Many
diagenetic events can be recorded in rocks as only subtle cement zones or
corrosion surfaces on mineral faces. To better observe and characterize
these features, Buckman and others illustrate the application of Charge
Contrast Imaging (CCI) to examine diagenetic features including zoning,
twinning, fractures, and geochemical changes. Applying the technique to a
complex Cretaceous coquina carbonate and Devonian reef carbonate sample
illustrates results comparable to SEM-Cathodoluminescence (and optical-CL), but
with several advantages. 1) CCI does not suffer from image smearing, due to
latency of the red light phase within CL, a different type of charge. 2)
CCI typically is faster than SEM-CL. 3) CCI appears to highlight fabric and
cement details within regions of carbonate that appear nonluminescent under CL.
Nonetheless, as with cathodoluminescence, the specific character of CCI varies
as a function of elemental composition and lattice dislocations.
Charge contrast imaging (CCI): revealing enhanced diagenetic features of a coquina limestone by James O. Buckman, Patrick W.M.
Corbett, and Lauren Mitchell
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