Geology Test 2-Earth Processes – Flashcards

-At a particular point, the nature of processes acting on the Earth's surface are strongly influenced by endogenic processes. -Those associated to the energy of the Earth's interior -Associated to plate tectonics and orogeny -Define rock types and topography

Varying composition, textures, and vulnerabilities to surface processes

Geologic setting->Sculptured by Surface Processes->Characteristic Landform

A distinctive pattern, product, or characteristic by which someone or something can be identified

Scars, deposits, and topography

-Mass Wasting, Surface Erosion, Fluvial, Shoreline, and Aeolian -All form characteristic landform and sedimentary rocks

-External processes occurring at or neat the Earth's surface -Powered by the energy from the sun and gravity -Basic component of the rock cycle

-The physical breakdown (disintegration) and chemical alteration (decomposition) of rocks at or near the Earth's surface -The response of Earth's material being exposed to a new environment different from where they were originally created

Mechanical Chemical

-The physical breakdown of rocks into smaller pieces -Increases the amount of surface area where chemical weathering can occur

Frost Wedging Salt Crystal Growth Exfoliation (sheeting) Biological

-Water can expand by 9% when it freezes -When water inside rock crevices freezes it can exert a force that breaks the rock -When it occurs at a cliff face, it creates a deposit called talus slope

-Common on rocky shorelines -Sea spray or salty groundwater penetrates rock crevices and pores -Salt crystals form and grow, enlarging the pores until they break (brittle deformation)

-Common when large igneous plutons are exposed to the surface -Slabs break off -Reduction in lithostatic pressure -Landform is an 'exfoliation zone

-Plant roots searching for water wedge into rock crevices -Burrowing animals help break down the rock by moving loose material to the surface

-Chemical transformation of rock into on or more new compounds -Can create opportunities for mechanical weathering processes to operate -Produces new substances that tend to be in a more stable state within their surroundings that in their unweathered condition -Dissolved materials in water (rainfall) are a trigger to chemical weathering -Rain picks up CO2 in the air and organic compounds in the vegetations and becomes acidic meaning it reacts. Rocks are dissolved.

Spheroidal Weathering

Water along cracks chemically weathers rocks following a spherical shape

-Rock Characteristics -Climate

-Some minerals are more reactive than others -Physical features (texture, density of cracks) can control the rate and extent of water penetration into rocks

Controls frequency of freeze-thaw conditions (frost wedging), controls type and abundance of vegetation (root wedging), abundance of moisture and temperature which when abundant and warm promote chemical reactions

-More resistant rocks stick above surrounding terrain -Easily erodible rocks erode faster and produce low spots