Geological Insights & Event News

Tracy Dembrowski refines the Trimble Granite age and links it to older Eolus phases (“U Pb zircon analysis…1457±17.8 Ma”). Nick Risedorf shows Permian–Pennsylvanian carbonates on the Big Gypsum megaflap record early halokinetic deformation. Katrina Bryant finds sondes only weakly track Animas River metals (“turbidity yielded the strongest correlation”). Dani Vitarelli maps complex, segmented Sangre de Cristo fault scarps with variable slip. In Prez Sez, Rebecca Pendleton highlights the Greater Aneth core workshop, the Annual Picnic, and the NMGS Ouray–Silverton Field Conference.

Dr. M. Beatrice Magnani examines how seismic reflection data distinguish natural from induced earthquakes in the Central US, showing long active faults in the Mississippi Embayment versus anomalous, likely induced seismicity in the Fort Worth Basin. In her Prez Sez column, President Rebecca Pendleton calls for volunteers to help plan the 2020 AAPG RMS Meeting. Regional news includes upcoming Front Range field trips and the 2017 NMGS Ouray–Silverton conference.

Dr. Rusty Riese outlines a complex Fruitland Fm. hydrocarbon system where the resource is affected by multiple tectonic events as well as four hydrologic regimes. Thermogenic methane is supplemented by biogenic gas introduced by microbes brought in from surface waters 35–40 Ma. Jim Corken volunteered to fill the vacant President-Elect position for the remainder of the season. The BLM will hold rulemaking hearings on fossil collecting on public lands. In Prez Sez, President Rebecca Pendleton highlights summer planning and promotes the NMGS Fall Fieldtrip.

The Society mourns the loss of President-Elect Laurie VanIngen who passed away November 30th from thyroid cancer. The board is filling in for him for the rest of the year. Odin D. Christensen, President and Chief Geologist of Hardrock Mineral Exploration, reviews the Gravel Creek epithermal Ag-Au deposit, where Miocene boiling fluids formed stratabound breccias and high grade fault hosted ore. The 2016 resources total 1.4 Moz Au and 21 Moz Ag. President Rebecca Pendleton highlights plans to support the 2017 NMGS Ouray–Silverton fieldtrip. Regional news includes upcoming talks and courses.

Dr. Stephen Cossey will present the "Gulf of Mexico drawdown hypothesis" based on his research on Mexico’s Chicontepec Fm. He postulates an early Eocene isolation of the Gulf of Mexico, due to the Cuban arc colliding with the Bahamas, closing the Florida Straits and resulting in a rapid ≥200 m drawdown of water level after 55.8 Ma. Lower water levels resulted in canyon cutting and exposed bathyal beds for up to 850 kyr before refill. Bitumen bearing outcrops, rooting features, and Paleocene–Eocene salt/gypsum support this hypothesis. The resulting methane release is possibly linked to PETM.

Dr. Marsha W. French’s abstract explains how advanced SEM CL, EBSD WDS, and SIMS analyses reveal complex quartz overgrowth histories and trace element controls that help predict porosity preservation in deep, hot sandstones. In her Prez Sez column, Rebecca Helms highlights strong fall programming, praises the Tocito–El Vado–Gallup Sands field trip, and notes plans for future trips. Regional news includes NMGS, RMAG, GSA, PTTC, and university seminar events.