Petrified Wood

Object/Artifact

-

Crater Rock Museum

Name/Title

Petrified Wood

Entry/Object ID

06.58.25

Description

Assemblage Zone: sediments Chemical Composition: Si O2 Crystal System: Hexagonal Description: Family: Laurelaceae Common Name: Laurel - like Age: Eocene Location data: Payne Cliff Formation, Sams Valley, Jackson County, Oregon, USA Description: A branch like with a very knobby outer side a rusty-tan color the polished end show brown, tan, and beige colors with pits of the rusty tan color, some grain apparent. Type of Fossils Present: Plants Fracture: conchoidal Grain Size: Fine Hardness: 7 Quartz Lithofacies: nearshore environments Luster: Glassy Occurrence: Late Eocene nearshore environments are represented by conglomerates and sand of the Payne Cliffs formation exposed in a northwest trending belt along the Bear Creek Valley near Ashland. Grading upward into ash, tuffs and lava flows, the Payne also record the earliest volcanic activity of the Western Cascades and the deposition was primarilyby a extensive braided river which flowed to the north. Pressure: Moderate Rock Color: Medium Rock Origin: Post-depositional Rock Type: Sedimentary Specific Gravity: 2.6 Surface Process: Not apparent Streak: white Temperature: Low to moderate Texture: Mircrocrystalline Variety: Petrified woods here are hydrous microcrystalline variety of quartz that can be generally termed as chalcedony. Silicified wood, which is the fossilization and opalization of organic woody matter by the deposition of SiO2 in a anaerobic environment to prevent decay. This means that the wood must somehow be buried in an oxygen free enviroment, possibly in the silt-laden river or the bottom of a lake or buried by volcanic ash or related volcanic mudflow. The organic material in the wood is then replaced by silica (SiO2), other minerals determined its colors.

Collection

Petrified Wood Collection

Acquisition

Accession

06.58

Source or Donor

Petrified Wood Collection

Acquisition Method

Donation

Other Names and Numbers

Other Number

Other Number: 2006.58.25

Dimensions

Width

2-1/8 in

Depth

5-1/4 in

Length

1-1/2 in

Dimension Notes

Dimension taken at widest points

Location

Location

Container

Center

Drawer

Top Shelf

Shelf

Right

Cabinet

Case #106

Wall

North Wall

Building

Mentzer Hall - Petrified Wood Room

Category

Permanent