Dataset Information

The Middle Miocene freshwater mollusk fauna of Lake Gacko (SE Bosnia and Herzegovina): taxonomic revision and paleoenvironmental analysis.

ABSTRACT: AbstractThe early Middle Miocene Lake Gacko was part of the Dinaride Lake System (DLS) and gave rise to a poorly known freshwater mollusk fauna. This was subject to malacological studies from the late 19th century onwards. Herein, we provide the first thorough taxonomic survey of Lake Gacko including revisions of several taxa. A total amount of 1,077 specimens was obtained from 17 samples, comprising at least 11 freshwater and 2 terrestrial gastropod species and 6 bivalve species. So far, none of the described taxa has been documented outside the Dinarides and the DLS, respectively. The fauna shows variable overlap with other paleolakes of the DLS, proofing once more the complex biogeographic patchwork of this system. The current paleoenvironmental reconstructions are tested and refined by application of a statistical analysis. This confirms the partition of the sedimentary history of Lake Gacko into three major depositional phases responding to astronomically forced climate changes. The low diverse mollusk assemblage in the initial phase, with abundant pulmonate and rissooid gastropods, signals a more arid climate with lowered lake level. During the second interval, the fauna becomes more diverse with common rissooid and melanopsid gastropods. It represents a more humid interval with enhanced precipitation and increased lake level, entailing the installation of a perennial lacustrine environment. The final phase is a return to arid conditions with the same elements as in the initial pulmonate?rissooid assemblage. The sphaeriid Pisidium vukovici n. sp. is introduced as new species. (© 2013 WILEY?VCH Verlag GmbH & Co. KGaA, Weinheim)

SUBMITTER: Neubauer TA

PROVIDER: S-EPMC7168484 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:In the Early to Middle Miocene, a series of lakes, collectively termed the Dinaride Lake System (DLS), spread out across the north-western part of the Dinaride-Anatolian continental block. Its deposits, preserved in numerous intra-montane basins, allow a glimpse into the palaeoenvironmental, palaeobiogeographic and geodynamic evolution of the region. Lake Gacko, situated in southern Bosnia and Herzegovina, is one of the constituent lakes of the DLS, and its deposits are excellently exposed in the Gračanica open-cast coal-mine. A detailed study of the sedimentary succession that addresses facies, sediment petrography, geophysical properties, and fossil mollusc palaeoecology reveals repetitive changes in lake level. These are interpreted to reflect changes in the regional water budget. First-order chronologic constraints arise from the integration of radio-isotopic and palaeomagnetic data. (40)Ar/(39)Ar measurements on feldspar crystals from a tephra bed in the upper part of the sedimentary succession indicate a 15.31 ± 0.16 Ma age for this level. The reversed magnetic polarity signal that characterises the larger part of the investigated section correlates to chron C5Br of the Astronomically Tuned Neogene Timescale. Guided by these chronologic data and a detailed cyclostratigraphic analysis, the observed variations in lake-level, evident as two ~ 40-m and seven ~ 10-m scale transgression-regression cycles, are tuned to ~ 400-kyr and ~ 100-kyr eccentricity cycles. From the tuning, it can be inferred that the sediments in the Gacko Basin accumulated between ~ 15.8 and ~ 15.2 Ma. The economically valuable lignite accumulations in the lower part of the succession are interpreted to indicate the development of swamp forests in conjunction with lake-level falls corresponding to ~ 100-kyr eccentricity minima. Pedogenesis, rhizoliths and palustrine carbonate breccias in the upper part of the section reveal long-term aridity coinciding with a ~ 400-kyr eccentricity minimum. Eccentricity maxima are interpreted to trigger lake-level high-stands. These are accompanied by eutrophication events caused by enhanced denudation of the surrounding basement and increased detrital input into the basin. The presented age model proves that Lake Gacko arose during the Middle Miocene Climatic Optimum and that the optimum climatic conditions triggered the formation of this long-lived lake.

Project description:This study aimed to describe street food and takeaway food purchasing patterns in Sarajevo and Banja Luka, throughout the day and by city location. A cross-sectional evaluation of street food and takeaway food customers was conducted in 2017. All eligible vending sites (n = 348) in the vicinity of selected markets and bus stops were included. Data on the food items purchased, and time and geographic location of the purchases were collected. A total of 755 customers purchased 929 food items. Takeaway venues showed higher customer influx (5.0 vs. 2.0 customers observed per 10 min of observation, p < 0.001) and buying rates (6.7 vs. 2.0 items bought per 10 min of observation, p < 0.001; 1.5 vs. 1.0 items bought per customer, p < 0.001) than street food sites. These rates were higher in city peripheries for street food venues, and in city centres for takeaway establishments. The purchase of industrial food products prevailed throughout the day in street food venues, whereas most takeaway purchases comprised homemade foods, with or without industrial beverages. The proportion of customers buying foods and beverages together was higher in takeaway venues (15.3% vs. 6.0%, p < 0.001), especially during lunchtime and in city centres. In street food vending sites, sweet and savoury snacks seemed to be preferred in the afternoon, whereas in takeaway food establishments, savoury pastries and main dishes were mostly purchased at breakfast or lunch, and bread during the morning. Soft drinks and industrial juices were frequently purchased in both types of vending site and at all hours of the day, particularly in the afternoon. Our findings provide an overview of street food and takeaway food buying habits and consumer demands in these cities, reflecting local food culture and dietary behaviours. The identification of the meal contexts and city sub-regions in which specific purchasing practices emerge point to potential priority targets. These insights can be useful when designing interventions adapted to the specificities of these food environments and the food habits of customers.

Dataset Information

The Middle Miocene freshwater mollusk fauna of Lake Gacko (SE Bosnia and Herzegovina): taxonomic revision and paleoenvironmental analysis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets