Tuesday, January 24, 2017

AE Interview: Get to Know Murray Gingras

Murray Gingras is a professor at the University of Alberta, Department of Earth and Atmospheric Sciences

Q. What’s your research?

A: Studying animal–sediment relationships and sedimentary geology in general.  I view my role in this field as someone who takes a specific dataset and integrates it into established sedimentological datasets that have included aspects of ichnology, and as a result my work is applied from the Precambrian all the way through to the Modern, usually with the intention of refining our understanding of what the sedimentary environment was—and by refining I mean inferring things that we can’t infer from normal sedimentology, things like very highly refined sedimentation rates, timescales that vary from minutes to days to months, which we can’t do with geochronology, and chemical aspects of the sedimentary environment including relative levels of oxygenation and relative salinities. This type of parameterization allows us to take sedimentary interpretations to a much higher level. The end goal of this is to understand the ancient world and the modern world better but it also helps us establish better sequence stratigraphic frameworks, to understand paleogeographic restorations better, and it has very practical applications in refining facies interpretations in the subsurface so that oil and gas exploration can be brought to another level with better sedimentological analyses.

Q: Do you think rocks without animals are boring?

A: No! As long as there is awesome stratification or cool surface features like microbial wrinkle marks, or nifty casts, I think that is all really interesting.  I must admit that unburrowed, planar bedded silts and shales are a little too tedious for me sometimes. I was really trained as a geologist, not a sedimentologists, so I don’t find rocks boring ever, at all. I like igneous rocks, I have a mineral collection…and metamorphic rocks are hard to beat.

Q. What is your favorite field area and why?

A: Willapa Bay [Washington State, U.S.A.]. I did my PhD there. It has everything I love! Every time I go there I learn something new, I find that something I thought was right becomes incorrect in the face on new information gleaned from Willapa Bay. I have never walked along the shorelines there and not had an idea for a paper. I suppose if I followed up on the we could have 300 papers on Willapa Bay. It’s just a remarkable place to work. The west coast food culture has gotten steadily so excellent that you can go out to Astoria or Long Beach peninsula and get salmon…or a nice oyster stew. I’ve been all over the world, I’ve worked Argentina, Spain, France, Australia, New Zealand, and they were all great but Willapa Bay still wins, for sure.

Q. What was your favorite JSR paper “back in the day” (or the last year)?

A: Traces in the dark: sedimentary processes and facies gradients in the Upper Shale Member of the Upper Devonian–Lower Mississippian Bakken Formation, Williston Basin, North Dakota, U.S.A., by Sven Eggenhoff and Neil Fishman. They took an important dataset and showed that what a lot of people were assuming was incorrect. A lot of these unbioturbated units actually had bioturbation and that’s not trivial because a lot of organic-rich deposits we tend to think of as euxinic deposits, meaning no oxygen and very sulphitic water conditions, i.e., animal life can’t exist, so ichnofossils can’t exist. If you show that’s wrong it implies that something really fundamental about the way we view some organic deposits is incorrect and we need to recalibrate how we view them.

Hyperpycnal rivers and prodeltaic shelves in the Cretaceous seaway of North America, by Janok Bhattacharya and James MacEachern. I like the breadth of the undertaking—they looked at scalar data regarding deltas, sedimentological models, they used rock pictures, schematics, they really built a beautiful interpretation of the distribution, occurrence, and importance of hyperpycnites that I think was the result of thinking about it for many years. It was areally well executed synthesis, because Bhattacharya is so creative in how he articulates himself and MacEachern is so capable of precise technical prose that to me was a writing match made in heaven.

Q. What are your hobbies?

A: I read a lot of science fiction. When I retire, I am going to form a "Sasquatch Research Group" and prove the existence of Sasquatch.

Q. Oooh, can I help with the Sasquatch research?

A: Yes!

I also like building things around the house---bunny frames, trellises, etc. I made a nice strawberry frame to keep the birds out! I have to admit geology is as much my hobby as it is my job.

Q. What is your favorite Pandora station?

A: What is Pandora?

Q: A streaming music service.

A: Oh! In Canada I use Deezer. D-e-e-zed-e-r. I think the channel I most use is the ELO playlist, and David Bowie, Led Zepplin. For new music I like Eminem, Bruno Mars. My favorite new indie group is Fun.

This interview was done via Skype and transcribed and edited semi-accurately by Melissa Lester on January 19, 2017.

Tuesday, January 17, 2017

Highlights: Permian Plants Provide Pangean Perspectives

Plants provide important insights into paleo-landscapes and -climate, yet commonly are not well preserved in the geologic record. This paper by Simon et al. describes a perplexing case where the features of the abandoned channel deposits, plant fossils and paleosol sections suggest that conditions were relatively wet, although the formation has been interpreted to have been deposited under semi-arid to arid conditions. Within the Leonardian (Permian) Clear Fork Formation of north-central Texas, the Colwell Creek Pond site represents an abandoned channel Integrated field, sedimentologic, mineralogic, paleobotanic, and taphonomic observations reveal the formative conditions and preservation of the laminated mudstone beds, as well as the types of plants preserved and biomineralization process. The findings of this paper broaden understanding of the conditions within the equatorial regions of Permian Pangea, providing perspectives on these unique systems without complete modern analogs.

Wednesday, January 11, 2017

Highlights: On Hybrids (Event Beds, not Cars)

Although hybrid event beds (HEBs) occur in many of deep-water systems, the mechanisms responsible for their formation remain ambiguous. Most workers agree that acquisition of mud or muddy material is a key factor, with many hybrid flow models favoring an origin for the mud in up-dip channels, channel-lobe transition zones or slope sectors. In this study, Fonnesu and others describe outer-fan-lobe and confined-basin-plain sheet deposits of the Cretaceous–Paleocene Gottero Sandstone cropping out on Mount Ramaceto and Mount Zatta (NW Apennines, Italy). The succession includes cm- to m-deep erosional scours below sheet-like HEBs, features which appear to provide the mud necessary for local flow transformation. Extensive substrate delamination in distal deep-water environments has not been described in detail before nor linked to the local formation of HEBs.This hybrid flow model may apply generally, with implications for the distribution and heterogeneity of HEB muddy divisions and hence hydrocarbon reservoir properties.

Marco Fonnesu, Marco Patacci, Peter D.W. Haughton, Fabrizio Felletti, and William D. McCaffrey