Geology Midterm Flashcards
What is Environmental Geology?
focuses on the relationships between humans and earth -drinking water -soils -resources -disaster prevention Includes all branches of Geology
What is Geology?
The study of the Earth
What branches are included in the study of Geology?
- minerology and economic geology (mineral resources)
- petrology (rock)
- sedimentology (sedimentary rocks, weathering and erosion)
- structural geology (rocks deformed, bending/breaking)
- hydrology (study of H2O)
What is Hydrology?
The study of the earth’s water systems.
- surface water
- ground (subsurface) water
What is Hydrogeology?
the science that applies geologic methods to understanding hydrologic problems.
What are the methods of Hydrogeology?
- Contour Mapping
- Cross Sections (vertical profiles and side views)
3 categories required for hydrogeological reports
- stratigraphic
- structural
- geomorphic
What is Stratigraphic Information?
deals with the physical characteristics of the rock units and their relationships to other rock units in the area.
What information does stratigraphic information include?
- nomenclature (name, group, formation member)
- age (0-4.5 byr)
- bed unit/thickness
- areal extent
- lithology (rock type: sand-sediment, sandstone-rock)
- texture(grain size, sorting, porosity, permeability)
- composition (minerals)
- erosion surfaces (unconformities)
What does Structural Information deal with?
deformatin of rock units (bending and breaking) and their resulting shapes and interrelationships.
3 categories of rock deformation/structural information
- folding (bending)
- fracturing (breaking rx)
- faulting (breaking rx)
What is Geomorphologic Information?
deals with the physical featured present on the earth’s surface (landforms)
Geomorphologic information includes info on the topics?
- erosional features (valley - river, sinkholes; sinkholes)
- depositional features (sand dunes, morraines
- petrogenic features (landscapes resulting from rx forming process that are mainly igneous in origin. lava flow, caldera)
Definition of Rock?
Condolidated or partly consolidated aggregate of 1 or more minerals, glass, or solidified organic matter.
Definition of Sediment?
loose grains or particles resulting from erosion of any pre-existing rocks.
Definition of Soil?
Allows plant growth
weathered rocks and mineral grains (sediments) that are capable of supporting plant life.
What are the rock processes?
- weathering
- lithification
- metamorphism
- melting
- crystallization
Def. of weathering?
process acting at/near the surface of the earth, which causes physical changes in and/or chemical decomposition of rock.
2 major categories of weathering?
physical and chemical weathering
What is Physical Weathering?
creates small pebbles from alrger rocks without changing their chemical composition
causes of physical weathering?
- frost wedging (freezing/thawing of h2o in rock fractures)
- abrasion (friction and impact)
- pressure release (exfoliation)
- burrowing organisms
- plant roots
What is chemical weathering?
alteration of a rock through chemical reactions between rock and atmospheric chemicals. results in formation of new minerals and dissolution of existing ones.
specific rnxs involved in chemical weathering?
- solution
- oxidation
- hydration
- hydrolosis
Solution rxn for chemical weathering?
dissolving pre-existing rx.
main acid causing solution is CO2