Tectonic controls of Late Cenozoic monogenetic intraplate volcanism at the Wulanhada volcanic field, Northern China

Abstract

The role of India-Eurasian collision and Western-Pacific subduction on the formation of intraplate volcanoes in East Asian is unclear. Wulanhada in North China is a perfect study case for this problem as an intraplate monogenetic volcanic field. We identified 18 volcanoes and 41 vents in Wulanhada volcanic field and divided them into three groups according to notably spatial alignments. Geochemical data show the three groups have similar characteristics in rock classification and trace element patterns. Consequently, the three groups of volcanoes could be treated as one volcanic system. Our K-Ar age data indicate that the volcanism in WVF occurred since the late Miocene and lasted until Quaternary. The feeder fractures far from the W-G fault generally strike ENE-NE, consistent with the maximum principal compressive stress of this region, while the feeder fractures near the W-G fault trend WNW, subparallel to this pre-existing fault. Based on the couplings of stress field and feeder dyke in orientation and timing consistency between the India-Eurasian collision and the volcanism at Wulanhada, the tectonic control from the Tibet Plateau is a dominant factor on the volcanism at WVF. The W-G fault is another indispensable factor for concentration of stress and the distribution of volcanoes at WVF.