Download Draft minutes from the 1518th (Mar. 29)

Draft Minutes for the 1518th Meeting of the Geological Society of Washington
Wednesday, March 29th, 2017
John Wesley Powell Auditorium
Cosmos Club, Washington, D.C.
The 62 ladies, gentlemen, and geologists in attendance of the 1518th meeting ignored President
Bentley’s call to order at 20:01 EDT. At the behest of Former President Toulmin, President
Bentley called forth the power of Odin and laid down the Special Gavel with the force of 1000
mighty Viking warriors, at which point, the attendees shuffled to their seats, beers in hand.
The minutes of the 1517th meeting were accepted with one correction.
Five guests were not intimidated by President Bentley’s forceful blow, and remained:
Catherine Thompson (affiliation unidentified)
Nicholas Mecholsky of Catholic University of America’s Vitreous State Laboratory
David Smallwood
Robert Smith, formerly of the EPA and USGS
Jennifer Mayo of NASA’s Goddard Spaceflight Center
One new member was announced:
Walter Guidroz of the USGS
President Bentley assumed the somber duty of announcing the passing of Robert G. Luedke.
Robert was a talented geologist, dedicating his work to mineral resources and volcanic rocks of
the Colorado Plateau. In 1966, he co-authored a GSW talk with Wilbur Sweat Burbank, a talk
that subsequently won Best Paper of the Year. Robert devoted more than 60 years of his life to
the USGS, from the early 1950’s, past his retirement in 1995, and as emeritus until 2015. Roberts
was a GSW member from 1955 until 1997 and passed away on March 21st, 2017.
Members observed a moment of silence.
Announcements:
Kori Newman was not in attendance this week to solicit judges for local science fairs.
President Bentley announced the Annual Bradley Lecture will be rescheduled for November 8th.
This year’s speaker is Iain Stewart, possibly the only geologist to have his own IMDB page.
President Bentley announced the National Association of Geoscience Teachers Eastern Section
meeting to be held June 8-11, 2017 in Catonsville, Maryland. Flyers were available on the back
table.
Informal Communications:
Member Jim Hayes spoke briefly regarding Holocene temperature variations. Mr. Hayes
presented temperature curves from eight sources (listed in a handout provided by Mr. Hayes)
recording temperature variability throughout the Holocene on a multi-centennial scale. Because
of limitations of data sampling, the chart cannot resolve temperature fluctuations faster than ~300
years. Due to the resolution, it is impossible to know if other, short-term temperature fluctuations
have occurred and only time, or better resolution data, will tell.
Dr. Dan Doctor gave a brief synopsis about the Spring Field Trip to Sugarloaf Mountain, MD.
Sixteen attendees managed to make it to the East View Parking Area, thanks to Dan’s excellent
directions given during the previous meeting. The hikers enjoyed a brisk, cloudy day exploring
the mysterious geology of Sugarloaf Mountain, an overturned anticlinal fold of pre-Cambrian
quartzose sandstone and quartzite, thrust from the Blue Ridge, eastward, overtop of the younger
rocks of the Piedmont by the Martic fault.
Formal Program:
Jean-Arthur Olive of Columbia University’s Lamont Doherty Earth Observatory gave a talk titled
“What’s Shaping the Ocean Floor?”
In his talk, Dr. Olive presented simple models that relate the texture of the ocean floor (abyssal
hill spacing and amplitude) to magmatic and tectonic activity at the mid-ocean ridge where it
formed. These models were used to assess the bathymetric expression of spatio-temporal
variability in mid-ocean ridge magma supply, and better understand the deep and shallow
processes that may affect this variability. Essentially, the amplitude and spacing (wavelength), are
directly proportional to the spreading rate, and therefore, magma supply, of the associated
spreading center.
Questions were asked by Ved Lekic of UMD, Past President Jamie Allen (NSF), An unidentified
gentleman in a yellow shirt and tie next to Laura Helmuth, Kevin Marvel of the American
Astronomical Society, and Pete Toulmin (USGS, retired).
Carrie M. Anderson gave a talk titled “Organic Inventory at Titan’s poles Inferred from nearly 15
years of Cassini Observations”.
Titan possesses high amounts of organic aerosol particles in the atmosphere, which creates
abundant smog. Dr. Anderson explained that these aerosol particles are important for nucleation
sites for organic ice clouds, which form successive ice layers as particles descend in the
atmosphere. Abundances and chemical compositions of the clouds in north and south winter polar
stratospheric ices are different. These differences may be due to 1) Reversal of meridianal
circulation, 2) differences in relative organic abundances, or 3) temperature differentials.
Regardless of season, however, Titan’s aerosol ices precipitate and settle giving observed soil
conditions.
One question was asked by Pete Toulmin (USGS, retired).
Michael Ackerson gave a talk titled “New Perspectives on an Age-Old Question: How do granites
form?”
In his talk, Dr. Ackerson discussed novel analytical and experimental techniques, which allowed
him to investigate the thermal and chemical evolution of granite formation. Using the Tuolumne
Intrusive Suite from the Sierra Nevada Batholith as a case study, Dr. Ackerson demonstrated that
granitic rocks can crystallize at temperatures hundreds of degrees below the traditional wet
solidus. These observations are helping to re-evaluate long-held petrologic models for granite
formation and the relationships between plutonic and volcanic rocks.
Questions were asked by 2nd VP Carl-Henry Geschwind, Jane Hammerstrom of the USGS, an
unidentified gentleman in blue denim, Past President Pete Toulmin, Laura Waters of the
Smithsonian Institution, and Dan Doctor of the USGS.
Following the final question, President Bentley announced the program for the 1519th meeting on
April 12th and adjourned the 1518th meeting at 2155 EDT.