Limb Cast in Lahar

Object/Artifact

-

Crater Rock Museum

Name/Title

Limb Cast in Lahar

Entry/Object ID

07.58.52

Description

Assemblage Zone: volcanic tuff Chemical Composition: Si O2 Crystal System: Hexagonal Description: Age: Miocene Location data: Granger Creek, Modoc County, California USA Description: Wood branch is in a fine grained volcanic tuff material which is brown to reddish the branch is shown a complete stick with simlar colors to the tuff as tanish brown to reddish brown Size of branch: diameter 1/2 " length 6 1/2" Type of Fossils Present: Plants Fracture: conchoidal Grain Size: Fine Hardness: 7 Quartz Lithofacies: Flood Basalt Luster: Glassy Occurrence: Silicified wood, which is the fossilization and/or 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 volcanic related mudflow. The organic material in the wood is then replaced by silica, other minerals determined the colors of the petrified wood. Pressure: Low-Moderate Rock Color: Medium Rock Origin: Post-depositional Rock Type: Sedimentary Specific Gravity: 2.6 Surface Process: Not apparent Streak: white Temperature: Low Texture: microcrystalline Variety: Petrified wood is hydrous microcrystalline variety of quartz that can be defined in general term of chalcedony

Collection

Petrified Wood Collection

Acquisition

Accession

07.58

Source or Donor

Petrified Wood Collection

Acquisition Method

Donation

Other Names and Numbers

Other Number

Other Number: 2007.58.52

Dimensions

Width

1/2 in

Depth

3/4 in

Length

6-1/2 in

Dimension Notes

Dimension taken at widest points

Location

Location

Display Case

PW-12

Room

Petrified Wood Room

Building

Crater Rock Museum

Category

Exhibit

Moved By

Catherine Boyd

Date

March 6, 2008