The valley, here 10 m. The ridges lie in vast folds and wrinkles; and elevations in the valley are often found to be pierced by erosion. Cave Hill, ft. Campbell and others entered, thus discovering the cavern now described. The Luray cavern does not date beyond the Tertiary period, though carved from the Silurian limestone.
At some period, long subsequent to its original excavation, and after many large stalactites had grown, it was completely filled with glacial mud charged with acid, whereby the dripstone was eroded into singularly grotesque shapes. After the mud had been mostly removed by flowing water, these eroded forms remained amid the new growths. To this contrast may be ascribed some of the most striking scenes in the cave.
The many and extraordinary monuments of aqueous energy include massive columns wrenched from their place in the ceiling and prostrate on the floor; the Hollow Column, 40 ft. The stalactitic display exceeds that of any other cavern known. The old material is yellow, brown or red; and its wavy surface often shows layers like the gnarled grain of costly woods.
The new stalactites growing from the old, and made of hard carbonates that had already once been used, are usually white as snow, though often pink, blue or amber-coloured. The Empress Column is a stalagmite 35 ft. The double column, named from Professors Henry and Baird, is made of two fluted pillars side by side, the one 25 and the other 60 ft. Several stalactites in the Giant Hall exceed 50 ft.
The smaller pendants are innumerable; in the canopy above the Imperial Spring it is estimated that 40, are visible at once. The Chalcedony Cascade displays a variety of colours. The Swords of the Titans are monstrous blades, eight in number, 50 ft. Their origin and also that of certain so-called scarfs and blankets is from carbonates deposited by water trickling down a sloping and corrugated surface.
