Jack Souther | |
|---|---|
| Born | (1924-04-25)April 25, 1924 |
| Died | June 1, 2014(2014-06-01) (aged 90) |
| Nationality | American Canadian |
| Alma mater | University of British Columbia;Princeton University |
| Known for | Studyingvolcanoes andvolcanism |
| Awards | Bancroft Award,Royal Society of Canada, 1984 Career Achievement Award,Geological Association of Canada, 1995 |
| Scientific career | |
| Fields | Geology,volcanology |
Jack Gordon Souther (April 25, 1924 – June 1, 2014) was anAmerican-born Canadiangeologist,volcanologist,professor andengineer. He contributed significantly to the early understanding ofrecent volcanic activity in theCanadian Cordillera. Many of his publications continue to be regarded as classics in their field, even now several decades after they were written.
Souther was born inChicago,Illinois, United States on April 25, 1924.[1] As a young child he moved to theU.S. state ofAlabama. In his teenage years, Souther relocated with his family to the Canadian province ofAlberta at a cattle ranch near theFirst Nations settlement ofMorley. After his family lost the ranch, Souther moved with his family to the mountain town ofBanff. Here, he attended Banff High School. In 1945 at the age of 21, Souther graduated as theclass president. He was later accepted into ageological engineering program at theUniversity of British Columbia inVancouver.[2]
He was offered a full scholarship toPrinceton University inPrinceton, New Jersey, after excelling to such a degree at the University of British Columbia. Consequently, he enrolled in thePh.D. program forgeology.[2] After completing his degree, Souther joined theGeological Survey of Canada (GSC) office in Vancouver and carved out a remarkable career as one of the country's leading authorities on geothermal resources and volcanism in theCanadian Cordillera.[2][3]
Souther had long been in demand as a public speaker because of his ability to communicate scientific ideas to lay audiences. This included his ability to be a principal in media interviews, a participant in radio and television open-line shows and as a main figure in television broadcasts handling with its scientific concentration.[3]
Souther received theBancroft Award for "publication, instruction, and research in the earth sciences that have conspicuously contributed to public understanding and appreciation of the subject" from theRoyal Society of Canada in 1984.[3][4] After retiring to the position ofemeritus scientist in 1992, Souther began his second career as a ski guide/mountain host at theWhistler Blackcombski resort.[1][5] In 1995, he received theCareer Achievement Award in volcanology andigneous petrology by theGeological Association of Canada.[5]
Jack Souther was one of the first members to join the Whistler Naturalists, a society founded in theresort town ofWhistler, British Columbia, during the late 1990s. During his time with the society he discussed the geology andnatural history of the Whistler area.[2]
Jack Souther died on June 1, 2014, in Lions Gate Hospital,North Vancouver at the age of 90 following a long battle with cancer.[1][2] He is survived by his wife Betty and their three daughters Anne, Barbara and Janet.[1]
Souther's scientific work embraced a broad spectrum of topics, includingvolcanology,stratigraphy,hydrogeology,landslides,tectonics andmineral deposits. But his most influential work was in the fields of volcanoes and volcanism. When he joined the Geological Survey of Canada, there was a curious gap in thePacific Ring of Fire between the U.S. states ofAlaska andWashington. This began to change in 1956 when the crash mapping program of Operation Stikine identified a number ofCenozoic volcanoes in northwestern British Columbia. Among these wereLevel Mountain, theIskut-Unuk River Cones and theMount Edziza volcanic complex.[5] Masterminded by Jack Souther, Operation Stikine continued to work in the late 1950s and 1960s.[6][7]
During an expedition of theCanadian Arctic in 1963, Jack Souther observed and named twogeological formations. TheStrand Fiord Formation on west-centralAxel Heiberg Island,Nunavut consists mainly ofbasaltic lava flows andagglomerates. Souther established atype section for this formation near the western tip of the Kanguk Peninsula. The overlyingKanguk Formation was named after its locality.[8] It comprises dark greyshale andsiltstone with subordinatesandstone and some local thinbentonitic andtuffaceous beds.[9]
In 1965, Canadian geologistJohn Oliver Wheeler foresaw the need for a volcanological program in Canada's western Cordillera. Souther was given the job of working on the Mount Edziza complex with the able assistance of Maurice Lambert. By 1970, the two geologists had established that eruptions ofalkali basalt, followed by extrusion ofsilicicperalkaline lavas, had occurred episodically at Edziza for the past 10 million years and that volcanism was accompanied by east-west extension and incipientrifting. However, the regional tectonic context was still unresolved.[5] During his geological studies in the area Jack Souther namedEve Cone after a localFirst Nations woman, Eve Brown Edzerza.[10] Edziza remained a significant study area for Souther until his last year of serious field work in 1992.[5][11] During this year he highlighted the importance and size of the region and proposed that numerous eruptions emplaced lava in a sub-ice or ice-contact environment.[11][12] This was confirmed by other scientists in 2006.[12]
As part of Operation St. Elias, Jack Souther studied the stratigraphy, structure and evolution of the Wrangell lavas of southwestYukon in the mid 1970s.[13] He was surprised by the difference in volcanic style between the Wrangell lavas where an enormous volume ofandesite lava had issued without any apparent breaks and was accompanied by profoundtectonic uplift and compressivefolding, in contrast to the episodic eruption of alkaline basalt and highly fractionated silicic peralkaline rocks at Edziza. The differences in eruptive style and chemistry of the Wrangell lavas led Souther to speculate they were related to acalc-alkalinevolcanic arc that formed along aconverging plate boundary.[5]
In 1977, a book published under the titleVolcanic Regimes in Canada included achapter on Cordilleran tectonics by Jack Souther. This information contributed significantly to the early understanding of Quaternary volcanism in Canada.[14] However, the origins of the east-west trendingAnahim Volcanic Belt was still not understood.[5]
Several features in theMount Cayley volcanic field were illustrated by Jack Souther in 1980, includingMount Cayley,Ember Ridge,Mount Fee,Cauldron Dome,Pali Dome,Slag Hill andRing Mountain, the later of which he calledCrucible Dome. This resulted in the recreation of ageologic map that showed the regional terrain and locations of the volcanoes.[15] Souther conducted the first detailed study of Mount Cayley itself during this period. At least three stages of volcanic activity were identified at the volcano.[16] He also hypothesized that the Ember Ridge domes shared a common magma source. However, significant variations in the percentage ofphenocrysts in the six domes prove otherwise.[17]
Jack Souther added several hundredQuaternary aged volcanoes on Canadian maps throughout his career.[14] His work contributed to the closing of Canada's gap in the Pacific Ring of Fire.[5]
Jack Souther described the geology ofWhistler Mountain for the Whistler Naturalists Society on May 11, 2001. He speculated that itsshale originated as mud on the seafloor of a prehistoric ocean.Granular material, such asclay,sand andsilt, was carried into the ancient ocean by rivers that existed during theCretaceous period. As the Cretaceous rivers continuously sent granular material into the former ocean, it was deposited yearly to eventually form layers of sedimentary material. Once the sedimentary material was compressed, it created the shale that now forms portions of Whistler Mountain.[18]
The most common rocks, andesite and dacite lavas, were said to have been deposited when volcanic activity created a series of islands and lava flows in the ancient ocean. Once the shale and lavas were deposited, they began to deform, crumple and uplift due to the extreme pressures created by movement of theNorth American Plate and thetectonic plates under thePacific Ocean. The large masses of solidified lava that formerly created the volcanic island chain and underwater lava flows yielded by demolishing into massive, mountain-sized blocks while the less dense, thinly layered shale was compressed, folded and crushed between the associated lavas. Souther classified these rocks as part of theGambier Group, a geologic formation that was created within a shallow underwater basin about 100 million years ago during theEarly Cretaceous period.[18]
On August 12, 2004, Jack Souther convinced thatFlute Summit is an exposedsubvolcanicintrusion of an ancient volcano. The subvolcanic magma heated and set up convention in nearby groundwater, creating ahydrothermal system. This ancient hydrothermal system, combined with sulfurous gasses released from the magma, caused chemical alteration of both the crystallizing subvolcanic intrusion and the adjacent rocks. The weathering ofpyrite crystals inside the subvolcanic rock toiron oxide has resulted in the redness of Flute Summit.[19]
The greenPiccolo Summit consists of lava flows that Souther speculated to have erupted about 100 million years ago.[2]
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