Draft Minutes for the 1515Th Meeting
Geological Society of Washington
Draft Minutes for the 1515th meeting
Wednesday, February 1, 2017
John Wesley Powell Auditorium,
Cosmos Club, Washington, DC
President Callan Bentley called the 1515th meeting of the Geological Society to order at 20:01 EDT.
The minutes of the 1514th meeting was approved at 20:03 with three corrections.
One guest, David Smallwood, was introduced.
There were no new members.
Announcements:
President Callan Bentley formally acknowledged the passings of Drs. Charles “Skip” Cunningham and Eugene Roseboom, which were mentioned briefly by Pete Toulmin during the 1514th meeting. Dr. Cunningham is recognized as having authored and coi-authored more than 250 publications during his tenure at the USGS; he joined GSW in 1984 but was last a member soon after that.Dr. Roseboom may be most well known for the discovery of djurleite and was a member of GSW from 1957 until 2012. Members observed a moment of silence.
President Callan Bentley announced the March for Science, a science awareness rally to be held in Washington, DC on April 22, 2017. More information can be found at
Dan Doctor announced the annual spring field trip to Sugarloaf Mt. on March 26, 2017.
Kori Newman announced local science fairs and called for volunteers to act as judges
Informal communications:
Bill Burton of the USGS gave an informal communication regarding a recent series eruptions of the Bogoslof Volcano in the Aleutian Island Arc.
On December 20th, 2016, an explosive eruption of the Bogoslof Volcano was reported, with ash clouds rising to elevations of ~34,000 ft. Seismic, as well as ultrasound, and lightning detector data show that several prior eruptions went unnoticed because nearest seismometers are situated more than 50 km from the island. More than 27 total eruptions were recorded, with the most dramatic occurring on January 31st. Burton stressed the importance of keeping abreast of Aleutian Island arc eruptions, as the arc lies along a highly travelled Pacific flyway, and ash plumes can have serious and detrimental impact on commercial flights.
Formal program (20:21):
Raj Moulik of the University of MD gave a talk titled, “Signatures of chemical heterogeneity in the lowermost mantle from full-spectrum seismic tomography”.
Geochemical differences in basalts have long been interpreted as indicating the presence of a chemically heterogeneous mantle (i.e. existence of separate reservoirs for OIB, MORB, etc.). After a brief background on seismic wave analyses with respect to the earth’s interior, Moulikshowed that differences in seismic wave velocities are best explained by thermo-chemical variations in the mantle, rather than thermal or density perturbations alone.
One question was asked by Carl-HenryGeschwind, retired, independent researcher.
Steven Olson of the Legend Gold Corporation gave a talk titled, “2 billion and 20 years in 20 minutes – Proterozoic evolution of Africa”. Olson gave a condensed version of the geologic evolution of Africa, encompassing the Late Archean and Cambrian-Ordovician boundary. Accretion of the four major African cratons led to Andean style continental margins during the Late Archean to Proterozoic, and ending with extensive granitic magmatism of the so-called Pan-African Event in the Cambrian to Ordovician. The talk was enhanced with photographs of some spectacular views of African landscape, and stories of travelling the continent during the 1980s and 1990s.
Questions were asked by Jamie Allen of NSF, Bill Burton of USGS, and Carl-Henry Geschwind, retired independent researcher.
Following questions, President Bentley announced 1516th meeting program, and adjourned the 1515th meeting of the Geological Society of Washington at 21:37.
Respectfully submitted,
Nikolaus Deems
Meeting Secretary