
COLLINS, STEVEN L., Consultant, Martinsville, VA
The Kentucky Geological Survey provided data on 372 full bed channel
samples representing 35 coal beds of Early and Middle Pennsylvanian (Namurian
through Westphalin D) age. Principle components (PC) analysis was performed
on eight rank parameters. PC scores were regressed on sample position,
then rank anomalies were identified by mapping regression residuals (the
actual PC score minus the score estimated by regression).
The first principle component (R1) explains 43% of the variance of
the eight rank parameters. It has large positive loadings on mean maximum
vitrinite reflectance, heating value, and free swelling index; and large
negative loadings on volatile matter and elemental ratios O/C, H/C, and
S/C. (N/C has a small loading.) Regression of R1 on easting, northing,
and bed number (assigned to quantify stratigraphic position) explains 53%
of the variance of R1. R1 increases toward S43°E and downward, as calculated
from regression coefficients, consistent with the trend to greater burial
depths. Ba, Sr, Mg, and Yb also increase southeastward within 5° of
S43°E, and Na increases toward S51°E.
R1 is anomalously high immediately northwest of the Pine Mountain thrust
fault. This and the coincident directions of increase of elements expected
to be present in orogenic fluids are interpreted as being the effects of
hot orogenic fluids channeled under the Pine Mountain thrust fault as they
moved northwestward during the Alleghany orogeny.
R1 is anomalously low over the Floyd County channel and adjacent parts
of the Rome trough. Evidently thicker Lower Paleozoic shales insulated
overlying Pennsylvanian coals from escaping heat.