Finds of Lithospermum Nuts at Archaeological Sites in Ukraine

Lithospermum officinale L. and Buglossoides arvensis (L.) I.M. Johnston [syn. Lithospermum arvense L.] nuts were found among the fossil grains and seeds in the materials of various archaeological cultures of the territory of Ukraine. These finds have attracted the researchers’ attention for their large number, which sometimes reaches tens of thousands. Why were our ancestors interested in these small, unattractive plants? They have neither brightly fragrant flowers, nor edible fruits. The oldest and largest find, more than 40,000 nuts of Lithospermum officinale L., was found in two pots from Trypillia settlement Ozhevo-Ostriv (the last phase of ВІ — В / I stages, Cucuteni A4) dated by the last third of the 5th millennium BC. For what purpose was such a number of nuts collected? In the article there is data on the finds of gromwell nuts in Europe and the reasons for their gathering. There are several of them: the usage of nuts for future crops and preparation of plants roots with red coloring; making beads from nuts; the usage of nuts in herbal medicine as diuretics, anesthetics and as an aphrodisiac. For what purpose was a large number of nuts collected by the residents of Trypillia settlement Ozhevo-Ostriv? The ancient population may have used nuts as a folk remedy and as a dye. However, the laying of vessels with nuts under the platform No. 4 at the Ozhevo-Ostriv settlement did not imply such household usage. Probably, these nuts were collected and placed in vessels for ritual purposes and they should be considered as ritual items. The finds in materials from other archaeological cultures are less numerous. It is possible that gromwell nuts were used as herbal medicine or as a dye. The gromwell nuts are also of interest to modern researchers. Thanks to recent studies by K. Pustovoytov and S. Riehl, the possibility of using biogenic carbonate from the shells of nuts for radiocarbon dating has been established. Thus, the biogenic carbonate of the nut shell is a new source of chronological information. The same researchers established the relationship between the isotopic composition of oxygen from the biogenic carbonate of nuts and climatic conditions.

Geochemical survey of Lake Balaton sediments: holocene paleoenvironment and paleoclimate

<p>In the winter of 2017 three undisturbed sediment cores were retrieved from the Szemes Basin of Lake Balaton. The sediments were sampled for AMS <sup>14</sup>C dating and we used 8 of the radiocarbon dates for age-depth modelling. Based on this, the investigated sediment sequence covers the entire Holocene and Late Glacial period and the bottom of the sediment is ca. ~16,000 cal yr BP old. X-ray fluorescence spectrometry (XRF) was used to reconstruct rapid changes in the element content of the lake sediment. The evaluation of the measured results makes it possible to reconstruct the changes in the discharge environment and lake water level that can be related to the climate and human impact. Based on the data, two major evaporation events can be observed at 5500 BP and 8100 BP. These results were also verified by oxygen isotope studies. To reconstruct the energy of the deposition environment, particle size analysis was performed. The obtained results confirmed that river sediments are common at the bottom of Lake Balaton sediments, while biogenic carbonate dominates in the upper, Holocene part of the sediment core. To identify each mineral phase in the sediment, X-ray diffraction (XRD) studies were used to determine the ratio of calcite to Mg-calcite. Based on our XRF measurements, focusing primarily on quantitative changes in magnesium and calcium, transmission electron microscopy (TEM) studies were performed, mainly in the Mg enrichment layer around 8100 BP. The precipitation of biogenic carbonate in Lake Balaton is still taking place, mainly in the form of calcite and Mg-calcite. Their relative proportions strongly depend on the Mg saturation of the water and the substrates on which they are separated. From our results we can draw conclusions about the possible previous deeper phases of the lake and the evaporation conditions of the water. The data obtained from transmission electron microscopy shows a good agreement with the results of the XRF measurement, the proportion of Mg-calcite increases around 8100 BP that likely indicate drier climatic conditions connectable to the well know 8.2 ka cal BP climatic reversal.</p>

Representative monitoring of the calcifying alga Phacotus lenticularis (Chlamydophyceae) in lentic ecosystems

The biogenic carbonate precipitation by the freshwater alga Phacotus lenticularis may play a role in long-term carbon (C) fixation that has not yet been quantified. This is partly due to the absence of a standardised methodology to representatively sample and assess the cell density and sedimentation of P. lenticularis in lakes. The objective of the present study was to define an adequate sampling methodology taking into account the spatiotemporal variation of P. lenticularis as well as the sedimentation and dissolution of calcite shells. Simultaneous measurements in three different lake sub-basins of Lake Grosser Ostersee, Germany, showed that the spatial cell density of P. lenticularis was similar in each sub-basin. At all sites, the vertical P. lenticularis cell density maxima corresponded with the slowly downshifting thermocline from depths of 2 to 6 m. During the entire growth period, composite samples from 0 to 7 m included 89% of the total P. lenticularis population. Lake bathymetry, as well as external factors like wind exposure, did not appear to affect the abundance of these calcifying algae. Sediment traps at a depth below the thermocline (at 7 m) and 1 m above the lake bottom recorded sedimentation rates of P. lenticularis shell halves (sh) between 1.1×106 and 1.1×108 sh m−2 d−1, while mean cell concentrations in the water column were between 1.1×108 and 1.7×109 shells per m². Sinking velocity ranged between 3 and 4 m d−1. Sediment from traps installed at a depth of 7 m did not reflect mean shell concentrations in the water column above. Dissolution of carbonates reduced the number of shells in sediment traps at the lake bottom and during the storage of samples. A laboratory experiment showed that even distilled water used for dilution during microscopic analysis led to dissolution of P. lenticularis shells. In conclusion, combined sampling of P. lenticularis from open water and sediment traps close to the lake bottom delivers a most representative assessment of biogenic carbonate precipitation. Due to dissolution effects, high temporal resolution along with appropriate sample preservation are crucial, whereas spatial representativeness was already achieved with low number of sampling sites per lake.

Biogenic carbonate mercury and marine temperature records reveal global influence of Late Cretaceous Deccan Traps

The climate and environmental significance of the Deccan Traps large igneous province of west-central India has been the subject of debate in paleontological communities. Nearly one million years of semi-continuous Deccan eruptive activity spanned the Cretaceous-Paleogene boundary, which is renowned for the extinction of most dinosaur groups. Whereas the Chicxulub impactor is acknowledged as the principal cause of these extinctions, the Deccan Traps eruptions are believed to have contributed to extinction patterns and/or enhanced ecological pressures on biota during this interval of geologic time. We present the first coupled records of biogenic carbonate clumped isotope paleothermometry and mercury concentrations as measured from a broad geographic distribution of marine mollusk fossils. These fossils preserve evidence of simultaneous increases in coastal marine temperatures and mercury concentrations at a global scale, which appear attributable to volcanic CO2 and mercury emissions. These early findings warrant further investigation with additional records of combined Late Cretaceous temperatures and mercury concentrations of biogenic carbonate.