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Calc-alkaline plutonism along the Pacific rim of southern Alaska

January 1, 1979

Field, petrology, and age data on southern Alaska plutonic rocks now enable the delineation of eight calc-alkaline plutonic belts. These belts of plutons or batholithic complexes are curvilinear to linear and trend parallel or subparallel to the continental margin. The belts represent the principal loci of emplacement for plutons of specific ages and although there is spatial or temporal overlap in some cases, they are more commonly spatially and temporally distinct. Intermediate lithologies such as quartz diorite, tonalite, and granodiorite dominate in most of the Belts but granodiorite and granite characterize one. The belts are of Mesozoic or Cenozoic age and plutonism began in six of them at about 195, 175, 120, 75, 60, and 40 m.y. ago; age relations in two are poorly known. Recognition of the belts is important for future studies of regional geology, tectonism, and magmatism along the Pacific rim of southern Alaska.

Publication Year 1979
Title Calc-alkaline plutonism along the Pacific rim of southern Alaska
DOI 10.3133/ofr79953
Authors Travis Hudson
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Open-File Report
Series Number 79-953
Index ID ofr79953
Record Source USGS Publications Warehouse