LSU Luther Geol 1003 exam 2 MC

Which Period is often called the "Age of Fishes"

Devonian

True or False: Insects in the Paleozoic were much larger than they are today

true: very high 02 levels in the atmosphere

Which of the following major strategies for acquiring nutrients was responsible for the increasingly oxygen rich atmosphere of the Proterozoic Eon.

Photosynthesis

What is a carton?

Undeformed core of the continent that is at least 1.0 billion years old

Correlation of early Archean rocks with fossils is routinely done by geologists

flase

Which of the following statements describes one way in which the Cambrian fauna differs from previous organisms

The Cambrian explosion results in the first diverse set of animals with hard parts that live in the ocean

Earths atmosphere has changes little since its formation

False

Archean rocks have blueschists and parallel metamorphic belts

false

What is the significance of the ediacaran fossils

fossils of the earliest animals

tiny skeletal fossils preserved by what are knows as "small shelly fauna" of the Cambrian period

phosphate

there were at least 2 supercontinents during the precambrian

true

where do arcane rocks form?

oceans

which of these is NOT a result of predator-prey relationships during the Paleozoic

the ability to escape to land

The ediacaran animals did not develop hard parts, likely because there were no predators at the time

true

burrows get more complex throughout geologic time

true

how did eukaryotes evolve from prokaryotes

symbiosis

what caused black (organic-rich) shale deposition in the middle Paleozoic?

addutuin of chemical ions and depletion of oxygen

what was the composition of the hadean crust?

ultramafic

When did Red beds appear on earths surface?

2000 million years ago

When did oxygen begin to appear in the atmosphere?

2000 million years ago

How much nitrogen and carbon dioxide were in the atmosphere at 1500 million years ago

80% and 10%

what structure is being built in this image above (the organism involved is cyanobacteria)

stromatolite

what are the oldest eukaryotes?

grypania (coiled algae)

which of these is NOT a feature of the acadian organ?

extension leading to a new ocean

the first seed-bearing plants appeared in the Devonian, these are the

angiosperms

which of these was the first orogenic event that began to build the Appalachian Mountains

taconic

during which eon or era did the prokaryotic cell first appear

Archean

which of the following statements is NOT true

The Jack Hills zircon crystals originally crystallized in the earths first komatite crust

what essential evidence exists for Snowball Earth

glacial striations near the equator

some scientists believe that life may have originated at hydrothermal vents. This view has been bolstered by the discovery of ____________ that can live under extreme conditions, these organisms obtain energy through ________

Archaebacteria, Chemosynthesis

Red Beds, in general, appeared in the geologic record after banded iron formations

False

During the Proterozoic eon, when large amounts of carbonate rocks formed, CO2 levels _______ which would eventually lead to global _______

dropped, cooling

Archean fossils are ______, and are ______ biostratigraphic tools

Unicellular, poor

Which of the following events did NOT occur during the Archean Eon

formation of Pangea, it formed in the paleozoic

the Archean eon ended _____ billion years ago

2.5

Greenstone belts were _____ during the Archean, indicating that subduction zones were _____ common during this time

common, less or common, more

banded iron formations are not found in ______ eon rocks

Phanerozoic

the oldest fossils found were discovered in ______ and are _____

limestone, prokaryotic

Cyanobacteria use _____ to produce energy, and ____ considered to be autotrophs

photosynthesis, are

if life did in fact arise on earth, It must have evolved in an environment where contact with the free oxygen of the atmosphere was limited. of the following environments, which would fit this criteria?

hydrothermal vents

how does differentiation occur

cooling of the earth

which correlation technique is useful in Archean rocks

isotopic dating

during the hadean or Archean, impacts from extraterrestrial objects were very rare as the early atmosphere protected the earths surface

false

When compared to oceanic lithosphere, continental lithosphere is _____ dense, and therefore is _____ likely to subject at plate boundaries

less, less

in which of the following tectonic environments is orogenic rare?

in the middle of tectonic plates

the collision between continents usually results in crustal thinning and the formation of normal faults

false

stromatolites are formed ______

in water, contains this layers, by cyanobacteria

according to the Walther's law of facies states that for an unbroken sequence of rocks ______ superimposed facies _____ laterally adjacent to each other during deposition

vertically, were

burial of organic carbon causes an ____ in atmospheric oxygen, but also generally causes a ____ in carbon dioxide. (2025 note: "burial of organic carbon" = trees photosynthesizing, eg.)

increase, decrease

carbonate sedimentation usually occurs at or near the tropics where the water is warm and shallow

true

under normal condition ______, and during mass extinctions species disappear in a relatively ______ amount of geologic time

some extinctions occur, short

photosynthesis involves the use of sunlight, water and _____, to produce sugars and _____ as a waste gas

carbon dioxide, ocygen

when the solar system formed _____ elements moved farther away from the sun, and when the earth formed _____ elements moved towards the center (core)

lighter, heavier

the precambrian does NOT include the _____ eon

Proterozoic

which of the following events occurred last

Photosynthesis begins

the earth is approximately _____ billion years old

4.6

what geologic feature forms the ancient hear of the continents

cratons

how much oxygen and nitrogen was in the atmosphere when cyanobacteria formed?

O2 = 0% ; N2 = 75%

which feature do we use to interpret the age of the earth

meteorites

during which geologic period did amphibians first appear in the fossil record

silurian - devonian

which of these time periods is the longest

precambrain

which large orogenic event occurred in North America during the formation of the supercontinent rodinia

grenville

which of these processes can increase CO2 in the atmosphere?

volcanism

in general, global sea level was relatively ______ during the early and middle Paleozoic era, leading to the accumulation of thick sequences of ____ sediments on the continental shelves

high, marine

which of the following was not part of gondwana

british isles (Great Britain)

the _____ period is often called the "age of the fishes"

devonian

with regards to the formation of continental lithosphere, which is true for the Archean eon

protoconinents formed

what are the significance of banded iron formations

represents deposition of iron oxide rick rocks on the ocean floor

why are ediacaran organisms so well-preserved?

they were buried in an anoxic environment

what are the unique archean sedimentary sequences of volcanics and sediments called

greenstone belts

which of these is NOT a characteristic of the ordovician

simple burrows

Earth's atmosphere has changed very little since its formation

false

stanley miller and Harold Urey's experiments showed that the amino acids required for life can be produced without available free oxyen

true

by the end of the Proterozoic which of the following occured

multicellular life appeared, an oxygen richer atmosphere has developed, red beds had appeared in the rock records

how many episodes of snowball earth glaciation happened

2, perhaps 3 (depending on what counts)

why are paleomagnetic records of low-latitude glaciation important?

if it was cold enough for glaciers at sea level at the equator, then in must have been cold enough for glaciers everywhere else on earth

what rock type is evidence that significant portions of earth's oceans were anoxic during the snowball earth glaciations

banded iron formations

during the Proterozoic eon large amounts of carbonate rocks (limestone) formed and CO2 levels ______, which would eventually lead to global ____

dropped, cooling

stable isotopes like 016/018 help scientists determine past climate conditions

true

what feature do we date to find the age of the earth

meterorites

which of these is a feature of a typical, modern plate boundary

blueschist

which of these are possible feeding strategies for Archean-aged organisms?

both photo and chemo

which of the following statements is not true

the jack hills zircon crystals originally crystallized in the earths first komatitite crust

earths first crust had the composition of which type of igneous rock

komatitite

what is the next big milestone in earths history after the melting of the last snowball earth

the evolution of the first animals

early earth grew by adding space debris and planetesimals through the process known as

accretion

what does the (a) presence of chert, limestone, and BIFs and (b) the absence of clastic sedimentary rocks imply about conditions during the archean

there was no land

are there any fossils in archean sedimentary rocks

yes: microbially-induced sedimentary structures show microbial mats binding sedimentary grains together

when were the "snowball earth glaciations"

during neoproterozoic

relative to a glacial deposit called a tillite, we might look for striations ______

below the tillite, on the unconformity surface separating it from the bedrock beneath

the below diagram depict examples of tiny ohosphatized skeletons from the early Cambrian and represents _____

small shelly fossils

which of the following was not part of gondwana

British Isles (Great Britain)

why did animals develop hard parts

to protect against predators

which of these time periods is the longest

precambrian