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Sue M. Rimmer

Sue M. Rimmer, Research Professor, Professor Emerita



  • B.S. 1975, Southern Illinois University
  • M.S. 1978, University of Illinois at Urbana-Champaign
  • Ph.D. 1985, Penn State University

Research Interests

My research currently focuses on five main areas: 1) biogeochemical cycles in organic-rich sediments; 2) controls on stable isotope composition of organic matter (OM) and interpretation of C and N isotope records in organic-rich sediments and coals; 3) linkages between OM and past atmospheric composition; 4) coal maturation and the role of heating rate (contact metamorphism vs. burial maturation); and 5) maceral separation and geochemistry.

Sue Rimmer

Office: Parkinson Lab 201 D
Phone: 618-453-7369
Curriculum Vitae

1) Biogeochemical cycles in organic-rich sediments.

My students and I have been examining controls on organic carbon accumulation in Devonian-Mississippian and Ordovician black shales in the Appalachian and Illinois basins, USA. We have been evaluating redox conditions, productivity, and productivity-anoxia feedback mechanisms using trace-metal geochemistry (redox and productivity indicators) and C/P ratios, the role of clay minerals in the accumulation of OM in marine basins, C and N contents and stable isotope compositions, organic geochemistry, Rock-Eval pyrolysis data, and organic petrology. The inclusion of organic petrology in these studies adds an important, yet generally overlooked, dimension and allows us to evaluate the relative importance of different types of marine OM and, in Devonian and younger sediments, the significance of input of terrestrial OM.

2) Stable isotopic composition of OM and interpretation of C, N isotopic records.

Most published stable carbon and nitrogen isotope studies have focused on interpreting either bulk isotopic composition or compound-specific (CSIA) results. Unlike the solvent extractable organic fractions that can be studied using CSIA, most of the OM in fine-grained rocks is composed of dispersed macromolecular components that are insoluble in solvents (kerogen) and represent the major reservoir of organic carbon. Our lab has been developing a novel approach to isotopic analysis: the maceral-specific approach. By separating individual maceral components from a kerogen using density-gradient centrifugation (DGC), we are able to determine the isotopic composition of relatively pure (>95%) end-members.

3) Linkages between OM and past atmospheric compositions.

The evolution of marine and terrestrial organisms has had significant impact on atmospheric composition throughout Earth history. One of my interests focuses on using the presence and properties of inertinite (mostly fossil charcoal) that provides critical data to ground-truth O2 models. Following the earliest, scant occurrence of fossil charcoal (late Silurian) there is a general paucity of inertinite in the rock record until the Late Devonian by which time the first forests had evolved, along with what were likely the first true peats, and the first evidence of relatively widespread charcoal occurs, both in the terrestrial and marine record. Recent work in my lab has been focusing on both the terrestrial and marine record of these Late Devonian charcoals.

A second thrust of work relating organic petrology and atmospheric composition considers the role of intrusion of coals and organic-rich sediments. Intruded coals from the Karoo Basin (South Africa), the Illinois Basin (USA), the Raton Basin (USA), and Antarctica are being examined using isotopic, petrographic, and geochemical analyses to evaluate the role of such intrusions in a) the generation of coal-bed methane, and b) the possible introduction of large quantities of depleted volatiles into the atmosphere that may have altered atmospheric δ13C.

4) Coal maturation and the role of heating rate: Contact metamorphism vs. burial maturation.

Our work on intruded coals also allows us to examine the role of rapid heating (contact metamorphism) on the maturation pathways of coal and to compare this with the effects of more gradual heating associated with burial metamorphism. Our results suggest that rapid heating associated with intrusions may force coal to follow a different maturation pathway than is seen under normal coalification conditions.

5) Maceral separation and geochemistry.

As coal consists of many different organic components (macerals) and inorganic components (minerals), it is important to understand the contribution of each to the coal's bulk composition. This is important in both basic and applied research. Here at SIU, we have the only density-gradient centrifugation lab in the country dedicated to separating out individual macerals from coals and source rocks. These density separates are then used to better understand maceral geochemistry (including isotopic composition), as well as how organic materials respond to various processes (e.g., gasification, oxidative hydrothermal dissolution, or OHD).

Selected publications

Sanders, M.M., Rimmer, S.M., and Rowe, H.D., 2023, Carbon isotopic composition and organic petrography of thermally metamorphosed Antarctic coal: Implications for evaluation of δ13Corg excursions in paleo-atmospheric reconstruction. International Journal of Coal Geology, v. 267, 104182.

Abdi, Z., Rimmer, S.M., Rowe, H.D., and Nordeng, S., 2021, Controls on organic matter accumulation in the Bakken Formation, Williston Basin, USA. Chemical Geology, v. 586, 120588.

Sanders, M.M., and Rimmer, S.M., 2020, Revisiting the thermally metamorphosed coals of the Transantarctic Mountains, Antarctica. International Journal of Coal Geology, v. 228, 103550.

Li, K., Rimmer, S.M., Presswood, S., and Lui, Q., 2020, Micro-Raman spectroscopy of intruded coals from the Illinois Basin: correlation with rank and establishment of a paleogeothermometer. International Journal of Coal Geology, v. 219, 103369.

Li, K., Rimmer, S.M., and Lui, Q., 2018, Geochemical and petrographic analysis of graphitized coals from central Hunan, China. International Journal of Coal Geology, v. 195, p. 267-279.

Ocubalidet, S.G., Rimmer, S.M., and Conder, J., 2018, Redox conditions associated with organic carbon accumulation in the Late Devonian New Albany Shale, west-central Kentucky, Illinois Basin. International Journal of Coal Geology, v. 190, p. 42-55.

Wei, Q., Rimmer, S.M., and Dai, S., 2017, Distribution of trace elements in fractions after micronization and density-gradient centrifugation of high-Ge coals from the Wulantuga and Lincang Ge ore deposits, China. Energy and Fuels, v. 31, No. 11, p. 11818-11837.

Presswood, S., Rimmer, S.M., Anderson, K.B., and Filiberto, J., 2016, Geochemical and petrographic alteration of rapidly heated coals from the Herrin (No. 6) Coal seam, Illinois Basin. International Journal of Coal Geology, v. 165. p. 243-256.

Yoksoulian, L.E., Rimmer, S.M., and Rowe, H.D., 2016, Anatomy of an Intruded Coal, II: Effect of contact metamorphism on δ13C and implications for the release of thermogenic methane, Springfield (No. 5) Coal, Illinois Basin. International Journal of Coal Geology, v. 158. p. 129-136.

Rimmer, S.M., Hawkins, S.J., Scott, A.C., and Cressler, W.L., III, 2015, The rise of fire: Fossil charcoal in Late Devonian marine shales as an indicator of expanding terrestrial ecosystems, fire, and atmospheric change. American Journal of Science v. 315, p. 713-733.

Rimmer, S.M., Crelling, J.C., and Yoksoulian, L.E., 2015, An occurrence of coked bitumen, Raton Formation, Purgatoire River Valley, Colorado, U.S.A. International Journal of Coal Geology, v. 141-142, p. 63-73.

Hudspith, V.A., Rimmer, S.M., and Belcher, C.M., 2014, Latest Permian chars may derive from wildfires not coal combustion. Geology, v. 42, p. 879-882.

Rimmer, S.M., Yoksoulian, L. E., and Hower, J.C., 2009, Anatomy of an Intruded Coal, I: Effect of contact metamorphism on whole-coal geochemistry, Springfield (No. 5) (Pennsylvanian) coal, Illinois Basin, International Journal of Coal Geology, v. 79, p. 74-82.

Gröcke, D.R., Rimmer, S.M., Yoksoulian, L.E., Cairncross, B., Tsikos, H., and van Hunen, J., 2009, No evidence for thermogenic methane release in coal from the Karoo-Ferrar large igneous province. Earth and Planetary Science Letters, v. 277, p. 204-212.

Rowe, H.D., Loucks, R.G., Ruppel, S.C., and Rimmer, S.M., 2008, Mississippian Barnett Formation, Fort Worth Basin, Texas: Bulk geochemical inferences and Mo-TOC constraints on the severity of hydrographic restriction. Chemical Geology, v. 257, p. 16-25.

Cooper, J.R., Crelling, J.C., Rimmer, S.M., and Whittington, A.G., 2007, Coal metamorphism by igneous intrusion in the Raton Basin, CO and NM: Implications for generation of volatiles. International Journal of Coal Geology, v. 71, p. 15-27.

Rimmer, S.M., Rowe, H.D., Taulbee, D.N., and Hower, J.C., 2006, Influence of maceral content on δ13C and δ15N in a Middle Pennsylvanian coal. Chemical Geology, v. 225, p. 77-90.

Stewart, A.K., Massey, M., Padgett, P.L., Rimmer, S.M., and Hower, J.C., 2005, Influence of a basic intrusion on the vitrinite reflectance and chemistry of the Springfield (No. 5) Coal, Harrisburg, Illinois. International Journal of Coal Geology, v. 63, p. 58-67.

Rimmer, S.M., Thompson, J.A., Goodnight, S.A., and Robl, T., 2004, Multiple controls on the preservation of organic matter in Devonian-Mississippian marine black shales: Geochemical and petrographic evidence. Palaeogeography, Palaeoclimatology, and Palaeoecology, v. 215, p. 125-154.

Rimmer, S.M., 2004, Geochemical paleoredox indicators in Devonian-Mississippian black shales, central Appalachian Basin (U.S.A.). Chemical Geology, v. 206, p. 373-391.