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Title: Cathodoluminescence colors in sedimentary phosphates

Conference · · Geological Society of America, Abstracts with Programs; (United States)
OSTI ID:5623574
 [1];  [2]
  1. Ohio Univ., Athens, OH (United States). Dept. of Geological Sciences
  2. Savannah River Lab., Aiken, SC (United States)

Intensity and color of cathodoluminescence (CL) in sedimentary phosphates vary considerably. Colors include: pink, orange, violet, yellow, blue, green, brown, gray, and non-luminescent. Examples analyzed for trace element activators and quenchers of CL consist of: the Tokammane Formation of Spitsbergen (CL = bright pink-orange), the Wood Canyon Formation of California (CL = bright yellow and violet), eight Pennsylvanian black shales of Kansas/Oklahoma (CL = dull violet), the Phosphoria Formation of Montana (CL = dull violet), and the Monterey Formation of California (non-luminescent). Iron quenches CL, whereas manganese is as an activator. Preliminary data on the above samples and earlier studies by other workers investigating igneous and metamorphic apatite suggest that Mn activates yellow CL. Some rare earth elements also activate CL. Either the effectiveness of REE and/or their higher abundance in phosphates allows for dull to bright CL even in the presence of several Wt.% FeO. Analysis from additional phosphates suggests that phosphates from distinct depositional/diagenetic settings may exhibit unique CL color and/or intensity. Concretionary epicontinental sea phosphates are dull violet. Nearshore, reworked phosphates luminesce brightly (yellow and/or pink-orange).

OSTI ID:
5623574
Report Number(s):
CONF-921058-; CODEN: GAAPBC
Journal Information:
Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
Country of Publication:
United States
Language:
English