Milbanke Sound Group

Milbanke Sound Group
Milbanke Sound Cones
Aerial photo of the Milbanke Sound Group
Highest point
Peak	Helmet Peak
Elevation	335 m (1,099 ft)
Coordinates	52°21′17″N 128°21′01″W / 52.35472°N 128.35028°W / 52.35472; -128.35028Coordinates: 52°21′17″N 128°21′01″W / 52.35472°N 128.35028°W / 52.35472; -128.35028
Geography
Country	Canada
Province	British Columbia
District	Range 3 Coast Land District
Parent range	Kitimat Ranges
Geology
Age of rock	Formation: In the past 10,000 years (Holocene) Last eruption: Unknown Last activity: Unknown
Type of rock	Cinder cones, lava flows

The Milbanke Sound Group, also called the Milbanke Sound Cones, is an enigmatic group of five small basaltic volcanoes in the Kitimat Ranges of the Coast Mountains in British Columbia, Canada. Named for Milbanke Sound, this volcanic group straddles on at least four small islands (three of which are uninhabited), including Swindle, Price, Lady Douglas and Lake Island. Not much is known about this group of volcanoes and they remain undated. However, they all likely formed in the past 10,000 years after the last glacial period as evidenced by a small amount of erosion. The age of the most recent volcanic activity is also unknown. Most of the Milbanke Sound Cones are covered by mature forest. Kitasu Hill and Helmet Peak are the only two cones that are officially named.

This group of volcanoes is unlike many other volcanic groups in Canada as it resides on islands instead of on the mainland. The volcanoes form a northwest-southeast trend along the British Columbia Coast. To the west the Milbanke Sound Group is bounded by the Pacific Ocean and elsewhere it is surrounded by adjacent islands that form an archipelago. Although not related, the Milbanke Sound Group is close to the remains of a much older magmatic feature that was formed during the Tertiary period.

Just south of Kitasu Bay on the southwestern shore of Swindle Island, Kitasu Hill rises with an elevation of 250 m (820 ft) and a topographic prominence of 230 m (750 ft). This is a small symmetrical monogenetic cinder cone and the best preserved volcano associated with the Milbanke Sound Group. It is the northernmost and most prominent volcano of the Milbanke Sound Cones with a circular volcanic crater at its summit. The volcano produced basaltic lava flows that extend to the north. Subaerial tephra and volcanic bombs are the main volcanics comprising the volcano. These volcanics surround eroded remains of the basalt lava flows and are composed of the mineral olivine. Kitasu Hill rests on till that overlies glacially scoured bedrock.