High-resolution Sampling and Photogrammetry of the Permian-Triassic Boundary Within the Festningen Profile, Svalbard

2021 ◽  
Author(s):  
Lars Eivind Augland ◽  
Sverre Planke ◽  
Valentin Zuchuat ◽  
Morgan Jones ◽  
Kim Senger ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Outer Part ◽  
Easy Access ◽  
Tectonic Deformation ◽  
Pixel Resolution ◽  
Triassic Boundary ◽  
Ash Layer ◽  
Mass Extinction Event ◽  
Permian Triassic Boundary ◽  
Digital Outcrop

<p>The Permian period ended with a mass extinction event about 252 million years ago. A likely trigger of the mass extinction was the eruption of large volumes of magma which had moved through the Tunguska Basin in Siberia. The renowned Festningen section in the outer part of Isfjorden, western Spitsbergen, offers a c. 7 km long nearly continuous stratigraphic section of Lower Carboniferous to Cenozoic strata, where the end-Permian extinction interval is well-exposed. Tectonic deformation associated with the Paleogene West Spitsbergen fold-and-thrust-belt tilted the strata to near-vertical, allowing easy access along the shoreline. The section is a regionally important stratigraphic reference profile and is a key locality for geologists visiting Svalbard. The main objective of our fieldwork in September 2020 was to collect closely spaced mudstone (0.25 to 1 m interval) and ash layer (6 layers of 0.5 to 1.5 cm thickness) samples across the Festningen Permian-Triassic boundary for chemostratigraphic and geochronological assessments. Carbon isotope data reveal a well-defined negative deltaC13 excursion in the lower part of the Vardebukta Fm. Zircons are present in most of the ash layer samples and these will be dated at the University of Oslo TIMS U-Pb Isotope Geology Laboratory. In this contribution, we will also present a new digital outcrop model of the P-Tr boundary section acquired using a UAV (Mavic 2 Pro, 20MP Hasselblad camera). During acquisition, the maximum drone speed was set to 1 meter/second (i.e., “tripod mode”), and photographs were taken automatically at set time intervals (e.g., 1 photo every 5 seconds ≈ meters). The digital outcrop model offers a pixel resolution of 7.27 mm/pixel. The Festningen model will be available online through the Svalbox.no geoscience data platform.</p>

Marine Early Triassic Actinopterygii from the Candelaria Hills (Esmeralda County, Nevada, USA)

2019 ◽  
Vol 93 (5) ◽  
pp. 971-1000
Author(s):  
Carlo Romano ◽  
Adriana López-Arbarello ◽  
David Ware ◽  
James F. Jenks ◽  
Winand Brinkmann
Keyword(s):  
New Species ◽  
Mass Extinction ◽  
New Genus ◽  
Current Data ◽  
Early Triassic ◽  
Triassic Boundary ◽  
Bony Fishes ◽  
Mass Extinction Event ◽  
In The Beginning ◽  
Permian Triassic Boundary

AbstractA new locality for low-latitudinal, Early Triassic fishes was discovered in the Candelaria Hills, southwestern Nevada (USA). The fossils are derived from the lower Candelaria Formation, which was deposited during the middle–late Dienerian (late Induan), ca. 500 ka after the Permian-Triassic boundary mass extinction event. The articulated and disarticulated Osteichthyes (bony fishes), encompassing both Actinistia (coelacanths) and Actinopterygii (ray-fins), are preserved in large, silicified concretions that also contain rare coprolites. We describe the first actinopterygians from the Candelaria Hills. The specimens are referred toPteronisculus nevadanusnew species (Turseoidae?),Ardoreosomus occidentalisnew genus new species (Ptycholepidae), the stem neopterygianCandelarialepis argentusnew genus new species (Parasemionotidae), and Actinopterygii indet. representing additional taxa.Ardoreosomusn. gen. resembles other ptycholepids, but differs in its more angulate hyomandibula and lack of an elongate opercular process.Candelarialepisn. gen. is one of the largest parasemionotids, distinguished by its bipartite preopercle and scale ornamentation. Presented new species belong to genera (Pteronisculus) or families (Ptycholepidae, Parasemionotidae) that radiated globally after the mass extinction, thus underlining the striking similarities between Early Triassic (pre-Spathian) osteichthyan assemblages. The current data suggest that the diversity of low-latitudinal, Early Triassic bony fishes may have been greater than indicated thus far by the fossil record, probably due to sampling or taphonomic failure. All 24 fossils from the Candelaria Hills represent mid-sized or large osteichthyans, confirming the obvious absence of very small species (≤ 10 cm adult body length) in the beginning of the Mesozoic Era—even in low latitudes.UUID:http://zoobank.org/6a66ac96-d6b7-4617-94db-5a93cdb14215

Magnetostratigraphy across the end-Permian mass extinction event from the Meishan sections, southeastern China

Geology ◽  
2021 ◽  
Author(s):  
Min Zhang ◽  
Hua-Feng Qin ◽  
Kuang He ◽  
Yi-Fei Hou ◽  
Quan-Feng Zheng ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Southeastern China ◽  
Triassic Boundary ◽  
Biodiversity Crisis ◽  
Normal Polarity ◽  
Mass Extinction Event ◽  
Geomagnetic Polarity ◽  
Permian Mass Extinction ◽  
Permian Triassic Boundary ◽  
Geomagnetic Polarity Time Scale

The end-Permian mass extinction (EPME) has been recorded as the most severe biodiversity crisis in Earth’s history, although the timing of the marine and terrestrial extinctions remains debatable. We present a new high-resolution magnetostratigraphic succession across the EPME and the Permian-Triassic boundary (PTB) from the Meishan sections in southeastern China, which contain the global boundary stratotype section and point (GSSP) for the base of the Triassic (also the Induan Stage) and the base of the Changhsingian Stage. We identified five normal and five reverse magnetozones, including MS1n to MS5n and MS1r to MS5r, from oldest to youngest, in the Changhsingian and Induan Stages. The Induan Stage was determined to consist of two polarity intervals, where the upper one is reverse (MS5r), and the lower one is normal (MS5n). The Changhsingian Stage is dominated by normal polarity, intercalated with four short-term reverse magnetozones (MS1r to MS4r). Consequently, the PTB and the Wuchiapingian-Changhsingian boundary are clearly located in MS5n and MS1n, respectively. These new magnetostratigraphic results provide a potential reference geomagnetic polarity pattern with which to refine the geomagnetic polarity time scale for the EPME and the Permian-Triassic transition.

scholarly journals Siberian Trap volcanism, global warming and the Permian-Triassic mass extinction: New insights from Armenian Permian-Triassic sections: Comment

2021 ◽  
Author(s):  
Micha Horacek ◽  
Leopold Krystyn ◽  
Aymon Baud
Keyword(s):  
Global Warming ◽  
Mass Extinction ◽  
Seawater Temperature ◽  
Correct Position ◽  
Triassic Boundary ◽  
Temperature Changes ◽  
Siberian Trap ◽  
Stratotype Section ◽  
Permian Triassic Boundary

Joachimski et al. carried out geochemical investigations to study seawater temperature changes and their potential triggers across the Permian-Triassic Boundary (PTB). Unfortunately, in our opinion, an incorrect biochronology was applied to define the PTB, and the existing alternative was not considered, nor the reasoning explained. As a consequence, Joachimski et al. report diachronous temperature changes for the investigated Chanakhchi section with respect to the global stratotype section and point (GSSP) in Meishan, China. This discrepancy disappears when the, in our view, correct position of the PTB is adopted by using the proper biochronology.

scholarly journals Rebound from the Permian/Triassic mass extinction: evolutionary paleoecology of sequential early Triassic (Smithian to Spathian) marine paleocommunities

1992 ◽  
Vol 6 ◽  
pp. 261-261
Author(s):  
Jennifer K. Schubert ◽  
David J. Bottjer
Keyword(s):  
Mass Extinction ◽  
Lower Triassic ◽  
Upper Permian ◽  
Early Triassic ◽  
Triassic Boundary ◽  
Biotic Recovery ◽  
The Status ◽  
Life Habits ◽  
Stalked Crinoids ◽  
Permian Triassic Boundary

The Permian/Triassic mass extinction, the most devastating biotic crisis of the Phanerozoic, has aroused considerable scientific interest. However, because research has focused primarily on understanding the magnitude of diversity reduction and causal mechanisms, the nature and timing of biotic recovery in the Early Triassic are still poorly understood. Marine limestones in the Lower Triassic Moenkopi Formation, which disconformably overlies the Upper Permian of southeastern Nevada and southern Utah, provide a rare opportunity to study the aftermath of the mass extinction in shallow water carbonate environments.Two contemporaneous members of the Moenkopi record the first marine incursion from the northwest in the Early Triassic (Smithian), the very sparsely fossiliferous marginal marine Schnabkaib Member in Nevada and southwest Utah, and the Sinbad Limestone in central-southern Utah, a marine unit dominated by amalgamated and condensed fossil-rich beds. The Virgin Limestone member was deposited during a subsequent (Spathian) Early Triassic sea level rise, about 4-5 Ma following the Permian/Triassic boundary, and includes nearshore and inner shelf limestones characterized by fossiliferous storm beds.Because the fossiliferous limestones of the Smithian Sinbad and the Spathian Virgin were deposited in similar shallow subtidal settings, they provide an opportunity to compare and contrast the status of biotic rebound at different points along an Early Triassic “time transect.” Analysis of bulk samples reveals that the older Sinbad and younger Virgin are similar in each possessing 2-3 different benthic marine paleocommunities of low within-habitat species richness. There are, however, several important differences between the Sinbad and Virgin faunas. The richly fossiliferous Sinbad assemblages are primarily molluscan, composed of approximately 2-8 species of bivalves, which may or may not be accompanied by ammonoids and 0-11 species of gastropods. Small spines, possibly belonging to an echinoid, are numerous in some samples. Although bivalves are also abundant in Virgin Limestone assemblages, fossils of other higher taxa are well-represented, including abundant crinoid ossicles, common brachiopods, echinoid spines and plates, and rare ammonoids and gastropods. Sinbad faunas also appear to lack epibionts and borers, while they are present but not abundant in the Virgin.The addition from Sinbad to Virgin times of groups other than molluscs, with different life habits and strategies, most likely led to an increase in spatial partitioning and resource utilization, in particular the development of epifaunal tiering with the appearance of stalked crinoids in the Virgin. This pattern of earliest Triassic community dominance by molluscs followed by later more “Paleozoic-like” communities has been observed in other regions. Earliest Triassic paucity of epibionts and borers indicates significant reduction in the biotic component of taphonomic processes, including taphonomic feedback, when compared with other time intervals. Data from these Early Triassic assemblages thus indicate the initiation of both an evolutionary and an ecological rebound between Sinbad (Smithian) and Virgin (Spathian) times.

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