SURFICIAL DEPOSITS SHOWN ON THE GEOLOGIC MAP
HAYDEN CREEK DRIFT
The Hayden Creek Drift is here named for a stony till that is intermittently exposed in cuts along the Mowich Lake Road (fig. 7) from a point near the mouth of Hayden Creek (fig. 4, locality 4) westward beyond the park boundary.
The distribution of Hayden Creek Drift outside the park, as well as the drift's presence on some high ridges within the park, indicates deposition during a glaciation of icecap proportions, when glaciers west of Mount Rainier locally reached the western front of the Cascade Range. The entire park was covered by ice at that time. The Hayden Creek Drift probably was formed during a glacial episode that occurred between 35,000 and 50,000 years ago.
Extensive weathering in the Hayden Creek Drift shows it to be older than the Evans Creek Drift (described next), which was formed during the most recent major glaciation. Although initially brownish gray, the Hayden Creek till has been weathered to dark yellowish brown to a depth of 68 feet below the ground surface. Stones in the upper few feet of the till have been partly decomposed; these stones have weathered rinds or shells 13 mm thick (fig. 8). Hayden Creek Drift was found at the summits of Iron and Copper Mountains and at the top of a ridge that extends eastward from Tyee Peak. A brown bouldery till at least 100 feet thick on a ridge northwest of The Palisades probably is also Hayden Creek Drift.
Hayden Creek Drift underlies a thick deposit of Mount Rainier pumice on the north valley wall of the White River about 2 miles southeast of Yakima Park (fig. 4, locality 5). The pumice can be seen in a roadcut a short distance west of Yakima Creek where it is overlain by an old talus deposit and Evans Creek till. Wood in the pumice is more than 38,000 years old, as determined by radiocarbon dating. More than 50 feet of Hayden Creek till is exposed beneath the pumice in a steep bank downslope from the highway.
Last Updated: 01-Mar-2005