3.46 Ga Apex chert 'microfossils' reinterpreted as mineral artefacts produced during phyllosilicate exfoliation

We acknowledge the facilities, scientific and technical assistance of the Australian Microscopy & Microanalysis Research Facility at: Centre for Microscopy Characterisation and Analysis, The University of Western Australia; Electron Microscopy Unit, The University of New South Wales. These facilities are funded by the Universities, State and Commonwealth Governments. DW was funded by the European Commission and the Australian Research Council (FT140100321). This is ARC CCFS paper number XXX. We acknowledge Martin van Kranendonk, Owen Green, Cris Stoakes, Nicola McLoughlin, the late John Lindsay and the Geological Survey of Western Australia for fieldwork assistance, Thomas Becker for assistance with Raman microspectroscopy, Anthony Burgess from FEI for the preparation of one of the TEM wafers, and Russell Garwood, Tom Davies, Imran Rahman & Stephan Lautenschlager for training and advice on the SPIERS and AVIZO software suites. We thank Chris Fedo and an anonymous reviewer for comments that improved the manuscript.Peer reviewedPostprin

Primary aragonite and high-Mg calcite in the late Cambrian (Furongian) : Potential evidence from marine carbonates in Oman

Acknowledgements Fieldwork and sampling was funded by Petroleum Development Oman during S. Al Marjibis's Ph.D. Their help is gratefully acknowledged. We also thank colleagues at the University of Aberdeen, Julie Dougans (SUERC) for assisting with stable isotope analysis and Dr. Richard Hinton (EIMF) for assistance with ion microprobe analysis. Profs. Kiessling, Tucker, Bosence, Coleman, Dr. Dickson and an anonymous reviewer are thanked for their helpful and encouraging comments.Peer reviewedPostprin

Searching for Life in Hot Spring Carbonate Systems : Investigating Raman Spectra of Carotenoid-Bearing Organic Carbonaceous Inclusions from Travertines of Italy

Acknowledgements This study was carried out as part of a University of Aberdeen PhD, supported by the UKRI Centre for Doctoral Training in Oil & Gas. We must thank Professor Javier Martín-Torres for his valuable Martian insights, and Sig. Domenico Belli for allowing access to the Paliano spring locale, and Dr. Vereno Bisegna and Dr. Giuseppe Pagano for logistic and local assistance.Peer reviewedPostprin

Contributions of Professor Martin Brasier to the study of early life, stratigraphy and biogeochemistry

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Sequence stratigraphical and palaeoenvironmental implications of Cenomanian–Santonian dinocyst assemblages from the Trans¬-Sahara epicontinental seaway : a multivariate statistical approach.

ACKNOWLEDGEMENTS M.B. Usman thanks the Petroleum Technology Development Fund (PTDF) for funding this research at the University of Aberdeen. The editor and reviewer are also thanked for their corrections which improved the manuscript. We also acknowledge Stephen Ingram, Adamu Kimayim Gaduwang and Solomon Abafras for their contributions.Peer reviewedPublisher PD

What do we really know about early diagenesis of non-marine carbonates?

Non-marine carbonate rocks including cave, spring, stream, calcrete and lacustrine- palustrine sediments, are susceptible to early diagenetic processes. These can profoundly alter the carbonate fabric and affect paleoclimatic proxies. This review integrates recent insights into diagenesis of non-marine carbonates and in particular the variety of early diagenetic processes, and presents a conceptual framework to address them. With ability to study at smaller and smaller scales, down to nanometers, one can now observe diagenesis taking place the moment initial precipitates have formed, and continuing thereafter. Diagenesis may affect whole rocks, but it typically starts in nano- and micro-environments. The potential for diagenetic alteration depends on the reactivity of the initial precipitate, commonly being metastable phases like vaterite, Ca-oxalates, hydrous Mg‐carbonates and aragonite with regard to the ambient fluid. Furthermore, organic compounds commonly play a crucial role in hosting these early transformations. Processes like neomorphism (inversion and recrystallization), cementation and replacement generally result in an overall coarsening of the fabric and homogenization of the wide range of complex, primary microtextures. If early diagenetic modifications are completed in a short time span compared to the (annual to millennial) time scale of interest, then recorded paleoenvironmental signals and trends could still acceptably reflect original, depositional conditions. However, even compact, non-marine carbonate deposits may behave locally and temporarily as open systems to crystal- fluid exchange and overprinting of one or more geochemical proxies is not unexpected. Looking to the future, relatively few studies have examined the behaviour of promising geochemical records, such as clumped isotope thermometry and (non- conventional) stable isotopes, in well-constrained diagenetic settings. Ongoing and future in-vitro and in-situ experimental approaches will help to investigate and detangle sequences of intermediate, diagenetic products, processes and controls, and to quantify rates of early diagenesis, bridging a gap between nanoscale, molecular lab studies and the fossil field rock record of non-marine carbonates

Carbonate deposition in the Palaeoproterozoic Onega basin from Fennoscandia : a spotlight on the transition from the Lomagundi-Jatuli to Shunga events

Date of Acceptance: 08/05/2015 Date of online publication: 16/05/2015 Acknowledgements Elemental and isotopic data, thin and polished sections used in this contribution were obtained through two large umbrella-projects with grants provided by the Norwegian Research Council grant 191530/V30 to VAM and NERC grant NE/G00398X/1 to AEF. We thank A. Črne, the editor A. Strasser as well as one anonymous reviewer and D. Papineau for providing their valuable criticism and suggestions.Peer reviewedPostprin

Petrological evidence in support of the death mask model for Ediacaran soft-bodied preservation in South Australia

Microbially mediated early diagenetic pyrite formation in the immediate vicinity of organic material has been the favoured mechanism by which to explain widespread preservation of soft-bodied organisms in late Ediacaran sedimentary successions, but an alternative rapid silicification model has been proposed for macrofossil preservation in sandstones of the Ediacara Member in South Australia. We here provide petrological evidence from Nilpena National Heritage Site and Ediacara Conservation Park to demonstrate the presence of grain-coating iron oxides, framboidal hematite, and clay minerals along Ediacara Member sandstone bedding planes, including fossil-bearing bed soles. SEM and petrographic data reveal that framboids and grain coatings, which we interpret as oxidized pyrite, formed before the precipitation of silica cements. In conjunction with geochemical and taphonomic considerations, our data suggest that anactualistically high concentrations of silica need not be invoked to explain Ediacara Member fossil preservation: we conclude that the pyritic ‘death mask’ model remains compelling.AGL is funded by the Natural Environment Research Council [grant number NE/L011409/2]. SM acknowledges support from the European Union’s Horizon 2020 Research and Innovation Programme under Marie Skłodowska-Curie grant agreement 747877 ... JJM recognises support from Mitacs ..

The Steptoean Positive Carbon Isotope Excursion (SPICE), inorganic aragonite precipitation and seawater chemistry : Insights from the Middle - Late Cambrian Port au Port Group, Newfoundland

ACKNOWLEDGEMENTS The authors would like to thank the following bodies for funding this research: Shell Brazil through the ‘BG05: UoA-UFRGS_SWB Sedimentary Systems’ project at UFRGS, the Aberdeen Formation Evaluation Society and the University of Aberdeen. LAMIR, BGS and EPMA staff are also thanked for their assistance with stable isotope and electron microprobe analysis. Dr Ilse Kamerling and Dr. D. Kemp are thanked for their assistance with pXRF analysis, Marianna Skupinska with collection of point count data and Prof. D. McIlroy is thanked for his assistance during fieldwork. Reviews by Dr C. Pederson, Prof. P. Swart and two anonymous reviewers helped improve the manuscript significantly.Peer reviewedPublisher PD

Did the Benue Trough connect the Gulf of Guinea with the Tethys Ocean in the Cenomanian? : New evidence from the Palynostratigraphy of the Yola Sub-basin

Acknowledgements: M.B. Usman gratefully acknowledges the Petroleum Technology Development Fund (PTDF) for the award of a scholarship to study at the University of Aberdeen. The anonymous reviewers and the editor Eduardo Koutsoukos are thanked for their suggestions and corrections of the manuscript. We also acknowledge Roger David Burgess and Kelly Rebecca Snow for their technical assistance at the palynological laboratory of the University of Aberdeen.Peer reviewedPostprin