Provenance interpretation of quartz by scanning electron microscope–cathodoluminescence fabric analysis

Provenance analysis of the Paparoa and Brunner Coal Measures using integrated SEM‐cathodoluminescence and optical microscopy

“…The evaluation was limited to grains of > 100 μm in diameter in order to avoid ambiguous data due to finer grain sizes becoming smaller than the size of CL features. The different CL characteristics and features can be used to discriminate between quartz of plutonic, volcanic, and metamorphic origin, as outlined by Seyedolali et al (1997) and Bernet & Bassett (2005).…”

“…The dark featureless CL appearance is typical of quartz having undergone annealing and dynamic recrystallisation erasing all primary CL characteristics and features. These correspond with the polycrystalline and strongly undulose grains visible by optical microscopy and are typical of low to medium-grade metamorphic quartz (Seyedolali et al 1997;Bernet & Bassett 2005). Most of the quartz grains in all samples were derived from a low-grade metamorphic source with a possible minor addition from a higher grade source.…”

“…The CL of quartz, however, is weak compared to the CL of many other minerals; therefore, a high-resolution scanning electron microscope (SEM) is required in order to make features of interest visible (Sippel 1968). Single grains reveal a range of textural features that can provide provenance information, which, in large part, is unobtainable with other presently available petrographic methods (Seyedolali et al 1997;Bernet & Bassett 2005). The distinctive fabrics and features that can be observed in SEM-CL include zoning, microcracks, complex shears, planar features, and dark CL streaks and patches.…”

“…Several studies have tried to relate cathodoluminescence (CL) colour of quartz to source rock type (Zinkernagel 1978;Matter & Ramseyer 1985;Owen & Carozzi 1986;Marshall 1988;Field 1989); however, due to the overlap of colours, it is not possible to assign a particular CL colour to a specific source rock type (Owen 1991;Boggs et al 2002). A more successful application of CL to provenance analysis involves monochromatic CL, which reveals minor intracrystalline variations expressed as variations in luminescence intensity (D'Lemos et al 1997;Seyedolali et al 1997;Bernet & Bassett 2005). The CL of quartz, however, is weak compared to the CL of many other minerals; therefore, a high-resolution scanning electron microscope (SEM) is required in order to make features of interest visible (Sippel 1968).…”

Fluid-rock interaction processes in the Te Kopia geothermal field (New Zealand) revealed by SEM-CL imaging

“…The SEM-CL technique has enabled a range of geological problems to be resolved, such as sedimentary provenance (Seyedolali et al, 1997), the nature of diagenetic and pressure solution processes (Schieber et al, 2000), sandstone fracturing (Milliken and Laubach, 2000) and the character of crystallisation and deformation processes in granite (Müller et al, 2002;Sekine, 2003). SEM-CL has proven to be useful in hydrothermal alteration studies, with the potential to reveal a range of diagnostic depositional processes, including the relationship between electrum precipitation and specific fluid composition/quartz-precipitation events (Wilkinson et al, 1999), the role of temperature-pressure change in (quartz) vein formation (Rusk and Reed, 2002;Batkhishig et al, submitted for publication), quartz vein chronology (Penniston-Dorland, 2001), and occurrence of CL-distinctive hydrothermal quartz overprinting igneous quartz (Sekine, 2003).…”