ESS grade 9 Test 1 Flashcards
What does Geology stand for
Geo = earth
logy = study of
What are the two types of geology
physical and historical
what is geology
it is an evolving science
it is extremely controversial
it seeks to understand the origin of our planet and our place in the universe
it connects to all other sciences
What are the two ideologies in geology
catastrophism
Uniformitarianism
What is relative dating
putting geological events in chronological order with rules or laws
What are the laws of relative dating
law of original horizontality
law of superposition
principle of fossil succession
law of cross cutting relationships
What is the law of original horizontality
anything that settles, settles horizonatily
What is the law of superposition
the layer below is older than the layer on the top
what is the principle of fossil succession
Life forms succeed one another in a definite order. If a fossil is on a higher layer, it can’t be older than a fossil on a lower level
What is the law of cross cutting relationships
if a rock cuts through another rock, it has to be younger than the rock it cuts through
What is absolute dating (radiometric)? How it works and examples
it is a lot more specific than relative dating
using radioactive decay of elements to determine the absolute age
only works for hard rocks
Find decay product in a fossil, connect it with it’s parent and check how long the half life is
Ex. Potassium_40 becomes Argon_40 in 1.3 billion years
Journey to the center of the earth
atmosphere (gas)
ocean (liquid)
oceanic/continental crust (solid)
crust - lithosphere
Moyo
Mantle (sliquid/slimy)
upper outer core (molten metal - liquid)
lower outer core
Inner core (solid iron)
What are stromatolites and why are they important
Layered structures, built up by cyanobacteria (uses photosynthesis and releases oxygen) Their formation altered the environment, leading to the formation of the atmosphere, the accumulation of breathable oxygen, and the evolution of multi-cellular life
What is the Tiktaalik and why is it important
a 375 million year old fossil fish with land creature like attributes such as a moveable neck, strong ribcage, lungs, and strong fins. Its discovery shows when the very first fish ventured out onto land.
What is hypoxia and anoxia
hypoxia is too much oxygen in atmosphere
anoxia is too little oxygen
Examples of living fossils
Coelacanth, horseshoe crab, stromatolites
Hadean Eon
Named after hades because of the hellish conditions (high volcanic activity, molten surface, etc)
Archean Eon
ancient beginning
single celled organisms evolved (with no nucleus)
we have evidence from the time in the form of living fossils (stromatolites) and BIFs
Proterozoic Eon
Early life
when endosymbiotic theory appeared
Phanerozoic Eon
Visible life
Broken down into periods/ages by mass extinctions
Order of Eons
Hadean, archean, proterozoic, phanerozoic
Order of living organisms
fish
amphibians
reptiles
dinosaurs
mammals
birds
Order of mass extinctions
ordovician - silurian
devonian
permian
triassic
cretaceous
triasage of mammals
Ordovician - silurian extiction
caused by global cooling
86% of life died (all sea life bc there was no land life)
Devonian extinction
75% of life dead (both sea and land)
caused by hypoxia (too much oxygen) as a result of stromatolites
Permian extinction
known as the Great Dying
96% of life died (not in equal proportion)
caused by volcanism and greenhouse affect
Triassic extinction
killed the first set of dinosaurs
85% of all life lost
cause is unknown (maybe volcanism)
Cretaceous extinction
most well known
caused by a meteorite/cluster of them which triggered a train reaction of earthquakes, volcanos, etc which caused a blanket of ash which changed CO2 levels
66% of life dead (a lot of mammals survived)
65-66 MYA
Triasage of mammals/holocene extinction
present time
man made extinction
every year, 100 times more species go extinct
What are all extinction events caused by
a change in atmospheric or oceanic chemistry
Endosymbiosis
The theory that Eukaryotic cells are descendants of prokaryotic cells. A bigger cell engulfed a smaller one and instead of absorbing it, they profited off each other and eventually this became a genetically inherited event. The smaller cell became the mitochondrion
Prokaryotes vs eukaryotes
prokaryotes are single celled organism without a nucleus or organelles
eukaryotes are organism whose cells contain a nucleus and organelles
Transitional Fossil
linking animal between groups of organisms. For example, fish and tetrapod (the prequel to amphibians)
What are living fossils
animals that haven’t evolved in millions of years and yet still exist (aren’t a real fossil)
What is the great unconformity
when big ‘holes’ appear in layers of rocks; caused by particles not cementing properly due to extreme wind, water erosion, or an ice age (ice and particles mix so when the ice melts, the particles are brought away with the water - called snowball theory)
Coelacanth
lobe finned fish
related to tiktaalik
fleshy fins
ovoviviparous (eggs inside but live birth)
living fossil
discovered by Courtney-Latimer
Rocks
solid mixture of minerals
may be organic (made of dead things)
can have crystals because of minerals
classified by how they are formed
identified by composition (what minerals + amount) and texture (size, shape, position of grains, etc)
minerals
naturally formed of elements or compounds
inorganic solid (non living)
definite chemical makeup
has crystals
not made of rock
classified by chemical composition
Igneous rocks
formed when magma or lava cools and hardens
there are two types, intrusive and extrusive
all types of rocks can be changed into igneous rocks by melting and cooling naturally
Types of igneous rocks
Intrusive = inside the volcano
made from magma
cools slowly beneath earth’s surface
larger crystals
coarse grained
Extrusive = outside of volcano
made from lava
smaller crystals and smoother
BIFs
Banded Iron Formations
iron in rock formations rust due to oxygen causing a red color
shows periods in which there was oxygen and when there was not
Up until a certain point, the oxygen reacted with minerals in the ocean (like iron) so when BIFs stopped forming completely is when the oxygen started to accumulate
What is sedimentary rock
when particles are cemented together through a process
1. weathering (rain beating on rocks)
2. erosion (sediments fall off rocks)
3. deposition (sediments fall into body of water)
4. compaction (sediments are compressed under water and gravity)
5. cementation (they squish a lot over time until they form rock)
These rocks are usually softer and visibly sedimentary
Types of sedimentary rock
Organic =
fossilized remains of plants or animals compressed together
the fossils must remain fossilized, not decomposed.
calcium carbonate (limestone + chalk)
Clastic =
fragments of rock are compacted together (different types randomly stick together)
chemical =
sediments are glued together by dissolving minerals
Metamorphic rock
formed when existing roc is changed into new rock by the heating from the rock and pressure from rocks around it
found near the core of the earth (where theres a lot of heat and pressure)
usually very pretty
very hard
all rocks can become metamorphic through heat and pressure
types of metamorphic rock
Foliated =
crystals aligned in layers (usually previously sedimentary)
Non foliated =
crystals arranged randomly (usually previously igneous)
What is physical Geology
physical - examines materials and processes of earth
What is historical Geology
historical - examines origin and evolution of earth
What is uniformitarianism
Uniformitarianism says that the same processes at work today were at work in the past, late 1700s, James Hutton, is the current theory
What is catastrophism
catastrophism - biblical view, mid 1600s, James Ussher
Cambrian Explosion
Time period when the diversification and abundance of life began
Rock cycle
The cycle which describes the processes needed for rocks to transition between the three main types of rock
When did humans appear
3,500,000 years ago
what is ecology
the study of life and how it relates to other life and the earth
Food/ energy pyramid
decomposers
producers (plants)
primary consumers (herbivores)
secondary consumers (omnivores)
Apex predator (carnivore)
as energy moves up, only 10 % is gained
food chain
a linear sequence showing how energy and nutrients flow from one organism to another
food web
a complex network of interlinked food chains representing multiple pathways through which energy and nutrients pass in an ecosystem
mutualism
benefits both species
commensalism
one species benefits, the other is neither helped nor harmed
parasitism
one species benefits at the expense of another
predation
one organism eats another
competition
two organisms compete for a resource
habitat
the natural enviornment where an organism lives
niche
the role an organism plays in its enviornment, including it shabitat, resources use, and interaction with other organisms (how they survive) Ex. beak shape canary vs finch
endangered species
a species at risk of extinction due to habitat loss, pollution, or other factors
