“U–Pb calcite age of the Late Permian Castile Formation, Delaware Basin: a constraint on the age of the Permian–Triassic boundary(?)”: Reply to a comment by Ian Metcalfe

2004 ◽  
Vol 217 (3-4) ◽  
pp. 469-471 ◽  
Author(s):  
M.L Becker ◽  
E.T Rasbury ◽  
W.J Meyers ◽  
G.N Hanson
Keyword(s):  
Late Permian ◽  
Triassic Boundary ◽  
Delaware Basin ◽  
Permian Triassic Boundary

Nature and origin of the volcanic ash beds near the Permian–Triassic boundary in South China: new data and their geological implications

2019 ◽  
Vol 157 (4) ◽  
pp. 677-689 ◽  
Author(s):  
Binsong Zheng ◽  
Chuanlong Mou ◽  
Renjie Zhou ◽  
Xiuping Wang ◽  
Zhaohui Xiao ◽  
...  
Keyword(s):  
Trace Element ◽  
Continental Margin ◽  
South China ◽  
Volcanic Ash ◽  
Active Continental Margin ◽  
Main Body ◽  
Early Triassic ◽  
Late Permian ◽  
Triassic Boundary ◽  
Permian Triassic Boundary

AbstractPermian–Triassic boundary (PTB) volcanic ash beds are widely distributed in South China and were proposed to have a connection with the PTB mass extinction and the assemblage of Pangea. However, their source and tectonic affinity have been highly debated. We present zircon U–Pb ages, trace-element and Hf isotopic data on three new-found PTB volcanic ash beds in the western Hubei area, South China. Laser ablation inductively coupled plasma mass spectrometry U–Pb dating of zircons yields ages of 252.2 ± 3.6 Ma, 251.6 ± 4.9 Ma and 250.4 ± 2.4 Ma for these three volcanic ash beds. Zircons of age c. 240–270 Ma zircons have negative εHf(t) values (–18.17 to –3.91) and Mesoproterozoic–Palaeoproterozoic two-stage Hf model ages (THf2) (1.33–2.23 Ga). Integrated with other PTB ash beds in South China, zircon trace-element signatures and Hf isotopes indicate that they were likely sourced from intermediate to felsic volcanic centres along the Simao–Indochina convergent continental margin. The Qinling convergent continental margin might be another possible source but needs further investigation. Our data support the model that strong convergent margin volcanism took place around South China during late Permian – Early Triassic time, especially in the Simao–Indochina active continental margin and possibly the Qinling active continental margin. These volcanisms overlap temporally with the PTB biocrisis triggered by the Siberian Large Igneous Province. In addition, our data argue that the South China Craton and the Simao–Indochina block had not been amalgamated with the main body of Pangea by late Permian – Early Triassic time.

Are Late Permian carbon isotope excursions of local or of global significance?

2019 ◽  
Vol 132 (3-4) ◽  
pp. 521-544 ◽  
Author(s):  
Borhan Bagherpour ◽  
Hugo Bucher ◽  
Torsten Vennemann ◽  
Elke Schneebeli-Hermann ◽  
Dong-xun Yuan ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
South China ◽  
Sea Water ◽  
Equatorial Position ◽  
Late Permian ◽  
Terrestrial Organic Matter ◽  
Triassic Boundary ◽  
Atmospheric Propagation ◽  
Isotope Record ◽  
Permian Triassic Boundary

Abstract We present a new, biostratigraphically calibrated organic and inorganic C-isotope record spanning the basal Late Permian to earliest Triassic from southern Guizhou (Nanpanjiang basin, South China). After fluctuations of a likely diagenetic overprint are removed, three negative carbon isotope excursions (CIEs) persist. These include a short-lived CIE during the early Wuchiapingian, a protracted CIE ending shortly after the Wuchiapingian–Changhsingian Boundary, and a third CIE straddling the Permian–Triassic boundary. Comparison of our new C-isotope record with others from the same basin suggests that influences of local bathymetry and of the amount of buried terrestrial organic matter are of importance. Comparison with other coeval time series outside of South China also highlights that only the negative CIE at the Permian–Triassic boundary is a global signal. These differences can be explained by the different volumes of erupted basalts between the Late Permian Emeishan and the younger Siberian large igneous provinces and their distinct eruptive modalities. Emeishan volcanism was largely submarine, implying that sea water was an efficient buffer against atmospheric propagation of volatiles. The equatorial position of Emeishan was also an additional obstacle for volatiles to reach the stratosphere and benefit from an efficient global distribution. Consequently, the local significance of these CIEs calls into question global correlations based on C-isotope chemostratigraphy during the Late Permian. The timing of the Late Permian Chinese CIEs is also not reflected in changes in species diversity or ecology, unlike the sudden and global Permian–Triassic boundary crisis and subsequent Early Triassic upheavals.

scholarly journals Stratigraphic significance of carbon isotope variations in the shallow-marine Seis/Siusi Permian–Triassic boundary section (Southern Alps, Italy)

Fossil Record ◽  
2009 ◽  
Vol 12 (2) ◽  
pp. 197-205 ◽  
Author(s):  
S. H. Kraus ◽  
S. Siegert ◽  
W. Mette ◽  
U. Struck ◽  
C. Korte
Keyword(s):  
Carbon Isotope ◽  
Southern Alps ◽  
Late Permian ◽  
Current Event ◽  
Triassic Boundary ◽  
Shallow Marine ◽  
Carbonate Carbon ◽  
Biostratigraphic Correlation ◽  
Positive Peak ◽  
Permian Triassic Boundary

Carbonate carbon-isotope values from the Permian–Triassic (P–T) boundary section at Seis/Siusi (Southern Alps, Italy) show a trend similar to that in numerous other P–T boundary sections worldwide. Values decrease from 3.2‰ (V-PDB) in the upper <i>Bellerophon</i> Limestone Formation (Late Permian) to a minimum of –1.7‰ in the lower Mazzin Member. This minimum may represent the P–T boundary. The overall declining carbon-isotope trend is interrupted by a ca. 1‰ positive excursion in the higher Tesero Oolite Horizon. This positive peak is located at a higher lithostratigraphic level than a comparable peak in the adjacent Pufels section, which suggests that the Tesero Oolite Horizon in the Seis section is stratigraphically slightly older than in the Pufels section, and this is also suggested by palaeomagnetic correlation. It is therefore concluded that the base of the Tesero Oolite Horizon does not reflect a synchronous "current event" but is slightly diachronous, a result that was previously shown by biostratigraphic correlation. Nevertheless, this suggestion should be verified by further detailed litho-, magneto- and chemostratigraphic analysis of other P–T sections in the Southern Alps. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.200900007" target="_blank">10.1002/mmng.200900007</a>

scholarly journals High-resolution stratigraphy of the Changhsingian (Late Permian) successions of NW Iran and the Transcaucasus based on lithological features, conodonts and ammonoids

Fossil Record ◽  
2014 ◽  
Vol 17 (1) ◽  
pp. 41-57 ◽  
Author(s):  
A. Ghaderi ◽  
L. Leda ◽  
M. Schobben ◽  
D. Korn ◽  
A. R. Ashouri
Keyword(s):  
Late Permian ◽  
Triassic Boundary ◽  
Nw Iran ◽  
The Earth ◽  
Extinction Event ◽  
History Of ◽  
Mass Extinction Event ◽  
Bottom To Top ◽  
Permian Triassic Boundary ◽  
North Western

Abstract. The Permian–Triassic boundary sections in north-western Iran belong to the most complete successions, in which the largest mass extinction event in the history of the Earth can be studied. We investigated the Changhsingian stage in six sections in the area of Julfa (Aras Valley) for their lithology, conodonts and ammonoids. Revision of the biostratigraphy led to the separation of 10 conodont zones (from bottom to top Clarkina orientalis–C. subcarinata interval zone, C. subcarinata, C. changxingensis, C. bachmanni, C. nodosa, C. yini, C. abadehensis, C. hauschkei, Hindeodus praeparvus–H. changxingensis and Merrilina ultima–Stepanovites ?mostleri zones) and 8 ammonoid zones (from bottom to top Iranites transcaucasius–Phisonites triangulus, Dzhulfites nodosus, Shevyrevites shevyrevi, Paratirolites trapezoidalis, P. waageni, Stoyanowites dieneri, Abichites stoyanowi and Arasella minuta zones). The new ammonoid genera Stoyanowites and Arasella are described.

A Permian Overtoniid Brachiopod in Early Triassic Sediments of Axel Heiberg Island, Canadian Arctic and its Implications on the Permian—Triassic Boundary

1972 ◽  
Vol 9 (5) ◽  
pp. 486-499 ◽  
Author(s):  
J. B. Waterhouse
Keyword(s):  
Canadian Arctic ◽  
Late Paleozoic ◽  
Ventral Valve ◽  
Early Triassic ◽  
Late Permian ◽  
Triassic Boundary ◽  
Axel Heiberg Island ◽  
Permian Triassic Boundary ◽  
Green Land

The ventral valve of an overtoniid productacean brachiopod generally thought to have been restricted to the late Paleozoic Era is described from the Blind Fiord Formation, Axel Heiberg Island, of Griesbachian (Early Triassic) age. It is not clear whether the specimen was derived from Permian rocks or was really of Griesbachian age. The latter appears likely from the fact that no similar specimens are known from underlying Permian. Genuine occurrences of Permian-type brachiopods in early Triassic rocks are rare. Half of the examples reported, from Armenia, Iran, and West Pakistan, are shown here to be dated erroneously, occurring in middle or late Permian rocks misdated as Triassic, Other examples, such as those from Green-land, are probably reworked because the Triassic beds conformably overlie mid-Permian rocks, and contain similar mid-Permian brachiopods, probably reworked from the underlying deposits.

Conodont zonation across the Permian–Triassic boundary at the Xiakou section, Yichang city, Hubei Province and its correlation with the Global Stratotype Section and Point of the PTB

2004 ◽  
Vol 41 (3) ◽  
pp. 323-330 ◽  
Author(s):  
Wang Guoqing ◽  
Xia Wenchen
Keyword(s):  
High Precision ◽  
Early Triassic ◽  
Clay Layer ◽  
Late Permian ◽  
Yangtze Platform ◽  
Triassic Boundary ◽  
Conodont Zonation ◽  
Stratotype Section ◽  
Clay Layers ◽  
Permian Triassic Boundary

Xiakou section is situated north of the central Yangtze platform with successive Late Permian to Early Triassic strata, thicker than the Global Stratotype Section and Point (GSSP) of the Permian–Triassic boundary (PTB). We recognized three conodont zones across the PTB in this section by high-precision biostratigraphy. They are the Hindeodus latidentatus – Clarkina meishanensis Zone, Hindeodus parvus Zone, and Isarcicella isarcica Zone in ascending order, which correspond well with the GSSP. The present biostratigraphic work on Xiakou section certainly confirmed the conodont zonation through the PTB at the GSSP and also testified to the correctness of the PTB demarcation in Xiakou section. Based on this precise demarcation of the PTB, the appearance of a clay layer, bed ZSJI266, just beneath the PTB should be an important advantage over the GSSP, because this clay layer approaches to the PTB much in contrast with those two clay layers, bed 26 and bed 28, in the GSSP. Therefore, the radiometric isotopic dating in bed ZSJI266 at Xiakou section should give a more accurate age for the PTB.

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