You are searching for fossils in the surface bedrock in Elmira, New York. Why are you unlikely to find dinosaur fossils at this location?
Because the bedrock there is Devonian and was transported there way after the extinction of the dinosaurs.
Rocks containing fossils of the earliest land plants could most likely be found in New York State bedrock near
1) Syracuse
2) Oswego
3) Ithaca
4) Old Forge
1) Syracuse
Approximately how long ago were the Taconic Mountains uplifted?
470 million years ago
What is the estimated age of Earth as a planet in millions of years?
4600 million years old
The ___________ supereon occured between 4600 and 542 million years ago.
Precambrian
What type of lifeforms existed in the Precambrian Supereon?
single cell organisms.
What is the term for rocky mounds of mineral structures secreted by bacteria?
Stromatolites
What was the major breakthrough of the Proterozoic eon?
The major breakthrough was that until then, the Atmosphere was free of oxygen.
How many billion years ago did the first sexually reproducing organisms occur on earth, and in what supereon was this?
1.3 billion years ago, Middle Precambrian Supereon
In what eon did the largest change in life occur?
The phanerozoic era
Within both ________s, there are several different _________s, and within those, there are several _______s, the unit of time below that is the ________.
supereon, eon, era, period
What is the largest unit of time?
An eon
Dinosaurs existed _____ to _____ million years ago.
68 to 65 million years ago
Brontosaurus, stegosaurus, spereodactyl, and tyrannosaurus were all reptiles of what era?
the MESOZOIC ERA
There are ___ eras in the Phanerozoic Eon.
3
The Triassic, Jurassic and Cretaceous are all which type of time unit?
a PERIOD
What period started at around 206 million years ago?
The Triassic Period
How many millions of years ago did the Cretaceous Period end?
144 million years ago
What is the term for the time unit that is a subdivision of a PERIOD?
an EPOCH
The Late Cretaceous __________ occured from ___ to ___ million years ago.
EPOCH, 99 million years ago, 66 million years ago
Which era are we currently in?
The Cenozoic Era
Earth's first coral reefs formed in the ___________ period.
ORCOVIDIAN
The appearance of the dinosaurs did not occur until the ____ epoch of the _________ period
late, triassic
We are currently living in the ________ epoch of the __________ period.
HOLOCENE, QUARTERNARY
The earliest grasses on Earth begun to grow in the O___________ epoch of the P__________ era.
OLGIOCENE, PALEOCENE
Gaps in the rock record are known as _____________.
UNCONFORMITIES
In the ________ period, the earliest fishes formed, but there were no plants, and life only existed in the ocean.
CAMBRIAN
A mountain forming event where large/vast pieces of land are uplifted is called a(n) ________.
ORGENY
What is a main cause of large plateaus?
OROGENYS
What is an epoch?
A subdivision of a period.
Which epoch lasted from 99 million years ago to 65 million years ago?
The LATE CRETACEOUS
Who theorized that the continents were once together but are now apart
Alfred Wegner
Some evidence of continental movement is that continents seem to fit together like a puzzle, ___________ ___________ in _______ ________ and _____ ________ match up, some _______ of the same exact ________ were found in both _____ _______ and _______, and __________ structures match up
Mountain ranges, North America (Appalachian Range), North Africa (Atlas Range), fossils, species, South America, Africa, bedrock.
What two devices helped evaluate Wegner’s theory of continental drift?
Sonar, and Magnetic Anomaly Detectors (MADs)
What does M.A.D stand for?
Magnetic Anomaly Detector
What happens to density when depth increases?
It increases as well
What does M.O.R. stand for?
Mid-Ocean Ridge.
What is seafloor spreading?
The formation of new areas of oceanic crust which occurs through the upwelling of magma at mid-ocean ridges and its subsequent outward movement on either side.
Why is Iceland volcanic?
Because the Atlantic Mid-Ocean Ridge passes directly through it.
What rock composes the majority of the ocean crust?
Basalt
Which has higher magnetism, the ocean crust or the continental crust?
The ocean crust
Is the continental crust composed of Mafic or Felsic rock?
Felsic
What rock is the continental crust rich in?
Granite
Which crust has low Iron content?
The Continental Crust.
The Mid-Atlantic ridge is formed by magma upwelling from the Earth’s _______________.
Asthenosphere
What dynamic equilibrium is occurring that is causing the Mid-Atlantic Ridge to continuously widen?
The fact that as fast as the crust is being split apart, the magma fills in the space, pushing it out more and more. It is a cycle.
What other movements is the Mid-Atlantic Ridge responsible for?
The movement of the Earth’s continents.
Magma has a ____er density than the surrounding rocks of the Mantle and Crust.
Lower
What are two expected similarities between rock samples found equal distances from and on opposite sides of the Mid-Atlantic Ridge?
Magnetic Pointing Directon, Age *
Igneous materials found along mid-ocean ridges contain magnetic particles that show reversal of magnetic orientation. This is evidence that
C) Earth's magnetic poles have exchanged their positions
The crustal material on both sides of the ridge indicates that the tectonic plates are
D) diverging
As the distance from the center of the ridge increases, the age of the rocks
D) decreases
When magma pushes the plates apart, what is it called?
a RIDGE PUSH
What is it called when Magma and Gravity pull plates back into the lithosphere?
a SLAB PULL
The moving of plates cause _____________ distinct Plate Boundries
THREE
Areas where tectonic plates meet and interact relative to each other are called _____________.
PLATE BOUNDRIES
What are the three types of plate boundries?
1. DIVERGENT BOUNDRY
2. CONVERGENT BOUNDRY
3. TRANSFORM BOUNDRY
Which plate contains almost no continental crust on top of it?
THE PACIFIC PLATE
How do Convection cells cause Plate tectonics?
By RIDGE PUSHes and SLAB PULLs
In which type of boundry do tectonic plates slide by eachother?
a TRANSFORM PLATE BOUNDRY
What type of Plate Boundry is the San Andreas Fault?
a TRANSFORM PLATE BOUNDRY
What type of Plate Boundry is the Rift Valley?
a DIVERGENT PLATE BOUNDRY
In what type of plate boundry do tectonic plates spread apart, causing the crust to split?
a DIVERGENT PLATE BOUNDRY
On land, a Divergent plate boundry forms a ___________, while in the ocean it forms a ____________.
rift valley, Mid-ocean Ridge
What does necking create?
Fault Block Mountains
When crust is thinned, it is called __________.
Necking
What type of plate boundry creates a deep ocean trench?
a CONVERGENT PLATE BOUNDRY
What is an ISLAND ARC?
A chain of volcanic islands that can be anywhere from 60 to 100 miles in length
What type of plate boundry forms mountain chains?
A CONVERGENT PLATE BOUNDRY
What forms when very hot, silica poor, fluid lava erupts and forms relatively flat layers which become islands?
a SHIELD VOLCANO
What characterizes a stratovolcano?
A cone like shape, and felsic magma
What do most earthquakes occur in?
Trenches
______________ created Japan.
Subduction
When two plates collide, and one of them is an ocean plate, what happens to one of the plates?
It subducts
What does viscosity determine?
How sticky/gloopy a liquid is
What type of magma creates STRATOVOLCANOES?
Felsic magma
What mineral is Felsic Magma rich in?
Silica
What type of magma contains a lot of iron?
Mafic Magma
What type of volcanoes does mafic magma create?
SHIELD volcanoes
What forms big visible faults?
TRANSFORM PLATE BOUNDRY ZONES
When heat from the earth's core uprises and melts the rock, eventually bursting through the crust, it creates a __________.
HOTSPOT
What are hotspots?
Stationary Magma Plumes.
What forms when very hot silica-poor fluid iron erupts, what does it form?
Shiled Volcanoes
What are Seamounts?
Volcanic islands that have been lowered below sea level by erosion.
What type of crust are volcanic islands made of?
OCEANIC crust
Determining the order of past events through stratigraphic relationships between layers of rock or sedimentary deposits is known as __________________________________________.
RELATIVE DATING.
In superposition the _____est rock layer will be at the bottom. The ______est rock layer will be at the top.
OLDEST, YOUNGEST
How are sedimentary rocks always deposited?
HORIZONTALLY
Are horizontal rocks distorted before or after they are deposited?
AFTER
What action within the rock layers creates a fold?
A COMPRESSION in rock layers
What is older, folds or the rock layers in which they form?
FOLDS
What causes folds?
TECTONIC PLATE BOUNDRIES
What event would change the position of older and younger rock layers so that the older layers are on the top?
Folds overturning the rock layers.
What is caused by igneous intrusions in sedimentary rock?
Metamorphic rock in between the intrusion and the sedimentary rock.
do FAULT LINES form after or before the rocks they occur in?
AFTER
What is an UNCONFORMITY?
A buried erosion surface separating two rock strata of different ages.
What do UNCONFORMITIES indicate?
Where sediment deposition was not continous in a certain area.
What is the term for fossils that are used to define and identify geologic periods.
index fossils
What must be true of all index fossils?
That they have lived for a short period of time, and that they have lived globally
Author
mglicc
ID
65558
Card Set
Earth science Geologic History, Continental Movement, Plate Tectonics, and Relative Dating
Description
geologic history, continental movement, plate tectonics, and relative dating packets.
