age. The very name Carboniferous originated in
the fact that the rocks of this geologic period contain productive coal
beds in so many parts of the world. The coal measures of Great Britain,
of Germany, Belgium, and northern France, of Russia, and the largest
coal beds of China are all of Carboniferous age. Deposits of this period
include the bulk of the world's anthracite and high-grade bituminous
coal. Coal deposits of more recent age are numerous, but in general they
have had less time in which to undergo the processes of condensation and
refinement, and hence their general grade is lower. In the western
United States there are great quantities of subbituminous coal of
Cretaceous age, and of Tertiary lignites which have locally been
converted by mountain upbuilding into bituminous and semibituminous
coals. Jurassic coals are known in many parts of the world outside of
North America, and lignites of Tertiary age are widely distributed
through Asia and Europe.

PETROLEUM

ECONOMIC FEATURES

Petroleum is second only to coal as an energy resource. The rapid
acceleration in demand from the automobile industry and in the use of
fuel oil for power seems to be limited only by the amounts of raw
material available.

=Production and reserves.= The distribution by countries of the present
annual production of petroleum, the past total production, and the
estimated reserves, is indicated in terms of percentages of the world's
total in the table[19] on the opposite page.

This table indicates the great dominance of the United States both in
present and past production of petroleum, as well as the concentration
of the industry in a few countries. In addition the United States
controls much of the Mexican production as well as production in other
parts of the world, making its total control of production at least 70
per cent. of the world's total. Notwithstanding its large domestic
production, the United States has recently consumed more oil than it
produces. Imports of crude oil are about balanced by exports of
kerosene, fuel oils, lubricants, etc. The per capita consumption of
petroleum in the United States is said to be twenty times greater than
in England. On the other hand, the remaining principal producers consume
far less than they produce, the excess being exported.

The oil from the United States, Russia, the Dutch East Indies, India,
Roumania, and Galicia is for the most part treated at refineries near
the so