Cliff Ridge Member of the Tiger Formation (revised) is named for Cliff Ridge in northeastern WA. Consists of coarse, massive conglomerate composed of greenstone, granite, dolomite, and volcanic rock. Boulder conglomerates are common. Overlies Precambrian greenstone and possibly Cretaceous granite, but has no stratigraphic relationship to other members of the Tiger Formation. Thickness is 400 m at the type section, but may be as much as 1700 m. Age ranges from early middle Eocene, based on inclusions of late early to early middle Eocene volcanic rock clasts, through middle Miocene, based on middle Miocene faults that bound the Tiger Formation, although the age determination of middle Miocene is less definite. (B1565)

Source: GNU records (USGS DDS-6; Menlo GNULEX).