Offset plutons and history of movement along the McKinley segment of the Denali Fault system, Alaska

GSA Bulletin
By:  and 

Links

Abstract

The Foraker and McGonagall plutons, bodies of granodiorite with nearly identical mineralogy and chemistry, are considered to be parts of a single igneous mass that has undergone right-lateral displacement of about 38 km along the McKinley segment of the Denali fault system since the igneous mass crystallized about 38 m.y. ago. These offset plutons place severe constraints on the amount and rate of movement along the McKinley segment since the beginning of the Oligocene Epoch. The 38-km displacement indicates an average rate of 0.1 cm/yr if movement began immediately after crystallization in early Oligocene time or an average rate of 0.4 cm/yr if movement began 10 m.y. ago in late Miocene time. These rates, however, are considerably less than Holocene movement rates measured along the fault further to the east, which suggests that the Holocene displacement rate is greater than the pre-Holocene rate or that right-lateral movement along the fault may diminish to the west.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Offset plutons and history of movement along the McKinley segment of the Denali Fault system, Alaska
Series title GSA Bulletin
DOI 10.1130/0016-7606(1974)85<1883:OPAHOM>2.0.CO;2
Volume 85
Issue 12
Year Published 1974
Language English
Publisher GSW
Description 10 p.
First page 1883
Last page 1892
Google Analytic Metrics Metrics page