A multi-proxy approach to constrain reducing conditions in the Baltic Basin during the late Silurian Lau carbon isotope excursion

2021 ◽  
Vol 581 ◽  
pp. 110624
Author(s):  
Chelsie N. Bowman ◽  
Theodore R. Them ◽  
Marisa D. Knight ◽  
Dimitri Kaljo ◽  
Mats E. Eriksson ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Baltic Basin ◽  
Reducing Conditions ◽  
Carbon Isotope Excursion ◽  
The Baltic

scholarly journals Linking the progressive expansion of reducing conditions to a stepwise mass extinction event in the late Silurian oceans

Geology ◽  
2019 ◽  
Vol 47 (10) ◽  
pp. 968-972 ◽  
Author(s):  
Chelsie N. Bowman ◽  
Seth A. Young ◽  
Dimitri Kaljo ◽  
Mats E. Eriksson ◽  
Theodore R. Them ◽  
...  
Keyword(s):  
Mass Extinctions ◽  
Turnover Rates ◽  
Baltic Basin ◽  
Faunal Turnover ◽  
Isotope Data ◽  
Reducing Conditions ◽  
Carbon Isotope Excursion ◽  
Extinction Event ◽  
Mass Extinction Event ◽  
The Baltic

Abstract The late Ludlow Lau Event was a severe biotic crisis in the Silurian, characterized by resurgent microbial facies and faunal turnover rates otherwise only documented during the “big five” mass extinctions. This asynchronous late Silurian marine extinction event preceded an associated positive carbon isotope excursion (CIE), the Lau CIE, although a mechanism for this temporal offset remains poorly constrained. Here, we report thallium isotope data from locally reducing late Ludlow strata within the Baltic Basin to document the earliest onset of global marine deoxygenation. The initial expansion of anoxia coincided with the onset of the extinction and therefore preceded the Lau CIE. Additionally, sulfur isotope data record a large positive excursion parallel to the Lau CIE, interpreted to indicate an increase in pyrite burial associated with the widely documented CIE. This suggests a possible global expansion of euxinia (anoxic and sulfidic water column) following deoxygenation. These data are the most direct proxy evidence of paleoredox conditions linking the known extinction to the Lau CIE through the progressive expansion of anoxia, and most likely euxinia, across portions of the late Silurian oceans.

CERIUM ANOMALY ACROSS THE EARLY MISSISSIPPIAN KINDERHOOKIAN–OSAGEAN CARBON ISOTOPE EXCURSION

2019 ◽  
Author(s):  
Deborah C. Morales ◽  
◽  
Ganqing Jiang ◽  
Shichun Huang ◽  
Audrey Warren ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Carbon Isotope Excursion ◽  
Cerium Anomaly

Satellite altimetry of large lakes of the Baltic Basin

2014 ◽  
Author(s):  
S. A. Lebedev ◽  
Yu. I. Troitskaya ◽  
G. V. Rybushkina ◽  
M. N. Dobrovolsky
Keyword(s):  
Satellite Altimetry ◽  
Baltic Basin ◽  
Large Lakes ◽  
The Baltic

Reconstructing the Younger Dryas ice dammed lake in the Baltic Basin: Bathymetry, area and volume

2007 ◽  
Vol 57 (3-4) ◽  
pp. 355-370 ◽  
Author(s):  
Martin Jakobsson ◽  
Svante Björck ◽  
Göran Alm ◽  
Thomas Andrén ◽  
Greger Lindeberg ◽  
...  
Keyword(s):  
Younger Dryas ◽  
Baltic Basin ◽  
Dammed Lake ◽  
The Baltic ◽  
Area And Volume

scholarly journals Controlling Shipping Along the North European Trade Axis

1971 ◽  
Vol 24 (4) ◽  
pp. 553-556
Author(s):  
D. J. Lindsay
Keyword(s):  
Weather Conditions ◽  
North Coast ◽  
Baltic Basin ◽  
Long Distance ◽  
The North ◽  
Large Numbers ◽  
Straight Line ◽  
European Trade ◽  
Trade Route ◽  
The Baltic

By the North European Trade Axis is meant the trade route from Ushant and Land's End, up the English Channel, through the Dover Strait fanning out to serve eastern England, the north coast of continental Europe and leading to the Baltic Basin. Recent events in this area have left a feeling that some form of tightening of control is not only desirable, but is rapidly becoming imperative. There is a basic conflict between the two forms of shipping using the area: the local users who use the area more or less constantly, and the long-distance traders, usually much larger, which arrive in the area for a brief stay after a prolonged period at sea, which has usually been in good weather conditions. Frequently these latter ships have a very poor notion of the hornet's nest into which they are steaming when they arrive. The net result is all too often the same: the local users, with familiarity breeding contempt, wander about as they see fit, with scant regard for routing or the regulations; all too often the big ships arrive from sea with navigating staffs who are too confused, sometimes too ignorant—and sometimes too terrified—to do much more than blunder forward in a straight line hoping for the best. Quite obviously this is not a total picture, and there are large numbers of ships which navigate perfectly competently, but the minority of those which do not seem to be rising rapidly, and show every sign of continuing to increase.

Field evidence for coal combustion links the 252 My-old Siberian Traps with global carbon disruption

2021 ◽  
Author(s):  
Linda Elkins-Tanton ◽  
Steven Grasby ◽  
Benjamin Black ◽  
Roman Veselovskiy ◽  
Omid Ardakani ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbon Isotope ◽  
Flood Basalts ◽  
Siberian Traps ◽  
Field Evidence ◽  
Carbon Isotope Excursion ◽  
Show Evidence ◽  
Volcaniclastic Rocks ◽  
Atmospheric Changes ◽  
Global Carbon

<p>The Permo-Triassic Extinction was the most severe in Earth history. The Siberian Traps eruptions are strongly implicated in the global atmospheric changes that likely drove the extinction. A sharp negative carbon isotope excursion coincides within geochronological uncertainty with the oldest dated rocks from the Norilsk section of the Siberian flood basalts. The source of this light carbon has been debated for decades.</p><p>We focused on the voluminous volcaniclastic rocks of the Siberian Traps, relatively unstudied as potential carriers of carbon-bearing gases. Over six field seasons we collected rocks from across the Siberian platform and show the first direct evidence that the earliest eruptions particularly in the southern part of the province burned large volumes of a combination of vegetation and coal. Samples from the Maymecha-Kotuy region, from the Nizhnyaya Tunguska, Podkamennaya Tunguska, and Angara Rivers all show evidence of high-temperature organic matter carbonization and combustion.</p><p>Field evidence indicates a process in which ascending magmas entrain xenoliths of coal and carbonaceous sediments that are carbonized in the subsurface and also combusted either through reduction of magmas or when exposed to the atmosphere. We demonstrate that the volume and composition of organic matter interactions with magmas may explain the global carbon isotope signal, and have significantly driven the extinction.</p>

The recovery of early vertebrates and reef ecosystems following the late Silurian carbon isotope excursion: the Burgen outlier, Gotland, Sweden

2021 ◽  
Author(s):  
Emilia Jarochowska ◽  
Oskar Bremer ◽  
Alexandra Yiu ◽  
Tiiu Märss ◽  
Henning Blom ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Carbonate Platform ◽  
Fish Diversity ◽  
Global Environmental ◽  
Carbon Isotope Excursion ◽  
Low Diversity ◽  
Early Vertebrates ◽  
Carbonate Factory ◽  
Faunal Distribution ◽  
Rapid Regression

<p>The Ludfordian Carbon Isotope Excursion (LCIE) reached the highest known δ<sup>13</sup>C values in the Phanerozoic. It was a global environmental perturbation manifested in a rapid regression attributed to glacial eustasy. Previous studies suggested that it has also heavily affected the diversity of conodonts, early vertebrates and reef ecosystems, but the timing of the crisis and recovery remained complicated owing to the lateral variability of δ<sup>13</sup>C values in epeiric platforms and rapid facies shifts, which drove faunal distribution. One of the best records of this interval is available in the Swedish island of Gotland, which preserves tectonically undisturbed strata deposited in a Silurian tropical carbonate platform. We revisited the world-renowned collection of the late Lennart Jeppsson, hosted at the Swedish Museum of Natural History, Stockholm, which holds the key to reconstruct the dynamics of faunal immigration and diversification following the LCIE. Here we focus on the Burgen erosional outlier, which remained a mystery, as it had been correlated with the excursion strata, but preserved a high diversity of conodonts and reefal ecosystems. We re-examined key outcrops and characterized macro- and microfacies, as well as chemostratigraphy and unpublished fauna in the collection. Strata in the Burgen outlier represent back-shoal facies of the Burgsvik Oolite Member and correspond to the Ozarkodina snajdri Conodont Biozone. The shallow-marine position compared to the more continental setting of coeval strata in southern Gotland, is reflected in the higher δ<sup>13</sup>C<sub>carb</sub> values, reaching +9.2‰. The back-shoal succession in this outcrop includes reefs, which contain a large proportion of microbial carbonates and have therefore been previously compared with low-diversity buildups developed in a stressed ecosystem. However, the framework of these reefs is built by a diverse coral-stromatoporoid-bryozoan fauna, indicating that a high microbial contribution might be a characteristic of the local carbonate factory rather than a reflection of restricted conditions. In the case of conodonts, impoverishment following the LCIE might be a product of facies preferences, as the diverse environments in the outlier yielded at least 20 of the 21 species known from the Burgsvik Formation in Gotland. Fish diversity also returned to normal levels following the LCIE with an estimated minimum of 9 species. Thelodont scales appear to dominate samples from the Burgen outlier, which is in line with previous reports. Our observations highlight how palaeoenvironmental reconstructions inform fossil niche and diversity analyses, but also how fossil museum collections continuously contribute new data on past biodiversity.</p>

Factors controlling pore network development of thermally mature Early Palaeozoic mudstones from the Baltic Basin (N Poland)

2021 ◽  
pp. 105328
Author(s):  
P. Słomski ◽  
J. Szczepański ◽  
T. Topór ◽  
M. Mastalerz ◽  
A. Pluymakers ◽  
...  
Keyword(s):  
Pore Network ◽  
Network Development ◽  
Baltic Basin ◽  
Early Palaeozoic ◽  
The Baltic
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