TY - JOUR AU - Scott, William E. PY - 1990/09/09 Y2 - 2024/03/28 TI - Patterns of Volcanism in the Cascade Arc During the Past 15,000 Years JF - Geoscience Canada JA - GS VL - 17 IS - 3 SE - Articles DO - UR - https://journals.lib.unb.ca/index.php/GC/article/view/3675 SP - AB - About 110 well-dated and 70 poorly dated eruptive periods less than 15,000 years old at individual volcanoes in the Cascade arc constitute a data set for identifying spatial and temporal patterns of eruptive activity. Key features of the record include: (1) the mean frequency of eruptive periods during the past 4,000 years is approximately two per century, however, the variance about the mean may be large; (2) at most major centres, episodes of activity lasting several thousand years are defined by groups of eruptive periods separated by apparent dormant intervals of roughly similar duration, (3) arc-wide clustering of eruptive activity may exist at 0-4 ka, 6-8 ka, and 10-14 ka. Such clustering would be remarkable in light of significant along-arc changes in crustal structure, stress field, and subduction-zone geometry. ER -