It’s getting hot and humid here in Blacksburg, so summer is in full swing. The Sedimentary Systems Research group is scattered a bit as three of the four graduate students (Sarah Jancuska, Neal Auchter, and Cody Mason) are away doing internships in Texas. I saw them and many other colleagues/friends at the recent AAPG conference in Denver, which turned out to be a very good meeting for us. Cody and Sarah both presented posters and Neal gave a great talk.

Master’s candidate Kristin Chilton is here this summer and she is neck-deep in sample preparation for her project. Kristin is building on a preliminary dataset that undergraduate researchers (all now graduated) and I generated to examine the variability in abyssal bottom-current intensity across the Eocene-Oligocene Transition (~34 Ma). Kristin added to this dataset this spring and the preliminary results suggest there is a change that corresponds with the transition, but (as always) it may not be as straightforward as we predicted. She will be working this summer to prep many more samples for grain-size analysis to better constrain the problem.

I am heading to the NOC (National Oceanography Centre) in Southampton, UK, next week to give a talk and work with some collaborators on this same Eocene-Oligocene Transition effort. Following that, I’ll be attending the IODP (International Ocean Discovery Program) Science Evaluation Panel meeting in Brest, France.

The Chile Slope Systems project is highlighted in our department’s April 2015 newsletter. Click here or on the image above to read the full feature (note: link opens a PDF).

The 2015 field season for the Chile Slope Systems project is now over and a great success. Despite some not-so-great weather towards the end of the 7-week season the team was very productive. Ph.D. candidate Neal Auchter and M.S. student Sarah Jancuska amassed an impressive amount of data this season.

Here are some photos (captions are below each photo):

Neal and Sarah measuring section along Rio Zamora. The first half of the field season was unusually dry and the river level quite a bit lower. We were able to see some new section that is typically under water!

Neal with Rio Zamora in the background. The outcrops Neal is working up are a result of rapid incision by this river over the past several thousand years, which has produced some magnificent exposures along the river canyon walls.

We did a bit of mudstone sampling this year.

I was fortunate enough to be able to attend a trip to the Argentine side of the border where these same Upper Cretaceous foreland basin strata are exposed. This outcrop, not far from Perito Moreno glacier, highlights some fascinating transitional flow deposits of the Punta Barrosa Formation. These rocks are currently being studied by the Stanford Project of Deep-water Depositional Systems group.

Stunning view of Upsala glacier in Argentina while examining the older part of the basin history.

Typical Patagonia traffic jam.

What I ate for lunch most of the field season: canned tuna, avacado, and hot sauce on a cracker.

Some spirited debate during our sponsor’s trip regarding the nature of inclined surfaces in submarine channel strata.

A view of Cordillera Manuel Senoret from one of the areas worked up this year by a Univ of Calgary student as part of the collaborative Chile Slope Systems effort.

Ph.D. candidate Cody Mason and I spent the past week out at his research area in Panamint Valley, California. This was the final field data and sample collection trip for this project (at least on this grant). There’s still much to do on the project, but field work is done!

January in the greater Death Valley region is a lovely time of year for field work — not too hot and very few gnats to contend with. Here are some photos with the caption that describes the image below the photo:

Standing on an alluvial fan looking west toward the basin (Panamint Valley). Note the bar and swale morphology.

View of the Panamint Valley playa (which actually had some water in it) from a canyon incised into the outcropping Pleistocene deposits we are studying.

The research we are doing requires good age control, which is notoriously difficult to get in alluvial deposits. The main goal of this trip was to collect samples for optically stimulated luminescence (OSL) dating. Here’s Cody hammering the sampling tube into the sediment.

A view of the Panamint Mountains in the late afternoon sun light. The lower hills in the middle ground is the proximal part of the now-exhumed alluvial/lacustrine deposits we are characterizing.

Geologist, educator, and GigaPanner extraordinaire Ron Schott was kind enough to meet up with us one afternoon to shoot a few GigaPan images of the field site. The photo above shows the GigaPan rig doing it’s thing. There are three GigaPans, from three locations in the playa: Position #1, Position #2, and Position #3. Cody and I will be using these images to help with facies correlations across the outcrop.

There was actually standing water down in the playa and one morning it was so still we had to stop and appreciate the reflections.

Although these sedimentary deposits are geologically young (<1 Ma) they are cemented and indurated enough to erode into vertical cliffs. Here, we took a quick detour into a very narrow slot canyon.

The focus of our work here is the ~0.2 to 1.5 Ma old deposits but we spent a day exploring the younger (<0.15 Ma) deposits associated with more recent lake highstands. These deposits sit atop the outcrops we’ve been studying in small and sparse outcrops. Above you can see a roadcut exposure behind Cody.

These exposures of the younger sediments may not be extensive but they are quite interesting. Here are some dipping laminated sands interbedded with granule-pebble conglomerate truncated by flatter-lying pebble-cobble conglomerate beds. The Jake staff in the upper right is 1.5 m tall. We interpret the lower dipping beds to have been deposited on steeply dipping foresets of a fan delta building out into the lake.

Next week is the annual Fall Meeting for the American Geophysical Union (AGU) and a contingent of Sedimentary Systems Research group be there presenting the latest on our work:

Monday is a big day for us:

• Julie Fosdick (Indiana Univ) is giving an invited talk (Brian Romans is a collaborator and co-author) in session EP11C-01 about detrital records of tectonics titled “Unraveling burial heating and sediment recycling in retroarc foreland basins: Detrital thermochronologic insights from the northern Magallanes Basin, Patagonian Andes”
  • when: Monday at 8:00am (first talk of the early morning session)
  • where: Moscone West 2005

• Brian Romans is giving an invited talk in session EP12A-08 about the propagation and preservation of signals in the sedimentary record titled “Sediment flux from stratigraphy: Insights from <1 Ma and >300 Ma sedimentary archives” 
  • when: Monday at 12:05pm (final talk in the late morning session)
  • where: Moscone West 2003

• Ph.D. candidate Neal Auchter is presenting poster EP13C-3533 titled “Multi-phase submarine channel history recorded by stratigraphic architectures in outcropping slope-channel deposits, Tres Pasos Formation, Chile”
  • when: Monday afternoon (1:40-6:00pm)
  • where: Moscone South poster hall

• Ph.D. candidate Cody Mason is presenting poser EP13B-3519 titled “Are catchment denudation signals stored in alluvial-fan stratigraphy? Measuring paleodenudation rates using cosmogenic radionuclides in Pleistocene Pleasant Canyon Complex, Panamint Mountains, California”
  • when: Monday afternoon (1:40-6:00pm)
  • where: Moscone South poster hall

Cody and Neal’s posters are in different sessions, but in the same theme, so they will likely be somewhat close to each other. Come on by and see the latest and greatest related to their Ph.D. projects.

And then we have a couple of presentations on Friday:

• Former SSR student Patrick Boyle has a poster (PP51E-1175) based on his completed master’s thesis titled “Cenozoic circulation history of the North Atlantic Ocean from seismic stratigraphy of the Newfoundland Drift Complex”. Unfortunately, Pat cannot make it to AGU so Brian Romans (2nd author) will be presenting the poster.
  • when: Friday morning (8:00am-12:20pm)
  • where: Moscone West poster hall

• Steve Hubbard (Univ of Calgary) is giving an invited talk (Brian Romans is collaborator and co-author) in session EP53E-04 about comparison of fluvial and submarine channel processes and deposits titled “The stratigraphic expression of formative processes in channels”
  • when: Friday 2:25-2:40pm (early afternoon session)
  • where: Moscone West 2007

Hope to see you there!

UPDATE (August 2015): This position is filled.

My department is advertising for a new faculty position in the broad field of ‘energy geoscience’. Below is the full advertisement text and here is where to apply: https://listings.jobs.vt.edu/postings/52633

I was recently interviewed by a podcast called People Behind the Science, whose goal is to tell the stories of scientists and researchers from a personal point of view. That is, what path did I take to find myself doing this, what failures and successes have I experienced, and how do I keep motivated? PBtS has interviewed more than 150 scientists, including several National Academy of Science scientists.

Here’s the link to my interview: http://www.peoplebehindthescience.com/dr-brian-romans/ 

A quick summer update from the Sedimentary Systems Research group.

We say farewell to Patrick Boyle who finished his master’s degree in May and is soon starting a career as an applied geoscientist in Houston, Texas. Pat and I are still working together this summer, along with some collaborators, to prepare a manuscript based on his thesis for submission to a journal by the end of the summer. At the same time, we welcome new master’s student, Sarah Jancuska, who will join the department next month. Sarah will be doing her research as part of the Chile Slope Systems project. So, one student out, but another student in — we remain at steady state!

Ph.D candidate Neal Auchter is away this summer doing an internship in Houston, Texas. Ph.D candidate Cody Mason spent a few intense weeks at the PRIME Lab at Purdue University last month preparing his samples for cosmogenic radionuclide (10Be and 26Al) analysis. If all goes according to plan, we should have some initial results this fall.

I’ve been spending my time working on multiple manuscripts, including a review paper to be submitted to Earth-Science Reviews next month on the topic of signal propagation in sedimentary systems across a wide range of timescales. I’m also working on some new/updated exercises for my Sed-Strat course as well as some content for a Basin Analysis course I’ll be co-teaching this fall.

I’m co-chairing a session (along with David Van Rooij from Ghent University) at the 2014 AGU Fall Meeting titled The Paleoceanographic Value of Contourite Archives. If you work on the sedimentary dynamics of contourites and/or use them to reconstruct paleoceanographic conditions, please consider submitting to the session. Abstract deadline is August 6th.

Congratulations to Sedimentary Systems Research group member Patrick Boyle on the successful completion of his master’s degree. Pat is the first student to graduate from this new research program and will be moving to Houston, Texas this summer to start a full-time job with ConocoPhillips as a geoscientist.

Pat’s thesis was focused on the investigation of the Cenozoic history of the Deep Western Boundary Current in the North Atlantic Ocean. Pat used seismic-reflection data constrained by Integrated Ocean Drilling Program (IODP) Expedition 342 cores to map the spatial and temporal distribution of deep-sea ‘contourite’ deposits and their relationship to global climatic changes. We are now finishing up a manuscript to be submitted to a journal, which will happen in the next month or so. Stay tuned for the paper!

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Also, the broader sedimentary geology group here at Virginia Tech just got back from a six-day, grad-student-run field trip examining various Paleozoic sedimentary successions in the central Appalachians. This trip was the culmination of a semester-long seminar where each student chose a topic of interest and researched potential outcrops to visit. The students then worked together to produce a field guide and planned the trip. We saw a lot of great geology and had a great time.

My collaborators and I have a new paper out in the journal GSA Bulletin about sediment transfer across deep-marine slopes as recorded in the stratigraphy of submarine channel deposits. (It’s worth mentioning that this paper is also open access!)

Deep-sea channels, as we can map them on the modern Earth surface, extend for 1000s of km into ocean basins and rival the planet’s biggest rivers as conveyors of sediment and other material. Much progress has been made in recent years in tools and technology for mapping and studying the ocean floor. Additionally, numerical modeling of the physics of sediment transport in the submarine realm is advancing our understanding of turbidity currents. However, ancient sedimentary deposits that are now exposed in outcrop provide the opportunity to examine the relationships of individual turbidity current event beds to the larger-scale stratigraphy that they construct. Examining the stratigraphic architecture allows for reconstruction of longer-term evolution of the depositional system.

With examples from exceptionally exposed strata from the Magallanes Basin in southern Chile, we emphasize the importance of the fine-grained and thin-bedded deposits that are preserved at the margins of sedimentary bodies we interpret as channels. Although the thick-bedded and coarse-grained deposits make up most of the volume of the composite features, it’s the margin deposits that contain the history of sediment transfer through the channel.