Smackover Lithium: Origins of a Critical Mineral
Presented by: Stephen G. Franks, Ph.D.
In-Person
Where: The Petroleum Club of Shreveport, 15th floor
Member Cost: $25 • Non-Member Cost: $35
SGS now accepts Tap Pay via Zelle for meeting payments!
If you’d like a seat, kindly use the form below to make your reservation by the preceding Friday.
We encourage members to invite guests, spouses, and friends to any of our meetings.
Virtual
Via Zoom
Member Cost: $10 • Non-Member Cost $15
**After checkout, you will receive an email with the Zoom Meeting details. You may sign up anytime before the meeting begins.
Stephen G. Franks, Ph.D.
GreenLite Resources, Inc.
RockFluid Systems, Inc.
Biography
Steve Franks graduated from Millsaps College in 1968 with a B.S. in Geology, followed by an M.S. in Geology from the University of Mississippi and a Ph.D. from Case Western Reserve University. In 1974, he joined Atlantic Richfield’s (ARCO) Geological Research Group in Dallas, where his work centered on water–rock interaction and pre-drill reservoir quality prediction.
After nine years in research, Steve moved into exploration, serving with ARCO Alaska in Anchorage and later as Area Explorationist for the Onshore Gulf of Mexico in Lafayette, Louisiana. He returned to research in 1992, focusing on the use of produced-water chemistry to investigate petroleum migration, reservoir continuity, and reservoir dynamics. His expertise earned him election to ARCO’s Advisor Program, where he served as both Senior Exploration Advisor and Senior Research Advisor until his retirement in 1999.
Following retirement, Steve founded RockFluid Systems, Inc., providing consulting services to major international oil companies as well as independent operators. In 2001, he accepted a position as Senior Research Advisor in Saudi Aramco’s Advanced Research Center in Dhahran, Saudi Arabia. After retiring from Aramco in 2010, he resumed his consulting practice. Most recently, in 2023, he co-founded GreenLite Resources, Inc., a lithium-brine exploration company.
Abstract
Stephen G. Franks, Ph.D., GreenLite Resources, Inc.; RockFluid Systems, Inc.
Timothy J. Palmer, Mississippi State University
The origin of lithium in the high-Li brines of the Smackover Formation has remained unresolved despite their global significance as a critical minerals resource. This talk explores new isotopic and geochemical evidence pointing to Eagle Mills mudstones as the hidden source of lithium in Smackover brines. Evaluation of candidate Li sources, including evaporated seawater, Smackover organic matter, and Eagle Mills mafic intrusives shows that none can account for the high Li concentrations (≥200 mg/L) observed in Smackover. Instead, Eagle Mills mudstones, rich in micaceous minerals, provide the most plausible Li source. Illitized micaceous phases contain up to ~300–415 ppm Li and correlate strongly with K₂O and trace elements Nb, Ta, Th, Ga, and Cs, characteristic of evolved felsic sources.
Mg-K-rich brines derived from Werner–Louann evaporites infiltrated Eagle Mills sediments via compaction-drive flow, reacting with detrital micas and releasing Li into pore waters. Compaction of thousands of feet of Eagle Mills mudstone expelled Li-rich pore water along structural conduits (faults, salt welds, and pinchouts) into the Smackover. The Buckner Anhydrite aquitard provided an overlying seal and helped prevent dilution of the Smackover brines. Ion relationships, 87Sr/86Sr, and lithium isotopes of brines support a siliciclastic origin, consistent with previous interpretation on the origin of Smackover brines. Collectively, these results identify the Eagle Mills Formation as the primary Li source for Smackover brines and highlight the role of felsic provenance and evaporite–siliciclastic interaction in generating Li-rich basinal fluids.
