Late Silurian zircon U–Pb ages from the Ludlow and Downton bone beds, Welsh Basin, UK
Name:
jgs2020-107.full.pdf
Size:
3.135Mb
Format:
PDF
Description:
Published/publisher’s pdf
Average rating
Cast your vote
You can rate an item by clicking the amount of stars they wish to award to
this item.
When enough users have cast their vote on this item, the average rating will also be shown.
Star rating
Your vote was cast
Thank you for your feedback
Thank you for your feedback
Issue date
2020-09-21Submitted date
2020-11-12Subject Terms
Welsh BasinCowie Harbour Fish Bed
Pr ídol Series
land arthropod-bearing sediments
UK
Po žáry Section
Cathodoluminescence images show
Ludlow Bone Bed marks
CA
Detrital zircon grains
Downton Bone Beds
SIMS
Ion Mass Spectrometry
Ludlow Bone Bed
Metadata
Show full item recordAbstract
The Ludlow Bone Bed (Welsh Basin) is a critical stratigraphic horizon and contains a rich assemblage of fish scales. Units above provide insights into the early evolution of animal and plant life. The bed has not yet been radioisotopically dated. Here, we report 207 secondary ion mass spectrometry (SIMS) ages from 102 zircon (ZrSiO4) grains from the Ludlow (n = 2) and stratigraphically higher Downton (n = 1) bone beds. SIMS ages are middle Ordovician (471.6 ± 20.7 Ma) to late Devonian (375.7 ± 14.6 Ma, 238U–206Pb, ±1σ analytical uncertainty). Cathodoluminescence images show that the youngest ages appear affected by alteration. Chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-ID-TIMS) U–Pb geochronology was utilized to improve precision. Detrital zircon grains from Downton yield 424.91 ± 0.34/0.42/0.63 Ma and from Ludlow 424.85 ± 0.32/0.41/0.62 Ma (n = 5 each, 238U–206Pb, ±2σ analytical, tracer or systematic uncertainty). These ages provide a maximum deposition age. Results overlap the basal Přídolí age (423.0 ± 2.3 Ma) in its stratotype (Požáry Section, Reporyje, Prague, Czech Republic). The Ludlow Bone Bed marks the base of the local Downton Group, which has previously been correlated with the base of the Přídolí Series. The CA-ID-TIMS ages are older than those for other land arthropod-bearing sediments, such as the Cowie Harbour Fish Bed and Rhynie Chert.Citation
Elizabeth J. Catlos, Darren F. Mark, Stephanie Suarez, Michael E. Brookfield, C. Giles Miller, Axel K. Schmitt, Vincent Gallagher, Anne Kelly; Late Silurian zircon U–Pb ages from the Ludlow and Downton bone beds, Welsh Basin, UK. Journal of the Geological Society doi: https://doi.org/10.1144/jgs2020-107Publisher
Geological Society of LondonAdditional Links
https://doi.org/10.6084/m9.figshare.c.5087031Type
Journal ArticleItem Description
© 2020 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License (http://creativecommons.org/ licenses/by/4.0/). Published by The Geological Society of London. Publishing disclaimer: www.geolsoc.org.uk/pub_ethicsISSN
0016-7649EISSN
2041-479Xae974a485f413a2113503eed53cd6c53
10.1144/jgs2020-107
Scopus Count
Collections