Oligocene plant assemblage from Rebiszow, Lower Silesia: First “volcanic flora” from Poland

Fossil plant macroremains preserved in laminated diatomites from Łysa Góra near Rębiszów, Lower Silesia, have been documented for the first time. The fossil assemblage consists mostly of leaves, but fruits, seeds and sporadic flowers also occur. Forty-three identified taxa represent nineteen plant families: Aceraceae, Berberidaceae, Betulaceae, Cornaceae, Cupressaceae, Elaeocarpaceae, Ericaceae, Fagaceae, Lauraceae, ?Leguminosae, ?Meliaceae, Magnoliaceae, Pinaceae, Rhamnaceae, Rosaceae, Salicaceae, Tilioideae, Ulmaceae, Vitaceae, and one incertae sedis. The prevalence of entire margined leaves, mostly represented by Majanthemophyllum basinerve and Daphnogene cinnamomifolia, and a significant presence of Calocedrus suleticensis and Liriodendron haueri, are characteristic features of the Rębiszów flora. The composition of the plant assemblage points to a mesophytic forest with some riparian elements and suggests favourable, warm climatic conditions. Radiometrically dated basalts overlying fossiliferous layers and composition of palynoflora suggest at least Chattian (late Oligocene) age. The lithology and floristic composition link the Rębiszów flora with the so-called volcanic floras of the Nerchau-Flörsheim or Kleinsaubernitz floristic complex (Oligocene) from Germany and Czech Republic with Suletice-Berand flora being especially close

Palynology of Lower Oligocene brown coal and lowermost Middle Miocene sand deposits from the Łukowa-4 borehole (Carpathian Foredeep, SE Poland) : implications for palaeogeographical reconstructions

Brown coal and overlying sand strata from the Łukowa-4 borehole, located in the northeastern sector of the Carpathian Foredeep in Poland, were studied for palynology. These strata are underlain by Upper Eocene sands, and covered by Middle Miocene rocks. Coal beds yielded infrequent sporomorphs and freshwater algae Botryococcus. The presence of the latter indicates that these deposits accumulated in a freshwater environment whereas sporomorph assemblages point to the presence of mixed forests with a significant portion of thermophilous taxa. Age of the coal beds has been established based both on the presence of species that appear for the last time in the Early Oligocene, and on the similarity with sporomorph spectra from the Lower Oligocene of the Polish Lowlands. Overlying sands yielded marine dinoflagellate cysts, which point to a marine sedimentary setting, and frequent sporomorphs. The latter indicate the presence of mixed mesophytic forests, bush swamps, swamp forests, and riparian forests in the vicinity of lacustrine environments. Stratigraphic analysis of dinoflagellate cyst and sporomorph assemblages suggests that the sands accumulated in early stages of Miocene transgression in the Carpathian Foredeep in the latest Early–early Middle Miocene. Our climatic interpretation of the sporomorph spectra suggests that the climate during deposition of the strata was relatively warm, although less frequent thermophilous taxa recorded in the Miocene sands suggest a slightly cooler climate than that deducted from the spectra yielded by the underlying Lower Oligocene coal beds. Correlation of Lower Oligocene coal beds with neighbouring coeval marine sands suggests diverse morphological conditions in the Carpathian foreland at that time, partly covered by a sea, and partly emerged. A similar, morphologically diverse basement in the Carpathian foreland favoured accumulation of Lower Miocene phytogenic deposits. A similar stratigraphic position of both Lower Oligocene and Lower Miocene coal beds in the Carpathian Foredeep may result in a false correlation of these strata devoid of fossils, which are commonly regarded as Miocene

Pollen assemblage and environmental DNA changes: A 4300-year-old bat guano deposit from Jamaica

The discovery of two undisturbed caves in Jamaica with 14C and 210Pb dating indicating that the oldest layers of guano were ca. 200 years old in the first cave (81 cm long core), and as much as 4300 years old in the second cave (129 cm long core) provides exciting possibilities to examine past ecological communities. We analyzed genetic and pollen profiles in these ancient bat guano deposits and revealed DNA sequences most similar to arthropods, mainly insects such as caddisflies (Trichoptera), butterflies (Lepidoptera) and mayflies (Ephemeroptera), suggesting a potential source for past dietary data. Palynological analysis failed to recover well-preserved pollen grains and spores older than ca. 200 years, however in layers preserving pollen, angiosperms were the most abundant plants observed, with a regular occurrence of the potato (Solanaceae) and pepper families (Piperaceae), which are frequently bat-dispersed. In general, changes in frequency of particular plant taxa appear to reflect changes of vegetation and land use in the cave vicinity; however, some changes could be linked to hurricanes, leading to forest canopy damage and promoting the growth of light-demanding species such as guarumo (Cecropia). Higher amounts of mangrove (Rhizophora) pollen have also been recorded in the periods of heavy hurricane activities. Our data highlight the value of bat guano deposits in caves as a resource for the analysis of past ecological systems and stress the conservation values of these deposits

Investigation of inclusions trapped inside Libyan desert glass by Raman microscopy

Several specimens of Libyan Desert Glass (LDG), an enigmatic natural glass from Egypt, were subjected to investigation by micro-Raman spectroscopy. The spectra of inclusions inside the LDG samples were successfully measured through the layers of glass and the mineral species were identified on this basis. The presence of cristobalite as typical for high-temperature melt products was confirmed, together with co-existing quartz. TiO2 was determined in two polymorphic species, rutile and anatase. Micro-Raman spectroscopy proved also the presence of minerals unusual for high-temperature glasses such as anhydrite and aragonite