File:Basalt breccia (Ginkgo Basalt, Middle Miocene, 15.3 to 15.6 Ma; Yaquina Head, Oregon, USA) 4.jpg
Original file (4,288 × 2,848 pixels, file size: 8.24 MB, MIME type: image/jpeg)
Captions
Captions
Summary
[edit]_4.jpg&action=edit§ion=1){kind=link}
| Description |
English: Tholeiitic basalt breccia in the Miocene of Oregon, USA.
This is a loose boulder on a gravelly marine shoreline at Yaquina Head, Oregon. Most of the clasts at the site are cobbles. The rocks here have eroded from the Ginkgo Basalt, one of many lava flows in the Miocene-aged Columbia River Flood Basalt. Flood basalts are vast outpourings of lava from one or more large fractures in the crust. This rare type of volcanism is not occurring on Earth at present, but ancient flood basalt provinces can be examined - for example, the latest Cretaceous-aged Deccan Traps of India and the latest Permian Siberian Traps of Russia. Flood lavas are also known on Mercury, Venus, and the Moon. The Ginkgo Basalt is a voluminous lava flow that originated from a feeder dike in southeastern Washington State, traveled westward about 550 kilometers, and reached the Pacific Ocean. Yaquina Head, Oregon is the distal-most occurrence of the flow. Rocks in the Ginkgo Basalt include aphanitic basalt, microporphyritic basalt, porphyritic basalt, columnar jointed basalt, pillow basalt, basaltic glass (altered & unaltered), basalt breccia, vesicular basalt, scoriaceous basalt, aa flow tops, and pahoehoe flow tops. The boulder seen here is composed of basalt breccia, which formed when the original lava flow entered the Pacific Ocean. Lava-water interactions fragmented the material into variably-shaped and variably-sized clasts. The orangish to orangish-brown matrix between the breccia's clasts is palagonite, a hydrous weathering product from basaltic glass. Provenance: Ginkgo Basalt, Frenchman Springs Member, Wanapum Basalt, Columbia River Flood Basalt Group, Middle Miocene, 15.3 to 15.6 Ma Locality: boulder on marine shoreline on the southern side of Yaquina Head, coastal Oregon, USA Site-specific info. mostly synthesized from: Ho & Cashman (1997) - Temperature constraints on the Ginkgo Flow of the Columbia River Basalt Group. Geology 25: 403-406. and Mardock (1994) - A geologic overview of Yaquina Head, Oregon. Oregon Geology 56: 27-33. See also: www.usgs.gov/observatories/cvo/columbia-river-basalt-grou... |
| Date | |
| Source | https://www.flickr.com/photos/47445767@N05/53358998404/ |
| Author | James St. John |
Licensing
[edit]_4.jpg&action=edit§ion=2){kind=link}
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
|
This image was originally posted to Flickr by James St. John at https://flickr.com/photos/47445767@N05/53358998404. It was reviewed on 28 November 2023 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 21:01, 28 November 2023 | | 4,288 × 2,848 (8.24 MB) | Ser Amantio di Nicolao (talk | contribs) | Uploaded a work by James St. John from https://www.flickr.com/photos/47445767@N05/53358998404/ with UploadWizard |
You cannot overwrite this file.
File usage on Commons
The following page uses this file:
_4.jpg&oldid=887726962){kind=link}