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Number of results: 6
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Abstract

The mid-Ludfordian pronounced, positive carbon isotope excursion (CIE), coincident with the Lau/kozlowskii extinction event, has been widely studied so far in shallow-water, carbonate successions, whereas its deep-water record remains insufficiently known. The aim of this research is to reconstruct the sedimentary environments and the palaeoredox conditions in the axial part of the Baltic-Podolian Basin during the event. For these purposes, the Pasłęk IG-1 core section has been examined using microfacies analysis, framboid pyrite diameter and carbon isotope measurements. The prelude to the event records an increased influx of detrital dolomite interpreted as eolian dust, coupled with a pronounced decrease in the diameter of the pyrite framboids, indicating persistent euxinic conditions across the event. The event climax is recorded as the Reda Member and consists of calcisiltites, composed of calcite microcrystals (‘sparoids’), which are interpreted as suspensoids induced by phytoplankton blooms in the hipersaturation conditions present in the epipelagic layer of the basin. Both the prelude and climax facies show lamination, interpreted as having resulted from periodical settling of marine snow, combined with hydraulic sorting within a ‘benthic flocculent layer’, which additionally may be responsible for a low organic matter preservation rate due to methanogenic decomposition. Contrary to the observed basinward CIE decline in the benthic carbonates in the basin, the Reda Member records an extremely positive CIE (up to 8.25‰). Given the pelagic origin of the sparoids, the CIE seems to record surface-water carbon isotope ratios. This points to a large carbon isotope gradient and kinetic fractionation between surface and bottom waters during the mid-Ludfordian event in a strongly stratified basin. The Reda facies-isotope anomaly is regarded as undoubtedly globally triggered, but amplified by the stratified and euxinic conditions in the partly isolated, Baltic-Podolian basin. Hence, the common interpretation of the basin record as representative for the global ocean needs to be treated with great caution.

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Authors and Affiliations

Wojciech Kozłowski
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Abstract

The collections of the PAN Kórnik Library include one of the most interesting illuminated manuscripts of “Digestum vetus” made at the request of Emperor Justinian. The manuscript is marked by a very rich iconographic programme including 25 figurative initials and more than 230 marginal illustrations. Both types of image excellently correlate with the text of the legal manuscript and the marginal illustrations constitute a visual commentary to it. The manuscript contains a commentary by Accursius (Glossa ordinaria) as well as many earlier pre-accursian glosses. The manuscript was brought to Poland by Dziersław of Karnice, a scholaster from Płock, in the 15th century. He purchased it during his stay in Italy, where he studied law from 1469 until 1471. The manuscript spent the next 300 years in Plock, in the library of the cathedral chapter. It was subsequently purchased by Tadeusz Czacki, who added it to the collections of the Poryck Library. After a few years, the manuscript was bought by Adam Jerzy Czartoryski, who made it a part of the collections of the Puławy Library. Finally, the manuscript was brought to the Kórnik Library founded by the Działyński family.

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Authors and Affiliations

Wojciech Baran-Kozłowski
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Abstract

This contribution presents the record of an abundant assemblage of well-preserved, thallophytic noncalcified algae and of an epibiotic form that has been recognised as a putative graptolite from the upper Silurian (Ludlow, Gorstian–Ludfordian) of Podolia (western part of Ukraine). The sediments represent a shallow peritidal zone of the shelf. A new genus and species, Voronocladus dryganti, belonging to the Dasycladales Pascher, 1931, is established. Most of the specimens representing the algal thallus are overgrown by problematical epibiotic graptolites, described as Podoliagraptus algaeoides gen. et sp. nov. This phenomenon is explained as an epiphytic mode of life of the putative graptolite on algae, and is herein compared to recently known coexistences of algae with other organisms. The excellent state of preservation, and the abundance of studied Dasycladales algae and epibiotic problematics indicate that the investigated mudstone layer can be treated as a ‘Konservat Lagerstätte’ sensu Seilacher (1970).
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Authors and Affiliations

Stanisław Skompski
1
Anna Kozłowska
2
Wojciech Kozłowski
1
Piotr Łuczyński
1

  1. University of Warsaw, Faculty of Geology, Żwirki i Wigury 93, 02-089 Warszawa, Poland
  2. Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, 00-818 Warszawa, Poland

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