Fire Clay
Underclay, which consists of siliceous refractory clay rich in hydrous aluminium silicates, is also called fireclay. Just as not all underclays are fireclays, not all fireclays are underclays. Within Carboniferous and other coal bearing strata, fireclay quite commonly comprises many underclays. In Great Britain underclays, which are 1 to 3 metres ( 3 to 9 feet) thick, are major source of commercial fireclay deposits. The alteration of sediments by weathering, plants, and other soil processes comprising underclay resulted in the formation of vast majority of fireclay that comprises underclay.
Read more about this topic: Seatearth
Famous quotes containing the words fire and/or clay:
“Do they know they’re old,
These two who are my father and my mother
Whose fire from which I came, has now grown cold?”
—Elizabeth Jennings (b. 1926)
“And here the precious dust is layd;
Whose purely temper’d Clay was made
So fine, that it the guest betray’d.
Else the soule grew so fast within,
It broke the outward shell of sinne,
And so was hatch’d a Cherubin.”
—Thomas Carew (1589–1639)