Open Access. Powered by Scholars. Published by Universities.®
- Discipline
Articles 1 - 2 of 2
Full-Text Articles in Earth Sciences
Geology And Geochronology Of The East Dome Complex Within The Hog Heaven Volcanic Field, Flathead County, Montana, Ethan Coppage
Geology And Geochronology Of The East Dome Complex Within The Hog Heaven Volcanic Field, Flathead County, Montana, Ethan Coppage
Graduate Theses & Non-Theses
This study describes the style and timing of volcanic activity and mineralization in the East Dome Complex (EDC) of the 55-km2 Eocene-Oligocene Hog Heaven Volcanic Field (~36-30 Ma; HHVF) located in northwestern Montana. The HHVF consists of three NE-aligned, predominantly high-K rhyodacitic dome complexes (1.8-4.9 wt. % K2O; 63.2-72.9 wt. % SiO2) formed near the crest the Purcell Anticlinorium, a major Cordilleran fold-thrust belt structure deforming metasedimentary rocks of the Mesoproterozoic Belt Supergroup. Dome emplacement was controlled by a NE-striking fault associated with a pull-apart basin formed between two overlapping, NW-trending dextral oblique-slip faults. The objective of this study is …
Cordilleran Front Range Structural Features In Northwest Montana Interpreted From Vintage Seismic 2 Reflection Data, Mason Porter
Cordilleran Front Range Structural Features In Northwest Montana Interpreted From Vintage Seismic 2 Reflection Data, Mason Porter
Graduate Theses & Non-Theses
Industry seismic reflection data were collected in 1983 in the Rocky Mountain Cordillera front ranges of northwest Montana. These seismic profiles represent 160 km of deep reflection data that cross the eastern Purcell anticlinorium, Rocky Mountain Trench (RMT), Rocky Mountain Basal Detachment (RMBD), and Lewis thrust. We have reprocessed these data using modern processing techniques including refraction statics, pre-stack time migration (PSTM), and pre- and post-stack depth migration. The RMT contains Tertiary fill to 1 km depth and the RMT fault system has a minimum of 3-4 km of normal displacement. The RMT and Flathead fault systems are interpreted to …