The Nowa Sól deposit is a part of the newly discovered Northern Copper Belt and is situated some 30 km NW of the Lubin–Sieroszowice mining district (the so-called New Copper District) in SW Poland. The ore horizon spans across the upper part of the Lower Permian (Rotliegend) terrestrial redbeds and the lower part of the Upper Permian (Zechstein) marine rocks. It comprises three lithotypes: sandstone, shale and carbonate. The high-grade shale ore has polymetallic characteristics and is a crucial host for by-product metals such as Ag, Co and Ni (studied in this paper), but also Mo, V and Re. The results of bulk-rock and electron microprobe as well as mineralogical (optical and scanning electron microscope) data of the mineralized, organic-rich shale ore from the Nowa Sól deposit are presented. This thin stratigraphic horizon, ranging from 0.06 to 0.59 m, shows notable concentrations of critical metals, including on average 15.9 wt% Cu, 715 grams per tonne (g t ^-1 ) Ag, 318 g t ^-1 Co and 345 g t ^-1 Ni. It constitutes less than 10% of the total ore mass, but accounts for 36% of the Ag, 40% of the Ni and 42% of the Co found within the deposit. The ore sulfides in the mineralized shale in the Nowa Sól deposit include chalcocite, djurleite and bornite, accompanied by digenite, covellite, tennantite, galena, sphalerite and pyrite. The Ag content within the Cu sulfides exhibits a linear decrease: chalcocite > djurleite > bornite. Three primary Ag minerals are identified within the shale ore, namely native Ag, Ag amalgam and stromeyerite. Two types of Ag amalgam are observed: Hg-rich and Hg-poor. Cobaltite and gersdorffite represent the primary Co and Ni minerals, occurring as micrometre-sized inclusions within chalcocite and djurleite. Textural observations suggest that the Ag, Co and Ni mineralization postdates the major phase of Cu sulfide precipitation. It is shown that in the Nowa Sól deposit, the Kupferschiefer horizon has acted as a geochemical barrier for the above-mentioned metals during protracted time, from early syndepositional to late epigenetic stage of basin evolution. Supplementary material: The supplementary material contains the results of the electron microprobe analyses and the specific experimental conditions employed for these analyses – available at https://doi.org/10.6084/m9.figshare.c.6873631

Rosnące ceny fosforytów i nawozów fosforanowych, silna koncentracja producentów ograniczona do kilku państw na świecie, wyjątkowe znaczenie fosforu w rolnictwie, a dodatkowo brak możliwości jego substytucji to czynniki, które powodują, że fosforyty uznane zostały za surowce krytyczne. Alternatywą dla importu i sposobem na osiągnięcie bezpieczeństwa dostaw może być rozszerzenie i eksploatacja własnej bazy zasobowej. W Polsce fosforyty z północnego obrzeżenia Gór Świętokrzyskich wydobywane były metodą podziemną, której zaniechano od początku lat 70. XX wieku ze względu na brak opłacalności wydobycia. Jednakże w Polsce wschodniej i południowo-wschodniej występują płytko konkrecje fosforytowe wieku eoceńskiego, które mogą mieć lokalnie znaczenie złożowe, a wydobycie ich może odbywać się metodą odkrywkową. Ekonomika wydobycia w płytkich odkrywkach nie wymaga tak rygorystycznych parametrów granicznych dla złóż fosforytów jak obecnie obowiązujące, które dobrane są pod warunki eksploatacji metodą podziemną. W publikacji autorzy przeanalizowali współczesne uwarunkowania opłacalności eksploatacji złóż fosforytów, m.in., dynamikę zmian cen fosforytów, przegląd granicznych parametrów złożowych projektów fosforytowych na świecie i ekonomikę odkrywkowej eksploatacji kopaliny, gdzie jako punkt odniesienia (w Polsce) przyjęto kopalnię kruszyw o eksploatacji mieszanej (w części spod lustra wody). W efekcie zaproponowano dla eoceńskich fosforytów w Polsce nowe, graniczne parametry definiujące złoże i jego granice.

Based on the reinterpretation of gravimetric, magnetic, seismic and magnetotelluric studies, new features of the sub-Permian basement in the area between the Dolsk Fault and the Middle Odra Fault, SW Poland, are identified. Among numerous faults and lineaments indicated in the article, those limiting both the Wolsztyn–Pogorzela High and a positive anomaly in the Lower Silesian Basin, as well as the faults in the vicinity of the Odra River are particularly prominent. N-S oriented structural elements are also visible in the gravity image. One of them separates the Pogorzela High from the Wolsztyn High. In light of the obtained results, according to refraction seismic surveys, the Polish equivalent to the Mid-German Crystalline Rise is located farther north from commonly accepted position within the Middle Odra Metamorphic Complex. The study results, supported by data from the neighboring area of Germany, may be important for further prospecting for sediment-hosted Cu and other metal deposits. The reprocessing of archival geophysical data using method of effective reflection coefficients (ERC) enabled the creation of more accurate structural model of ore series within the area of the Nowa Sól deposit in SW Poland. In terms of mineral resource prospects, this creates the possibility of applying new results from the study area to the similar zones in the corresponding part of Germany, which is the area between the phyllite zone and the Harz Mountains hosting very diverse and rich mineralization.

The Northern Copper Belt is located in south-western Poland, a region well known for its copper and silver occurrences of varying significance. This area also includes the abandoned mines of the North-Sudetic Trough (Old Copper District), as well as the currently active New Copper District in the southern part of the Fore- Sudetic Monocline. The vast exploration programme of Miedzi Copper Corp. initiated in 2011 in the northern, deeper part of the Fore Sudetic Monocline provided new data about the deeper parts of this geological unit, located north of the known deposits. A number of prospective areas with Cu-Ag mineralization were investigated, which ultimately resulted in the discovery of three new Cu-Ag deposits. Both the prospective areas and the documented deposits form the so-called Northern Copper Belt, which as a whole has high potential for the identification of new ore deposits and an increase in resources. A description of these three new deposits is provided along with characteristics of the areas of their possible extension, and the additional prospective areas with hypothetical and speculative resources. The new deposits are compared to other Polish Cu-Ag ore deposits, with an emphasis on differences in their geological structure and mineralogy. The paper also presents a brief summary of the applied new exploration tools which have led to this discovery.

The discovery of the Northern Copper Belt in SW Poland is a result of an extensive exploration project with a key role played by various science-related methods. The project relied on mapping the distribution of mineral zones in the entire Fore-Sudetic Monocline, a unit known for its occurrences of Cu-Ag orebodies. This approach involved the examination of historical drill cores from over 400 oil and gas holes in this area, with the collection of samples for laboratory analyses. A close relationship was confirmed between the distribution of orebodies and the transformation of organic matter. Rock-Eval pyrolysis was also performed on selected samples. The tests of rock specimens were accompanied by the reprocessing of historical gravimetric and seismic surveying results. Field magnetotelluric surveying was also performed in certain areas. This phase resulted in the identification of areas with a high probability of finding the best ore, allowing for the initiation of the drilling stage. So far, 37 exploratory boreholes have been drilled in those locations, nearly all of them with highly positive results. The Northern Copper Belt consists of three deposits, Nowa Sól, Mozów, and Sulmierzyce North, along with numerous prognostic areas distributed therebetween. The future production of copper, silver, and the accompanying valuable elements presents a chance to provide the whole of Europe with a new plentiful supply of those critical raw materials.