Earth Science Test 3

Physical, chemical, and biological laws that operate today have also operated in the past, the forces and processes that we observe shaping the Earth today, have been operating for a very long time, Geologic processes occur over very long periods of time

Uniformitarianism

Who created Uniformitarianism

James Hutton

What falls under Uniformitarianism

Key processes and Rock formation

What is an example of Uniformitarianism

The erosion of the Appalachian mountains

The non-scientific notion that the Earth was shaped by catastrophic events/disasters of a short-term nature, No scientific evidence

Catastrophism

Is very long, Earth is 4.6 billion years old, based on radiometric (absolute) dating methods as well as relative dating techniques

Geologic Time

What falls under the Geologic Time scale

Eons, Eras, Periods and Epochs

How do we know how far back things in the Solid Earth are

Absolute dating & relative dating

Pinpoints the time in history when some geologic event took place. Our understanding of radioactivity allows us to accurately determine absolute dates for rock units that represent important events in Earth’s past, uses radiometric dating techniques

Absolute dating

Rocks and structures are placed in proper sequence or order, Rocks that comprise Earth in proper chronological order, only the chronological order of events is determined, absolute ages are not determined, it is accomplished on the basis of the law of superposition

Relative dating

What do we use when we can’t use absolute dating

Relative dating

In an undeformed sequence of sedimentary rocks or lava flow, each bed is older than the one above, and younger than the one below, youngest rocks always on top when pretty horizontal

Superposition

The remains or traces of prehistoric life

Fossils

What are fossils made of and what can we use for age

Carbon, Carbon dating

Fossil organisms succeed one another in a definite and determinable order, and any time period can be recognized by its fossil content

Fossil Succession

The Earth’s surface is continuously being altered, which are the results of which kinds of processes?

Endogenic and Exogenic

Processes inside the Earth that produce flows of heat and mass (internal processes), resulting from radioactive decay, the Earth’s surface moves, warps and breaks (earthquakes & volcanoes) - tends to build surface features, inside up and Earth → atmosphere.

Endogenic Process

What can endogenic processes create

New landscape

What process was the Appalachian mountains built by

Endogenic Process

Processes at the Earth’s surface & in the atmosphere (external processes); involve the movement of air, water & ice; they shape & move the landscape - tends to reduce surface features, top down, atmosphere → earth

Exogenic Process

What do exogenic processes do

Wear down landscape

Which process are responsible for the erosion of the Appalachian Mountains in North Carolina

Exogenic Process

Crust, the mantle and Earth’s core are part of what?

Earth’s internal structure

Earth is thought to have formed from a cloud of gas & dust (a nebula) 4.6 billion years ago; this takes a lot of

Pressure & heat

Earth is hottest & densest in the ______ and coldest & least dense at _____

Center, the Top

What are Earth’s layers

Inner Core, Outer Core, Lower Mantle, Upper Mantle, Crust

Center of the Earth, Hottest & Densest, solid Iron

Inner Core

Less dense, Less hot, magnesium, molten Iron

Outer Core

Why is the Iron molten in the Outer Core

Pressure reducing

Less Dense, cooler, silicate minerals (E.g., quartz)

Lower Mantle

What is the most common family group of minerals in Earth’s Crust

Silicates

The upper mantle is divided into ___ layers; ______, _______ & ______

3, Lowermost mantle, asthenosphere & Uppermost mantle

Stiff, Rigid & Rocky

Lowermost Mantle

Plastic/Silly Putty, gives, moves, oozes

Asthenosphere

Rigid, Rocky and dense

Uppermost mantle

What does the uppermost mantle have

High Velocity Zone

Seismic waves travel quickly in uppermost mantle

High Velocity Zone

How do we know about the inside of the earth

Energy waves traveling through material

With a greater load (e.g., when mountains lie above the crust) the crust rides lower in the asthenosphere; when some of the load is removed (e.g., due to erosion) the crust rides higher in the asthenosphere - “isostatic rebound”, as you add more weight to the crust, it will sink down into the asthenosphere, less material causes lifting

Isostasy

The crust is always ______ or ______ in response to its own changing weight

Rising, Sinking

A term that characterizes the cycling that takes place at the Earth-Atmosphere interface, Surface of the Earth

The Geologic Cycle

The Earth’s crust is in a constant state of ____

Flux

What is part of the Geologic Cycle

Hydrologic Cycle, Tectonic Cycle & Rock Cycle

Transports & deposits Material

Hydrologic Cycle

Moves heat energy and material to the surface, creating crustal movement & deformation, plate tectonics create new landforms

Tectonic Cycle

Generates the three basic rock types of the Earth’s crust, how we make more Earth material

Rock cycle

Continental Crust

Layer we live on

______ crust is thicker than _______ crust

Continental, Oceanic

______ crust is denser than ______ crust

Oceanic, Continental

Crust + underlying upper mantle and the difference in density is what

Lithosphere

What are tectonic plates composed of

Crust + underlying upper mantle

Refers to large-scale movement and deformation of Earth’s Crust

Plate Tectonics

Proposed by Alfred Wegner, proposed they moved through the oceanic crust

Continental Drift

All landmasses were once united in a giant “supercontinent”

Pangaea

Where were the continents grouped around and what did it cause

Equator, the Hot Climate

Fit of the continents, fossil evidence, rock types & structure match (similar rocks & rock formations), Ancient Climates (Evidence of glacierization in Southern India), Paleomagnetism and Magnetic reversals & seafloor spreading are evidence to what?

Continental Drift

The similarity between the coastlines on opposite sides of the _______ was noted by Wegner

South Atlantic

Wegner documented cases of several __________ that had been found on different landmasses but could not have crossed the present-day oceans which separate the continents

Fossil Organisms

A “snaggle-toothed” aquatic reptile whose fossil remains are limited to South America and Southern Africa

Mesosaurus

If continents were once joined, ____ and _______ on the margins of each continent should match in terms of age and type

Rocks, Structures

The ________ trend northeastward through the Eastern US and disappear off the coast of New foundland - comparable mountains (in age & structure) are found in the _______ and _______

Appalachians, British Isles, Scandinavia

What are the mountains in the British Isles and Scandinavia called

Caledonia Mountains

What else are Ancient Climates called

Paleoclimates

Near the end of the Paleozoic era (220 - 300 million years ago), ice sheets covered extensive areas of the Southern Hemisphere - layers of glacial till were discovered in ________, _________, _______ and _______ - in present - day subtropical and tropical climates

Southern Africa, South America, Australia and India

Deep strides in the Earth

Glacial Striations

Plate slams into another, where they come together

Convergent Plate boundaries

what is an example of convergent plate boundaries

The Alps

Divergent Plate Boundary

Plates Separate

What is an example of Divergent plate boundary

Mid Atlantic Ridge/Riff

What country sits on top of the Mid Atlantic Ridge/Riff

Iceland

Close plates move laterally to one another

Transform/Lateral plate boundary

What is associated with Transform/Lateral plate boundary

Earthquakes

What could Wegner not explain

Why the continents moved

The most persuasive evidence for continental drift/plate tectonics comes from the study of the

Earth’s magnetic field

the magnetic alignment of these rocks possessing ___________ (___________) has changed with time

Fossil Magnetism (paleomagnetism)

What are the two explanations for why Paleomagnetism has changed with time

The poles had wandered, the lava flows had moved over time

The Earth’s magnetic field periodically

Reverses Polarity

Magnetometers revealed alternating strips of _______ having different intensities of _____

Seafloor, Magnetism

Low intensity strips corresponded to ______ Polarity

Reverse

High intensity strips correspond to _____ polarity

Normal

Rocks come from

Molten Rocks

What is another term for molten rock?

Magma

Rocks will reflect the

Reverse Magmatism

Oceanic Crust provides a permanent record of the

Magmatism of Earth throughout time

What else can you use to tell the history of Earth’s Magmatism

Age of rocks

Youngest rocks at ______ of ridge, older as you move towards _____

Center, Crust

When we create, we must be destroying it at ________

Subduction Zone

Oceanic & Continental Crust make up a ________ (________)

Lithosphere (Tectonic Plate)

Ridge fractures occur in what?

Weak Spots

Ridge fractures are considered what

Offset

The Ridge fractures cause _______, which means _______ activity

Shock Waves, Earthquake

Ridge Fractures lead to what kind of fault

Transform Fault

The opposite tectonic plates create the

Ridges

On the sea floor there exists an interconnected worldwide mountain chain called “mid-ocean ridges”

Sea-Floor Spreading

What do mid-ocean ridges result from

Upswelling flows of magma from hot areas in the upper mantle & asthenosphere

Are the areas where the more dense oceanic crust collides with the less dense continental crust, The oceanic crust dives beneath the continental crust

Subduction Zone

What is an example of a subduction zone

Mariana Trench

The subducted crust is _______ in the mantle, & then _______ back up through the crust via _____ & _____ to form _____________

Re-melted, migrates, fissures, cracks, volcanic mountains

Upwelling mantle forms new sea floor & the plates are spread apart

Divergent Boundaries

Sea floor spreading center & the East Pacific Rise between Nacza Plate & Pacific Plate are examples of what

Divergent Boundaries