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Ulf Söderlund

Ulf Söderlund

Professor

Ulf Söderlund

U-Pb (zircon) age constraints on the timing and duration of Wen lock (Silurian) paleocommunity collapse and recovery during the "Big Crisis"

Författare

  • Bradley D. Cramer
  • Daniel J. Condon
  • Ulf Söderlund
  • Carly Marshall
  • Graham J. Worton
  • Alan T. Thomas
  • Mikael Calner
  • David C. Ray
  • Vincent Perrier
  • Ian Boomer
  • P. Jonathan Patchett
  • Lennart Jeppsson

Summary, in English

High-precision isotope-dilution U-Pb (zircon) dating was conducted on three volcanic ash fall (bentonite) samples from the Swedish island of Gotland, and on a fourth bentonite from the West Midlands, England. Zircons from the Ireviken, Grotlingbo, Djupvik (Gotland), and Wren's Nest Hill-15 (West Midlands) bentonites yielded weighted mean Pb-206/U-238 ages of 431.83 +/- 0.23/0.67 Ma, 428.45 +/- 035/0.73 Ma, 428.06 +/- 0.2110.66 Ma, and 427.86 +/- 032/0.71 Ma, respectively (analytical/total uncertainties). These biostratigraphically well-controlled age dates effectively bracket the Wenlock Epoch of the Silurian Period and provide control for the duration of one of the major Paleozoic biotic events and associated perturbations to the global carbon cycle (the "Big Crisis" or lundgreni event- graptolites; the NIulde Event-conodonts; the Mulde excursion-carbon isotopes). These new data suggest an older and shorter duration for the recalibration of the Wenlock Series and demonstrate that the cascade of biological and chemical events that took place during the Big Crisis happened on time scales of tens to hundreds of thousands of years.

Avdelning/ar

  • Berggrundsgeologi

Publiceringsår

2012

Språk

Engelska

Sidor

1841-1857

Publikation/Tidskrift/Serie

Geological Society of America Bulletin

Volym

124

Issue

11-12

Dokumenttyp

Artikel i tidskrift

Förlag

Geological Society of America

Ämne

  • Geology

Aktiv

Published

ISBN/ISSN/Övrigt

  • ISSN: 0016-7606