The earth fundamentals

Question 1

the rock cycle

Answer 1

still active on Earth because core hot enough to keep the mantle moving + atmosphere relatively thick + we have liquid water.

sedimentary rocks:
made from sediments that are then compressed and lithified (weathering and erosion)
= contain fossil organisms

igneous rocks:
= magma cools down
–> outside = extrusive (basalt)
–> inside = intrusive (granite)

metamorphic rocks
= can be both igneous and sediemntary
= pressure and heat
= gneiss, marble

Question 2

mass extinctions

Answer 2

● 443 MYA, end of Ordovician period = extinction of 100 families and associated species
● 350 MYA, end of Devonian = death of 70% of all marine invertebrates = change in acidity of the ocean
● 245 MYA, end of Permian = 95% of all marine species, possibly caused by more than a single catastrophe, life spanned for 7 million year period
● 65 MYA, end of Cretaceous = giant asteroid impact in vicinity of Yucatan Peninsula = extinction 70% of all genera (dominant species of dinosaurs = mammals took over the earth, setting stage for the evolution of mammals)
● 35 MYA = cooling and glaciation
● End of the Pleistocene to present = ongoing mass extinction of mammals, reptiles, amphibians, birds, fish and plants

Question 3

evolution

Question 4

magma

Answer 4

1. liquid (melt)
2. dissolved gases
3. mineral crystals (solids)

Question 5

igneous rocks

Answer 5

Intrusive = rock from magma that solidified underground = plutonic
● The magma from below solidifies below the earth’s surface because the temperature is much cooler
● Formation of crystals
● ex: granite / granitic

Extrusive = rock from magma that solidified at surface = volcanic
● Hot lava solidifies when it comes in contact with the atmosphere
● ex: basalt / basaltic
● Fine grained rocks = no time to actually form
● Coarse grained rocks

Question 6

dating with radioactivity

Answer 6

= Radiometric dating

An unstable radioactive isotope, called the parent, will decay and form stable daughter products.

Parent = unstable
Daughter = stable

The length of time for half of the nuclei of a radioactive isotope to decay is called the half-life of the isotope. If the half-life of the isotope is known and parent-daughter ratio can be measured, then age of the rock sample can be calculated.

Since the isotope is dependant on a mineral, it only works if the mineral has remained as a closed system during the entire time since its formation i.e. No addition or loss of parent and daughter isotopes. The solution is to use fresh, un-weathered material.

Question 7

Relative dating
stratography

Answer 7

–> law of superposition
–> principal of original horizontality
–> principal of cross-cutting relations

Question 8

law of superposition

Answer 8

rock sediments
—youngest bed supeposed on top of rock formation
—oldest at the base

Question 9

principal of original horizontality

Answer 9

stagnant area of water = deposit horizontally = lateral continuity

Question 10

principal of cross-cutting relations

Answer 10

geologic feature which cuts another = youngesté younger than other

Question 11

law of inclusion

Answer 11

something included in something else
= must have been formed at the same time

Question 12

unconformities

Answer 12

breaks in rock record
deposition of sediments interrupted
mark important events in history

Question 13

correlation (relative dating)

Answer 13

match rock from on place to another place

• using fossils
  = fossil succession
  —fossil organisms suceed one anothe in definite and determinable order = time interval can be identified by fossil content
  = TRILOBITES (index fossil)

Question 14

absolute dating

Answer 14

dating with radioactivity
= radimetric dating
—unstable isotope will decay and form stable product
parent = unstable
daughter = stable
half life ===length of time for half of a nuclei of radioactive isotope to decay
======parentédaughter ratio+ half life known = age of rock sample can be calculated

Question 15

minerals

Answer 15

formation:
-crystalize
-created

abundance and distribution:
-mineral deposits = locally rich concentration of minerals
-mineral reserves = sufficiant amount of given mineral in deposit
-ore = reserves of metallic minerals

metallic
- abundant = iron, magnesium, aluminium
-scarce = copper, zinc, tin, gold, silver

non metallic
- industrial and agricultural use = phosphates, nitrates, carbonates, sodium
- construction = sand, gravel, clay
-ceramics and abrasives = feldspars, quartz

Question 16

thrombolites

Answer 16

smallest organisms
living rock fossils
underwater microbial structures that look like reefs but are entirely millions of microbes (bacteria)

Canada and Australia

Question 17

james hutton

Question 18

MOVIE

Answer 18

earth had a twin = collided = earth consumed a part of twin = became laerger
==increase pull of gravity
==atmosphere need gravity to hold it down and function
mars = weak gravity = atmosphere leaked away = dead planet

Position in solar system
= right temperature for water to exist
= not too far nor too close to sun + orbit the right type of sun
= JUPITER is earths protector due to big gravitational field that attracts flying objects

Environment relatively stable
= too much stability = evolution stuck = catastrophe needed
ex: Yucutan Peninsula and meteorite impact
= cenote ring

Moon
= corner reflector
= moving away = earth will loose climatic stability