White siltstone composed of a fine grained quartz (<= 90um) and a matrix of 
muscovite/micaceous minerals within a foliated lenticular fabric. Grain size 
analysis of crushed quarry debris indicates the fine grained nature of the 
siltstone (48 % finer than 74 um, 32% finer than 20 um).  

Clay mineralogy : XRD indicates the presence of kaolinite/chlorite and 
muscovite/illite minerals. Fieldspec and PIMA SWIR spectra of rock/quarry debris 
also shows the presence of kaolinite, montmorillonite, muscovite/illite, gypsum, 
calcite and possible chlorite. 

Coarse mineralogy : Petrology of the fresh siltstone showed approximately 95 % 
fine grained quartz. XRF-normative analysis of crushed quarry debris indicates 
62% quartz, 22% muscovite/illite, 3% kaolinite, 2% calcite, 8% gypsum.

Spectral Description: The FTIR spectrum for this quarry sample clearly shows the 
quartz spectral features at 8.2, 8.625 and 12.3 um. The FTIR spectrum also shows 
a prominent spectral peak at 6.447 um and subdued 12.4 - 12.8 um doublet 
feature, typical of fine grained quartz. The subdued nature of the longer 
wavelength reststrahlen quartz band for the quarry debris can possibly be 
attributed to a coating of absorbing fine kaolinite and quartz grains adhered to 
larger quartz grains. The presence of kaolinite is also apparent from a FTIR 
peak at 9.9 um and a trough at 9.0 um. A broad spectral rise for both quarry 
samples at 11.3 - 11.6 um is possibly attributable to the presence of calcite. 
The broadened quartz reststrahlen peak at 9.0 - 9.6 um is probably caused by the 
presence of clay minerals.


