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Geology: Paleontology

See also Soil and Rock  

Mammoth and bison bones, grasses, sedges and microbes are visible in the frozen walls of the Permafrost Tunnel, offering a unique window into a time period that was vastly different from today.

 
  Bones Return to Top  

Below are images of some of the bones found in the Permafrost Tunnel. These bones are from an extinct bison (Bison priscus) found in the Tunnel. These bones are found within 15 meters of the entrance. Bison priscus was a cousin to the buffalo currently found in the United States (Bison bison), but had longer horns. All of the bones in the tunnel decomposed at or near the surface and were washed downstream (by Goldstream Creek) into the position were they are found today.
Jawbone Jawbone: Estimated 14,500 years old. This juvenile jawbone measures 45 centimeters and includes molars for chewing cud. The incisors for nipping off grass blades snapped off (right end) before the jaw was deposited. Scientists carved a small sample off the bottom edge for carbon dating and DNA testing.
Femur Femur: Estimated 14,000 years old. Five inches of bison priscus femur (thigh) protrudes from the right wall three feet from the floor. A small sample was removed to carbon date the bone and verify its DNA pattern.
Scapula Scapula: Estimated 14,000 years old. Humans have a flat, triangular shoulder blade, compared to the thicker, more elongated scapula found in cows and buffalo. This bone, from the Bison priscus must have supported more weight (approximately 1/2 ton) but didn't need need to provide much range of motion for their daily activities of grazing and eating grass. This scapula lies directly above the femur (pictured above) about 5 feet from the floor.
Tibia Tibia: Estimated 14,000 years old. This tibia includes a flange (left end of bone) where the fibula snapped off before deposition. These two bones frequently fuse together in buffalo (and probably did the same in Bison priscus) to help support the animal's large mass (although, this reduces the animal's ability to rotate their legs). Note the cup shape on the right end of the bone where the hoof would connect.
Broken Femur Broken Femur: This bone is probably a femur that snapped in two. This image shows the interior of the bone (the "spongy bone"") that produced the marrow and red blood cells.
Cervical Vertebrae Cervical Vertebrae: Estimated 14,000 years old, this cervical vertebrae is closest to the entryway and protrudes about four feet from the tunnel floor. Note the small cup shape on the bottom that allows room for the cartilage disk to cushion the bones from grinding against each other.
Lumbar Vertebrae Lumbar Vertebrae: Estimated 14,500 years old, this lumbar vertebrae is darker, thicker and more heavily calcified than the cervical vertebrae. Lumbar vertebrae are located lower in the spine and carry more weight. Note the small broken rib protruding below the vertebrae. Their proximity does not mean that they are from the same animal.

 
  Vegetation Return to Top  

Sedge Sedge is also common in wet lowlands. The image to the right shows an example of sedge in found in the tunnel carbon-dated at 32,000 years old. It is an exceptional specimen because still contains chlorophyll making it green. Chlorophyll is a relatively fragile molecule (think about how long grass clippings stay green in a mulch pile.) In this case, the sedge collapsed into a melting ice wedge in late summer and froze before it could rot. The ice wedge was covered with enough collapsing soil that it never thawed out again—giving us a preserved green specimen.

Also found in the permafrost tunnel are evidence of willow shrubs (common in wet lowlands), and birch and alder trees. Surprisingly, no evidence of black spruce, a very common conifer in Alaska today, was found in the tunnel. It turns out black spruce is a relative newcomer to Alaska, arriving only in the last last 7,000 to 9,000 years, but the youngest part of the permafrost tunnel, the entryway ceiling, is over 10,000 years old.

 
  Macrobiotics Return to Top  
 
Jawbone The tunnel is also a great resource for ancient Alaskan pollens, diatoms, and other macrobiotics. The snail pictured to the left measures one centimeter in length.
Lumbar Vertebrae Bacteria Frozen in Time: In 2000, Dr. Richard Hoover of NASA melted ice samples from a golden brown layer of permafrost that he speculated was at the base of an ancient pond. He was looking for diatoms (a form of algae that often settle in lake bottoms). What he found in his microscope, as the ice melted, was a form of bacteria (image left) coming back to life after 30,000 years of being frozen. Now named Carnobacterium pleistocenium this bacteria is being called an example that life could exist, suspended in permafrost, on other planets.

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