Core OL-92 from Owens Lake, southeast California
Macroscopic organic material from Owens Lake core
- W. Geoffrey Spaulding
- Dames & Moore, Las Vegas, NV 89119
The results of my analyses of the samples from Searles Lake core OL92-2,
identified in the field as macroscopic organic(?) material, are listed
below. The procedures for examination were those that we use to identify
macrobotanical materials from packrat middens and archaelogical contexts,
particularly those we have developed to identify carbonized wood and
charcoal. Each specimen was examined under a Wild-Heerbrugg stereo-
microscope at 60X to 500X using a combination of directed, tungsten-
halogen and diffuse tungsten light sources. Larger specimens were
fractured to reveal fresh surfaces.
In all cases there was a lack of critically diagnostic morphological
characteristics that would allow identification beyond "Plantae". These
are chiefly organized cellular patterns in cross-sections of the larger
pieces of wood, and features such as attachment scars or scales on the
smaller fragments. This may be attributable to the compression that the
specimens have undergone, and (or) to the distinctive chemical environment
of the sediments.
Results
- Sample: 812
- Depth: 207.99
- Description
- Fragments of organic material; black to very dark reddish brown; largest fragment ca. 5 x 8 mm; cellular structure obscured; organization of material varies from planar to amorphous; diagnostic surface features absent.
- Determination
- Plantae, vascular plant, possible root fragment.
- Sample: 825
- Depth: 237.57
- Description
- Fragments of organic material; black to very dark reddish brown; largest fragment ca. 4 x 3 mm; includes linear impression in clay ca. 12 x 10 mm; cellular structure obscured but organized in planar fashion; diagnostic surface features absent.
- Determination
- Plantae, possible vascular plant fragment.
- Sample: 826
- Depth: 240.82
- Description
- Single, linear fragment; black to very dark brown; ca. 12 x 1.5 mm; cellular structure not evident; diagnostic surface features absent; compressed; patterned surface (large, pseudo-reticulate) likely the result of compression and desiccation
- possible node evident on one end.
- Determination
- Plantae, vascular plant root or twig.
- Sample: 844
- Depth: 305.70
- Description
- Large, cuboid clasts; ca. 2 x 4 cm; very dark brown to reddish brown; freshly fractured exterior reveals tracheid-like linear structures that may represent cellular organization; cross-section fracture (perpendicular to above structures) shows overlapping planar structures ca. 1 x 3 mm, no rings, rays, or pores are revealed.
- Determination
- This is an enigmatic specimen. Initially determined to be inorganic, it likely represents highly compressed wood
- Plantae, vascular plant wood.
- Sample: 845
- Depth: 306.02
- Description
- Linear organic fragments (2); largest ca. 1 x 4 mm; black; cellular structure not evident; diagnostic surface features absent.
- Determination
- ?Plantae
- Sample: 848
- Depth: 308.76
- Description
- Disseminated organic fragments in clay matrix, largest 0.5 x 2 mm; black to yellowish brown; cellular structure not evident; diagnostic surface features absent.
- Determination
- Indeterminate, finely comminuted organic debris.
- Sample: 853
- Depth: 310.73
- Description
- Organic fragments (2), largest 2 x 3 mm; black to reddish brown; fracturing reveals distinct ray tracheids on radial aspect; cross-section fracture, however, reveals no rays, pores, or cellular structure; presence of rings equivocal.
- Determination
- Plantae, vascular plant wood, highly compressed.
- Sample: 854
- Depth: 312.15
- Description
- Organic fragments (2), largest 12 x 12 mm; black to reddish brown; fracturing reveals obscure ray tracheids in radial aspect; cross-section fracture fails to reveal rays, pores, or cellular structure; presence of rings equivocal.
- Determination
- Plantae, vascular plant wood, highly compressed.
- Sample: 859
- Depth: 320.34
- Description
- Dark gray, tabular fragments (4), largest 5 x 8 mm; linear structure revealed along long axis, possible tracheids; cross-section fractures reveals no structure; patterned, pseudo-reticulate surface evident on one fragment.
- Determination
- ?Plantae
U.S. Department of Interior, U.S. Geological Survey
URL of this page: https://pubs.usgs.gov/openfile/of93-683/6-organic/5-macro.html
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Last modified: 03.01.01 (krw)