Minutes for the 1617th Meeting

Wednesday, February 11th, 2026

Cosmos Club, John Wesley Powell Auditorium

President Mike Ackerson called the meeting to order at 20:03 EST.  

Attendance

There were 46 attendees.

Minutes

The meeting began with the reading and approval of the minutes from the previous meeting, the 1616th meeting, which was held on December 3, 2025.

Guests and New Members

Eleven guests were announced: John Faber (Husband of member and past president, Ester Sztein), Paul Signet (NVCC), James Mulqueeney (NMNH), Ana Martinez Garcia (Carnegie Science), Alejandra Bermeo Cevallos (Geosciences Institute of Spain), Devan Solanki (Kobald Metals), Eunice Cho (Wife of Devan Solanki), Chris Kennedy (Bloomberg Economics), Unknown (GSA), Unknown (Urban Planning) and Kathryn Hobart (USGS).

Two new members were announced: Mike Smith, (Albert Einstein Program, Legislative Fellow, U.S. Senate) and Jonathan Baldwin.

Obituaries

A moment of silence was observed in remembrance of George Rossman, who presented at GSW in 1981 and whom Ackerson called one of the great American mineralogists.

Announcements

President Ackerson announced that the Geological Society of Washington has launched a new, more user-friendly membership system using Wild Apricot, thanks to the significant volunteer efforts of Jonathan Tucker and Andy Campbell. Members are encouraged to sign up using their primary personal email and to note that the portal is only for membership, payment, and communications, not the main website. Ackerson also highlighted the society’s recent growth in membership, which has increased from 140 last year to 161 so far this year.

Informal Communication

President Ackerson delivered a fruitful exploration of the great āpricot vs. ăpricot pronunciation debate, noting the split between U.S. and U.K. usage, mapping dialects worldwide, and wading into the sticky realm of apricot etymology. He concluded by granting executive approval to either pronunciation.

Ackerson announced member Virginia Agostinelli’s artistic project to sketch past, present, and future GSW presidents as a new society tradition. Agostinelli presented recent president Ved Lekić with her drawing of him delivering his presidential address. Ackerson said that plans are underway to digitize the artwork.

Formal Program

The formal program commenced at 20:21 EST and consisted of three speakers: Kathryn Hobart (USGS), Ludmila Fonseca Teixeria (Smithsonian) and Katherine Turk (Smithsonian).

1st formal talk: Kathryn Hobart presented “Critical Minerals in Mine Waste: A Case Study on Sulfides from Volcanogenic Massive Sulfide Deposits.” Hobart presented her investigations into pyrite and pyrrhotite-rich tailings as a potential nontraditional source of critical minerals. Mine tailings rich in sulfide minerals also pose environmental risks, making reprocessing a possible dual solution. By analyzing trace element concentrations and their structural or inclusion-based enrichment across different deposit types, her study identified patterns of substitution and inclusion in sulfide minerals. Talk length: 20 minutes.

Questions were asked by: Devan Solanki (Kobold Metals), Jane Hammarstrom (USGS, Emeritus), Mong-Han Huang (UMD), Devan Solanki (Kobold Metals) and Mike Ackerson (Smithsonian NMNH).

2nd formal talk: Ludmila Fonseca Teixeria presented “How to Find Volcanoes That No Longer Exist?” Teixeria discussed the long-standing question of how silicic volcanic rocks relate to their plutonic counterparts and how often magma reservoirs erupt versus solidify underground. She presented a method to distinguish these in ancient systems using titanium thermometry in detrital quartz and zircon, which allows volcanic, plutonic, and pegmatitic crystals preserved in sediments to be identified. She said that this approach makes it possible to detect completely eroded volcanoes and better understand the evolution and growth of continental crust through time. Talk length: 18 minutes.

Questions were asked by: Ved Lekić (UMD), Mong-Han Huang (UMD), Jane Hammarstrom (USGS, Emeritus), Kevin Wong (Carnegie), Ved Lekić (UMD), Brooks Hanson (AGU, retired) and Jamie Allan (NSF, retired).

3rd formal talk: Katherine Turk presented “Behavioral Innovation at the Dawn of Modern Oceans.”  Turk described her research on how marine animals adapted behaviors during major oceanic changes, focusing on sediment-penetrative burrowing, a key process shaping seafloor structure, chemistry, and habitability. Using CT scans and a 2D U-Net deep learning model, she identified late Ediacaran (~539 Ma) burrow-like structures, including spirals over 4 centimeters deep, suggesting that critical ecosystem engineering behaviors predate the Cambrian and were more complex than previously recognized. Turk linked these ancient traces to modern analogs, specifically Priapulus, that she collected on tidal flats in northwest Germany. She described these arthropod-related worm-like animals as “deeply unpleasant to watch” but highly active burrowers that significantly alter sediment structure, providing insight into how early animals transformed benthic ecosystems.

Talk length: 17 minutes.

Questions were asked by: Jamie Allan (NSF, retired), Mong-Han Huang (UMD), Kevin Wong (Carnegie), Ved Lekić (UMD), Mike Walters (Carnegie), Kay Behrensmeyer (Smithsonian NMNH) and Andy Campbell (NRC, retired).

President Ackerson thanked Program Chair Ross Salerno for arranging the speakers, announced the next meeting on March 4th and adjourned the meeting at 21:45 EST.

Respectfully Submitted,  Beth Doyle  Substitute GSW Secretary  

Minutes for the 1618th Meeting

Wednesday, March 4th, 2026

Cosmos Club, John Wesley Powell Auditorium

President Ackerson called the meeting to order at 8:05 ET.

Attendance

There were 38 attendees in-person.

Minutes

The meeting began with announcements, then moved on to the approval of the minutes from the previous meeting (1617th). The minutes of the 1617th meeting had been posted online and a Minute’s Minute was read aloud at the 1617th meeting.

Guests and New Members

2 guests were announced, including Naoko Takahashi (Tohoku University) and Dan Hummer (University of Southern Illinois). 10 new members were announced: Devan Solanki, Katherine Turk, Terri Zak, Jonathan Arthur, Conor Hulse, Mariliis Eensalu, Jillian Singleton, Erika Carter, Rob Klein, and Brian Huber.

Obituaries

None

Announcements

Introduction of new members: We are now up to 166 total members Science fair volunteering: MD schools will be looking for judges, more details forthcoming.

Informal Communication

Larry Meinert gave an overview on the geology of Egypt as experienced on recent travel.

Formal Program

The formal program commenced at 8:21 ET and consisted of three speakers: Elizabeth Tomaszewski (USGS), Josh Rosera (USGS), and Oded Elazar (Carnegie Earth and Planets Laboratory).

1st formal talk: Coal Mine Waste as a Resource: How Fundamental Geochemistry Informs Critical Mineral Recovery Potential Beth gave a talk about coal mine drainages as sources of critical minerals. Coal mine drainage environments have diverse appearances and impacts, and dissolved minerals vary on a site basis with significant differences between anthracite and bituminous sites. There are also correlations between certain dissolved minerals and terrestrial carbon, with lessons for mineral extraction

8:22-8:39

Questions summary

Linda Rowan (CRS): did you use the USGS coal database?

Jane Hammerstrom, (USGS, ret): how did you collect samples in the field? Were sites sampled separately?

Mong-Han Huang (UMD): pond lining & treatment?

[Unknown]: what are the minerals that these elements are adsorbed onto?

Jake Harball, (USGS, ret): if metals are precipitating downstream, can they be extracted from those solids?

2nd formal talk: What’s the point? Tracking regional orientations of magmatism through time in the Rocky Mountains Josh gave a talk about how magmatism changed in the western US from Cretaceous felsic rocks to Miocene mafic rocks related to the subduction of the Farallon Plate transitioning to extension. New U-Pb zircon geochronology shows a unique belt of intrusive rocks indicating a possible shift in magmatic trends, and Fry point pattern analysis reveals changing magmatism orientation from Laramide compression 70-65 Ma, transition from 40-35 Ma, and rifting from 25-20 Ma.

8:49-9:10

Mike Ackerson (Smithsonian): why is the Colorado Mineral Belt perpendicular to the orientation of northern belts?

Mon-Han Huang (UMD): how does the fry technique account for area and change in surface elevation change?

Dan [last name unknown]: what’s the role of water content?

3rd formal talk: Metasomatic Fluids from Subducted Oceanic Crust Recorded by Potassium Isotopes in Sierra Leone Diamonds Oded gave a talk on records of cratonic volatiles from Proterozoic diamonds and their inclusions. Potassium isotope analysis was used to track melt fluid reservoirs and processes, revealing large dehydration prior to high-density fluid formation, an indicator of subduction.

9:18-9:37

Ross Salerno (USGS): how is the material from laser ablation collected?

Mike Walter (CSL): do very negative values indicate deeper dehydration? Are there any other trace element ratios that would correlate well with the deeper samples?

Mike Ackerson (Smithsonian): what are the fluids?

President Ackerson adjourned the meeting at 9:41.

Submitted by Karin Lehnigk, GSW meeting secretary

Minutes for the 1619th Meeting

Wednesday,  March 25th, 2026

Carnegie Earth and Planets Laboratory

President Ackerson called the meeting to order at 8:05 ET.

Attendance

There were 43 attendees in-person and 16 online.

Minutes

The meeting began with announcements, then moved on to the approval of the minutes from the previous meeting (1618th). The minutes of the 1618th meeting had been posted online and a Minute’s Minute was read aloud at the 1619th meeting.

Guests and New Members

5 guests were announced, including Chang-Yu Wen, Lehi Lebon, Unknown (Carnegie EPL), Lynn [Unknown], and Christine Bergman (UMD). 2 new members were announced: Paul Signet and Cain Wilson. Currently at 170 members.

Obituaries

None

Announcements

Big thank you to Carnegie!

Informal Communication

Mike Ackerson: councilmember Virginia Agostinelli is almost done with Dan Doctor’s portrait, it will be unveiled soon

Minutes for the 1620th Meeting

Wednesday, April 29th, 2026

Cosmos Club, John Wesley Powell Auditorium

President Ackerson called the meeting to order at 8:04 PM ET.

Attendance

There were 38 attendees in-person (no online).

Minutes

The meeting began with announcements, then moved on to the approval of the minutes from the previous meeting (1619th). The minutes of the 1619th meeting had been posted online and a Minutes Minute was read aloud and approved.

Guests and New Members

3 guests were announced, including Ryan Storm (UMD), Ed Ruder (Johns Hopkins University), and Dan Hummer (Southern Illinois University). No new members were announced. Currently at 171 members.

Obituaries

Dr. Peter M. Kranz: paleontologist, teacher, & founder of the Maryland Dinosaur Park (Presented by John Repetski, USGS)

JJ (John Julian) Hemley, USGS: geochemist and earth science advocate (Presented by Jane Hammerstrom, USGS)

Priestley (Pete) Toulmin III, USGS: experimental & planetary geochemist (Presented by Jane Hammerstrom, USGS)

Announcements

None

Informal Communication

None

Formal Program

The formal program commenced at 8:19 ET and consisted of three speakers: Andrea Goltz (Carnegie Earth and Planets Laboratory), Supratik Roy (Johns Hopkins University), and Kelsey Jenkins (Smithsonian Institution).

1st formal talk: Predicting the Stability of Igneous Amphibole using Machine Learning

Andrea made us all fall in love with amphiboles as an indicator of magmatic properties and ore-forming processes at subduction zones. The thermodynamic stability of amphiboles was assessed using random forest modeling, as was the accuracy of this approach (the first machine learning model to predict mineral stability!). The stability of amphibole was found to not obey the trace element threshold, so amphibole stability can’t be used on its own to predict ore-forming potential.

8:20-8:39

Mong-Han Huang (UMD): could you use ML to predict whether a sample falls above or below the trace element threshold?

Jamie Allen (ret.): did you account for halogens in the composition, since that can greatly affect the stability?

Larry Meinert (USGS): can you expand/change the model to incorporate other/additional elements, or using whole rocks?

Jamie Allen (ret.): are there naturally quenched environments like lakes or melt inclusions where you would have good temperature control at low pressures?

Maryann Malinconico (Lafayette College): why is there a gap in the subduction zone around Kashmir?

Mike Ackerson (Smithsonian): what about melt re-extraction Liz Cottrell (Smithsonian): what’s the flaw in the previous model?

 2nd formal talk: Constraining metamorphic rates in ancient orogens: insights from the Paleoproterozoic Lake Superior region (USA)

Supratik used two metamorphic nodes in Michigan to address the question of how plate tectonics has changed over the last 2 billion years. Absolute timing of magmatism in one node from U-Pb zircon dating was very accurate even for old rocks, as were dates from metasediments, showing that it took only 12 Myr to go from loose sediments to peak metamorphism. Raman spectroscopy of carbonaceous material in the other node allowed the rate of heating and metamorphism to be constrained, and mixed ages in 40Ar/39Ar dating of detrital white mica spectra revealed diffusive loss of Ar. The similarity of results at both nodes to the Grampian Orogeny in Scotland suggests that those rocks were also formed in less than 10 Myr, indicating that short-duration metamorphism might be more common than we currently assume.

8:48-9:10

Liz Cottrell (Smithsonian): what is the gold standard technique for zircon U-Pb dating?

Mong-Han Huang (UMD): can you use your techniques to get tectonic burial rates?

Ross Salerno (USGS): can you translate your metamorphic rate to a geothermal gradient that can be applied to modern systems?

Jane Hammerstrom (ret.): how important was magmatism in short-lived events?

Dan Hummer (SIU): can you use K/Ar or Ar/Ar on biotite mica?

Mike Ackerson (Smithsonian): the lead is being lost; what controls the loss, and where’s it going?

Larry Meinart (USGS): can you date other minerals like garnet using other techniques?

3rd formal talk: Sensing in a Strange Land: The Fossil Record’s Story of Sensory Evolution

Kelsey talked about a major transition in the fossil record: the evolution of sensory systems, and what they tell us about that animal. Ear bones first appeared in reptiles during the Permian, but they probably could only hear low frequencies through bone conduction. The degree of movement of fossil reptile ear bones was assessed by harmonic response analysis and categorized as similar to either tympanic or bone conducting hearing, supporting a single early emergence of tympanic hearing. Finally, “there are lots of ways to make a bad ear, but only one way to make a good one.”

9:21-9:41 (31 in-person, none online)

(Unknown): what were you using to characterize the attenuation?

Ross Salerno: what’s the evolutionary origin of the hole in the ear bone?

Karin Lehnigk (NASA GSFC): what causes the sharp spikes at high frequencies?

Mike (Carnegie): what’s the evolutionary advantage of not hearing well?

Mong-Han Huang (UMD): are there any reptiles alive today that have sacrificed the high frequencies?

Jamie Allen (ret.): when did echolocation and phase distinction emerge?

Kean Wilson (Carnegie): how do you account for boundaries between different materials in the bones?

President Ackerson adjourned the meeting at 9:51.

Respectfully submitted by Karin Lehnigk, GSW meeting secretary