MINING GEOLOGY 
89 
The somewhat phenomenal growth which Kentucky made dur¬ 
ing the last decade in coal production was due mainly to the dis¬ 
covery and development of new, thick, and marketable coals in 
the eastern counties. Thus, Letcher County entered the list of 
counties as producing commercial coal in 1912; and in four years 
headed the list and outrivaled her sister county. Pike, the then 
leader, which began producing commercial coal in 1904. Pike 
County returned to first place in 1917, and has led the state down 
to the present time. 
Harlan County saw a similar development. Kentucky’s out¬ 
put of coke was trebled the second year that Harlan began pro¬ 
ducing commercial coal. The third year after Harlan County 
entered the lists, the coke production for the State increased ten¬ 
fold. 
The Western coal-field increased its production greatly recently 
through the consolidation of operations and by the introduction 
of modern methods of stripping shallow coals with the steam- 
shovel. War demands stimulated coal output greatly in Ken¬ 
tucky. A reversion to normal conditions bids fair to maintain the 
figure, and the end is not yet in sight. 
The number of labor strikes in the coal-fields of Kentucky is 
notably low, indicating in general not only good labor conditions 
but also conditions of good and farseeing management. To these 
excellent operative factors must be added that of a vast tonnage 
not only unmined but still largely unopened and even unsurveyed, 
which facts when taken together reasonably assure Kentucky’s 
future position as a great national fuel asset. 
JiLLSON. 
Antiquity of Chupadera Mesa Iron Deposits. If ever there 
were iron deposits displaying undoubtable geological clue to their 
genesis and geological history they are those exposed in central 
New Mexico, recently uncovered on that broad plateau plain 
known as the Chupadera Mesa. By the miners of this region these 
bodies of magnetic iron ore are commonly regarded either igneous 
segregations or contact deposits, mainly for the reason, no doubt, 
that they hug extensive dike rocks. The prospectors’ opinions, 
wholly unsupported by scientific or geological evidences however, 
manifestly color all other interpretations. Even the latest formal 
