MarkDidier and Baarb,
Thanks,...good suggestions. I live in the Owens Valley
, just to the east of the crest of the Sierra Nevada, in California,...so, naturally, I was thinking in terms of describing the Sierra. It's probably the best studied major batholith in the world,...and, so, the literature is vast. I'll probably just present an overview,...since, anything more would be a mind-numbing overkill.
But, the essential paradigm is: about 200 million to 100 million years ago a trench existed off of what would become the Californian coast. The Farallon plate
was subducted over a period of over 100 million years, and. an island arc
emerged and was accreted to the North American continent. The Sierran Nevadab Batholith then was intruded from the depths as a consequence of this plate subduction.
...And,...Scott,...the Colorado Plateau was an inspiration for me too. I did some travelling one summer from the Sangre de Cristo Mountains near Santa Fe, New Mexico to the San Juan Mountains, of Southern Colorado (Telluride/Durango area). Fantastic !!!