News


New blogpost of the EGU


Dating mineral phases in geological remnants of early life

Blogpost written by Sebastian Viehmann (blog of the Biogeosciences Division of the European Geosciences Union)
https://blogs.egu.eu/divisions/bg/2020/05/21/dating-mineral-phases-in-geological-remnants-of-early-life/

PDF: Dating mineral phases in geological remnants of early life

Original article: https://www.sciencedirect.com/...


Cretaceous Climate Events and Short-Term Sea-Level Changes

The final Proceedings Volume of UNESCO-IGCP 609 has been published and printed. It is entitled "Cretaceous Climate Events and Short-Term Sea-Level Changes", edited by Michael Wagreich, Malcolm Hart (Plymouth), Benjamin Sames, and Ismail O. Yilmaz (Ankara) and has been published as Volume 498 of the Geological Society, London, Special Publications. The volume comprises an Introduction/Overview (open access) and 11 articles, including two review papers (one open access) and a set of case studies.

Sea level constitutes a critical planetary boundary for geological processes and human life. Sea-level fluctuations during major greenhouse phases are still enigmatic and strongly discussed in terms of changing climate systems. The geological record of the Cretaceous greenhouse period provides a deep-time view on greenhouse-phase Earth System processes that facilitates a much better understanding of the causes and consequences of global, geologically short-term, sea-level changes. Especially Cretaceous hothouse periods can serve as  laboratory to better understand a near-future greenhouse Earth. This volume presents high-resolution sea-level records from globally distributed sedimentary archives of the Cretaceous involving a large group of scientists from the International Geoscience Programme IGCP 609. Marine to non-marine sedimentary successions were analysed for revised age constraints, correlation of global palaeoclimate shifts and sea-level changes, tested for climate-driven cyclicities,and correlated within a high-resolution stratigraphic framework of the Geological Timescale. For hothouse periods, the hypothesis of significant global groundwater-related sea-level change, i.e. aquifer-eustasy as major process, is reviewed and substantiated.

Link: sp.lyellcollection.org/content/498/1

Cretaceous Climate Events and Short-Term Sea-Level Changes


Object of the Month (The Collections at Vienna University)

The new Object of the Month April 2020 is from the Geological Archive of the Department for Geodynamics and Sedimentology:
(Link:
https://bibliothek.univie.ac.at/...)

The geologic overview map of the Eastern Alps by Leopold Kober is a preliminary version of his view of the tectonic architecture of the Alps and the Dinarides, which was strongly influenced by the early ideas of nappe tectonics.
A strongly modified version of this map was later published in KOBER, L. (1938). Der Geologische Aufbau Österreichs. Wien, Julius Springer: 204 pp.


Best Paper Award in "Geosciences"

The review paper by Meister and Reyes (2019) on "The carbon-isotope record of the sub-seafloor biosphere" received the MDPI Geosciences best-paper award.

This interdisciplinary review paper summarizes the processes that lead to the formation of carbon isotope archives of past sub-seafloor biospheres. The paper demonstrates that these records are the result of a range of different factors, including isotope effects of microbial biochemical pathways, porefluid chemistry, transport processes, and diagenetic carbonate precipitation.  

Variations in carbon isotope signatures are found preserved in diagenetic carbonate records, documenting that microbial activity below the seafloor is not static, but changed over time in response to environmental conditions at the Earth’s surface.

The carbon-isotope record of the sub-seafloor biosphere

Meister, P. and Reyes, C. (2019) The carbon-isotope record of the sub-seafloor biosphere. In: "Tracking the Deep Biosphere through Time" (Eds. H. Drake, M. Ivarsson, C. Heim), Geosciences 9, 507, 1-25. https://doi:10.3390/geosciences9120507


New book from the Department of Geodynamics and Sedimentology

Dan Le Heron and colleagues have just published a new book entitled "Glaciated Margins: the Sedimentary and Geophysical Archive" under the flagship Special Publications series of the Geological Society of London.
This book arose out of a major international conference in 2016 held in Burlington House, London, and brings together contributions from deep time (Cryogenian, Ordovician, Carboniferous-Permian) and more recent (Pleistocene, Modern) in one tome, exploring the general traits of glaciated margins, including rifted margins where the signal of the glacial record becomes somewhat diluted. Collectively surveying marine geophysical datasets through to outcrop data, the broad scope of the book showcases the exciting aspects of Glaciated Margins Science across geological time.

https://sp.lyellcollection.org/online-first/475

Glaciated Margins


New Article

Le Heron, D.P. and Vandyk, T.M. 2019. A Slippery Slope or Cryogenian Diamictites? The Depositional Record, DOI: 10.1002/dep2.67 

How "glacial" really are ancient glacial deposits? Building on previous work that the published recently in Geology, Le Heron and Vandyk show that some of the famous, so-called "glacial" deposits of Death Valley, though to belong to the Marinoan (younger Cryogenian, ca. 650 Ma) global glaciation are unrelated to glaciation at all.
The study substantiates previous work by the likes of Jessica Creveling and colleagues, who emphasised the importance of platform instability and slope collapse. It really is important to not assume that diamictites- jumbled up deposits with large blocks and boulders inside- are glacial, without looking carefully first!