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Dolnokredowe fosforyty z NE obrzeżenia Gór Świętokrzyskichjako potencjalne źródło REE : badania wstępne

Zglinicki Karol, Szamałek Krzysztof, Salwa Sylwester, Górska Irena

Przegląd Geologiczny

2020

Vol. 68, nr 7

566--576

The PGI-NRI conducts geological research on the documentation of occurrence of REE deposits in Poland. The deposit potential may be related to the formation of Lower Cretaceous phosphorites from the NE margin of the Holy Cross Mountains. Two phosphorite deposits were exploited in this region in the past: Chałupki (1936-1959) and Annopol (1952-1970). From the Chałupki old mine dump, 34 samples of fine-grained sand were collected. The pseudonodules were extracted from this sand. The sand from the dump is composed of quartz, francolite (carbonate-rich fluorapatite) Ca5(PO4,CO3)3F, illite and a small amount of feldspar, calcite and heavy minerals. The heavy fraction is composed of zircon, monazite and rutile. Sand has a low content of REE ranging from 47.56 to 185.26ppm. The phosphorite pseudonodules underwent a detailed mineralogical and chemical analysis. They are composed of francolite, quartz, illite, glauconite, feldspar and minor heavy minerals: zircon and monazite. For the first time, the whole spectrum of REE was analysed in pseudonodules. The I.REE content in the nodules ranges from 177.37 to 354.18ppm. This level of REE indicates a serious need for further exploration and research of phosphorite pseudonodules within the whole Lower Cretaceous phosphorite series and moreover, also in the Eocene phosphorite formation in the Lublin region.

Sedimentological distinction in glacigenic sediments between load casts induced by periglacial processes from those induced by seismic shocks

Van Loon Antonius Johannes, Pisarska-Jamroży Małgorzata, Woronko Barbara

Geological Quarterly

2020

Vol. 64, No. 3

626--640

Loading processes and the resulting load structures induced by processes related to periglacial conditions are compared to those induced by seismic shocks. The load structures themselves are relatively easily recognizable but the responsible trigger mechanism is, though depending on the geological context, commonly difficult to establish. Load structures like load casts, pseudonodules, ball-and-pillow structures and flame structures are commonly ascribed to instable density gradients within sediments and to differential loading, but their formation always requires liquefaction. In glacigenic sediments, deformation structures have most commonly been ascribed to periglacial processes (as a type of cryoturbations), but it becomes ever more clear that glacigenic sediments can, particularly during ice-front fluctuations, be affected by faulting-related earthquakes (due to glacio-isostatic adjustment), and the thus triggered seismic shocks may result in deformations, including - most commonly - load structures. We inventory the evidence that may help to distinguish, on the basis of textural and structural features, load structures with a seismic origin from those that result from periglacial processes, taking into account that truly diagnostic criteria do not exist.