Ragnarok : the age of fire and gravel

38 THE DRIFT.

Drift,* and also with a peculiar drift-clay (agile plastique bigarrée), plastic and streaked.

Professor Hartt gives a cut from which I copy the following representation of drift-clay and pebbles overlying a gneiss hillock of the Serra do Mar, Brazil :

J

Drrt-Deposits iy THE Tropics.

a, drift-clay; #7, angular fragments of quartz; c, sheet of pebbles; dd, gneiss in situ; gg, quartz and granite veins traversing the gneiss, But here is the dilemma to which the glacialists are

reduced : If an ice-sheet a mile in thickness, or eyen one

hundred feet in thickness, was necessary to produce the

Drift, and if it covered the equatorial regions of Brazil,

then there is no reason why the same climatic conditions

should not have produced the same results in Africa and

Asia ; and the result would be that the entire globe, from

pole to pole, must have rolled for days, years, or centu-

ries, wrapped in a continuous casing, mantle, or shroud of ice, under which all vegetable and animal life must have utterly perished.

* “ Geology of Brazil,” p. 488.