Sandra S. Brake

Professor of Geology

Ph.D., Colorado School of Mines

Phone: 812-237-2270


Office: Science Building 189A

Educational Excellence Teaching Award 1999



Course Instruction: Physical Geology, Historical Geology, Astronomy, Mineralogy, Igneous and Metamorphic Petrology, Volcanology, Mineral Deposits, Introduction to Field Geology, Regional Geology, Groundwater Hydrology.

Research Interests: environmental geology, geochemistry and geomicrobiology of acid mine drainage systems

Research Profile: 

I am interested in the geochemistry and geobiology of acid mine drainage (AMD) environments.  My research group has studied water chemistry and storage of contaminants in sediments in AMD environments and in streams and lakes impacted by AMD in Indiana.  We have also conducted research on metal uptake in plants growing in areas where AMD forms seeps at the surface. 

A major part of my research focuses on microbial life in AMD environments.  My research group is currently involved in several collaborative projects with faculty and students from other universities to examine the role of eukaryotic and prokaryotic microorganisms in AMD environments.  We have identified iron-rich biolaminated structures (i.e., stromatolites) produced by the biological activity of eukaryote-dominated biofilm communities.  We are currently examining the micro- and macro-fabrics of the stromatolites and identifying biomolecular traces of these microorganisms that can be used to identify similar microorganisms in the early rock record and in such extraterrestrial environments as Mars. 

I have also had the pleasure of mentoring undergraduate research projects that have examined mineralization in volcanic-hosted, epithermal, precious metal deposits in Idaho, the stratigraphy of limestone deposits in central Indiana, a deltaic environment on Mars, mineral potential of a region in eastern Tennessee via the study of pan concentrates in stream sediments, igneous petrology of Devil’s Tower National Monument, and contaminant storage in tree rings.



Brake, S.S., Arango, I., Hasiotis, S.T., and Burch, K.R., 2014, Spatial and temporal distribution and characteristics of eukaryote-dominated microbial biofilms in an acid mine drainage environment: implications for development of iron-rich stromatolites: Environmental Earth Sciences: v. 72, no. 8, p. 2779-2796.

Das Gupta, S., Fang, J., Brake, S.S., and Hasiotis, S.T., 2013, Stable carbon isotopic composition of lipids in Euglena-dominated biofilms from an acid mine drainage site: implications of carbon limitation, microbial physiology, and biosynthetic pathways: Chemical Geology v. 354, p. 15-21.

Brake, S.S., and Hasiotis, S.T., 2012, Potential metal attenuation by eukaryotic-dominated biofilm communities in acid mine drainage at the Green Valley Coal Mine Site, Indiana: in J.B. Comer (ed.), Effects of Abandoned Mine Land Reclamation on Ground and Surface Water Quality: Research and Case Histories from Indiana: Indiana Geological Survey Special Report 72, p. 281-298.

Das Gupta, S., Fang, J., Brake, S.S., Hasiotis, S.T., and Zhang, L., 2012, Biosynthesis of sterols and wax esters by Euglena of acid mine drainage biofilms: implications for eukaryotic evolution and the early earth: Chemical Geology, v. 306-307C, p. 139-145.

Brake, S.S., and Hasiotis, S.T., 2010, Eukaryote-dominated biofilms and their significance in acidic environments, in Gadd, G.M., and Ravin, J., editors, Special Issue on Eukaryotic Microbiology: Geomicrobiology Journal, v. 27, no. 6 & 7, p. 534-558.

Jensen R.R., Brake, S.S., Wolf, S.F., Bekker, M.F., Hardin P.J., and Jackson, M.W., 2010, Chemical element concentrations in black locust (Robinia pseudoacacia L.) and green ash (Fraxinus pennsylavanica March.) leaves at the reclaimed Green Valley coal mine, Indiana, USA: Environmental Earth Sciences, v. 60, p. 1391-1405.

Brake, S.S., and Hasiotis, S.T., 2008, Eukaryote-dominated biofilms in extreme environments: The overlooked sources of information in the geologic record: PALAIOS, v. 23, p. 121-123.

Fang, J., Hasiotis, S.T., Das Gupta, S., Brake, S.S., and Bazylinski, D.A., 2007, Microbial biomass and community structure of a stromatolite from an acid mine drainage system as determined by lipid analysis: Chemical Geology, v. 243, p. 191-204.

Jensen, R.R., Brake, S.S., and Mattox, J.M., 2004, Trace element uptake in plants grown on fly ash amended soils: Toxicology and Environmental Chemistry, v. 86, no. 1–4, p. 217-228.

Brake, S.S., Jensen, R.R., and Mattox, J.M., 2004, Effects of coal fly ash amended soils on trace element uptake in plants: Environmental Geology, v. 45, p. 680-689.

Brake, S.S., Hasiotis, S.T., and Dannelly, H.K., 2004, Diatoms in acid mine drainage and their role in the formation of iron-rich stromatolites: Geomicrobiology Journal, v. 21. no. 5, p. 331-340.

Brake, S.S., Hasiotis, S.T., Dannelly, H. K., and Connors, K.A., 2002, Eukaryotic stromatolite builders in acid mine drainage: Implications for Precambrian iron formations and oxygenation of the atmosphere?: Geology, v. 30, p. 599-602.

Brake, S.S., Dannelly, H.K., and Connors, K.A., 2001, Controls on the nature and distribution of an alga in coal mine-waste environments and its potential impact on water quality: Environmental Geology, v. 40, p. 458-469.

Brake, S.S., Dannelly, H.K., Connors, K.A., and Hasiotis, S.T., 2001, Influence of water chemistry on the distribution of an acidophilic protozoan in an acid mine drainage system at the abandoned Green Valley coal mine, Indiana, U.S.A.: Applied Geochemistry, v. 16, p. 1641-1652.

Brake, S.S., Connors, K.A., and Romberger, S.B., 2001, A river runs through it: Impact of acid mine drainage on the geochemistry of West Little Sugar Creek pre- and post-reclamation at the Green Valley coal mine, Indiana, U.S.A.: Environmental Geology, v. 40, p. 1471-1481.

Brake, S.S., and Romberger, S.B., 2000, Precious metal transport and deposition at the New Savage Mine, Comstock district, Nevada, in Cluer, K., Price, J., Struhsacker, E., Hardyman, R., and Morris, C., eds., Geology and ore deposits 2000: The Great Basin and beyond: Symposium Proceedings, Geological Society Nevada, p. 177-186.