The Alaska

Alaska

Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

n island

Island

An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, cays or keys. An island in a river or lake may be called an eyot , or holm...

 called New Eddystone Rock is a pillar of basalt

Basalt

Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

. Sometime during the last 5 million years, the basalt came from fractures in the floor of Behm Canal

Behm Canal

Behm Canal is a channel in the Alexander Archipelago, in the southeastern part of the U.S. state of Alaska.About long, Behm Canal separates Revillagigedo Island from the mainland...

. The broken, haphazard texture of these basalts indicates that New Eddystone Rock was part of a volcanic vent where magma rose repeatedly to the surface of the earth.

When in its molten state, the basalt was very liquid, so that it spread out over a large area, like pancake batter on a griddle. These flows cooled from both the top and the bottom forming the hexagonal columns which are visible on several of the islands surrounding New Eddystone rock. After the basalt flows covered the floor of Behm Canal, another glacial advance scoured away much of the flow, leaving behind New Eddystone Rock and some of the islands to the northeast.