Geological Insights & Event News

Jonathan Moore describes the history and geology of Creede’s mining district. Epithermal veins, first prospected in 1876, led to major discoveries including Nicholas Creede’s Holy Moses claim, sparking an 1890 boom and over a century of Ag Pb Zn production. Mineralization formed along graben faults within the Bachelor caldera, producing rich low sulfide veins of quartz, barite, and rhodochrosite. In his Prez Sez column, President John Youle reflects on scientific progress through “biffing it,” urging members to embrace hard falls as part of good science.

Jonathan Harvey’s abstract examines how the Main Himalayan Thrust shapes seismicity and rapid uplift in the central Himalaya. New data from western Nepal reveal a major crustal discontinuity that splits the steep topography belt, altering seismic hazard patterns and informing context for the April 2015 M7.8 Gorkha earthquake. In Prez Sez, President John Youle highlights the Society’s strength in member dedication. We mourn the loss of Dr. Frank Bowman, who founded the geology department at FLC. The Foundation published a financial report. The FCGS horseshoe tournament was won by Chip Head.

FLC seniors presented their research to the Society. J. Girts models Silverton–San Juan caldera faults, revealing hidden structures and radial–concentric patterns tied to dome growth and collapse. C. Passehl’s OSL work suggests Durango glacial stratigraphy needs revision. S. Holden shows La Plata mineralization occurred in two pulses at ~57 Ma and ~27 Ma. J. Adams finds McElmo CO₂ reflects mixed crustal–mantle sources. In Prez Sez, President Paul Spear urges returning to basics in unconventional petrophysics and preparing for the next drilling boom. We regret the passing of Rob Blair.

Christine Smith Siddoway presents new U Pb detrital zircon data showing that the Tava sandstone dikes of the Colorado Front Range derive from Neoproterozoic (770–680 Ma) Rodinia strata, with DZ peaks matching Grenville and Colorado sources. The work constrains emplacement to Pennsylvanian or earlier and links the dikes to early movement on the ancestral Ute Pass fault. In his Prez Sez column, President Paul Spear describes Mancos concretions and thanks John Youle. Regional news includes the upcoming San Juan College Energy Conference and a part time Petroleum Geology teaching opportunity.

Estuarine sandstones in the Eubanks and Shuck pools have produced over 14 million barrels of oil and are now being assessed for CO₂ recovery. John Youle describes a narrow Mississippian incised valley up to 220' deep, filled by fluvial, salt marsh, tidal flat, and estuarine facies during transgression, with traps formed by stratigraphic pinchouts, Ouachita folding, and karst collapse. In his Prez Sez column, current president Paul Spear urges membership renewal, and previews Youle’s upcoming presentation, noting its parallels to the Burro Canyon IVF play.

Lillian D. Wakeley’s talk examines Mosul Dam, built on dissolving limestone, marl, and gypsum that require nonstop grouting to prevent failure. Her team’s 3D modeling showed a migrating dissolution front driven by structural dip, an anticline, and undersaturated reservoir water—issues highlighted again when ISIS briefly seized the dam. In his Prez Sez column, President Paul Spear reflects on career changes and shares classic quotes on risk, exploration, and innovation. We mourn the passing of longtime petroleum scout and member, Kevon Smith.