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DOCUMENTATION_FORMAT: PLANT
SAMPLE_ID: CA01-CECU-1
PLANT_TYPE: California chaparral shrub
PLANT: Buckbrush
LATIN_NAME: Ceanothus cuneatus (Hook.) Nutt.
COLLECTION_LOCALITY: Garden Valley area, in El Dorado county, approximately 60 km northeast of Sacramento, California
COLLECTION_LATITUDE: 38.842405 deg. N
COLLECTION_LONGITUDE: 120.884117 deg. W
DATUM: WGS-84
ORIGINAL_DONOR: Raymond F. Kokaly, USGS
SAMPLE_DESCRIPTION:
This spectrum is the average reflectance of 9 field measurements of a buckbrush bush (Ceanothus cuneatus). The measurements were made at 11:30 am local time on September 6, 2001. These spectra were made using an ASD FullRange spectrometer (model 653) in reflectance mode, relative to a Spectralon reference panel. The bare fiber of the spectrometer was used to measure the reflectance spectra of the bush. The leaves were green and small (1 to 2 cm in length) and sparse along the lengths of the spiny, light gray twigs. Some remnant flower pedestals (dried and brown) were present. The tips of the twigs/stems on the bush were brownish-red. On average the field of view of the spectrometer included 30% green leaves, 25% branches and stems, 35% shadows, and 10% background litter with little soil exposed. The fiber optic cable was pointed at nadir and held 30 cm above the top of the plant and moved around during the measurement. The instrument was programmed to record 6 second averages of reflectance (thus, each recorded spectrum was an average of 60 individual measurements). An average spectrum was computed from the recorded measurements and converted to absolute reflectance by multiplying by the reflectance spectrum of the Spectralon reference panel. Other samples of buckbrush were also measured, near this one, and are included in this spectral library, sample names: CA01-CECU-2 and CA01-CECU-3.
This spectrum was used in the following publication:
Swayze, G.A., Kokaly, R.F., Higgins, C.T., Clinkenbeard, J.P., Clark, R.N., Lowers, H.A, Sutley, and S.J., 2009,
Mapping potentially asbestos-bearing rocks using imaging spectroscopy, Geology Volume 37, pages 763-766.
http://dx.doi.org/10.1130/G30114A.1
IMAGE_OF_SAMPLE:
END_SAMPLE_DESCRIPTION.
COMPOSITIONAL_ANALYSIS_TYPE: None
COMPOSITION_DISCUSSION:
END_COMPOSITION_DISCUSSION.
TRACE_ELEMENT_ANALYSIS:
TRACE_ELEMENT_DISCUSSION:
END_TRACE_ELEMENT_DISCUSSION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1a2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns