Earth History GEOL 2110

Midterm 1Preparation/Review

Style of Questions• Matching term w/ definition, person w/

notable accomplishment

• Short definition of concepts/processes

• Name some of multiple characteristics

REVIEW PowerPoints!!

Understand Figures in Text.

Dramatic vs. Subtle Geological Events

Be able to give examples of each

Scales of Geologic Time

Important People and their Contributions to Geological Concepts

Leonardo Da VinciNicholas Steno Georges L. BuffonA.G. Werner James HuttonCuvier & BrongniartWilliam Smith

LamarckCharles Lyell Charles DarwinGregor MendelLord KelvinHall and DanaAlfred Wegener

Geological Concepts and PrinciplesConcepts• Cosmogony•Neptunism• Plutonism• Catastrophism• Uniformitarianism• Actualism• Evolution by Natural Selection• Continental Drift and Sea-floor Spreading

Principles• Superposition• Original Horizontality• Lateral Continuity• Walther’s Law• Fossil Correlation• Index Fossils

• Based on facts, but not a statement of certainty or truth

• Testable – holds up to repeated testing• Predictive – forward and backward in time• Explains many related natural phenomenon• Deemed by a majority of scientists to have a

high probability of being correct

Know the differences between a hypothesis, theory, and paradigm

Characteristics of a Scientific Theory

On the Origin of Species

Know Darwin’s 5 principle areas of

evidence that support his theory of

Evolution by Natural Selection

Genetic Theory The Mechanism behind Evolution

Lithostratigraphic (formation) – principle of superposition

Lithodemic (intrusion) – principle of cross-cutting relationships

Biostratigraphic (biozone) – principle of fossil correlation

Magnetopolarity

Pedostratigraphic

Allostratigraphic

Categories of Stratigraphic Units (Fundamental Units) and Relative Time

Types of Unconformities

and Regional/Global Time Markers

Absolute Age Dating

Understand the meaning of:• element vs. isotope• radioactive vs. stable isotope• types of radioactive decay• parent vs. daughter isotope• decay rate of a radioactive isotope• half-life of a radioactive isotope

The Solar Nebula Theory

Seismic Imaging the Deep Earth

CompositionalLayers

PhysicalLayers

MANTLE

SiO2 – 45%

MgO – 37%

FeO – 8%

Al2O3 – 4%

CaO – 3%

others – 3%

COREFe – 86%S – 10%Ni – 4%

OCEANIC

CONTINENTAL

CRUST CRUST

SiO2 47% 56%

Al2O3 16% 18%

FeO 13% 9%

MgO 10% 3%

CaO 10% 4%

Na2O 2% 5.5%

K2O 0.7% 2.5%

TiO2 1.1% 1.3%

P2O5 0.2% 0.7%

Layers of the Earth

= chondritic meteorites

---MohorovicicDiscontinuity

Continental CrustDistillation of Ocean Crust by Partial Melting Evidence in Solid Solution

Minerals

OCEANIC

CONTINENTAL

CRUST CRUST

SiO2 47% 56%

Al2O3 16% 18%

FeO 13% 9%

MgO 10% 3%

CaO 10% 4%

Na2O 2% 5.5%

K2O 0.7% 2.5%

TiO2 1.1% 1.3%

P2O5 0.2% 0.7%

Present-day Formation of CrustA Double Distillation Process

Melting the Mantle Makes Mafic Magma – ALWAYSMelting Crust Makes Intermediate to Felsic Magma

Evidence of Plate Tectonics Fit of the continents Fossil record indicating former land

bridges Similar geologic structures Similar paleoclimates Apparent polar wandering of continents Topography of the seafloor Magnetic polarity “striping” of seafloor Distribution of volcanoes and mountains Distribution of earthquakes (Benioff zones) Young age of the seafloor Age distribution of volcanic islands

Types and Features of Plate Boundaries