Unit is named the Locke Member of the Tiger Formation (revised). Is exposed in the Cusick region, northeastern WA. Consists of massive to horizontally and planar cross-stratified, coarse-grained sandstone fining upward to siltstone and carbonaceous shale and a minor amount of conglomerate. The base is not exposed but it presumably overlies Precambrian and Paleozoic strata; is a facies equivalent of, intertongues with, and is separated by a vertical arbitrary boundary from the Gibralter Rock Member (new) of the Tiger Formation; conformably underlies the Jared Member (new) of the Tiger Formation east of the Cusick Creek fault; unconformably underlies the Jared member west of the fault. Thickness is 34 m at the type section; inferred total thickness is 2000 m. Age ranges from early middle Eocene, based on the inclusion of late early to early middle Eocene volcanic rock clasts, through middle Miocene, based on middle Miocene regional 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).