Week One

Intro to G 101/202

What is Geology?

Physical Geology

The study of the physical products and processes that occur on earth

Historical Geology

The study of the Earth’s history and evolution

How do geologists “study” the earth?

Rocks and minerals

Minerals:

Groupings of minerals form rocks

Important economic resource

Important in understanding conditions of rock formation.

Rocks:

Three types: Igneous, Metamorphic, Sedimentary

Igneous: formed from molten rock (magma)

Metamorphic: formed as heat and/or pressure is applied to already existing rocks

Sedimentary: created by lithifying sediments or through precipitation

Bound together through the rock cycle

Mapping and observation of geologic structures

Faults, Mountains, Folded rocks etc…

Often use geologic maps to record information

Observation of surface processes

Rivers, glaciers, desert processes, groundwater etc…

Geologist use processes we see today to interpret the geologic past

Geologic Time

Considered “deep time”

Earth is scientifically measured at 4.6 billion years in age

Using methods of radioactive decay

Earth’s history is divided into Eons, Eras, Periods, and Epochs Geologic time table

Each boundary on the table was decided on based on relative dating techniques and/or fossil extinctions

Dates were added later (early 1900’s)

What is Geomorphology?

The study of earth’s surface features…how they form and how they change

What are the primary factors responsible for changing the surface features on earth?

Water

Chemically alters material

Physically moves material

Water is the primary agent on earth that causes changes in the earth’s surface

Wind

Causes abrasion

Physically moves material

Gravity

A force to move material

Plate tectonics (more next term)

Creates volcanic mountains and fault blocked mountains

Important processes/systems on the earth that shape it’s surface.

Desert systems

River systems

Mass wasting (land sliding)

Glacial systems

Groundwater systems

Beach and Ocean systems