Earth Science Quiz 5 Q2 Flashcards
These are remains and traces of prehistoric life.
Fossils
What type of rocks are fossils usually preserved in?
Sedimentary Rocks
a. All animals (may/ may not) turn into fossils.
b. Fossils (may/may not) always be index fossils.
a. may
b. may not
What is the study of fossils?
Paleontology
This is any animal or plant preserved in rock record of the Earth that is characteristic of a particular span of geologic time or environment.
Index Fossils
These types of fossils help in correlating rocks, they must be distinctive, abundant, and short range.
Index Fossils
What are the 3 conditions needed for fossilisation?
- Rapid Burial
- Protective cover or medium
- Possession of hard parts of durable tisues
This condition prevents decomposition of remains. Without oxygen from atmosphere, the rate of decay becomes at minimum.
Rapid Burial
This condition prevents attack of organisms living on dead organisms, and prevent air and moisture from building up.
Protective cover or medium
This condition include bones, teeth, shells, and other hard parts of an organism will most likely be preserved during fossilization. Soft tissues, organs, and flesh usually disintegrate.
Possession of hard parts of durable tissues
What are the 2 types of fossilisation?
Preservation without alteration
Preservation with alteration
Types of Fossilisa. There is no major chemical change occurs to the carcass. Most organic molecules are intact and suitable for studying ancient life.
Preservation without alteration
Types of Fossilisa. Includes altering chem composition of remains. The subtypes of this are dependent on process involved.
Preservtion with alteration
What are the 8 subtypes of preservation with alteration?
Petrification or Petrified
Recrystallization
Amber
Carbonization
Trace Fossils (Ichnofossils)
Cast
Impression
Mold
PRACTice CIM
Alter Subtype. Most common method, it is when woody components of remains are replaced by material such as silica, leaving a rock.
NAPALITAN YUNG CELLS
Petrification
Alter Subtype. Minerals that make up a shell experience change converting them into DIFF MINERAL, SAME CHEM COMPONENTS.
Wala nang mattrace na DNA
Recrystallization or Replacement
Alter Subtype. Process through which, soft tissues can be preserved. Because of pressure napiga yung carbon content.
Carbonization
Alter Subtype. _______ aren’t the carcass or remains of an organism, instead, they are the traces left by one.
Ichnofossils of Trace Fossils
Alter Subtype. Nabura yung carbon pero may natirang kulay itim (this is the ____ itself)
Impression
Alter Subtype. Nakukuha yung hugis ng shell after it melts. It forms when hollow space of mold are filled with minerals.
Cast
Alter Subtype. Yung mismong nasa loob, meaning this reflects the shape and outer markings (parang hollow).
Mold
Alter Subtype. Fossilized/hardened tree resin where the animal or tree is trapped.
Amber
This is a hierarchal set of divisions describing geologic time and serves as a “calendar” for significant historical occurrences.
Geologic Time Scale
Geochronologic units of GTS in descending order:
Eons –> Eras –> Periods –> Epochs –> Ages
GTS. This is the largest division of time, lasting thousands of millions of years.
Eons or Eonothems
What are the eons in GTS?
Phanerozoic (Current Eon)
Precambrian (of Proterozoic, Archean, Hadean)
GTS. These are the subdivision of eons. On the scale of hundreds of millions of years.
Eras or Erathems
What are the eras in GTS?
Cenozoic, Mesozoic, Paleozoic (Neo-, Meso-), Paleo-proterozoic (Neo-, Meso-, Paleo-, Eo-archean)
GTS. Also referred to as “systems”, are the subdivisions of eras lasting tens of millions of years.
Periods
What are the more famous periods in GTS?
Quaternary (current period)
Cretaceous
Jurassic
Triassic
Devonian
GTS. Also referred to as “series”, are subdivisions of periods. Range of several million years.
Epochs
What is the current epoch?
Holocene
Epoch. The _______ refers to the youngest part of the period and __________ refers to the oldest part of it.
Upper; Lower
GTS. Also referred to as “stages”, are the smallest units of geologic time. Usually only a few million years in length.
Ages
What is the current age in geologic time?
Meghalayan
Divisions in GTS is determined by varying events such as:
Reversals
Extinction
Magnetic Pole
Start of Species of Organisms
REMS
