourist evolution of the Grotta Gigante (Giant Cave), near Trieste (Italy) during 80 years (1908; 1989) of its opening to the public. At the beginning it entered in competition with some other local show caves, even much more famous (like Postojna and Stocjan), after the II World War on account of the change of the state boundaries it remained the sole show cave in that part of Italy. Then the Grotta Gigante succeeded, even if slowly, to cope with the changing tourist demands, improving more and more its facilities to follow the increasing tourist flows. In recent years the visitors decreased slowly but steadily. Such a decrease is due to reasons independent of the management of the Grotta Gigante; these facts are reported and analyzed and the cooperation of other show caves is asked in order to establish a common strategy when similar factors are present.