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2. E.g. Basin and Range Province of Nevada, Utah, Eastern CA, SE Oregon, AZ.
3. Often associated with precursory volcanic activity.
C. Upwarped Mountains
1. produced in assoication with broad arching or upwarping of the crust or of
vertical uplift along high angle reverse faults.
2. e.g. Black Hills of S.D. and Adirondack Mtns. of NY e.g. of broad arching or
uplift
3. Rocky Mtns of CO, NM result of vertical uplift, leave front range in which
mantle of sed. rocks are tilted upward along high angle faults.
a. results in hogbacks or flat-irons of front range
V. MOUNTAIN BUILDING: THE PROCESS OF MOUNTAIN CONSTRUCTION
A. Processes of Mountain Building have been studied in a variety of mountainous
terrains around the world, some of which are relatively recent developments (Cordillera, Island
arcs of S. Pacific, Himalayas), some of which are older remnants of orogenic events (e.g.
Appalachian Mtns., Ural Mtns of USSR)
B. Charcter of Mountain Belts
1. often include parallel ridges of folded and faulted sedimentary and volcanic
rocks
a. sedimentary rocks: sed. rx. often included in Mtn-bldg. events were
deposited long before the Mtn event, and were subsequently caught up in the deformation
process.
2. zones of metamorphosed rock bodies
3. igneous intrusions
C. Orogenesis at Subduction Zones
TIME AND GEOLOGY
I. Law of Uniformitarianism- the present is the key to the past. A basic premise of the
study of geology first presented by Scottish Geologist James Hutton in the 1700's.
The law states that the geological processes operating at present, have been operating the
same throughout geologic history. With many pieces of the geologic puzzle missing, we have to
assume that the processes have been operating the same throughout geologic time.
Historical Geology is the study of earth history. For geologists to adequately understand the
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