10 
HOLGATE : CARBONIFEROUS STRATA OF LEEDS. 
Open quarries are worked to the south and east of the town, 
some of which are 70 feet in depth. As they are always being- 
worked they constantly present a fresh face for study. Commencing 
on the east side of the town some feet below the base of the work- 
able coal seam known as the "Better Bed" ^the one lying next 
above the Elland Flagstone), and going from quarry to quarry, 
we may follow in an upward direction an almost uninterrupted 
succession of measures as they are laid bare through a vertical 
depth of upwards of 300 feet. This is owing to the dip of the 
strata, the quarries being at an almost equal elevation above the 
sea. The conditions have been very varied under which these 300 
feet of strata were laid down. There are few geological facts which 
are not here illustrated : land deposits and deposits made in almost 
still water or left by rapidly flowing streams, also plant and animal 
remains in immense quantities, though as far as can be made out of 
not many different kinds ; an examination however leads us to suspect 
that the varieties have been much more numerous, the traces having 
been obliterated or altered by the numerous changes that have 
taken place during the immense period of time that has elapsed 
since their deposition, so that none but the most indestructible 
forms are preserved, unless they are embedded in modules. The 
land has been repeatedly elevated and depressed, the chemical action 
of water permeating through the mass, here taking up elements in 
solution and there depositing them under different conditions, or 
exchanging them for other elements has also had an important share 
in the change. To speak of all the phases of these changes would be 
a great though an interesting task. I must content myself with 
giving a table briefly describing the different kinds of strata, and 
will only enlarge upon a few typical ones. 
"Waters. — There are many soluble salts present in the shales 
and binds producing mineral waters of different kinds. The .sand- 
stones allow the water to pass freely through them with but little 
change, and serve only as a mode of conveyance from one stratum 
of shale to another, so that they do not retain the salts. We find 
different kinds of mineral waters at different horizons ; some are 
medicinal, such as that known as the Holbeck Spa Water : others 
