Ob širjenju velikih kamnolomov pri Črnem Kalu in Črnotičah nad Koprom se kažejo različni kraški pojavi, od erozijsko razširjenih razpok do brezen in celo jam. Običajno so zapolnjeni s pleistocenskimi ...sedimenti. Ob enem izmed obiskov kamnoloma na Črnem Kalu je bil v ostanku sedimentov na sicer znanem paleolitskem in paleontološkem najdišču, delno raziskanem leta 1955, najden retuširan odbitek. V prispevku poskušamo novo najdbo stratigrafsko umestiti in tipološko opredeliti. Iz kamnoloma Črni Kal je znanih tudi nekaj novih paleontoloških najdb pleistocenske favne, ki jih podajamo le preliminarno. V sosednjem kamnolomu, ki leži bližje Črnotičam, je bil odkrit fragment kosti z vrezi. Ležal je v pleistocenskih sedimentih in verjetno potrjuje novo paleolitsko najdišče.
The Karstic thrust edge, a pronounced geomorphologic step, which is a result of the tectonostratigraphic evolution of the active Adria–Dinarides thrust zone, represents a major obstacle for the ...planned new railway route Divača–Koper. Thus, the geotechnical and structural properties as well as the geometry of the thrust-fault planes in this area are of great importance. Since geological mapping cannot give insight into the subsurface to reveal a complex 3D structure, and the numerous boreholes needed to investigate the area would be too expensive and time consuming, the application of a geophysical method such as ground penetrating radar (GPR) is needed. To test the method for determining near surface features and detecting low-angle inclined thrusts, a low frequency GPR system with 50 MHz rough terrain antenna was used to record 13 GPR profiles along all three floors of the Črnotiče quarry, where the spatial position of the Socerb thrust fault that separates limestones above and flysch layers below is relatively well documented. The profiles were positioned across selected existing boreholes. The GPR results were correlated with borehole data as well as geological mapping results. The GPR provided not only precise information on the geometry of the Socerb thrust fault, but was also very useful for establishing the position of some known as well as several potential cavities, both air- and sediment-filled. In areas further from the thrust-fault zone, where the limestone is less tectonically damaged, it was also possible to determine apparent dip angles of the strata, which after reconstruction matched the true dips gathered from geological mapping.
Five samples of clastic sediments from interior cave facies taken in three Slovenian relic caves (Trhlovca, Račiška pečina, and a cave in Črnotiče Quarry, Classical Karst, SW Slovenia) provided ...invertebrate fossil remains. Most of them belong to Oribatida but sparse individuals of Cladocera and insects were also identified. They represent the first pre-Quaternary invertebrate fossils found in sediments of continental temperate climate. The Pliocene/Pleistocene age of the sediments was determined by paleomagnetic dating chronologically calibrated by micromammal biostratigraphy. Invertebrate fossils could be validated as new proxy for the study of cave sediments due to their suitability for ecological and paleogeographic correlations in caves and outside the caves. They also bring additional information about cave formation and karst hydraulic regime in the area. Although the number of remains was very low, it is evidence that climatic conditions in caves allow a better preservation of fossil remains of some groups as compared to most of the surface habitats. This may open a new direction in the study of cave sediments.
For the first time in the Classical Karst, paleontological data enabled to match the magnetostratigraphic record precisely with the geomagnetic polarity timescale in two studied sites: (i) a series ...of speleothems alternating with red clays in Račiška pečina Cave (Matarsko podolje), and (ii) an unroofed paleocave of the Črnotiče II site (Podgorski kras Plateau) completely filled by fluvial clastic sediments covered by speleothems. The later sites are also characterized by a rich appearance of fossil tubes of autochthonous stygobiont serpulid Marifugia cavatica. The vertebrate record is composed mostly of enamel fragments of rodents and soricomorphs. Absence of rootless arvicolids as well as taxonomic composition of the mammalian fauna suggests the Pliocene age of both sites. For (i) Račiška pečina (with Apodemus, cf. Borsodia) it was estimated to middle to late MN17 (ca 1.8–2.4 Ma), while (ii) the assemblage from Črnotiče II (with Deinsdorfia sp., Beremedia fissidens, Apodemus cf. atavus, Rhagapodemus cf. frequens, Glirulus sp., Cseria sp.) is obviously quite older: MN15–MN16 (ca 3.0–4.1 Ma). In respect to congruence of biostratigraphic and paleomagnetic data and a reliable sedimentary setting of the samples we propose to apply the respective datum also as the time of one ancient speleogenetic phase in the Classical Karst.
The new railway route Divača - Koper is planned to cut through the Karstic thrust edge, a prominent geomorphologic step within the active Adria - Dinarides thrust zone. This represents a major ...obstacle for the railway construction, therefore it is crucial to understand the structural properties and the geometry of the thrust-fault planes within the area. This knowledge is also important for the calculation of exploitable material in a limestone quarry. For determining thrusts with a low-angle inclination we evaluated the use of the low frequency ground penetrating radar (GPR). We carried out a survey in the active Črnotiče quarry with a 50 MHz rough terrain antenna (RTA), correlated the GPR results with borehole data and constructed a precise 3D model of the Socerb thrust-fault plane. In addition to acquiring accurate structural information about the thrust-fault plane and dip of the strata, we were also able to detect different karst features. When the excavations in the quarry reached the thrust-fault in one part, we found it outcrops exactly where we had previously defined its position. We conducted an additional GPR survey using the 50 MHz RTA as well as a 250 MHz antenna, and obtained new information about the extent and the geometry of the Socerb thrust-fault plane.
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