Alder Leaf

Object/Artifact

-

Crater Rock Museum

Name/Title

Alder Leaf

Entry/Object ID

78.57.39

Description

Chemical Composition: Si O2 Crystal System: Subhedral Description: Family: Betualceae Genus: Alnus Common name: Alder leaf Age: Eocene Location data: Eagle Point, Oregon USA Description: Fossil leaf impression in light brown sandstone, serrated edge leaf Roxy fm. Size: 2.500"x 3.00"x .250" Type of Fossils Present: Plants Fracture: conchoidal Grain Size: Fine Hardness: 7 Quartz Luster: Vitreous 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: Dark Rock Origin: Marine/Freshwater Rock Type: Sedimentary Specific Gravity: 2.6 Surface Process: Not apparent Temperature: Low Texture: fine grain Variety: Leaf fossils in this case are carbon films that remain on the bedding surfaces of fine-grained sediments. Fossilization happened after the leaves sank to the bottom of a pond or lake and were later buried by additional fine-grained sediments. With burial, the leaves were compressed and the sediment surrounding them solidified. Eventually these fine-grained sediments became shale or mudstone. When all the volatile organic material in the living leaf was pressed out, only a thin carbon residue was left in the sediment, marking the outline and veins of the leaf.

Collection

Fossil Collection

Acquisition

Accession

78.57

Source or Donor

Delmar Smith Fossil Collection

Acquisition Method

Donation

Other Names and Numbers

Other Number

Other Number: 1978.57.39

Dimensions

Width

3 in

Depth

1/4 in

Length

2-1/2 in

Dimension Notes

Dimensions taken at widest points

Location

Location

Container

Left

Drawer

2nd Shelf

Shelf

Right

Cabinet

Case #107

Wall

North Wall

Building

Mentzer Hall - Petrified Wood Room

Category

Permanent