Laser microprobe analysis of trace element composition in quartz silt for source rock determination
- Univ. of Pittsburgh, PA (United States). Dept. of Geology
- Univ. of Pittsburgh, PA (United States). Dept. of Geology RJ Lee Group, Monroeville, PA (United States)
Provenance and source rock determination is one of the major problems that sedimentologists address. Undulatory extinction and polycrystallinity have been used to extract provenance information from sand-size quartz, but these are less informative with silt-size quartz. It is known that quartz contains trace elements which might be related to source rock. The purpose of this study was first to determine if the laser microprobe can detect trace elements in natural quartz, and second to determine if the quartz released from different crystalline source rocks have sufficiently different trace element composition to differentiate them. Ten silt samples from 5 source rocks (Pedlar Formation, Lovingston Fm. granitic gneiss, Lovingston Fm. mylonitic gneiss, an unnamed Precambrian layered granulite gneiss, and cataclastic rocks) of the Greenfield and Sherando Quadrangles of Virginia. Forty quartz grains for each sample were analyzed. The laser microprobe was able to detect Na, Mg, Al, K, Ca, Ti, Mn and Fe. Al and Fe were the most commonly observed trace element. The trace element content within quartz from each individual source was not uniform; one or more trace elements were detected in some grains while none were detected in others. In addition, there was overlap in the trace element distribution among the sources and quartz cannot be uniquely assigned to a source rock based on trace element composition. However, quartz from the Pedlar Fm. contains Al less frequently and quartz from the cataclastics and the layered granulite gneiss contains Fe more frequently than does quartz from the other sources. These results put some constraints on source rock interpretation and the analysis of more dissimilar rocks may show greater differences.
- OSTI ID:
- 6135508
- 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
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
QUARTZ
MULTI-ELEMENT ANALYSIS
SOURCE ROCKS
CHEMICAL ANALYSIS
ALUMINIUM
CALCIUM
IRON
LASERS
MAGNESIUM
MANGANESE
POTASSIUM
SEDIMENTARY BASINS
SODIUM
TITANIUM
TRACE AMOUNTS
VIRGINIA
ALKALI METALS
ALKALINE EARTH METALS
DEVELOPED COUNTRIES
ELEMENTS
GEOLOGIC STRUCTURES
METALS
MINERALS
NORTH AMERICA
OXIDE MINERALS
TRANSITION ELEMENTS
USA
580000* - Geosciences
400102 - Chemical & Spectral Procedures