Name/Title
Limb CastEntry/Object ID
78.58.128Description
Assemblage Zone: tropical, subtropical
Chemical Composition: Si O2
Crystal System: Hexagonal
Description: Age: Oligocene
Location data: Clarno Formation, Hampton Butte, Oregon, USA
Description: Wood has been brecciated in numerous places. Polished side shows woods in browns, reds, greens, tans, and greys. Numerous cracks are blue-grey agate filled, some crystalline in cracks. Numerous surface cracks are visible. Wood has been cut with the grain. Some partilly open crystalline areas. Delmar estimate this specimen to be 40 million years old. Probably from the oligocene epoch, (tertiary period, cenozoic)
Size: 8 3/4" x 12 3/8"x 1.00"
Type of Fossils Present: Plants
Fracture: conchoidal
Grain Size: Fine
Hardness: 7 Quartz
Lithofacies: Volcaniclastic
Luster: Glassy
Occurrence: 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 volcanic related mudflow. The organic material is then replaced by (SiO2) silica, other minerals determined its colors.
Pressure: Low-Moderate
Rock Color: Medium
Rock Origin: Post-depositional
Rock Type: Sedimentary
Specific Gravity: 2.6
Surface Process: Not apparent
Temperature: Low
Texture: microcrtystalline
Variety: Petrified woods ar hydrous microcrystalline varieties of quartz that can be generally termed as chalcedony .Collection
Petrified Wood CollectionAcquisition
Accession
78.58Source or Donor
Delmar Smith Petrified Wood CollectionAcquisition Method
DonationOther Names and Numbers
Other Number
Other Number: 1978.58.128Dimensions
Width
8-3/4 inDepth
1 inLength
12-3/8 inDimension Notes
Dimensions taken at widest pointsLocation
Location
Display Case
PW-13Room
Petrified Wood RoomBuilding
Crater Rock MuseumCategory
ExhibitDate
October 16, 2025Notes
Location added when performing inventory
