Historical Geology Flashcards

Flashcards covering key vocabulary and concepts from the lecture notes.

Pangea

The supercontinent that existed during the late Paleozoic and early Mesozoic eras.

What happens to Pangea during the Triassic period?

Pangea begins to rift apart into smaller landmasses.

Evidence of arid climate

Red beds, evaporite deposits, and lack of coal.

What did Pangea split into during the Jurassic period?

Laurasia and Gondwana.

Orogenies during the Cretaceous period

Nevadan Orogeny and Sevier Orogeny

Dominant land organisms during the Mesozoic Era

Dinosaurs

Dominant sea organisms during the Mesozoic era

Marine reptiles like ichthyosaurs, plesiosaurs, or mosasaurs

Dominant air organisms during the Mesozoic era

Pterosaurs

Why reptiles adapted back to the sea

To take advantage of available food sources and to escape land predators

Saurischians

“lizard-hipped” dinosaurs (included theropods and sauropods)

Ornithischians

“bird-hipped” herbivorous dinosaurs

Organisms evolved from theropods

Birds

Pterosaurs

Flying reptiles that lived during the Mesozoic, but were not dinosaurs or birds

Group that evolved into birds

Theropod dinosaurs

Archaeopteryx

A transitional fossil between dinosaurs and birds; it had feathers and wings but also teeth and a bony tail

Two mass extinctions in the Mesozoic

End-Triassic and End-Cretaceous

Cause of Cretaceous mass extinction

A large asteroid impact near the Yucatán Peninsula, plus volcanic activity and climate change

Archaeopteryx

The earliest known bird; fossil shows both dinosaur and bird characteristics

Bird

A warm blooded, feathered vertebrate that evolved from theropod dinosaurs

Coal Deposits

Layers of coal formed from ancient plant matter; rare in arid climates

Evaporite

Minerals formed by evaporation of water, common in dry environments

Gondwana

The southern supercontinent (part of Pangea) that included Africa, South America, Antarctica, Austrailia, and India

Laurasia

The northern supercontinent (part of Pangea) that included North America, Europe, and Asia.

Mass Extinction

A rapid and widespread decrease in the biodiversity on Earth

Nevadan Orogeny

A mountain building event during the late Jurassic to early Cretaceous in western North America

Ornithischian

Herbivorous, “bird-hipped” dinosaurs like Triceratops and stegosaurus

Pterosaurs

Winged reptiles that flew during the Mesozoic but were not dinosaurs or birds

Sevier Orogeny

A Cretaceous mountain-building event in western North America

Theropod

A group of bipedal, mostly carnivorous dinosaurs (like T. rex) that includes the ancestors of birds

Absolute age dating

Tree rings, isotopes, radiometric dating

Rock fragments produced from weathering of preexisting rocks

Clastic sediment

Rock layers through geological time will have different fossil assemblages

Principle of Fossil Succession

Sequence of rocks in the Grand Canyon represents

transgression

Geological process that leads to transgression

Sea level rise

What happens when an atom becomes a radioactive isotope?

The atom gained or lost a neutron

When molten rock cools and solidifies

Igneous Rock

Grain shape

The roundness of the grains

Oldest dated rocks on Earth have come specifically from

Igneous rocks

Gaps or periods of missing time in the rock record

Unconformity

Inclusion

A rock fragment of an older preexisting rock that has been incorporated into a younger rock layer

Interpretation can be made from a rock that is red

It contains a lot of iron

Two main divisions of geology

Physical and historical

Sediments produced from direct deposition/precipitation from from fluids

Chemical and biochemical sediments

Carbon-14 half-life

5700 years

Percentage of the daughter product after 2 half-lives

75%

Last step in the formation of sedimentary rocks

Cementation

Scientifically accepted radiometric age of Earth

4.6 billion years

Layer of sedimentary rock

Bed

A metamorphic rock undergoes extreme heat and pressure without melting

Metamorphic

Scientific theory

Well-tested and widely accepted view that explains certain observable facts

Importance of zircons in historical geology

Mineral used to date the oldest rocks on Earth

Smallest sediment grain size

Clay

Spontaneous decay in the structure of an atom’s nucleus

Radioactivity

Sedimentary depositional environments include marine, continental, and

Transitional

Geologists who determine the chronological order of events in the rock record are

Relative age dating

What is true about regressions?

Sediment grain size coarsens (increases) upward

An igneous rock is eroded into sediment, transported to the ocean, and cemented into a new rock

Sedimentary

First step in the scientific method

Make observations

To determine which event is oldest or youngest

Principle of Cross-Cutting Relationships

A limestone rock contains coral reef fossils in life position

Deposited in shallow warm waters

The study of layered rock successions

Stratigraphy

Henri Becquerel’s contribution to science

He discovered radioactivity

Prokaryote

A single-celled organism without a nucleus

The continuous genetic adaptation of organisms or species to the environment

Evolution

At which tectonic plate boundary is crust destroyed?

Convergent plate boundary

Which type of fossil preservation shows the fossil organism as it was when it died?

Unaltered

Shield

The portion of the craton that is exposed at the Earth’s surface

Considered the last event in the formation of our solar system

Supernova

Charles Darwin and Alfred Wallace’s contribution to science

Natural selection

The presence of BIFs in the Precambrian suggested biological organisms were producing which gas?

Oxygen (O2)

Driving mechanism of tectonic plate motion

Convection

Which two conditions are generally required for an organism to become a fossil?

Rapid burial and hard parts

Which type of plate tectonic boundary produces continental rifting?

Divergent plate boundary

How did continental crust form in the early Earth?

Formed from partial melting of oceanic crust

What was the climate like at the end of the Archean?

Warm, but cool enough for glaciers to form on land

Which of the following contributed gases to the Early Archean atmosphere?

Biological life

An oceanic-oceanic convergent plate boundary will produce which of the following?

Volcanic island arc

The Precambrian Eon is subdivided into the Archean and the Eon.

Proterozoic

Which type of fossil preservation has soft tissue being preserved as thin films of carbon?

Carbonization

Which of the following is generally accepted as the oldest/first evidence of life on Earth?

Stromatolites

Life is thought to have originated in what type of environment?

Anoxic conditions (no oxygen)

Natural selection

The process whereby organisms who are better adapted to their environment tend to survive and produce more offspring

Big bang theory

Theory that describes the formation of the universe

The grouping and naming of organisms is

Taxonomy

The lithosphere is broken up into

Tectonic plates

What type of fossil shows indications of life but no actual body part?

Trace fossil

What event produced the nebula cloud that formed our solar system?

Supernova

Which of the following statements about crust is true?

Oceanic crust is more dense than continental crust

The scientifically accepted first (oldest) evidence of life is dated to

~3.5 billion years

What event caused the formation of the moon?

Impact of another planet with Earth

What is the most common type of fossil in the fossil record?

Trace fossil

What will happen at a continental-continental convergent plate boundary?

Mountain building

Extinction

The end of existence of a species or group of organisms

Father of Genetics?

Gregor Mendel

_ is when a tectonic plate is pushed beneath another tectonic plate.

Subduction

What causes variations between offspring?

All of the above

Which biological process produces oxygen?

Photosynthesis

Which of the following is NOT a Proterozoic supercontinent?

Pangea

Metazoan

A multicellular eukaryote

Nuna

A supercontinent