thumbnail

Preliminary Geology of the North Meadow Creek Area, Tobacco Root Mountains, Southwest Montana: The North Meadow Creek Fault

Open-File Report 2025-1058
By: , , and 
https://doi.org/10.3133/ofr20251058

Links

Abstract

This report documents a previously unmapped fault, informally referred to herein as the North Meadow Creek fault, on the east flank of the Tobacco Mountains of southwestern Montana. This fault has an apparently long and complex history, including Quaternary offset of an older alluvial terrace, offset of a debris flow of presumed Pleistocene age, offset of rhyolite lava flows of presumed Tertiary age from their presumed source several kilometers east, on the opposite side of the fault, and offset and possible rotation of blocks of Archean gneiss on northeast side of the fault. The western part of the fault is covered by glacial moraines of two apparent ages, both Pleistocene.

Suggested Citation

Fuis, G.S., LeClair, P.J., and Ruleman, C.A., 2026, Preliminary geology of the North Meadow Creek Area, Tobacco Root Mountains, southwest Montana—The North Meadow Creek Fault: U.S. Geological Survey Open-File Report 2025–1058, 6 p., https://doi.org/10.3133/ofr20251058.

ISSN: 2331-1258 (online)

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Geology of the North Meadow Creek Region
  • Geologic History
  • Discussion
  • Conclusions
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Preliminary geology of the North Meadow Creek Area, Tobacco Root Mountains, southwest Montana: The North Meadow Creek Fault
Series title Open-File Report
Series number 2025-1058
DOI 10.3133/ofr20251058
Publication Date June 18, 2026
Year Published 2026
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Earthquake Science Center
Description Report: iv, 6 p.; Data Release; 1 supplemental figure
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Additional publication details