Trace Elements in West Virginia Coals

Ash Yield Distribution in West Virginia Coals

Chart of average ash yield, in percent on a dry whole coal basis, for each West Virginia coal bed in stratigraphic order (larger version) — Select the chart to open a larger version.

Ash Yield stratigraphic distribution in West Virginia coals shows low ash in coals of the Pocahontas through lower Kanawha Formations, then a gradual increase in average ash yields in coals from the upper Kanawha Formation through the Dunkard Group, with lower ash yield in coals of the Monongahela Group. Statistical correlations between ash yield and trace elements revealed that chromium (Cr) correlated well and other elements correlated moderately. Elements that correlated with ash yield were generally associated with clays and monazite. Rare earth elements (REE), despite their association with the detrital mineral monazite, correlated poorly with ash yield.

Spearman Correlation Coefficients (r) with Ash Yield
Element	Cr	Th	Sc	Cs	Rb	Li	V	Hf	Ce	La
r	+0.8348	+0.7912	+0.7691	+0.7623	+0.7473	+0.7393	+0.7304	+0.7058	+0.6875	+0.6738
# samples	n = 844	n = 822	n = 845	n = 781	n = 403	n = 845	n = 844	n = 509	n = 546	n = 545
Mineral association	clays and chromite	monazite	clays and phosphates	clays	clays	clays	clays	zircon	monazite	monazite
Group									REE	REE

Element	Zr	Ta	Nb	Dy	Ho	Pb	Sm	Eu	Ga	Te
r	+0.6705	+0.6576	+0.6541	+0.6462	+0.6451	+0.6440	+0.6349	+0.6177	+0.6159	+0.6078
# samples	n = 747	n = 462	n = 832	n = 78	n = 48	n = 842	n = 538	n = 540	n = 844	n = 113
Mineral association	zircon	zircon	rutile?	monazite	monazite	galena & clausthalite	monazite	monazite	clays & sulfides
Group				REE	REE		REE	REE

To request specific information from a Survey geologist, see Requests for Information.

Page content last revised: March 1, 2002