The last well-marked lowering of the land took place in the Pleistocene period, when it was accompanied by glacial conditions, through which the greater part of northern England and the Midlands was covered by ice; a state of things which led directly and indirectly to the deposition of those extensive boulder clays, sands and gravels which obscure so much of the older surface of the country in all but the southern counties.
She swung the boulder up, ducking as it slapped the side of the cliff just short of the ledge and fell back to her.
The door to the underground tunnel network was hidden behind a boulder and draped with moss.
To S., and the boulder clay, especially in N.
The lowest beds of this series, which from their position may belong either to the Permian or to the upper part of the Carboniferous, have yielded no recognizable fossils; but they include a conglomerate which closely resembles the boulder bed near the base of the Talchir series in India.
A boulder lying at the narrow end was supposed to be used to close the entrance.
Covering the higher parts of the south-western Palaeozoic area in most places are rolling hills of boulder clay or stony moraines; while the lower levels are plains gently sloping toward the nearest of the Great Lakes and sheeted with silt deposited in more ancient lakes when the St Lawrence outlet was blocked with ice at the end of the glacial period.
In the south-western parts a succession of strata, described as the Brown Coal or Lignite formations, intervenes between the chalk and the boulder clay; its name is derived from the deposits of lignite which occur in it.
Evans (14,330, Hayden), in Clear Creek county, and Rosalie Peak (13575), in Park county; a little farther north, in Gilpin, Grand and Clear Creek counties, James Peak (13,283, Hayden), and, in Boulder county, Long's Peak (14,271, Hayden).
The semi-centennial of this debate was celebrated in 1908, when the Illini Chapter, Daughters of the American Revolution, caused a suitably inscribed boulder weighing 23 tons to be set up in Washington Park as a memorial.