Carving Out Basalt Layers

Carving Out Basalt Layers. . When Ice Age floodwaters rushed across Quincy Basin and down the Columbia River, they gouged chunks of basalt from the scabland cliffs in front of you. During the last Ice Age, this area was repeatedly swept by floodwaters that tore away layer after layer of basalt. , , Resisting Powerful Floodwaters , Some layers were more resistant than others. The interpretive center was built on a high, flood-swept basalt layer called the “Museum Flow.” The floods removed the other flows that once rested above it, eroding the basalt down to this more flood-resistant layer. , , (Illustration Caption) , This illustration shows some of the basalt layers of the Vantage area. Floods removed up to 200 feet of basalt and sandstone from above the Museum Flow. These layers can still be seen in the nearby hills and in the cliffs across the river. , , (Photo Caption) , This photos shows the area before being inundated by water behind Wanapum Dam in 1963. The old town of Vantage is in the foreground. Vantage is now located less than a mile south of here. The bridge was moved to span the Snake River at Lyons Ferry.