TY - JOUR
T1 - A Link Between Rift-Related Volcanism and End-Ediacaran Extinction? Integrated Chemostratigraphy, Biostratigraphy, and U-Pb Geochronology from Sonora, Mexico
AU - Hodgin, Eben B.
AU - Nelson, Lyle L.
AU - Wall, Corey J.
AU - Barrón-Díaz, Arturo J.
AU - Webb, Lucy C.
AU - Schmitz, Mark D.
AU - Fike, David A.
AU - Hagadorn, James W.
AU - Smith, Emily F.
N1 - Funding Information:
We are grateful to A. Lizarraga for property access; J. Ramezani and I. Bennett (Massachusetts Institute of Technology, USA) and R. Mundil (Berkeley Geochronology Center, California, USA) for mineral separation assistance; J. Crowley (Boise State University, Idaho, USA) and G. Seward, F. Apen, A. Kylander-Clark, and F. Macdonald (University of California–Santa Barbara, USA) for U-Pb geochronology assistance; D. Brenner (Johns Hopkins University [JHU], Maryland, USA) and S. Moore (Washington University, St. Louis, Missouri, USA) for stable isotope analysis assistance; and Beck for field assistance. Our funding sources included U.S. National Science Foundation (NSF) Graduate Research Fellowship Program grant DGE-1746891 and National Geographic Early Career grant CP-002ER-17 to L.L. Nelson; NSF EAR-1827669 and support from the JHU Department of Earth and Planetary Sciences to E.F. Smith; and support from Harvard University to E.B. Hodgin. Constructive reviews from F. Bowyer, M. Zhu, and A. Prave improved this manuscript.
Publisher Copyright:
© 2020 Geological Society of America. For permission to copy, contact [email protected].
PY - 2021/2
Y1 - 2021/2
N2 - We present chemostratigraphy, biostratigraphy, and geochronology from a succession that spans the Ediacaran-Cambrian boundary in Sonora, Mexico. A sandy hematite-rich dolostone bed, which occurs 20 m above carbonates that record the nadir of the basal Cambrian carbon isotope excursion within the La Ciénega Formation, yielded a maximum depositional age of 539.40 ± 0.23 Ma using U-Pb chemical abrasion–isotope dilution–thermal ionization mass spectrometry on a population of sharply faceted volcanic zircon crystals. This bed, interpreted to contain reworked tuffaceous material, is above the last occurrences of late Ediacaran body fossils and below the first occurrence of the Cambrian trace fossil Treptichnus pedum, and so the age calibrates key markers of the Ediacaran-Cambrian boundary. The temporal coincidence of rift-related flood basalt volcanism in southern Laurentia (<250,000 km3 of basalt), a negative carbon isotope excursion, and biological turnover is consistent with a mechanistic link between the eruption of a large igneous province and end-Ediacaran extinction.
AB - We present chemostratigraphy, biostratigraphy, and geochronology from a succession that spans the Ediacaran-Cambrian boundary in Sonora, Mexico. A sandy hematite-rich dolostone bed, which occurs 20 m above carbonates that record the nadir of the basal Cambrian carbon isotope excursion within the La Ciénega Formation, yielded a maximum depositional age of 539.40 ± 0.23 Ma using U-Pb chemical abrasion–isotope dilution–thermal ionization mass spectrometry on a population of sharply faceted volcanic zircon crystals. This bed, interpreted to contain reworked tuffaceous material, is above the last occurrences of late Ediacaran body fossils and below the first occurrence of the Cambrian trace fossil Treptichnus pedum, and so the age calibrates key markers of the Ediacaran-Cambrian boundary. The temporal coincidence of rift-related flood basalt volcanism in southern Laurentia (<250,000 km3 of basalt), a negative carbon isotope excursion, and biological turnover is consistent with a mechanistic link between the eruption of a large igneous province and end-Ediacaran extinction.
UR - http://www.scopus.com/inward/record.url?scp=85100377194&partnerID=8YFLogxK
U2 - 10.1130/G47972.1
DO - 10.1130/G47972.1
M3 - Article
AN - SCOPUS:85100377194
SN - 0091-7613
VL - 49
SP - 115
EP - 119
JO - Geology
JF - Geology
IS - 2
ER -