Results 131 to 140 of about 3,860 (179)

Dolomitic Microfossil Preservation in a Cryogenian Microbial Reef, Arkaroola (South Australia)

open access: yesGeobiology, Volume 24, Issue 5, September/October 2026.
ABSTRACT Microbial dolostones that now form the Arkaroola reef, northern Adelaide Rift Complex, and were deposited during the Cryogenian interglacial period, display a wide range of meso‐scale stromatolite morphotypes in outcrop. Microcharacterisation involving optical microscopy, combined scanning electron microscopy and energy dispersive spectroscopy
France Champenois   +2 more
wiley   +1 more source

Red to Green: A Lipid Biomarker Record of Tonian‐Ediacaran Algae in Siberia

open access: yesGeobiology, Volume 24, Issue 5, September/October 2026.
ABSTRACT Multiple lines of evidence point to a major diversification of Eukarya in the late Tonian period, ca. 800–720 Ma ago. Regular steranes, lipid biomarkers primarily sourced from eukaryotes, are first unambiguously reported from multiple sites. Here, we present lipid biomarker stratigraphic records from two drill‐cores from the Lena‐Anabar Basin ...
Adriana I. Rizzo   +7 more
wiley   +1 more source

Thallium Isotopes Across the Smithian‐Spathian Boundary: Evidence for Anoxia Throughout Most of the Early Triassic

open access: yesGeobiology, Volume 24, Issue 5, September/October 2026.
ABSTRACT Following the largest known Phanerozoic extinction, the end‐Permian mass extinction, the Early Triassic is often considered an interval of slow biotic recovery. During this time, the minor Smithian‐Spathian extinction occurred, further delaying the biotic recovery of this epoch.
Sean M. Newby   +3 more
wiley   +1 more source

Uranium Isotope Evidence for Persistent Global Ocean Anoxia Across the Ediacaran–Cambrian Transition in Siberia

open access: yesGeobiology, Volume 24, Issue 5, September/October 2026.
ABSTRACT The enigmatic Ediacara biota represents Earth's earliest example of macroscopic, complex life, yet the driving forces promoting their mid‐Ediacaran evolution and subsequent extinction across the Ediacaran–Cambrian boundary remain speculative. If these were true animals requiring oxygen for aerobic respiration, their rise has often been linked ...
Andrew D. Doerrler   +10 more
wiley   +1 more source

Development of CCMb: A Low‐Mg Calcite Reference Material for In Situ Measurement of δ18O, δ13C and Selected Trace Elements

open access: yesGeostandards and Geoanalytical Research, Volume 50, Issue 3, Page 677-700, September 2026.
Key Points Low‐Mg calcite RM developed for in situ microanalysis applications in palaeoclimatology (δ18O, δ13C; Mg, Sr m/m). New data for calcite CRM IAEA‐603 (δ18O, δ13C by SIMS and GS‐IRMS; Mg m/m). No detectable IMF effect of Mg on SIMS δ18O determinations for mass fractions < 3650 μg g‐1.
Andreas T. Hertwig   +13 more
wiley   +1 more source

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