Fossils Flashcards
Study of past life
Paleontology
Evidence of organisms that lived in the past.
They may be actual remains like burrows, nests, and
dinosaurs’ footprints or even the ripples created in our
prehistoric shore.
Fossils
The process of becoming a fossil.
Fossilization
Small organisms or
past trapped in amber, hardened plant sap is being
observed.
Unaltered Preservation
Forms a rock-like fossil
Permineralization/Petrification
The organic
contents of bone and wood are filled by –, –, –.
Silica, Calcite, Pyrite
Hard parts are dissolved and replaced by other minerals, like calcite, silica, pyrite, or iron.
Replacement
Other elements are ionized and only the carbon remained.
Carbonization/Coalification
The hard parts are converted
into more stable minerals or small crystals turned into larger crystals.
Recrystallization
Molds and casts are
formed after most of the organisms have been
destroyed or dissolved.
Authigenic Preservation
Fossils in which minerals replace all or part of an organism.
Petrified Fossils
Most common type of fossil.
Both copy the shape of the organism.
Molds and Casts
Hollow area of sediment in the shape of the organism.
Mold
Is a copy of the shape of an organism.
Casts
Leaves extremely thin coating of carbon film outline
on rock.
Carbonization-Carbon Films
Fossilized mark that is formed in soft sediment by the movement or actions of an animal.
Trace Fossil
Preservation of remains
with little or no change.
Preserved Remains
It states that sediment
layers are deposited in
sequence – the lowest
stratum (or layer) are
always the oldest while the
layers above it are younger.
Principle of Superposition
Deformation in the strata
like folds, faults and
igneous intrusions that cut
across rocks are younger
than the rocks that they
cut across.
Principle of Cross-Cutting Relationships
It states that strata are
originally deposited in a
horizontal manner.
Principle of Original Horizontality
It states that sediment layers
are spread out continuously
in all directions.
Principle of Lateral Continuity
States that any rock fragments that are included in rock must be older than the rock in which they are included.
Principle of Inclusion
States that rock layers that contain fossils can be used to identify and correlate rocks.
Principle of Faunal Succession
Does not tell the exact age: only compare fossils as older or younger, depends on their position in rock layer
Relative Dating
Refers to a soil layers in a
deposit accumulate on top of one another, and that the bottom layers will be older than the top layers.
Stratigraphy
Determines the actual age of the fossil.
Absolute Dating
Are atoms of the same element but with different numbers of neutrons
Isotopes
Process in which the
decay of an atom of an isotope result in a change in the number of protons and the formation of a new element.
Radioactive Decay
Is a method of absolute dating using carbon-14 for fossils, bones, and wood up to 75 000
years old.
Radio Carbon
Is a method of determining the time of origin of rocks measuring the ratio of radioactive argon to radioactive
potassium in the rock.
Potassium-Argon Dating
