Research areas

EARLY EaRTH DEPOSITIONAL SYSTEMS

Silicification

Siliceous rocks are one of the most promising deep time preservation agents – they encapsulate the earliest putative micro-fossils and microbial communities and preserve the world’s oldest known bio-signatures.

However, the depositional environment and conditions of formation for these archival silica-rich precipitates are often in dispute. They form at the intersection of hydrothermal and sedimentary processes, making their intricate diagenetic and alteration histories difficult to decipher. Our lab has several projects that combine textural and geochemical tools to investigate fundamental questions that link to how Precambrian silica-rich rocks form.

Want to learn more about our work on silicificaiton? Check out these references: (1) https://eartharxiv.org/xk4av/; (2) https://www.sciencedirect.com/science/article/abs/pii/S0016703718301017; (3) https://onlinelibrary.wiley.com/doi/abs/10.1111/ter.12192

Early Earth depositional systems

Diagenesis

To interpret primary features in Precambrian rocks, we must first determine the metamorphic and diagenetic history.

Our lab specializes in mineral paragenesis in Precambrian sedimentary and hydrothermal rocks with an emphasis on sedimentary petrology and micro-analytical geochemical techniques. We have several on-going projects in Archean greenstone belt terranes as well as Proterozoic sedimentary basins, enhanced by our regional connection to the Precambrian.

Graduate student Sam Duncanson recently presented about diagenetic reactions in Paleoproterozoic iron formation at the virtual North-Central GSA section meeting (May 2020). You can view Sam’s presentation here! > https://gsa.confex.com/gsa/2020NC/meetingapp.cgi/Paper/346106

EARLY EARTH ANALOGS

Analogs

We collaborate with experts in modern hydrothermal systems.

Working in Precambrian terranes, we often utilize indirect approaches and work backwards to answer questions about ancient seawater or habitability on a nascent planet. We are fortunate to have recently begun collaborating with other scientists that work in modern hydrothermal systems to better understand processes of silicification and silica precipitation.

Science, Art and Communication

SciArt, SciComm

We have a funded project: “Involving UMD students across campus to update the museum-quality display cases in Heller Hall and connect to a modern audience” and are currently recruiting!

Project goal – The goal of this project is to involve UMD students from across campus in the re-design and renovation of the outdated museum-quality display cases on the first floor of Heller Hall.

Purpose – By updating the Heller Hall museum cases, we propose to bring the displays into the digital age and increase accessibility of the information for diverse audiences within our community. In re-designing the cases within an updated scientific framework, our goals are to improve: (1) science communication; (2) the connection between science and art; (3) diversity and accessibility of the displays.

Community impact – With the renovation we have the unique opportunity to increase public engagement with UMD by providing a free, accessible educational resource for classes, students, and the public.

Connecting with our community

Outreach

Our lab is dedicated to connecting with our local K-12 programs and broader community.

We have developed several outreach projects since the lab started in Fall 2015 and we remain committed to this goal. Check back in summer 2020 for our shared resources (to be posted here).

STUDENT ADVISEES

Graduate students supervised

  • Ann Marie Prue, M.S. student 2020 – present (primary advisor). In progress.
  • Sam Duncanson, M.S. student 2018 – present (primary advisor). In progress. Current thesis title: “Inferring primary seawater chemistry from sub-micron scale mineral mapping in silica-cemented horizons of the ~1900 Ma Biwabik Iron Formation.”

Undergraduate students supervised (research projects and UROPs)

  • Elizabeth Boor, Geological Sciences, B.S., (2019 – present).
  • Heidi Krauss, Geological Sciences, B.S., (2019 – present).
  • Emily Wojtowicz, Geological Sciences, B.S., (2019 – present).
  • Logan Carpenter, Geological Sciences, B.S., (2019 – present).
  • Danielle Stolze, Geological Sciences, B.S. (2019 – present). Project: “Comparative mineralogy of the ~2.7 Ga Soudan Iron Formation, Minnesota and the Deloro Iron Formation, Timmins, ON, and the Temagami Iron Formation, Temagami, ON.” https://conservancy.umn.edu/handle/11299/213805
  • Kendall Johnson, Geological Sciences B.S. (2017 – 2018). Project: “Grain size distributions and mineralogy of coated grains, detrital sand and silt within the 1.9 Ga Mesabi Iron Range, Minnesota”
  • Anthony Wetzel, Geological Sciences B.S. (2017 – 2018). Project: “Broadly constraining Proterozoic ocean pH by determining primary and secondary carbonate mineral reactions in iron formation from the ~1.9 Ga Mesabi Iron Range, MN”
  • Stephen Hanson, Geological Sciences, B.S. (2016 – 2017). Project: “A textural and mineralogical investigation of early diagenetic reactions in the ~1.9 Ga Biwabik iron formation, MN”

Undergraduate summer Research Assistants

  • Logan Carpenter, Geological Sciences, B.S., (2019 – present).
  • Danielle Stolze, Geological Sciences, B.S. (2019 – present).
  • Mady David, Geological Sciences B.S. (2018 – 2019).
  • Kendall Johnson, Geological Sciences B.S. (2017 – 2018).
  • Anthony Wetzel, Geological Sciences B.S. (2017 – 2018).
  • Stephen Hanson, Geological Sciences, B.S. (2016 – 2017).

Research employees

  • George Segee-Wright, Hamilton College, Summer/Fall 2017.
  • Kendall Johnson, Spring 2020.

Graduate student committees

  • Kristi Kotrapu, Geological Sciences, M.S., 2017 – 2018.
  • Amber Roberts, Geological Sciences, M.S., 2016 – 2018.
  • Matthew Matko, Geological Sciences. M.S., 2017 – 2018.
  • Margaret Upton, Geological Sciences, M.S., 2017 – 2018.

ABSTRACTS *graduate student authors, **undergraduate student authors

*Duncanson, S.D., Brengman, L.A., Fournelle, J., Moy, A. (2020). Reconstructing Fe-silicate paragenesis using paired textural and compositional data in the ~1.9 Ga Biwabik Iron Formation, MN. North-Central Geological Society of America, May 18-19, 2020 (virtual presentation, COVID-19).

Eyster, A., Brengman, L.A., Nichols, C., **Levitt, Z., Bergmann, K.D.  (2020), The tectonic context for the Gogebic Range iron formations. North-Central Geological Society of America, May 18-19, 2020 (virtual presentation, COVID-19).

**Boor, E., **Carpenter, L., **Krauss, H., **Wojtowicz, E., Brengman, L.A., Goodge, J.W., Hansen, V.L. (2020), Origin of Neoarchean metasedimentary rocks near Pike Lake, Vermilion District, Northeast, Minnesota. North-Central Geological Society of America (presentation cancelled, COVID-19).

Brengman, L.A., Stewart, E.K., **Stolze, D., **Faust, E., Wittkop, C. (2020), The role of silica in iron formations: textural, mineralogical, and geochemical comparisons from low metamorphic grade Neoarchean and Paleoproterozoic examples. North-Central Geological Society of America (presentation cancelled, COVID-19).

Brengman, L.A., Stewart, E. (2019), Textural and mineralogical characteristics of the <1710 Ma Freedom Formation compared to well-characterized, low-metamorphic grade Archean and Paleoproterozoic iron formations. PP51E-1406, American Geophysical Union.

Brengman, L.A., *Duncanson S.P., **Hanson, S., **Wetzel, A (2019). Crossing the redoxcline: an investigation into geochemical changes that directly link to textural transitions in the ~1.9 Ga Biwabik Iron Formation, MN. Geological Society of America Abstracts with Programs. Vol. 51, No. 5. doi: 10.1130/abs/2019AM-339533. https://gsa.confex.com/gsa/2019AM/webprogram/Paper339533.html

*Duncanson, S.P., Brengman, L.A., Fournelle, J.H., Moy, A (2019). Deciphering primary and diagenetic controls on mineralogy in the ~1.9 Ga Biwabik Iron Formation, MN using paired textural and geochemical analyses. Geological Society of America Abstracts with Programs. Vol. 51, No. 5. doi: 10.1130/abs/2019AM-339482. https://gsa.confex.com/gsa/2019AM/webprogram/Paper339482.html

Brengman, L. A., & Fedo, C (2018). Replacement minerals formed during alteration of volcanic rocks in the ~2.7 Ga Abitibi Greenstone Belt carry rare-earth element attributes of mixed hydrothermal fluids and seawater. American Geophysical Union Abstracts. https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/446424

Brengman, L.A., Stewart, E., Stewart, E., Moy, A., Fournelle, J., & **Segee-Wright, G. (2018) Reviving historical data >100 years later: a fresh look at the depositional setting and petrogenesis of the <1.71 ga freedom formation, Baraboo, Wi. Geological Society of America Abstracts. https://gsa.confex.com/gsa/2018AM/meetingapp.cgi/Paper/321325

Brengman, L.A., **Johnson, K., & Trower, L (2018). Grain size distributions and mineralogy of coated grains, detrital sand and silt within the 1.9 ga mesabi iron range, minnesota. Geological Society of America Abstracts. https://gsa.confex.com/gsa/2018AM/webprogram/Paper321622.html

Fedo, C., & Brengman, L.A. (2018) Geochemistry of multiple carbonate units from the ~3.7 ga isua greenstone belt, sw greenland. Geological Society of America Abstracts. https://gsa.confex.com/gsa/2018AM/meetingapp.cgi/Paper/321151

*Drazan, J., Brengman, L.A, & Fedo, C (2018). Preliminary petrographic and geochemical investigation of silicified volcanic rocks and silica-rich exhalative rocks from the ~2.7 Ga Abitibi Greenstone Belt, Canada. Institute of Lake Superior Geology (ILSG) Program and Abstracts.http://flash.lakeheadu.ca/~pnhollin/ILSGVolumes/2018%20ILSG%20Program%20and%20Abstracts.pdf

Stewart, E., Skalbeck, J., **Rasmussen, J., Gotkowitz, M., Brengman, L.A., **Segee-Wright, (2017) G. Developing a geologic framework for aquifer geometry through modeling of gravity and aeromagnetic data.  (American Water Resources Association, Wisconsin Section Annual Meeting, Appleton, WI)

Brengman, L. A. (Author & Presenter), Fedo, C.M., Whitehouse, M.J. (2016), American Geophysical Union, “Textural and isotopic evidence for silica cementation in ~1.88 Ga Granular Iron Formation,” San Francisco, California, United States. (December 12, 2016).

Brengman, L. A. (Author & Presenter), Larson, P., **Hanson, S. (2016), Geological Society of America, “A textural and mineralogical investigation of early diagenetic reactions in the ~1.88 Ga Biwabik iron formation, MN,” Denver, Colorado, United States. Geological Society of America, Abstracts with Programs. v. 48, n. 7. (September 25, 2016).

Brengman, L.A., Fedo, C. M., Whitehouse, M. J. (2015) Micro-scale silicon isotope heterogeneity observed in hydrothermal quartz precipitates from the >3.7 Ga Isua Greenstone Belt, SW Greenland. Geological Society of America, Abstracts with Programs, Annual Meeting, Baltimore, MD, v. 47, n. 7, p.786.

Brengman, L. A., Fedo, C. M., Whitehouse, M. J. (2014) From source to sink: silicon isotope composition of bedrock, detrital quartz arenites, and siliceous precipitates from the ~3 Ga Buhwa Greenstone Belt, Zimbabwe. Geological Society of America, Abstracts with Programs, Annual Meeting, Vancouver, BC, v. 46, n. 6, p. 221.

Fedo, C. M., Brengman, L. A., (2014) Revisiting the stratigraphic setting of the ~3 Ga Buhwa Greenstone Belt, Zimbabwe. Geological Society of America, Abstracts with Programs, Annual Meeting, Vancouver, BC, v. 46, n. 6, p. 221.

Prentice, A., Jabeen, I, Webb, E., Banerjee, N., Ali, A., Brengman, L.A., Fedo, C. (2014). Dual Si and O Measurements Using IRMS-BrF5 Fluorination. Goldschmidt Conference, Sacramento, C.A., p. 1988.

Brengman, L. A., Fedo, C. M., Whitehouse, M. J. (2013). Silicon isotope composition of Archean cherts from >3.7 Ga to 2.7 Ga determined by Secondary Ion Mass Spectrometry (SIMS). Geological Society of America, Abstracts with Programs, Annual Meeting, Charlotte, N.C., v. 44, n. 7, p. 36.

Brengman, L. A., Fedo, C.M. (2012). Origin of BIF-like jaspilite in the 2.72 Ga Hunter Mine Group, Abitibi Greenstone Belt, Quebec by metasomatic replacement of felsic volcanic rocks. Geological Society of America, Abstracts with Programs, Annual Meeting, Charlotte, N.C., v. 45, n. 7, p. 627.