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Hydrogeologic framework of the Johns Creek subbasin and vicinity, Mason County, Washington

September 28, 2011

This report describes the hydrogeologic framework of the groundwater-flow system in the Johns Creek subbasin and vicinity. The study area covers 97 square miles in southeastern Mason County, Washington, and includes the Johns Creek subbasin, which drains an area of about 11 square miles. The study area extends beyond the Johns Creek subbasin to include major hydrologic features that could be used as regional groundwater-flow model boundaries. The subbasin is underlain by a thick sequence of unconsolidated Quaternary glacial and interglacial deposits, which overlie Tertiary igneous and sedimentary bedrock units. Geologic units were grouped into eight hydrogeologic units consisting of aquifers, confining units, undifferentiated deposits, and an underlying bedrock unit. A surficial hydrogeologic map was developed and used with lithologic information from 200 drillers' logs to construct 4 hydrogeologic sections, and unit extent and thickness maps.

Citation Information

Publication Year 2011
Title Hydrogeologic framework of the Johns Creek subbasin and vicinity, Mason County, Washington
DOI 10.3133/sir20115168
Authors Wendy B. Welch, Mark E. Savoca
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Scientific Investigations Report
Series Number 2011-5168
Index ID sir20115168
Record Source USGS Publications Warehouse
USGS Organization Washington Water Science Center