By taking proper precautions while traveling across crevassed snow and ice, and guarding against avalanches and snow-blindness, an excursion can be made above the snow-line with as little danger as in better known and more frequented regions.
PART III.
SKETCH OF THE GEOLOGY OF THE ST. ELIAS REGION.
GENERAL FEATURES.
In the preceding narrative, many references have been made to the character of the rocks and to the geological structure of the region explored. It was not practicable during the journey to carry on detailed geological studies, but such facts as were noted are of interest, for this reason, if for no other: they relate to a country previously unknown.
My reconnoissance enabled me to determine that there are three well-defined formations in the St. Elias region. These are—
1. The sandstones and shales about Yakutat bay and westward along the foot of the mountain to Icy bay, named the Yakutat system.
2. A system of probably later date, composed of shale, conglomerate, limestone, sandstone, etc., best exposed in the cliffs of Pinnacle pass and along the northern and western borders of the Samovar hills, and named the Pinnacle system.
3. The metamorphic rocks of the main St. Elias range, called the St. Elias schist.