32. Flood basalts Dan Barker April 2009 Creag Mhor, Isle of Mull, Scotland.

32. Flood basaltsDan Barker April 2009

Creag Mhor, Isle of Mull, Scotland

About 55 million years ago, while the North Atlantic opened up, enormous outpourings of basalt lava covered western Scotland, Northern Ireland, and eastern Greenland. Creaga Ghaill, Mull.

Thick stacks of lava flows built up in a few million years. Mostflood basalts erupt from long fissure systems, not from a central vent. Bearraich. Mull

Floddigarry, Isle of Skye

Struan, Isle of Skye

The same thing happened in NE Africa, starting about 40million years ago. 89 km south of Asmara, Eritrea

The Simien Mountains, Ethiopia, are a spectacular remnantof these flood basalts.

Wrangellia Basalts, Vancouver Island, BC, formed 230 million years ago on an oceanic plateau in the SW Pacific, before colliding with North America.

Another view of the Wrangellia Basalts,Vancouver Island, BC

North America's youngest flood basalts cover about half ofWashington State. Columbia River Basalts, Snake River.

Eruption of the Columbia River Basalts, WA, peaked about16 million years ago, and 95% of the volume erupted in lessthan 1 million years.

Many Columbia River Basalt flows show prismatic joints, from interactions with surface water. Palouse River WA

There was enough time between flows for thick soils to develop. From Wishram Heights WA

The Dalles WA

Wanapum Basalt at the Dalles

Columbia River Basalts warped by an anticline, WA