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Earth and environmental sciences cover all planetary and Earth science aspects, including solid Earth processes, development of Earth, environmental issues, ecology, marine and freshwater systems, as well as the human interaction with these systems.
Earth and Environmental Sciences
Stone masonry arch bridges in North Hungary represent cultural heritage values. For the maintenance and preservation of these bridges detailed mapping of lithologies and weathering forms are required. The purpose of this paper is to present the identified lithotypes, their conditions (weathering grade) and their petrophysical properties by using in situ lithological mapping, documentation of weathering forms, non-destructive tests and laboratory analyses. Furthermore these analyses demonstrate the difficulties of characterization and diagnostics of the historical construction materials. Additionally the results of condition assessments and the properties of the four different dimension stones from four different sites provide examples for the large dissimilarities regarding the strength parameters. The above-listed parameters are required as input data for stability calculations and modeling of these structures.
The paper provides information on the mechanical properties of granitic rocks that were subjected to heat. Two types of granitic rocks were tested under laboratory conditions at temperatures of 23 °C, 300 °C and 600 °C. The granitic rock from Bátaapáti (Mórágy Granite) is a pinkish leucocratic monzogranitic type while the second type is grey granite from Mauthausen (Austria). The samples were placed in furnace and temperature raised to 300 °C. Other set of samples were heated to 600 °C. Mechanical tests were performed on non-heated and heated samples and the test results were compared. Heating to 300 °C caused a slight increase in the uniaxial compressive strength and in indirect tensile strength, with reference to the samples kept at 23 °C. A drastic drop in both values was observed when samples were heated to 600 °C. The density of the samples did not show a major change up to 300 °C. On the contrary, a decrease in ultrasonic pulse velocity was observed, with an additional significant loss when samples subjected to 600 °C were compared to the reference samples of 23 °C. This decrease can be related to the initiation of micro-cracks. With increasing temperature the Young modulus of both granites was reduced.
This paper aims at determining the behavior of thermal water brought to surface and how this might impact reinjection wells and the rock during reinjection. The biggest problem is that reinjection wells are predisposed to choking. We searched for a method to examine this process, including a model for physico-chemical changes in the water—rock interaction. Two different samples of powdered rock (designated α and β) were analyzed using thermal water samples from production and reinjection wells. The pH shows significant differences between the samples from wells where free water treatment was carried out, and those from the aerated thermal waters, as well as for the rock sample. Basically, a decrease in sediment volume can be obtained by increasing the pH. The salt effect was more coherent. Its result was an interesting case of W-shaped graphs from the producing well. On the other hand there is virtually no difference between the samples with acid titration.
This article evaluates the known rare earth elements (REE), Ti and Li occurrences and exploration potential in Finland, based on existing data combined with new geochemistry and mineralogy, heavy mineral studies, geophysical measurements, geologic mapping and recent drilling of new targets.
The potential rock types for REE include carbonatite (Sokli, Korsnäs), alkaline rocks (Otanmäki, Lamujärvi, and Iivaara), rapakivi granite and pegmatite (Kovela), and kaolin-bearing weathering crusts in eastern and northern Finland. The highest REE concentrations occur in late magmatic carbonatite veins in the fenite area of the Sokli carbonatite complex. Detailed mineralogical investigations have revealed three distinct types of REE mineralization as phosphates, carbonates and silicates in the studied areas. Mineralogical and mineral chemical evidence demonstrates that hydrothermal processes are responsible for the REE mineralization in the studied rocks and confirms that such processes are predominant in the formation of REE minerals in carbonatite, calc-silicate rocks and albitite. Titanium occurs as ilmenite in hard rock deposits in Paleoproterozoic subalkaline mafic intrusions. The Otanmäki ilmenite was mined together with vanadium-rich magnetite from 1953 to 1985 from a small gabbro—anorthosite complex, which still contains potential for Ti resources. Other major ilmenite deposits are within the Koivusaarenneva ilmenite gabbro intrusion and Kauhajärvi apatite—ilmenite—magnetite gabbro complex. Possible Ti resources are included in Ti-magnetite gabbro of the large layered mafic intrusions in northern Finland, such as at the former Mustavaara vanadium mine. For several years, Rare Element (RE)-pegmatite of the Kaustinen and Somero—Tammela areas has been the objective of Li exploration by the Geological Survey of Finland (GTK). At Kaustinen, Li-pegmatite occurs as subparallel dyke swarms in an area of 500 km2 within Paleoproterozoic mica schists and metavolcanic rocks. Li pegmatite contains more than 10% spodumene as megacrysts (1–10 cm), albite, quartz, K-feldspar, muscovite and accessory minerals such as columbite-group minerals, apatite, tourmaline, beryl, Fe-oxide minerals and garnet. The Kaustinen spodumene pegmatite and Somero—Tammela petalite—spodumene pegmatite contain potential Li resources for the battery industry in EU countries.
Magma/wet sediment interaction (e.g. autobrecciation, magma-sediment mingling, hyaloclastite and peperite-forming, etc.) is a common phenomenon, where hot magma intrudes into unconsolidated or poorly consolidated water saturated sediment. In the Eastern Borsod Basin (NE-Hungary) relatively small (2–30 m) subvolcanic bodies, sills and dykes with contact lithofacies zones were found generated by mechanical stress and quenching of the magma, and interacting with unconsolidated wet andesitic lapilli-tuff and tuff-breccia. Close to the contact between sediment and intrusions, thermal and mechanical effects may occur in the host sediment. Hydrothermal alteration and stratification of the host sediment were developed only locally along the contact zone, probably due to the paleo-hydrogeologic and paleo-rheological inhomogeneities of the lapilli-tuff–tuff-breccia deposits. Processes of magma/wet sediment interaction may be difficult to recognize because of limited exposure and/or certain similarities of the brecciated intrusions to the characteristics of the host sediment; hence detailed field work (geologic mapping or profiling) was required to demonstrate the subvolcanic origin of the brecciated andesite bodies.