Local Geology
Dark gray fissile rock unit composing much of Durango's scenic backdrop (Perins Peak/Hogsback).
What is the Mancos Shale?
A typical granite is dominantly composed of what two minerals?
What is alkali feldspar and quartz?
An area in the Earth's crust that accommodates stress/motion of rocks.
What are faults?
This rock is the product of contact metamorphism of a quartz sandstone.
What is quartzite?
Famous supercontinent assembled during the late Paleozoic.
What is Pangea?
Rocks in the Animas River Valley dip (or slope) in this direction.
Common mafic-ultramafic mineral with a gem variety of peridot.
What is Olivine?
The Basin and Range Province of Western North America is dominated by this fault type.
What are normal faults?
This process is the transformation from loose sediments into rock.
What is lithification?
Western North America during much of the Cretaceous inundated by.
What is the Western Interior Seaway?
The La Plata Mountains are made of which of the three main rock types (igneous/sedimentary/metamorphic).
Colorado's state mineral, gemstone, and rock.
What is rhodochrosite, aquamarine, Yule Marble?
"Striped" pattern in metamorphic rocks resulting from ductile deformation.
What is foliation?
Statement of Steno's Law of Superposition.
What is the idea of younger materials deposited atop older materials?
Largest mass extinction in the Earth's History.
What is the Permian-Triassic Extinction?
The San Juan Mountains trace their origin to this time span.
What is the Eocene to Oligocene (40-28Ma)?
Most common polymetallic sulfide constituents of quartz veins mined in the San Juan Mountains.
What is pyrite, galena, sphalerite, chalcopyrite?
Volcanoes of the Pacific Northwest are part of this subduction-related system.
What is the Cascadia Subduction Zone/Cascade Volcanic Arc?
Process of repeated avalanches on the "lee" or "downstream" side of dunes creates this sedimentary structure.
What is crossbedding?
"Cool" hypothesis for explaining the global Great Unconformity.
What is Snowball Earth?
Geologic unit famously hosting caves and crystal-lined solution cavities throughout the San Juan Mountains.
What is the Mississippian Leadville Limestone?
Uniaxial negative mineral often mined from pegmatites as a gemstone.
What is tourmaline?
Define strain in the context of structural geology.
What is a change in size or shape in response to imposed stresses.
Isotope pair typically used to date zircons in clastic sedimentary rocks.
What is U-Pb?
Theorized to have formed the Earth's moon.
What is Theia protoplanet collision?