| Description |
The majority of the large metalliferous mines of Montana are closely associated with the Boulder batholith, and yet no report of any extent has been made on the intrusion as a whole. Several small districts have been thoroughly studied and reported, but the great distances which separate those areas make the reports in question of little value in giving any idea of the batholith in its entirety. From personal experience the writers have come to feel that the absence of any fairly complete description of the batholith, as a whole, is a serious hinderance to any study that might be made of local mining districts. And it is with the intention of removing this handicap to as great an extent as lies in our power that we take up this work. Our interest in the district is due to several causes. First, is its tremendous richness for from the mines an this batholith has come more than two thirds of the wealth that places Montana ahead of all her sister states in value of metals produced. Then too, in this great mass of intrusive rocks are present the field examples of those great dynamical and structural problems which have seldom failed to excite a desire for a further knowledge. |
