PROBABILITY OF METEORITES HAVING FALLEN hon 
surface took its shape long before the beginning of our geological 
record, so that if such evidence is to be found on the earth, such lavas 
of extra-terrestrial origin must be among Archaean rocks, where the 
unraveling of the tale would be extremely difficult, or they would be 
hidden under superincumbent strata. It is to be noted also that 
even in this stage of the evolution of our solar system there remain 
bodies in order of size such as would in falling upon the surface of 
the larger spheres produce the effect which we observe in the maria; 
thus the group of asteroids between Mars and Jupiter, though gener- 
ally of far greater mass than would be required by impact to melt the 
larger of the mare fields, probably contains many bodies which in 
case of collision with our satellite would bring about the consequences 
which can be noted. At least one such mass of matter, Eros, has 
recently been discovered at no great distance from the earth." It 
is probable that in a former state of the solar system when the moon 
was assuming its present surface features, these detached masses of 
matter were more abundant than they are at present. The tendency 
would be for those near the great spheres to be drawn in upon them, 
with the result that they would become rarer near the planets and 
the larger satellites. 
Having then established the fact that giant meteors may have 
fallen on the earth and may have melted up tracts of country which 
would be deluged with lava without apparent vent or orifice from the 
interior, we can legitimately inquire whether there are any evidences 
of such occurrences on the earth’s surface ? There are many vast tracts 
of lava known on the Earth which offer tempting fields for speculation 
in this connection, such as the great lava sheets of the Snake River 
in Idaho, the Deccan traps of India and the Kapte Plains of British 
East Africa, and even the occurrence on these of small cinder cones 
and beds of ash and tuff does not necessarily prove that the material 
came from the interior of the earth, any more than the small blister 
cones on a flow of molten iron prove that the subjacent floor is riddled 
with blowholes, but I wish in this introductory statement to confine 
my remarks to one field which I know thoroughly. 
In the district of Prieska, south of the Orange River, there is a 
tN. S. Shaler, “‘A Comparison of the Features of the Earth and the Moon,” 
Smithsonian Contributions to Knowledge, XXXIV, No. 1438, Washington, 1903. 
