[dinosaur] Volcanic mercury and Triassic mass extinction + Navajo Sandstone dates + Jehol stratigraphy + Cedar Mountain stratigraphy

Ben Creisler
[email protected]

Some recent Mesozoic papers that may be of interest:

Free pdf:

Sofie Lindström, Hamed Sanei, Bas van de Schootbrugge, Gunver K. Pedersen,
Charles E. Lesher, Christian Tegner, Carmen Heunisch, Karen Dybkjær and
Peter M. Outridge (2019)
Volcanic mercury and mutagenesis in land plants during the end-Triassic
mass extinction
Science Advances 5(10): eaaw4018
DOI: 10.1126/sciadv.aaw4018
https://urldefense.proofpoint.com/v2/url?u=https-3A__advances.sciencemag.org_content_5_10_eaaw4018&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=fPNE6fYiKIlQD4RW6XYIjMW6FI4BQHSKJThvpzu9MLc&s=dZOitsGhXKHCGatNzvRqEO5N22Gpm2BuKkmXko90OOA&e= 

During the past 600 million years of Earth history, four of five major
extinction events were synchronous with volcanism in large igneous
provinces. Despite improved temporal frameworks for these events, the
mechanisms causing extinctions remain unclear. Volcanic emissions of
greenhouse gases, SO2, and halocarbons are generally considered as major
factors in the biotic crises, resulting in global warming, acid deposition,
and ozone layer depletion. Here, we show that pulsed elevated
concentrations of mercury in marine and terrestrial sediments across the
Triassic-Jurassic boundary in southern Scandinavia and northern Germany
correlate with intense volcanic activity in the Central Atlantic Magmatic
Province. The increased levels of mercury--the most genotoxic element on
Earth--also correlate with high occurrences of abnormal fern spores,
indicating severe environmental stress and genetic disturbance in the
parent plants. We conclude that this offers compelling evidence that
emissions of toxic volcanogenic substances contributed to the end-Triassic
biotic crisis.


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Free pdf:

Judith Totman Parrish, E. Troy Rasbury, Marjorie A. Chan & Stephen T.
Hasiotis (2019)
Earliest Jurassic U-Pb ages from carbonate deposits in the Navajo
Sandstone, southeastern Utah, USA.
Geology 47(11): 1015-1019.
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1130_G46338.1&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=fPNE6fYiKIlQD4RW6XYIjMW6FI4BQHSKJThvpzu9MLc&s=KvZRzbbfucXfwW_bpb1wBFOfXiuwdEby00kHV_Du9gI&e= 

Free pdf:
https://urldefense.proofpoint.com/v2/url?u=https-3A__pubs.geoscienceworld.org_geology_article-2Dpdf_47_11_1015_4852055_1015.pdf&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=fPNE6fYiKIlQD4RW6XYIjMW6FI4BQHSKJThvpzu9MLc&s=w4T0Nbz5UqSYfCkFWeU8jDSv4PCNXM3UXWF753QptWY&e= 


New uranium-lead (U-Pb) analyses of carbonate deposits in the Navajo
Sandstone in southeastern Utah (USA) yielded dates of 200.5 ± 1.5 Ma
(earliest Jurassic, Hettangian Age) and 195.0 ± 7.7 Ma (Early Jurassic,
Sinemurian Age). These radioisotopic ages—the first reported from the
Navajo erg and the oldest ages reported for this formation—are critical for
understanding Colorado Plateau stratigraphy because they demonstrate that
initial Navajo Sandstone deposition began just after the Triassic and that
the base of the unit is strongly time-transgressive by at least 5.5 m.y.


===

Pay-walled papers:



Hansheng Cao & Wentong He (2019)
Correlation of carbon isotope stratigraphy and paleoenvironmental
conditions in the Cretaceous Jehol Group, northeastern China.
International Geology Review (advance online publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1080_00206814.2019.1681303&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=fPNE6fYiKIlQD4RW6XYIjMW6FI4BQHSKJThvpzu9MLc&s=ZgYEt3dnv_Hj7yH3NFIUV3--G7TfdunRQuvp5FEMS-0&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.tandfonline.com_doi_full_10.1080_00206814.2019.1681303&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=fPNE6fYiKIlQD4RW6XYIjMW6FI4BQHSKJThvpzu9MLc&s=0483RbChtkh5kQVp0GTD2TxT9zbPWowt-3Su_M0OBhU&e= 



The Jehol Biota represents an important phase in the history of biological
evolution on Earth. Two sites with Aptian Jehol Biota, located in western
Liaoning Province and in northern Hebei Province, northeastern China, have
generated a major debate about the relationships between their
fossil-bearing layers, resulting in confusions about their stratigraphic
correlation and biogenetic sequence. We have applied carbon isotope
analysis of total organic carbon to provide new data relevant to this
debate and have re-examined the connection between volcanism and carbon
cycle perturbations, with consideration of the paleoenvironmental
conditions. The rare earth element data show that the provenances of the
Jehol Group in western Liaoning and northern Hebei were similar and derived
mainly from the underlying andesite. Constrained by the radiometric age,
the δ13Corg curve suggests that the Dadianzi Formation in northern Hebei is
comparable to the three lacustrine layers of the Yixian Formation (ranging
from the Jianshangou Bed to the Jingangshan Bed) in western Liaoning. These
layers are highly correlated with the early Aptian marine sequence in
Oceanic Anoxic Event 1a (OAE 1a), implying that a possible teleconnection
(possibly related to a large igneous province) existed between oceanic and
terrestrial realms. We also propose that the Xiguayuan Formation above the
Dadianzi Formation in northern Hebei is equivalent to the Huanghuashan
Breccia Bed at the top of the Yixian Formation in western Liaoning.
Moreover, the δ13Corg and element geochemical data suggest that the carbon
cycle perturbation and the paleolimnological environments were distinctly
influenced by the effects of volcanic CO2 during the early Aptian.

===

R. M. Joeckel, G. A. Ludvigson, A. Möller, C. L. Hotton, M. B. Suarez, C.
A. Suarez,  B. Sames,  J. I. Kirkland and B. Hendrix (2019)
Chronostratigraphy and Terrestrial Palaeoclimatology of
Berriasian–Hauterivian Strata of the Cedar Mountain Formation, Utah, USA.
Geological Society Special Publications 498: Cretaceous Climate Events and
Short-Term Sea-Level Changes (accepted article)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1144_SP498-2D2018-2D133&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=fPNE6fYiKIlQD4RW6XYIjMW6FI4BQHSKJThvpzu9MLc&s=TdM2R_zsoqxn1lhqWKmRDfviKmb9pj0QQfQLdUuETws&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__sp.lyellcollection.org_content_early_2019_10_16_SP498-2D2018-2D133&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=fPNE6fYiKIlQD4RW6XYIjMW6FI4BQHSKJThvpzu9MLc&s=jOvN935HkL5RfVI3T_yFaqpZKNjdrM-2Jp-OrJRkaHA&e= 


This paper presents breakthroughs in the chronostratigraphy of the
heretofore poorly-constrained Yellow Cat Member of the Cedar Mountain
Formation, which is an important record of terrestrial environments,
ecosystems, and global change in the ancient North American Cordilleran
foreland. Zircon populations from ten stratigraphic horizons in the Yellow
Cat Member yield youngest single grain ages ranging from 142.5±2.7 Ma to
133.7±2.7 Ma (Berriasian-late Valanginian); those from one mudstone
palaeosol yield a robust Concordia Age of 136.3±1.3 (Valanginian).
Additionally, a new palynoflora--one of a few to be published from the
Cedar Mountain Formation--is assigned to the middle Berriasian to early
Hauterivian stages, based on the presence of Foraminisporis wonthaggiensis
and Trilobosporites sp. cf. T. canadensis, and the absence of F.
asymmetricus, Appendicisporites spp. and angiosperms. Furthermore, these
chronostratigraphic data allow us to interpret part of the so-called
“Weissert Event” C-isotope excursion (Valanginian) in a new C-isotope
profile through a palaeosol-bearing alluvial succession in the Yellow Cat
Member. This research extends a firm understanding of the formation further
back into the Early Cretaceous than was the case previously and sets the
stage for future advancements.

Supplementary material at https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.6084_m9.figshare.c.4697138&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=fPNE6fYiKIlQD4RW6XYIjMW6FI4BQHSKJThvpzu9MLc&s=1lqI8fROyup3cTymV0T_VmFFzBvGlBKejcpfWA8NQOw&e= 


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