TERRY PAVLIS: FROM DESERT RAT TO SOURDOUGH TO YETI, AND BACK

I have worked with Terry in Alaska, the Himalayas, and Death Valley. He can work with almost anybody, has incredible intuitive insights, and is exceedingly modest. He explores all angles and spews out ideas without fear of being scooped. His multiauthor papers attest to his ability to collaborate. Wherever Terry is, the whole is greater than the sum of the parts.

Terry’s work in Alaska, his “Sourdough” years, began in the early 80s working on the Border Ranges fault (BRF) system, the best exposed arc-forearc boundary in the world (Pavlis 1982). He then joined TACT (Trans Alaska Crustal Transect) and used the new data to produce the seminal paper on the BRF system (Pavlis and Roeske 2007). While with TACT, he recognized late Cretaceous extension of the Yukon Tanana terrane (Pavlis et al. 1993) and proposed that a high-temperature low pressure metamorphic region that occurred in the Chugach forearc was due to subduction of an active spreading ridge (Pavlis and Sisson 1995).

The multi-disciplinary nature of TACT laid the foundation for Terry to initiate STEEP (St. Elias Erosion and Tectonics Project). STEEP defined the collisional effects of the Yakutat plate near Mt. Saint Elias and the subsequent rapid erosion by glaciers. Some 40 papers from STEEP appeared between 2004 and 2015. The interweaving of collision tectonic and glaciation processes combined to form the world’s highest mountains at a continent’s edge.

Terry also contributed significantly to understanding the role of melt in the flow of rock. In 1985 he recognized the interplay between flow of crystal mush and thrusting in settings where the solidus temperature was close to the ambient temperature (Pavlis 1995). The recognition of the interplay of melt and thrusting was fundamental for the development of the channel flow hypothesis (Grujic et al. 1996). These were Terry’s “Yeti” years.

Terry is also a “Desert Rat”. When the rocks in Alaska are snow covered, or the monsoon is raging in the Himalayas, he maps the Panamint and Black Mountain ranges where he works on geometric problems related to Death Valley extension. There, he uses his toolbox of understanding deformation processes to define the timing and amount of Neogene uplift of the Black Mountains (Pavlis 1995). If I live long enough, I hope he and I will complete a metamorphic study of some rocks we collected that record the uplift.