Regional compilation of bedrock geology at 1:250,000 scale shows 

 Monture Creek and the Clearwater Valley (both drainages may be 

 contributing areas to glacial deposition at this site) underlain 

 by outcrops of all Proterozoic Y (Belt) formations from the Helena 

 Formation through the Bonner Quart zite. In addition, Monture Creek 

 outcrops include both older (Empire and Spokane Formations) and 

 younger (McNamara Formation) Belt units. Both drainages include 

 large areas of the dominantly carbonate Helena Formation. 



Beaver Creek 



Bibliographic source: Geoindex lat-long search 



Author: Witkind, I.J and W.M. Weber 



Title: Reconnaissance geologic map of the Big Fork - Avon 



Environmental Study Area, Flathead, Lake, Lewis and Clark, 

 Missoula and Powell Counties, Montana. 



Series: USGS Miscellaneous Investigations Series Map 1-1380 



Date: 1982 



Geologic mapping at 1:125,000 scale emphasizing surficial deposits 

 shows the sampling site to be underlain by late Pleistocene till 

 of the Placid Creek glacier. Till texture is described as coarse, 

 with abundant cobbles and boulders in typically sandy or silty 

 matrix. Soil drainage described as poor. Nearby 

 Pre-Quaternary outcrops are mapped as undifferentiated Proterozoic 

 Y (Belt). WNW trending normal faults (concealed beneath surficial 

 deposits) traverse the area, and are shown as bracketing the 

 wetland site. This document provides no direct hydrologic or 

 hydrogeologic information. 



Bibliographic source: Geoindex lat-long search. 



Author: Mudge, M.R. , R.L. Earhart, J.W.Whipple and J.E. Harrison. 



Title: Geologic and structure map of the Choteau 1X2 quadrangle, 

 western Montana. 



Series: USGS Miscellaneous Investigations Series Map 1-1300. 



Date: 1982 



Regional compilation of bedrock geology shows the pe«-Quaternary 



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