exam 2 geo spring 2023
As a result of the impact of a 10-km-wide meteorite at the present of Yucatan Peninsula in Mexico,where a 100-km-wide by 16-km-deep scar called the ______ crater was created, then the CretaceousPeriod came to a close and ________ disappeared.
Chicxulub, dinosaurs
___________ is the process by which sediment settles out of the transporting material
Deposition
Gneiss is a kind of sandstone that formed by the lithification of fossils
False
Metamorphic rock is one that forms when a preexisting rock, or protolith, undergoes a fluid-statechange in response to the modification of its environment
False
Quartzite is one kind of sandstone.
False
Radical climate shifts occurred on Earth at the end of the Proterozoic Eon. Specially, accumulations ofglacial sediments occur worldwide indicating the whole Earth's surface was covered by ice twice in thehistory of Earth
False
Rhyolitic lavas can flow great distance.
False
Sediments generally accumulate in continuous sheets, which is called the principle of horizontality.
False
The class of foliated metamorphic rocks includes shale, slate, phyllite, metaconglomerate, schist, andgneiss
False
a' flows have smooth, ropy surfaces, whereas Pahoehoe flows have rough, rubbly surfaces
False
there are ___ major classes of sedimentary rocks
Four
The water that resides under the surface of the Earth is called
Groundwater
_________ provides the age of a geologic feature in years
Numerical age
________ is a measure of the ease with which fluids can flow through a porous material
Permeability
_____ refers to the total volume of empty space in a material, usually expressed as apercentage
Porosity
_________ specifies whether one geologic feature is older or younger than another.
Relative age
Successive collision ultimately brought together most continental crust on Earth into a single and thefirst supercontinent, name __________, by around 1 Ga
Rodinia
__________ of clasts indicates the degree to which the clasts in a rock are all the same size orinclude a variety of sizes.
Sorting
____ are natural outlets from which groundwater flows
Springs
An igneous intrusion "bakes" surrounding rocks. The rock that has been baked must be older than theintrusion, which is called the principle of baked contacts
True
Artesian well can flow water automatically out of the subsurface to the ground
True
Changing temperature and pressure are the two important factors causing the metamorphism
True
Effusive eruptions (i.e., basaltic eruption) produce only flows of lava, whereas explosive eruptions(i.e., rhyolitic eruption) produce cloud and flow of pyroclastic debris.
True
Groundwater flows wherever the water table has a hydraulic gradient, and moves slowly from recharge areas to discharge areas
True
Rocks below an angular unconformity are usually tilted or folded before the unconformity developed.
True
Slate is a kind of metamorphic rock derived from the metamorphism of shale.
True
Trilobites used to be living and grazing the sea floor during the Paleozoic Era
True
The river stream channel cross-sectional shape resemble the letter ____; this landform is called a
V V-shaped valley
_________ are vents at which molten rock (lava), pyroclastic debris, gas and aerosols erupt at theEarth's surface
Volcanoes
Much of the transformation of the Earth's atmosphere from the oxygen-poor volcanic gas mix of theArchean Eon to an oxygen-rich mix had occurred by about 1.8 Ga. This transition led to the globaldeposition of
banded iron formation
Fluvial deposits may accumulate along the stream bed in elongate mounds called
bars
___consists of shells
bio chem sedimentary rock
coral reef is one kind of
bio chem sedimentary rock
If a stream divides into numerous strands weaving back and forth between elongate mounds or barsof gravel and sand, the result is a _________ stream
braided
The summit of an erupting volcano may collapse to form a bowl-shaped depression called a
caldera
Beginning with the Cambrian Period, life on Earth left a clear record of evolution. The fossil recordindicates that soon after the Cambrian began, life underwent remarkable diversification. This event,which paleontologists refer to as the
cambrian explosion
clastic rocks form from ___ grains
cemented together
____is made up of minerals that precipitate directly from water solutions
chemical sedimentary rock
Piles of tephra form a cone-shaped
cinder cone
Technically speaking, we define ________ as the volume of water passing through an imaginarycross section of the stream in a unit of time
discharge
Geologists refer to volcanoes that have not erupted for hundreds to thousands of years but do have the potential to erupt again in the future as
dormant volcanoes
A drainage network collects water from a broad region, variously called a _______, catchment or watershed.
drainage basin
The highland, or ridge, that separate one watershed from another is a
drainage divide
Permanent streams flow all year long, whereas _________ streams flow only part of the year.
ephemeral
When the volume of water flowing in a stream exceeds the volume of the channel, a ______ occurs
flood
A stream may overtop the banks of its channel and spread out over its
floodplain
Preferred mineral orientation in a piece of metamorphic rock is
foliation
A fountain of steam and hot water that erupts episodically from a vent in the ground is called
geyser
Physicists can measure how long it takes for half of a group of parent isotopes to decay. This time iscalled
half life
. The potential energy available to drive the flow of a volume of groundwater at a given location iscalled the __
hydraulic head
Some life species existed only for a short interval of the geologic column, and thus are diagnostic of a particular period or epoch. The fossil of such species are called
index fossil
Very wet mixtures of volcanic ash, coarser debris, and water during a volcano eruption form a slurryknown as a
lahar
Pea- to plum-sized fragments of glassy lava and scoria from basaltic eruption are called cinders, or
lapilli
The metamorphism of _________ yields marble.
limestone
the transformation of loose sediment into solid rock is
lithification
For part of the early 600 million years of Earth history, the Hadean Eon, the planet was so hot that itssurface was a _________ ocean
magma
Reiver cannot sail in a straight line, for the river channel winds back and forth in a series of snake-like curves called
meanders
Changes in a rock that result in the formation of a metamorphic mineral assemblage, and/ormetamorphic foliation, in response to change in temperature, and/or pressure, to the application ofdifferential stress, and to interaction with hydrothermal fluids are called _
metamorphism
___consists of carbon rich relicts of plants
organic sedimentary rocks
Radioactive isotopes in the rocks are unstable; after a given time, they undergo a change called
radioactive decay
During the metamorphism, changes in shape and size of grains without changing the identity of themineral constituting the grains are called
recrystallization
___ broadly defined, consists of loose fragments of rocks or mineral broken off bedrock, mineral crystals that precipitate directly out of water, and shells or shell fragments.
sediment
geologists refer to the total volume of sediment carried by a stream as its
sediment load
Some water flows downslope as a thin film called
sheetwash
Unconsolidated deposits of volcano pyroclastic grains, regardless of size, constitute
tephra
As the main channel lengthens, new side channels form nearby. These side channels or ______always merge with the main channel trunk
tributaries
A surface representing a period of nondeposition and possibly erosion is called
unconformity
Physical processes we observe today also operated in the past at roughly the same rates and wereresponsible for the formation of the geologic features we see in outcrops. This principle is called
uniformitarianism
The characteristics of a lava flow depend on its _______, which in turn depends on its temperatureand composition
viscosity
Above ________, the pore spaces in the sediments or rocks contain mostly aire and below which theycontain only water
water table
