Wrocław, Poland
Wrocław, Poland

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Krajcarz M.T.,Instytut Nauk Geologicznych | Sudol M.,Nicolaus Copernicus University | Krajcarz M.,Instytut Nauk Geologicznych | Cyrek K.,Nicolaus Copernicus University
Przeglad Geologiczny | Year: 2012

The Shelter above the Zegar Cave (Shelter No 388) (N 50°25'41" E 19°40 '27") is located in the Zegarowe Rocks ridge in the Ryczów Upland (southern part of the Czȩstochowa Upland), municipality Wolbrom, district Olkusz. In 2009, Mrs. Jadwiga and Mr. Lucjan Wodarz found an archeological flint artifact in a type of leaf point at the slope below the Shelter. This finding allowed suspectine the presence of Palaeolithic cultural layers inside or near the Shelter. The authors 'aim was to recognize the geological context of the Palaeolithic settlement of the Shelter above the Zegar Cave and its neighborhood, and in further perspective of the entire southern part of the Ryczów Upland micro-region. Four layers were discovered in the Shelter during field works (downward): I-humic silty loam, Holocene; II-loess altered by secondary soil processes during the Holocene; III- unaltered loess, dated to MOIS 2; IV-silty cave loam with limestone rubble, dated to MOIS 3. The chronostratigraphy is based on lithostratigraphy and confirmed by radiocarbon and thermoluminescence dating. An archaeological cultural level occurs in layer IV, most probably related to the shift from the Middle to Upper Palaeolithic. The sequence of cave sediments may be well correlated with numerous profiles of cave sites from the Kraków-Cza̧stochowa Upland.

Zuchiewicz W.,AGH University of Science and Technology | Tokarski A.K.,Instytut Nauk Geologicznych | Swierczewska A.,AGH University of Science and Technology | Zasadni J.,AGH University of Science and Technology | Sieminska A.,AGH University of Science and Technology
Przeglad Geologiczny | Year: 2011

The paper presents the first example of Holocene faults in the Outer Western Carpathians in Poland. Small-scale normal faults at Koninki, Gorce Mts., cut both Palaeocene strata of the Ropianka Formation of the Magura Nappe and overlying coarse-clastic bedload fades of Holocene alluvium that builds a 5-5.5-high terrace step of a small valley. These NE-trending faults are accompanied by reorientation ofclast a-b planes subparallel to fault planes and by clast fracturing. Such deformations must have been induced by relatively strong earthquakes, unknown from historical record of the Outer Carpathian seismicity. Fault attitude points to NW-oriented axis of the minimum principal stress, which is compatible with parameters of the present-day stress field in the Outer Western Carpathians of Poland.

Mikulski S.Z.,Panstwowy Instytut Geologiczny | Bakun-Czubarow N.,Instytut Nauk Geologicznych | Xu D.,Guangzhou Instytut Geochemiczny Chinskiej Akademii Nauk | Wang Z.,Guangzhou Instytut Geochemiczny Chinskiej Akademii Nauk
Biuletyn - Panstwowego Instytutu Geologicznego | Year: 2012

The famous Shilu iron-polymetallic ore mining district located in western Hainan Island, South China, occurs within Meso- and Neoproterozoic low-grade metamorphosed volcanoclastics and carbonates, that belong to the 6th sequence of the Shilu Group. Granitoid intrusions of different ages occur in the surroundings of the mining area. The Shilu deposit is considered to be a structurally reworked as well as hydrothermally altered and enriched ore deposit of a Banded Iron Formation type. The deposit is a very important iron producer from hematite (and minor magnetite) ores. Our work focused on the polymetallic sulfide mineralization that underlies the iron oxide ores. We selected several samples of sulfide ores from the Shilu deposit of the Beiyi mine and its close vicinity. We performed detailed ore microscopic studies as well as electron microprobe analyses using the CAMECA SX 100 equipped with EDS and WDS systems. Pyrrhotite, chalcopyrite and Co-bearing pyrite (up to 11 wt% Co) dominated among ore sulfides in the studied samples. These ore minerals occur in calc-silicate rocks and strongly silicified diopside, tremolite-bearing rocks, either as disseminated grains, sometimes in veinlets, or in aggregates that may form massive ores. Pyrrhotite and chalcopyrite may contain numerous solid inclusions, overgrowths and intergrowths of subordinate sulfides (sphalerite, galena), sulfosalts (glaucodot, costibite, cobaltite, arsenopyrite, ullmannite), sulfospinels (siegenite) and cassiterite that belong to the minerals crystallizing at medium to low temperatures. Among these minerals, siegenite and Co-bravoite dominate. Tiny crystals (10-20 μm in size) of Bi-minerals (matildite, cosalite) and argentite are also present. Moreover, in association with barite, calcite and chlorite, Ag-Hg amalgamate and cinnabar can occur. The results of our study point to the multistage medium- to low-temperature hydrothermal precipitation of ore sulfides during 4-5 separate stages. Preliminary results of Re-Os isotope datings indicate that pyrites of younger generation (lack of significant Co admixture) crystallized during 240-260 Ma.

Chondrites NWA-869 (L3.9-6S2), Tsarev (L5 S5), Ghubara (L5 S4), Zag (H3-6 S3) from the Jacek Siemiatkowski Collection show evidence of multiple brecciation. Petrographic and microprobe analyses of thin sections allowed to identify and distinguish syn- and postaccretion impact and thermal transformations which took place on the chondrite parent bodies. The studied meteorites contain clasts of chemically equilibrated and unequilibrated rocks as well as many unusual achondritic-like clasts. The latter are cognate impact-melt rocks. All the clasts provide records of complex metamorphic and deformational histories of the parent bodies. Chondrites displayed numerous metamorphic transformations and deformations caused by many shock or shock-related processes under conditions ranging from impact-related shearing to HP shock-induced shattering and melting. These processes led to the formation of quenched impact melts, metal veins and nodules, darkened clasts and locally cataclasis.

In 21 st century the chronostratigraphy of cave sediments is built on the basis of modern methods: sedimentological analysis, statistical analysis of palaeozoological data, radiometric and luminescence dating and many others. For the time of last 50 000 years the four geochronological units (or appropriate chronostratigraphic units) are usually proposed in Poland in the researches of cave sediments. They are: Interpleniglacial, Upper/Younger Pleniglacial, Late Glacial and Holocene. That scheme has over 150 years of evolution, and its origin was tied with biostratigraphical scheme built by Edouard Lartet in a middle of 19 th century. Lartet's stratigraphy for the same period was also made of four units: Cave Bear Epoch, Mammoth and Wooly Rhinoceros Epoch, Reindeer Epoch and Auroch Epoch. Although basing on different methods and using different terminology, the two schemes - from the 19 th and from 21 st centuries - are similar and correlatable.

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