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Summer 2023 update

What has the Sedimentary Systems Research group been up to lately? This post provides an update on the activities and accomplishments of the current and recently-finished SSR students and a bit about what I’ve been doing and have planned.

Ph.D. student Natalia Varela is on her way back from the 2023 Urbino Summer School in Paleoclimatology in Italy. This school is for doctoral students and focuses on …

… past climate dynamics with special emphasis on the analysis of long-term carbon cycling and its implications in the understanding of present and future climates. USSP integrates lectures, symposia, field trips, and exercises on the many different areas of paleoclimatology including biogeochemical cycling, paleoceanography, continental systems, and all aspects of deep-time climate modelling. These techniques and systems are explored through interactive discussions of Cretaceous OAEs, P/E hyperthermals, the Greenhouse-Icehouse transition, Neogene and Quaternary climate dynamics.

This content and training is a fantastic addition to Natalia’s strong background in sedimentology, stratigraphy, and basin analysis and sets her up nicely to make scientific contributions in deep-time paleoclimate research going forward. Natalia will be wrapping up her Ph.D. and her time at Virginia Tech later this year, so stay tuned for updates about exciting next steps in her career.

M.S. student Michala Puckett has finished her first year in the program (time flies!) and is busy this summer working on her thesis research. Michala joined the Chile Slope Systems team for the 2023 field season in southern Chile in February-March. In addition to helping out other students with field work and attending the sponsor’s field workshop, Michala collected more than 50 sandstone samples from submarine channel deposits of the Tres Pasos Formation for her thesis project. Here’s Michala at one of the sampling transects along Alvarez Ridge.

Michala will be generating quantitative grain size and sorting data from thin sections to investigate textural variability as a function of channel architecture. Additionally, we plan to make her photomicrographs and size/sorting data available to use as a ‘benchmark’ data set for emerging automated workflows and other image-analysis methods. Michala’s thin sections (pictured below) arrived a couple weeks ago and she’s now getting to work on the characterization.

SSR alum Sebastian Kaempfe (Ph.D., 2022) participated in this year’s field season, helping the team immensely with data collection, field planning and logistics, and as a translator and liaison with the local communities. Sebastian also has the first (of three) dissertation chapters submitted and currently in review (at Sedimentology). This first paper focuses on submarine channel architecture of the Tres Pasos Formation and will hopefully be out and available this fall. The next chapter will be submitted soon!

One of the chapter’s of the dissertation of SSR alum Drew Parent (Ph.D., 2022) is now submitted and in review at Paleoceanography & Paleoclimatology. This study summarizes our work on reconstructing the bottom-current history of the Newfoundland Ridges contourite drifts (using cores from IODP Exp 342) with an emphasis on addressing the long-standing question: Did North Atlantic circulation intensify in response to the Eocene-Oligocene Transition? This work goes back several years, including initial work on one of the sites by SSR alum Kristin Chilton (M.S., 2016) and in collaboration with Tim van Peer, Paul Wilson, Steve Bohaty, and several others working on these questions. I’m very excited to get this work out to the Cenozoic paleoceanography community, stay tuned for updates.

As for me, I’m currently on research leave, and the first of two major activities was a five-week visit at the University of Geneva (Switzerland) in June and early July working with my host Sebastien Castelltort, colleagues, and students. Sebastien and I had collaborated on a source-to-sink review paper several years ago, but haven’t had the opportunity to collaborate more closely since then. Thus, my visit was aimed at revisiting key ideas about signal propagation in source-to-sink sedimentary systems and thinking about what work has been done over the past several years, where we are, and next steps. As part of this, we organized and ran a two-day workshop (pictured below) with other sedimentary system researchers in Europe and with a focus on the Ph.D. students participating in the S2S Future program. It was really fantastic to see the amazing work these students are doing.

During this time I was able to make some progress on a long-languishing paper that includes Sebastien (among others). Time for deep focus on a single research task is exceedingly rare at this point in my career, so I was very happy to be able to regain momentum on several ideas for papers and future proposals. Many thanks to Sebastien for being a fantastic host and to the Swiss National Science Foundation for funding. Additionally, we made sure to visit the Alps for both geology and fun while there.

My second major activity during this research leave is participating as a shipboard scientist on IODP Expedition 400 (NW Greenland Margin), which departs Reykjavik on August 12th. I’m sailing on the core description team and very excited about the sediment cores we hope to recover. More about this expedition in a future post.

Welcome new M.S. student Michala Puckett

I’m very happy to welcome Michala Puckett to the VT Sedimentary Systems Research group. Michala arrived in August 2022 as an M.S. student.

Michala is from Mooresville, North Carolina and received a Bachelor’s in Geology from Appalachian State (in Boone, NC) in May 2022. She found the idea of using geology to make interpretations of the past to be fascinating, which is why Michala’s undergrad research dealt with geoarcheology, to look at humans’ past, and now her graduate research will focus on sedimentology, to reconstruct aspects of the Earth’s past.

Michala’s master’s research will be supported by the Chile Slope Systems project (which is nearing a decade of continuous funding!) and will focus on micro-scale (thin section-scale) characterization of sedimentary texture in deep-marine sedimentary rocks. After many years of field mapping and observation, we can now address questions such as: How does grain size, sorting, grain shape, etc. vary as a function of submarine channel stratigraphic architecture? Michala’s work will also evaluate recent advancements in photomicrographic image-analysis techniques. 

We are excited to have her on board. Welcome Michala!

Congratulations to Sebastian Kaempfe on successfully finishing his Ph.D.!

Congratulations to (now former) SSR graduate student Sebastian Kaempfe on successfully defending his dissertation in May 2022 and officially graduating from the program and obtaining his Ph.D.! Sebastian (who is originally from Punta Arenas, Chile) and I first met back in 2014, when he approached us asking if he could be a field assistant for the Chile Slope Systems research group. Sebastian joined us each February-March the next couple of field seasons, both helping us out and learning about the work we were doing. The result of this interaction was Sebastian coming here to Blacksburg, VA in January 2016 to start a Ph.D. and develop research projects on the geology of a region he grew up exploring.

Sebastian’s dissertation is titled Multi-scale deep-marine stratigraphic expressions in the Cretaceous Magallanes Basin, Chile: Implications for depositional architecture and basin evolution, comprising three chapters that span a range of scales, from detailed (bed-scale) sedimentology to basin-scale paleogeography. All three projects involved extensive field work in the Cerro Toro and Tres Pasos Formations of southern Chile:

(1) The Stratigraphic Expression of Early Channel-fill Deposits During the Evolution of Submarine Slope Channels in the Upper Cretaceous Tres Pasos Formation, Magallanes Basin, Chile

This work summarizes Sebastian’s work on a truly unique and exceptional outcrop exposure of submarine channel system deposits. While the outcrop belt that this location is part of contains abundant quality exposures of sandstone-rich channel-fills that our group has worked on for many years, this particular location reveals details of dominantly fine-grained elements of the system (mud-filled channels and levee overbank) that are typically poorly constrained in outcrops. Sebastian collected a tremendous amount of detailed sedimentological data over a few field seasons. In this paper, which we plan to submit very soon, we present ideas about how stacking patterns in submarine channel systems change through time and also share results about deposits associated with channels in their “young” phase, which are rarely preserved.

(2) Stratigraphy and Syn-Depositional Faulting of an Overbank Succession in a Large Submarine Channel-Levee System, Upper Cretaceous Cerro Toro Formation at El Chingue Bluff, Southern Chile

This chapter presents new findings about another outcrop in the Magallanes Basin that has been visited numerous times over the years, but lacked sufficient amount and type of data to be fully understood. The ~500 meter-thick exposure of dominantly fine-grained and thin-bedded turbidites also contains numerous normal faults that had previously been interpreted to be syn-sedimentary in nature. Sebastian generated an amazing field data set that integrated sedimentological information with structural measurements (e.g., fault orientation/attitude) to finally test these ideas. These new data, combined with previously published age control from our group, suggest that most of this succession is part of a slope system associated with the overbank of the very large Cerro Toro channel-levee system. The paper that summarizes this study discusses the possible controls of this depositional-deformational interaction and will be submitted later this year, so look for it in 2023!

(3) Deciphering the Depositional Age of Coarse-Grained Deep-Marine Sedimentation in a Previously Undocumented Location in the Magallanes Foreland Basin, Southern Chile

Sebastian’s final chapter ‘zooms out’ in scale and considers regional paleogeography of generally similarly aged depositional units in the region south of Puerto Natales, Chile, which was essentially frontier territory (geologically speaking). The relationship to the better-studied units to the north had been assumed for decades based on large-scale geologic mapping, but there wasn’t any actual age control. Sebastian led multiple excursions to this very-difficult-to-access location to collect samples for detrital zircon geochronology. Due to the relatively high abundance of nearly contemporaneous zircons in Magallanes Basin strata, we’ve been able to constrain depositional ages of stratigraphic units much more accurately than previously known. Sebastian’s work shows that the conglomeratic deposits that make up the bulk of this location are actually younger than similar-looking units to the north and, therefore, likely represent a wholly different sediment-routing system.

As I mentioned in the recent post about Drew Parent finishing, it’s always so bittersweet — when graduate students succeed, that means they leave! I am so happy to have worked with Sebastian on these projects and look forward to future collaborations (and getting these papers out!). Sebastian has moved back to Chile and will be working on numerous interesting educational, public outreach, and research projects as an independent consultant. Congratulations Sebastian!!

Sebastian and Brian in the field (2015) and then following Sebastian’s PhD defense (2022).

Congratulations to Drew Parent on successfully finishing his Ph.D.!

This post is coming many months after it should, but better late the never! Congratulations to SSR graduate student Drew Parent on successfully defending his dissertation in December 2021 and officially graduating from the program and obtaining his Ph.D. in January 2022! Drew’s dissertation is titled Deep-marine depositional systems of the western North Atlantic: Insights into climate and passive-margin evolution, comprising three chapters that span a diverse range of approaches and topics, including experimental sedimentology, paleoceanography, and source-to-sink analysis, with applications focused on the North Atlantic Ocean and eastern margin of North America:

(1) Comparative analysis of flume experiments and natural systems: Implications
for application of sortable silt to deep-sea bottom-current reconstruction

This work summarizes Drew’s contributions to a collaboration we had with Kyle Strom and his Fluid & Sediment Dynamics group in Civil and Environmental Engineering here at Virginia Tech. This project aimed to test aspects of the widely used physical paleoceanographic proxy known as ‘sortable silt’ in an experimental flume. Our first paper, which summarizes the experimental design and basic results, was published in Sedimentology in 2021. Drew’s chapter about this research focuses on the implications to the usage of sortable silt for paleoceanography, including quantitative comparison with published data from the literature. We plan to submit this manuscript later this year.

(2) Eocene-Oligocene intensification of the Deep Western Boundary
Current in the North Atlantic Ocean

This chapter applies the sortable silt proxy (mentioned above) to a ~9 million-year-long succession of deep-sea contourite drift deposits on the Newfoundland ridges that includes the Eocene-Oligocene Transition (EOT; ~34 Ma). The EOT is the most significant climate transition of the past ~60 million years of Earth history and is characterized by significant global cooling and rapid expansion of land ice on Antarctica. Drew’s research built on data collected by former SSR student Kristin Chilton (M.S., 2016) and investigates the long-standing hypothesis that North Atlantic deep circulation intensified during the EOT. Drew’s work suggests that deep ocean circulation did indeed intensify over this time, but gradually over million-year timescales. This manuscript will be submitted this summer (once our co-authors give it a thorough review!).

(3) Sediment routing system connectivity of the mid-Atlantic U.S. margin
during the Early Cretaceous: Insights from detrital zircon geochronology

This final chapter is focused on the western part of the North Atlantic Ocean and continental margin of eastern North America. While this work also highlights deep-marine sediments and processes, it’s distinct from chapters 1 and 2 in that it ventures further back in time and applies different methods. Drew generated new detrital zircon geochronology data in a proximal-distal transect for the Early Cretaceous as a way to examine the linkage of onshore (fluvial) depositional systems to offshore (turbidite fan) systems, which has implications for broader landscape reconstructions and evolution.

Graduate students finishing is such a bittersweet event — when they succeed that means they leave! I am so happy to have worked with Drew on these projects and look forward to getting this science out to the community and working on new collaborations in the future. Drew also TA’d several times during his time here becoming a talented educator and mentor in addition to researcher. Drew is now working as a geoscientist at Shell in Houston, Texas. Congratulations Drew!!

Drew Parent’s GSA 2020 presentation on U.S. Atlantic margin sedimentation during the Early Cretaceous

Sedimentary Systems Research group Ph.D. student Drew Parent gave a talk at the 2020 Geological Society of American (GSA) annual meeting about his work using detrital zircon geochronology to investigate passive-margin sedimentation on the U.S. mid-Atlantic during the Early Cretaceous.

Check out this recording of the talk:

Drone videos from Patagonia field work

Ph.D. candidate and Sedimentary Systems Research group member Sebastian Kaempfe created these two jaw-dropping drone videos of outcrops of the Cretaceous Magallanes Basin in southern Chile. (I recommend watching on a laptop or big monitor in ‘full screen’ view.)

The first video is from a locale known locally as El Chingue Bluff (the word ‘chingue’ means skunk in this part of Chile and is the name of the estancia). This turbiditic sandstone package forming the top of the bluff is interpreted as a partially ponded intra-slope system marking the transition from underlying Cerro Toro Formation to overlying Tres Pasos Formation.

This second video (below) is from the eastern end of a mountain range called Sierra del Toro and shows off strata that are interpreted as overbank (levee) deposits of the Cerro Toro Formation deep-marine channel system.

To see more of Sebastian’s photos and videos, please visit his Instagram page.

Presentations at AGU 2019

Three out of four of the members of Sedimentary Systems Research group will be attending the American Geophysical Union (AGU) Fall 2019 meeting in San Francisco next week. Here’s a rundown of our activities:

Monday (Dec 9) morning:

  • Ph.D. candidate Drew Parent is presenting a poster summarizing our flume experiment research testing the ‘sortable silt’ bottom-current proxy — Sorting of silt by bottom currents part II: Grain-size metrics and applicability to paleoceanography (PP11D-1415)
  • Also check out part I of this work, a companion poster in the same session led by our collaborator Kyle Strom from the Dept. of Civil & Environmental Engineering, which summarizes the flume design and details about the experiments — Sorting of silt by bottom currents part I: Laboratory experiments (PP11D-1412)

Friday (Dec 13) morning:

  • Brian Romans is giving a talk in the session Multiproxy Approaches to Resolving Climatic and Tectonic Controls on Landscape Evolution about sediment recycling based on work from the Magallanes Basin — Effects of intrabasinal recycling on the preservation of tectonic and climate signal determined from provenance analysis (T52B-02) — this talk is at 10:35am in Moscone West 2004 L2

Friday (Dec 13) afternoon:

  • Ph.D. candidate Natalia Varela is presenting a poster in the session Southern Ocean Climate and Antarctic Ice Sheet Dynamics with some brand new results from IODP Exp 374 core samples analyzed over the past several months — A physical record of Antarctic Bottom Water (AABW) outflow in the Ross Sea from the late Pliocene (3.3 Ma) through present (PP53C-1456)

We are looking forward to sharing our latest work, hope to see you there!

New graduate student Sebastian Kaempfe

I’m very happy to welcome Sebastian Kaempfe to the VT Sedimentary Systems Research group. Sebastian is starting a M.S. degree and his research will be part of the Chile Slope Systems program, which is in the first year of another three-year phase.

Sebastian is from southern Chile (Punta Arenas), not far from the field area that is the focus on this research. He received a Bachelor’s in Geology at the Universidad de Concepción in 2009. Sebastian came to us after finding out from a mentor and friend that we were doing sedimentary geology research in Chilean Patagonia. He approached us a few years ago and asked if he could help out as a field assistant and learn about what we were doing. This relationship grew and he’s now working on his own project in the group.

We are excited to have him on board. ¡Bienvenidos Sebastian!

Sed Systems Research group at AAPG 2015

aapgNext week is the annual meeting of the American Association of Petroleum Geologists (AAPG) in Denver, CO. Sedimentary geology plays an important role in AAPG so there will be a strong contingent of the Sedimentary Systems Research group there presenting our latest research. As you’ll see below, the majority of our presentations are updates on the multi-disciplinary and multi-institutional Chile Slope Systems project, which had an incredibly productive past year.

[Unfortunately, I can’t link to static pages of each abstract — they have one of these systems where you have to log in and create an itinerary and all that. The entire technical program is here.]


Monday, June 1st:

  • Steve Hubbard (Univ of Calgary) is presenting a poster (Brian Romans is a collaborator and co-author) in the SEPM Research Symposium Channels: From Geomorphic Expression to Stratigraphic Record with a poster titled “How many turbidity currents pass through a submarine channel and what is their stratigraphic expression?” I know you want to know the answer to that question.
    • when: 8:30am-5:00pm
    • where: Exhibition Hall

Tuesday, June 2nd:

  • Brian Romans is co-chairing the first of two oral sessions as part of the SEPM Research Symposium Channels: From Geomorphic Expression to Stratigraphic Record, which will include talks from Mike Blum, John Holbrook, Kyle Straub, and many more. (And make sure to check out the second oral session later that afternoon.)
    • when: 8am-11:50am
    • where: Four Seasons Ballroom 4
  • Casey Meirovitz (Univ of Utah) is presenting poster (Brian Romans is a co-author) in session ACE 13 titled “Quantifying inter- and intra-channel architecture controls on reservoir performance in a deep-water slope channel system, Tres Pasos Formation, Magallanes Basin”
    • when: 8:30am-5:00pm
    • where: Exhibition Hall
  • Ph.D. candidate Cody Mason is presenting poster in session ACE 04 titled “Quantifying sediment supply in stratigraphy using cosmogenic nuclides: Insights from the Pleasant Canyon complex, Panamint Mountains, California”
    • when: 8:30am-5:00pm
    • where: Exhibition Hall
  • Jake Covault (Chevron) is giving a talk (Brian Romans is a collaborator and co-author) in the SEPM Research Symposium Channels: From Geomorphic Expression to Stratigraphic Record with a poster titled “Geomorphic and stratigraphic records of the composite evolution of submarine channels”
    • when: 2:20-2:40pm
    • where: Four Seasons Ballroom 4
  • Ph.D. candidate Neal Auchter is giving a talk in session ACE 04 titled “Outcrop example of intrastratal slope deformation controlled by depositional architecture, Tres Pasos Formation, Magallanes Basin, Chile”
    • when: 4:45-5:05pm [last talk of the day, stick around for it!]
    • where: Room 605/607

Wednesday, June 3rd:

  • Allie Jackson (Univ of Utah) is giving a talk (Brian Romans is a co-author) in session ACE 04 titled “Characterizing static reservoir connectivity of deepwater slope deposits using sub-seismic outcrop-based facies models, Tres Pasos Formation, Magallanes Basin, Chilean Patagonia”
    • when: 8:45-9:05am
    • where: Room 501/502/503
  • Lisa Stright (Univ of Utah) is giving a talk (Brian Romans is a co-author) in session ACE 04 titled “Optimizing the preservation of deepwater intra-channel architecture and model connectivity during upscaling, Tres Pasos Formation, Magallanes Basin, Chilean Patagonia”
    • when: 10:30-10:50am
    • where: Room 501/502/503
  • Sarah Jancuska is presenting a poster in session ACE 00 titled “Stratigraphic expression of the transition from basin plain to slope sedimentation in outcropping strata of the Magallanes Basin, Chilean Patagonia”
    • when: 8:30am-noon
    • where: Exhibition Hall
  • Daniel Niquet (Univ of Calgary) is presenting poster (Brian Romans is a co-author) in session ACE 04 titled “The orientation of sandstone-filled U-shaped trace fossils as indicators of deepwater channel axis position, Tres Pasos Formation, Chile”
    • when: 8:30am-noon
    • where: Exhibition Hall
  • Ben Daniels (Univ of Calgary) is presenting poster (Brian Romans and Neal Auchter are co-authors) in session ACE 04 titled “Constructing a seismic-scale 3-D geo-model of stacked slope channel deposits grounded in high-resolution outcrop observations, Magallanes Basin, Chile”
    • when: 8:30am-noon
    • where: Exhibition Hall

 

Fall 2014 Update — New Faces for the New Academic Year

The VT Sedimentary Systems Research group has a combination of continuing ‘veterans’ and some new faces to start off the 2014-2015 academic year.

Ph.D. candidates Neal Auchter and Cody Mason are starting their 3rd year and are plugging away at their respective research projects. Neal will be working on sample preparation for strontium isotope analysis this semester. Cody is anxiously awaiting cosmogenic radionuclide results from PRIME Lab, where he spent several weeks this summer preparing his samples for analysis. We expect those data to come in any time! In addition, both Neal and Cody will be taking their Ph.D. preliminary examinations (aka ‘prelims’) later this semester.

New master’s candidate, Sarah Jancuska, joined the group this semester and will be part of the Chile Slope Systems consortium examining Cretaceous deep-marine strata in southern Chile. Sarah is diving right into graduate school by helping me teach our undergraduate Sedimentology-Stratigraphy course as a teaching assistant in addition to taking courses and starting research.

Undergraduate researcher Rachel Corrigan started some work last spring semester and will be continuing this semester, which is her last in the department. Rachel is investigating the response of a long-lived abyssal current in the deep North Atlantic Ocean to climate change at the Oligocene-Miocene boundary. She’ll be documenting changes in terrigenous grain size, including amounts of outsized material that is likely ice-rated debris.

New undergraduate researcher Eric Lahart, also in his last semester before graduating, will be doing similar work as Rachel, but over the Eocene-Oligocene boundary.

Finally, sophomore Rob Ulrich will be investigating grain-size and textural differences in thin sections of Cretaceous submarine channel sandstones. Rob will be developing and testing image-analysis methods to detect and quantify differences between sandstone deposits as a function of stratigraphic architecture.

I am teaching Sedimentology-Stratigraphy, as I do every fall, and co-teaching a graduate Basin Analysis course with colleague Dr. Ken Eriksson. In the meantime, I’m also working with co-authors on a review paper for the journal Earth-Science Reviews that discusses the propagation of tectonic and climatic signals through sedimentary systems at different timescales. We are within a few weeks of submitting and excited about the contribution.