Cirque A bowl shaped bedrock depression
holding and collecting ground water and snow melt.
Core Spherical center of the earth.
Crust The lighter, rocky surface of the earth. About four miles thick under the ocean and forty miles thick under the mountains.
Faceted Spur (arete) sharp crest formed between two cirques by alpine glaciation.
Front Range The row of mountains running north and south along the east side of the Rockies
Glacier A large natural accumulation of land ice that flows downhill under the force of gravity.
Hanging Valley A stream valley that has been truncated by glacial erosion so as to appear in cross section in the upper wall of a glacial trough.
Igneous rock Rock consolidated from a high temperature or molten state.
Inner Core Solid ball of iron and nickel in the center of the earth. Pressure keeps it a solid.
Mantle Rock layer about 1800 miles thick between the crust and outer core.
Mass-wasting Spontaneous downward movement of soil, regolith and bedrock by gravity; does not include water as an agent.
Mass-wasting Collective term used to explain why gravity is important in mountain erosion.
Metamorphic Rock Rock altered in physical structure or mineral composition by heat or pressure far below the earth's surface.
Molten Made liquid by heat, melted, glowing.
Orogeny Something that you will learn about
in the Eighth grade.
Also, major episode of severe tectonic deformation often
resulting in mountain building.
Outer Core Molten rock about 1400 miles thick
between the mantle and inner core.
Reach An arbitrary designation of a section
of a creek or river.
Subduction Descent of a plate so as to pass beneath and under the edge of the adjoining plate along the active margin.
Tarn A small lake occupying a rock basin in a cirque or glacial trough.
Tectonics Branch of geology relating tectonic activity and the features it produces.
Tectonic Plates Large plates floating on the Earth's mantle.
Subduction Occurs when one tectonic plate
is forced under another.