- Geology of the Snoqualmie Batholith (washingtonminerals.com)
Snoqualmie Batholith - late Oligocene to early Miocene (28 Ma[million years ago] to 22 Ma). Uplift and erosion of the Old Cascade Volcanic Arc exposed plutonic rock of the Snoqualmie Batholith near Snoqualmie Pass between Interstate 90 and State Highway 2. The batholith consists of at least eight intrusive phases, emplaced at a depth of about 4,000 and 8,000 feet. Intrusive rock types found within the Snoqualmie Batholith range in composition from granite to gabbro. Granodiorite is the most prevalent rock type, making up about 80 percent the batholith (Erikson, 1969). Other lithologies within the batholith include porphyritic dacite, andesite, aplite, and intrusive breccia (Livingston, 1971).
- Renton, Washington (Wikipedia)
Renton is a city in King County, Washington, and an inner-ring suburb of Seattle. Situated 11 miles (18 km) southeast of downtown Seattle, Renton straddles the southeast shore of Lake Washington, at the mouth of the Cedar River. As of the 2020 census, the population of Renton was 106,785, up from 90,927 at the 2010 census. The city is currently the sixth-largest municipality in greater Seattle and the ninth-largest in Washington state.