GONGGIRI SECTION
Good trilobite collecting
can be had in mudshales of the middle Machari Formation at the Gonggiri
section. The locality is a hillside exposure at a hairpin turn of a
narrow mountain “road”. The sloping forest floor adjacent to the cut also
has weathered rock at the surface. We are walking distance north of the
tiny village of Gonggiri & about 2-3 km south of Mt. Sambang & about 15
km north of the city of Yeongwol in northeastern South Korea.
The middle Machari Formation
at Gonggiri has 115 recognizable units in 53 meters of section. Agnostoid
and polymeroid trilobites are common here. The Koreans have documented 22
trilobites species from three Late Cambrian trilobite biozones here.
GPS of cut: 37° 18.696' North, 128°
26.124' East.
Above: Cambrian researchers from
around the world (Germany, Sweden, America, Taiwan, Korea, Britain) collecting
trilobites from the Machari Formation at Gonggiri, South Korea.
Above: Machari Formation
mudshales at Gonggiri. Person at right is Sung Kwun Chough, a geology
professor from Seoul National University (SNU). Chough is probably the
world's top expert on the regional geology of Korea.
Above: View from the Gonggiri
section, looking south. The village of
Gonggiri is hidden behind
the trees in the valley at center.
Above: James St. John at the
Gonggiri section in South Korea. The smile is sincere because he's just
found several decent trilobite fossils.