Complex sentence: The pegmatites and country rock are part of the Spruce Pine thrust block, the highest thrust sheet of the Blue Ridge belt, the latter being part of the Tugaloo Terrane which was accreted to North America during the Taconic Orogeny.
Split into simpler sentences: The pegmatites and country rock are part of the Spruce Pine thrust block, the highest thrust sheet of the Blue Ridge belt. The latter beeing part of the Tugaloo Terrane which was accreted to North America during the Taconic Orogeny.