Basalt (UK: / ˈ b æ s ɒ l t,-ɔː l t,-əl t /; [1] [2] US: / b ə ˈ s ɔː l t, ˈ b eɪ s ɔː l t /) [3] is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90% of all ...

Basalt is a dark-colored, fine-grained, igneous rock composed mainly of plagioclase and pyroxene minerals. It most commonly forms as an extrusive rock, such as a lava flow, but can also form in small intrusive bodies, such as an igneous dike or a thin sill. It …

A 3-4m (10-12 ft) high outcrop of basalt lava, part of a broader lava flow. These flows were erupted about 300,000 years ago following basalt dike intrusions in a rear-arc region of northern California.

The Columbia River Basalt Group (CRBG) is the youngest, smallest and one of the best-preserved continental flood basalt provinces on Earth, covering over 210,000 km 2 (81,000 sq mi) mainly eastern Oregon and Washington, western Idaho, and part of northern Nevada. [1]

The McClellan Peak Basalt in the Mustang outcrop is grayish black when freshly broken but is often reddish-brown colored on weathered surfaces because of oxidation of iron, which is abundant in the basalt.

A 3-4m (10-12 ft) high outcrop of basalt lava, part of a broader lava flow. These flows were erupted about 300,000 years ago following basalt dike intrusions in a rear-arc region of northern California.

After making a difficult portage around the “Great Shute” rapids on November 2, 1805, the expedition continued downstream, noting the large basalt outcrop called Beacon Rock. Clark recorded that the river bottom and the mountains on each side of the river were thickly timbered with pine, spruce, cottonwood, and alder.35

Feb 8, 2024 · A basalt column is a pillar of rock formed from hardened lava in the aftermath of a volcanic eruption. A basalt column takes thousands of years, sometimes millions, to form. This article describes the process of lava turning to basalt columns.

An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth and other terrestrial planets. [1]

May 19, 2010 · Near South Cove, in the upper part of Lake Mead, The Sandy Point basalt outcrop under the navigation light is as important to geologists investigating the origin and evolution of Grand Canyon as the Sandy Point navigation light is to boaters.