Holocene volcanoes of the Jingpohu region, Heilongjiang Province, are situated i Three gagatite samples from the strata of the first and second sub-cycles of Nos. I and V (Daganpao) craters of the 'Crater Forest' and the first sub-cycle of No. XII crater of the 'Frog Pool' respectively were used for 14C dating. The dating results are 3430±60, 2470±120, 2470 ±110 and 3490±140 years respectively (the gagatite sample collected from No. V crater was measured twice). Based on the existence of three volcanic sub-cycles in the study area, as well as the geological characteristics and the oldest age of the trees in the study area, it is inferred that the last volcanic eruption happened about 2000 years to 1000 years ago. The interval of two eruptions is about 1000 years. It shows that the Jingpohu volcano is one of the most dangerous volcanoes in Northeast China. Great differences in petrological and geochemical characteristics of the basaltic rocks and mantle inclusions between the 'Crater Forest' and the 'Frog Pool' show the extreme heterogeneity of the mantle source beneath the Jingpohu region 3490 years ago. It was probably related to the third-class activity of the mantle plume beneath the area.
Zhang Z.;Li Z.;Li S.;Xin Y.;Wang X.;Yin J.
Acta Geologica Sinica