Natural Hokkaido Amber
Cretaceous Aptian
Yezo Group
Nakagawa
Hokkaido
Japan
 
extract from : Earth History of Asia- II October 31 - November 3, Niigata, Japan
 
"The Yezo Group is exposed in a belt roughly 1200 km long from Sakhalin Island to southern Hokkaido and consists of a thick Aptian to Paleocene fore-arc silicoclastic sequence. Amber-concentrated strata are intercalated in the lowest part of the Yezo Group in Nakagawaarea, northern Hokkaido, Japan. "