Geomorphology and geochemistry of the late Cenozoic volcanoes in the Halaha River-Chaoer River volcanic fields, western Greater Hinggan Mountain Range, NE China
AbstractThe Halaha River-Chaoer River (HC) volcanic field in the Greater Hinggan Mountain Range (NE China) consists of at least 41 monogenetic basaltic volcanoes. Strombolian, violent Strombolian, and phreatomagmatic eruptions, as well as the transitional eruptions, generated simple volcanic cone (single vent) and composite volcanic cone (multiple vents). Simple elongated cone is the most abundant geomorphology type. By analyzing the elongated crater and coalescent aligned circular crater, cone breaching and depression, and aligned vents, we identified a number of magma-feeding fissures. The majority of these fissures strike NE-ENE. Accordingly, we infer that the regional stress field affected volcanism in the HC field. The lavas in this field are alkali basalts that are enriched in light rare earth elements (La/YbN = 7.9 to 24.5). Their OIB-like REE and spider-diagram patterns, high Nb/U ratios, and high TiO2 contents (> 2 wt. %) indicate that the basalts were derived from the asthenosphere mantle. Both the asthenosphere upwelling and the tectonic forces are the key controlling factors of the volcanism in the HC field.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5355233