remnants of volcanic material erupted from the Slag Hill proper, but it represents a separate volcanic vent due to its geographical appearance. This small subglacial volcano possibly formed between 25,000 and 10,000 years ago throughout the waning stages of the Fraser Glaciation. Ring Mountain, a flow-dominated tuya lying at the northern portion of the Mount Cayley volcanic field, consists of a pile of at least five andesite lava flows lying on a mountain ridge. Its steep-sided flanks reach heights of and are composed of volcanic rubble. This makes it impossible to measure its exact base elevation or how many lava flows constitute the edifice. With a summit elevation of , Ring Mountain had its last volcanic activity between 25,000 and 10,000 years ago when the Fraser Glaciation was close to its maximum. Northwest of Ring Mountain lies a minor andesite lava flow. Its chemistry is somewhat unlike other andesite flows comprising Ring Mountain, but it probably erupted from a volcanic vent adjacent to or at Ring Mountain. The part of it that lies higher in elevation contains some features that indicate lava-ice interactions, while the lower-elevation portion of it does not. Therefore, this minor lava flow was likely extruded after Ring Mountain formed but when glacial ice covered a broader area than it does currently, and that the lava flow extends beyond the region in which glacial ice existed at that time. Northern segment The Mount Meager massif is the most voluminous composite volcano in the Garibaldi chain and British Columbia, as well as the most recent to erupt. It has a volume of and consists of an eroded stratovolcano, ranging in composition from andesite to rhyodacite. Several dissected lava domes and volcanic plugs are present on its glaciated summit, as well as a clearly defined volcanic crater with a lava dome placed within it. At least eight volcanic vents compose the complex and have been the sources for volcanic activity throughout massif's 2.2 million year history. A well-documented history of volcanism is present at the Mount Meager massif, with its most recent eruption about 2,350 years ago that was similar in character to the 1980 eruption of Mount St. Helens and the continuous eruption of Soufrière Hills on the island of Montserrat. This is the largest recorded Holocene explosive eruption in Canada, originating from a volcanic vent on the northeastern flank of Plinth Peak. It was Plinian in nature,