Complex sentence: The lower part of this formation is found proximal to the Bronson Hill Island Arc and consists of basaltic and rhyolitic volcanic rocks along with low grade metamorphic shale and in the upper part of this formation are the youngest rocks of the Presidential Range.
Split into simpler sentences: The lower part of this formation is found proximal to the Bronson Hill Island Arc. In this section, there are basaltic and rhyolitic volcanic rocks along with low grade metamorphic shale and in the upper part of this formation are the youngest rocks of the Presidential Range.