Wednesday, April 30, 2014

Geo 730: April 30, Day 486: Wine Sign

This is actually the text below the map in yesterday's photo, and it's particularly appropriate, given the view from the top of the hill. It's also a little misleading. In addition, wine grapes are grown locally on laterites developed from basalts in the area (which includes Columbia River Basalt, and I think also Siletz River Volcanics, though I'm not positive about the second), and in soils developed from Eocene sandstones and siltstones, equivalent to the Tyee Formation. Farther south, west of Roseburg, there are a growing number of vinyards growing in soils developed from the Lookingglass Formation (pre-Tyee sediments derived from erosion in the Klamath Mountains). So it's not incorrect, but neither does it paint a very complete picture. As I said in Monday's post, take these sorts of signs with a grain of salt.

Photo unmodified. July 10, 2012. FlashEarth location.


Dougo said...

Intriguing. I would think most of the sediment from the Missoula floods would deposit on flat ground in the valley, but most of the grapes (that I see) are planted on the hills.

Lockwood said...

You're correct in that more sediment would be deposited on the valley floor than on the hillsides. But wine grapes (I have no idea about preferences of "eating" grapes) need to be well-drained. The valley floors tend to be wetter. So while hillsides have less of the sediment, they're a preferable environment for vineyards.