Geology Flashcards
It is a dynamic planet and constantly changing structure; and is a layered sphere.
Earth
Layer of Earth (3 answers)
- Core
- Mantle
- Crust
or interior, is composed of a dense, intensely hot mass of metal, mostly
iron, thousands of kilometers in diameter.
Core
is surrounding the molten outer core. It is a hot, pliable layer of rock.
Mantle
is the cool, lightweight, brittle rock outermost layer of the earth.
Crust
8 most common Chemical Elements
- iron
- oxygen
- silicon
- magnesium
- nickel
- calcium
- aluminum
- sodium
In 1885, _____went so far as to publish a sketch showing how the two
continents could fit together, jigsaw-puzzle fashion.
Antonio Snider
Climatologist ______ was struck not only by the matching coastlines, but by geologic evidence from the continents.
Alfred Wegener
It may preserve evidence of the ancient climate of the time and
place in which this were deposited. Such evidence shows that the climate in many places has varied widely through time. It also preserve fossil remains of ancient life. Some plants and animals, long extinct, seem to have lived only in a few very restricted areas, which now are widely separated geographically on different continents.
Sedimentary rocks
remains of which are found in limited
areas of widely separated lands including India, southern Africa, and even Antarctica.
Glossopteris
A supercontinent (Greek for “all lands”)
Pangaea
Wegener proposed that all the continental landmasses had once formed a single supercontinent, Pangaea (Greek for “all lands”), which had then split apart, the modern continents moving to their present positions via a process called
continental
drift.
Continental “drift” turned out to be just one consequence of processes encompassed by a broader theory known as. It relates such deformation to the existence and movement of rigid “plates” over a weaker, more plastic layer in the earth’s upper mantle.
plate tectonics
is the study of large scale movement and deformation of the earth’s outer
layers.
Tectonics
The earth’s crust and uppermost mantle are somewhat brittle and elastic.
Together they make up the outer solid layer of the earth called the ______,
from the Greek word lithos , meaning “rock.”
lithosphere
Lithosphere is thinnest underneath the oceans, where it extends to a depth of about _____
50 kilometers (about 30 miles).
Lithosphere under the continents is both thicker on average than is oceanic
lithosphere, and more variable in thickness, extending in places to about
250
kilometers (over 150 miles).
The layer below the lithosphere is the ____, which derives its name
from the Greek word asthenes, meaning “without strength.”
asthenosphere
The asthenosphere extends to an average depth of about ________ in the mantle.
300 kilometers (close to
200 miles)
Type of Plate Boundaries (3 answers)
- Convergent Plate Boundaries
- Divergent Plate Boundaries
- Transform Boundaries
lithospheric plates MOVE APART.
Divergent plate boundary
are the most common type of divergent boundary worldwide, and it is already noted the formation of new oceanic lithosphere at these ridges.
SEAFLOOR SPREADING RIDGES
If the continental rifting continues, a new ocean basin will form between the
pieces of the continent as shown in above figure. This is happening now in
northeast Africa, where three rift zones meet in what is called a ________.
triple junction
plates are MOVING TOWARD EACH OTHER.
Convergent plate boundary
Continental crust is relatively low in density, so continental lithosphere is
therefore buoyant with respect to the dense, iron rich mantle, and it tends to
“_____” on the asthenosphere.
float
This type of plate boundary, where one plate is carried down below (subducted
beneath) another, is called a ___________.
subduction zone
At an ocean-ocean convergence, the result is commonly a line of volcanic islands
island arc
The offset is a special kind of fault, or break in the lithosphere, known as a
transform fault.
is a naturally occurring, inorganic, solid element or compound with a
definite chemical composition and a regular internal crystal structure.
mineral
are solids in which the atoms or ions are arranged in regular, repeating patterns.
Crystalline materials
The two fundamental characteristics of a mineral that together distinguish it from all other minerals are its: (2)
- chemical composition
- crystal structure
A mineral’s composition and crystal structure can usually be determined only by
__________.
using sophisticated laboratory equipment
Types of Minerals (2 answers)
- silicates
- nonsilicates
group is the largest compositional group of minerals, all of which are compounds containing silicon and oxygen, and most of which contain other elements as well.
Silicate
Two most common elements in the
earth’s crust are ______.
silicon and oxygen
Silicate Minerals (5 answers)
- Quartz
- Feldspars
- Ferromagnesian
- Micas
- Clays
- probably the best known silicate.
Compositionally, it is the simplest,
containing only silicon and oxygen. It is a framework silicate, with silica tetrahedra linked in three dimensions, which helps make it relatively hard and weathering resistant.
Quartz
- The most abundant group of minerals in
the crust is a set of chemically similar minerals. They are
composed of silicon, oxygen, aluminum, and either
sodium, potassium, or calcium, or some
combination of these three.
Feldspars
- The general term used to
describe those silicates—usually dark-colored (black, brown, or green)— that contain iron and/or magnesium, with or without additional elements.
Ferromagnesian
are another group of several silicate minerals with similar physical
properties, compositions, and crystal
structures. These are sheet silicates, built on an atomic scale of stacked-up sheets of linked silicon and oxygen atoms.
Micas
are another family within the sheet
silicates, the sheets tend to slide
past each other, a characteristic that contributes to the slippery feel of
this material and related minerals. these are somewhat unusual among the silicates in that their structures can absorb or lose water, depending on how wet conditions are.
Clays
