The Arxan-Chaihe Volcanic Field, Inner Mongolia, NE China is a Pleistocene to Recent volcanic field still considered to be active. In this chapter we provide an update of current volcanological research conducted in the last four years to describe the volcanic architecture of the identified vents, their eruptive history and potential volcanic hazards. Here we provide an evidence-based summary of the most common volcanic eruption styles and types the field experienced in its evolution. The volcanic field is strongly controlled by older structural elements of the region. Hence most of the volcanoes of the field are fissure-controlled, fissure-aligned and erupted in Hawaiian to Strombolian-style creating lava spatter and scoria cone cone chains. One of the largest and most complex volcano of the field (Tongxin) experienced a violent phreatomagmatic explosive phase creating a maar in an intra-mountain basin, while the youngest known eruptions formed a triple vent set (Yanshan) that reached violent Strombolian phases and created an extensive ash and lapilli plains in the surrounding areas. This complex vent system also emitted voluminous lava flows that change the landscape by damming fluival networks, providing a volcanological paradise for the recently established Arxan UNESCO GLobal Geopark.
Part of the book: Updates in Volcanology
Fissure eruption is the most prominent type of Pleistocene to Holocene volcanism in Arxan-Chaihe Volcanic Field recording vent migration along fissures. This research is examined Sentinel Satellite Images to outline the youngest lava flows in the region in conjunction with field observations. Also, GIS-based analyses were performed with the aim to calculate the volumes of lava flows to determine the length of the lava flow emissions. Topographic cross sections and various geomorphological parameters (e.g., geomorphon and topographic position index) were used to reconstruct the pre-eruptive geomorphology of the region to simulate lava flow inundation using Q-LAVHA plug in the QGIS package. Pre-eruptive topography was created, and various simulations were used to obtain the best-fit lava inundation. This process yielded to estimate an average of 5 m lava flow thickness. The same parameters of the lava flow simulations were used to run on the post-eruptive topography to simulate future lava flow inundation. Results showed that the lava flows best simulate if they emitted along a NE–SE trending fissure between two young vent zones or in an extensive elongated area following the NW–SE trending valley axis initiated from the Yanshan vents.
Part of the book: Updates in Volcanology