Complex sentence: The Tianshan Volcanic Group is a volcanic field in the Tianshan Mountains in Northwest China, it contains the Historically active Cone of Pechan (also known as Peishan, Baishan, Hochan, Aghie, Bichbalick, Khala, and Boschan).
Split into simpler sentences: The Tianshan Volcanic Group is a volcanic field in the Tianshan Mountains in Northwest China. The historically active Cone of Pechan is within the group (also known as Peishan, Baishan, Hochan, Aghie, Bichbalick, Khala, and Boschan).