subbituminous
- adjective
- /ˌsʌbˌbɪtʃəˈmɪnəs/
- Specialized
:
subbituminoso
- Experts estimate that roughly 54% of the reserve underground—comprising anthracite, bituminous, subbituminous, and lignite rock—is recoverable.
Examples
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The power plant utilizes subbituminous coal for its efficient burning properties.
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They range from lignite through subbituminous and bituminous to anthracite, reflecting the progressive response of individual deposits of coal to increasing heat and pressure.
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With a carbon content of 35-45%, subbituminous coal lies between lignite and bituminous in the coal classification.
How Mature
Surface Forms
Morphology
subbituminous = bituminous (transparent) = sub + bituminous
Formation is a straightforward prefixation: the productive prefix 'sub-' (meaning 'below' or 'slightly less than') attaches to the adjective 'bituminous' to indicate a lower rank.
Etymology
Subbituminous breaks into sub- ('under' or 'less than') and bituminous, from bitumen ('tar' or 'tar-like'), so the word gives a clear image of being 'below' full bituminous coal. This helps you remember it as an adjective for coal that is lower in quality than bituminous — a middle kind between the softest and the harder types of coal.