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Saturday, January 25, 2014

National City Mastodon Butchering Site- State Route 34 Paleontological Mitigation Program, Final Report, Prepared for Caltrans District 11, July 28, 1995


 


State Route 34 Paleontological Mitigation Program, Final Report, Prepared for Caltrans District 11, July 28, 1995. Thomas Demere, Richard Cerutti and Paul Majors, Department of Paleontology, San Diego Natural History Museum.

“…Radiometric dating of ivory and soil carbonate from the quarry yielded dates of 335+/-35Ka (thousands of years before present) and 196+/-15Ka respectively…”

“…Overall, the collecting localities and their contained fossil remains represent the most significant Pleistocene paleontological discoveries yet known from coastal San Diego County…”

“…Many bones were fragmentary and displayed distinct types of breakage. . . Of special note was the discovery of both isolated femur heads side by-side, one with its articular surface up (#252) and one with its articular surface down (#258)…”

“…There was no articulation of mastodon elements and no anatomical trend to their placement in quarry…”

“…Adjacent to the femur heads lay fragments of ribs, one of which (#253) was found lying directly on a plutonic cobble (#254). Also found in this concentration was a large piece of a long bone shaft displaying distinct spiral fracturing. In units J4 and K4 a large, sharply fractured piece of long bone (#340) was found with a distinct impact scar on its internal surface. This fractured bone occurs adjacent to two complete thoracic vertebrae and two complete ribs…”

“…In contrast to the disarticulated condition of the mastodon remains was the discovery of a partially articulated skeleton…American Coot…The entire pectoral region including right and left wings and coracoids was found still articulated with the sternum. Articulated portions of the legs were also recovered…”

“…Several rodent skulls recovered from Bed E were found with articulated lower jaws…”

“…In Unit B2 the distal 70 cm of a tusk (#56) was found distal end down in an upright orientation (62°-64° dip), concave portion of curvature to the south. The proximal end of the tusk had been removed by the backhoe at the level of Bed E . . . The tusk extended from Bed E through Bed D, reaching 65 cm into Bed C . . .Coarse sand from Bed D was found as an infilling alongside the tusk some 40 cm into Bed C…”

“…In one case, portions of a single mastodon molar were found scattered over three units…”

“…The boulders and rock fragments recovered from Bed E consisted of fine-grained metavolcanic rocks (andesite) and coarse-grained plutonic rocks (pegmatite)…”

“…The more intact larger rocks displayed smoothly rounded surfaces, indicative of stream transport. Many of the smaller rock fragments had sharp, angular edges that lacked signs of abrasion…”

“…There are seven instances in which rock fragments and/ or boulders found separated in the quarry were able to be reassembled after laboratory preparation…” 

 
Mike Waters’ late colleague, Rob Bonnichsen, participated in the fieldwork at the National City Mastodon Butchering Site (6). See page 3 of the site report.


Deméré et al., State Route 54 Paleontological Mitigation Program, Final Report, Prepared for Caltrans, District  11, open file report, 52 plus appendices (1995)

http://bandstex.globat.com/Caltrans_mastodon_1995.pdf 

 












Charlie Hatchett

PreClovis Artifacts from Central Texas

http://www.pre-clovis.com
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