Rt. 36 Roadcut of the
Hwanggangri Formation
A nice exposure of
Hwanggangri Formation diamictite occurs in a Rt. 36 roadcut about 2-3 km
northeast of the Rt. 36-Rt. 531 intersection, near the southwestern corner of
Lake Chungju. GPS of cut: 36° 55.010' North, 128° 01.891' East.
This is the same unit that
was exposed along the Hwangcheon River in Woraksan National Park. Unlike
the Hwangcheon River exposures, the diamictites at the Rt. 36 cut are not silicified.
We've got diamictites (“pebbly mudstones”) of the Hwanggangri Formation
(undetermined age) having a very dark siliciclastic mudstone/phyllite
matrix. It was raining during this visit, but the pic below still shows
well a conspicuous clast in dark matrix. The clasts seen here are usually
limestones.
