The rank of climatic oscillations during MIS 11c (OHO and YHO) and post-interglacial cooling during MIS 11b and MIS 11a in eastern Poland

Lacustrine sediments representing Marine Isotope Stage 11 (MIS 11) were found in Hermanów (SE Poland) in a present-day closed depression under a thin cover of Weichselian and Holocene deposits (1.4 m). These sediments filled a palaeolake created as a result of melting of a dead-ice block at the end of MIS 12. Geological research has excluded the presence of an ice sheet during MIS 12 in this area. The lobe of the ice sheet of this glaciation was located several kilometres to the west of Hermanów. The palaeolake was part of a larger palaeolakeland in southeastern Poland, formed during MIS 11. The palaeomorphology of this interglacial is evident in the contemporary relief of the area and the outline of the lakes corresponds to the pattern of the closed palaeodepressions. Based on the record of sediments from Hermanów, a new perspective regarding the sub-division of MIS 11 is presented. Two regressive phases are observed in the Holsteinian Interglacial (MIS 11c) - OHO and YHO. The subsequent substages with five cold fluctuations according to the newest stratigraphic standards should be assigned to MIS 11b with a very clear cooling and a slightly warmer MIS 11a. Carbon isotopic composition of organic matter corroborates geological and environmental analysis. The isotopic composition suggests two cooling periods: OHO and MIS 11b. Stable climatic conditions with little temperature fluctuations persisted between the cooling periods

Gypsum mineralization in hieroglyphic beds of the Jankowa anticline – preliminary research results (Outer Western Carpathians)

Sulfate mineralization occurs in almost all lithostratigraphic beds of the Carpathians and has been described for at least the last century. While carrying out cartographic studies near Bobowa, a new site of gypsum mineralization was discovered within the hieroglyphic beds of the Jankowa anticline. The gypsum crystals found there reach up to several centimetres in length and, so far, no similar ones have been described in the Carpathian flysch deposits. Gypsum from Jankowa occurs in the form of intergrowth and twinnings, rosettes and larkspurs, and vein fillings

The geochemical and isotopic carbon cycle in an urban pond in the City of Wroclaw

The aim of this study was a recognition of the carbon cycle in a small anthropogenic reservoir located in Wrocław (SW Poland). The research investigated the geochemical processes and isotopic interactions in the water column as well as those between the water column and the sediment. Moreover, an attempt was made to identify the sources of carbon in the studied water body. Observations of temporal and spatial (vertical and horizontal) geochemical trends were the subject of this research. Chemical and isotopic analyses were the main tool used in this study. A total of 49 samples of water, sediment and plants were prepared, with sampling carried out in the period from October 2015 to May 2017. Two periods: autumn and spring were chosen for the study. During the autumn cycle, smaller variations in the values of δ13C in DIC were found compared to the spring cycle. The enrichment of dissolved inorganic carbon (DIC) in the heavy isotope during the spring period was caused by the dynamic growth of microorganisms. The process of assimilative reduction of dissolved inorganic carbon by aquatic organisms, which use inorganic carbon in biochemical reactions, occurred in the reservoir. This process led to an enrichment of DIC in the 13C isotope. The analysis of the sedimentary organic carbon revealed a greater enrichment in the heavy isotope of carbon (by about 3‰) in April compared to May. This is due to the growth of microorganisms responsible for degradation of sedimentary organic matter and plant detritus. The sediment and the water column were shown to interact through the exchange of carbon

Variability of sulfur speciation in sediments from Sulejów,Turawa and Siemianówka dam reservoirs (Poland)

A study on sulfur circulation in sediments wascarried out in dam reservoirs (Sulejów, Siemianówka, Turawa)with different hydrological and age characteristicsas well as with a different level of sediment accumulationand organic matter content.Differences in the isotopic composition of SO2−4 in the watercolumn and small variations in the concentration ofthis ion were observed in the Turawa reservoir. The investigationsdid not show vertical variation in the watercolumnconcentrations and isotopic composition. This isdue to the small depths of the reservoir and mixing of water.A part of sulfate sulfur from the water column is reducedby incorporating it into cell structures, while a partof it is deposited in the sediment. The study revealed asmall exchange of SO2−4 between thewater column and thesediment. Depending on the season of the year and thesediment sampling site, biogeochemical transformationsof sulfur species are observed.A significant variation in the biogeochemical processeswas found between the Siemianówka and Sulejów reservoirs,both in the concentrations and in the isotopic compositionof particular sulfur species. This primarily resultsfrom the different characteristics of either of these reservoirs(flows, sedimentation, and material discharge to thelake). The main source of sulfur supplied to the sedimentsin the Siemianówka reservoir is organic sulfur contained inorganic matter deposited at the bottom. In the sediment,organic sulfur is bacterially oxidized and fixed as SO2−4 .This is manifested in a substantial enrichment of sulfate in34S. The presence of polysulfides was found in both reservoirs,but a distinct depletion of δ34S(S2−) in the light sulfurisotope was observed in the Siemianówka reservoir. Ina part of the Sulejów reservoir, polysulfides are oxidized toSO2−4 ,probably at the sediment/water interface

Preliminary results of sulphur isotope studies on sulfides from selected ore deposits and occurrences in the Karkonosze–Izera Massif (the Sudety Mts., Poland)

Preliminary sulphur isotope data are presented for selected ore deposits and occurrences in the Karkonosze-Izera Massif, namely, polymetallic mineralization sites at Budniki, Ciechanowice, Izerskie Garby and Sowia Dolina, and the pyrite deposit at Wieściszowice. The data reveal two populations of δ34S values: from 2.74 to 3.95‰ (pyrrhotites and pyrites in Sowia Dolina, and some pyrites in Wieściszowice) and from 0.79 to 1.8‰ (pyrites in Budniki, Ciechanowice and Izerskie Garby, and some pyrites from Wieściszowice). All of the data are indicative of endogenic sulphur typical of hydrothermal mineralization despite the genetic differences between the sites

Evaluation of acidogenesis products’ effect on biogas production performed with metagenomics and isotopic approaches

Abstract Background During the acetogenic step of anaerobic digestion, the products of acidogenesis are oxidized to substrates for methanogenesis: hydrogen, carbon dioxide and acetate. Acetogenesis and methanogenesis are highly interconnected processes due to the syntrophic associations between acetogenic bacteria and hydrogenotrophic methanogens, allowing the whole process to become thermodynamically favorable. The aim of this study is to determine the influence of the dominant acidic products on the metabolic pathways of methane formation and to find a core microbiome and substrate-specific species in a mixed biogas-producing system. Results Four methane-producing microbial communities were fed with artificial media having one dominant component, respectively, lactate, butyrate, propionate and acetate, for 896 days in 3.5-L Up-flow Anaerobic Sludge Blanket (UASB) bioreactors. All the microbial communities showed moderately different methane production and utilization of the substrates. Analyses of stable carbon isotope composition of the fermentation gas and the substrates showed differences in average values of δ13C(CH4) and δ13C(CO2) revealing that acetate and lactate strongly favored the acetotrophic pathway, while butyrate and propionate favored the hydrogenotrophic pathway of methane formation. Genome-centric metagenomic analysis recovered 234 Metagenome Assembled Genomes (MAGs), including 31 archaeal and 203 bacterial species, mostly unknown and uncultivable. MAGs accounted for 54%–67% of the entire microbial community (depending on the bioreactor) and evidenced that the microbiome is extremely complex in terms of the number of species. The core microbiome was composed of Methanothrix soehngenii (the most abundant), Methanoculleus sp., unknown Bacteroidales and Spirochaetaceae. Relative abundance analysis of all the samples revealed microbes having substrate preferences. Substrate-specific species were mostly unknown and not predominant in the microbial communities. Conclusions In this experimental system, the dominant fermentation products subjected to methanogenesis moderately modified the final effect of bioreactor performance. At the molecular level, a different contribution of acetotrophic and hydrogenotrophic pathways for methane production, a very high level of new species recovered, and a moderate variability in microbial composition depending on substrate availability were evidenced. Propionate was not a factor ceasing methane production. All these findings are relevant because lactate, acetate, propionate and butyrate are the universal products of acidogenesis, regardless of feedstock