quiz 3 Flashcards
Two main types of fossils
Body and trace fossils
Processes important for fossilization =
rapid burial + mineralization
Taphonomy
Study of what happens to an organism after death
Factors affecting likelihood of rapid burial
Factors affecting preservation of an organism/its parts
Finding fossils
Primarily in sedimentary rock
Primary vs. secondary context
Unconformity due to
erosion OR non-deposition
Radioactive decay
half-life
Stratigraphic analysis is based on 3 core principles:
superpostion; original horizontality; and original lateral continuity
stratum means
layer
Relative dating example:
stratigraphy, a stratigraphic analysis is the foundation of all geological dating.
The origin, physical characteristics, and spatial relationships of stratified rocks are studied to
understand the history of the events documented in the strata.
most important process leading to changes in the orientation of stratigraphic rocks is
plate tectonics
One of the most important geological features in paleoanthropology is the series of
rift valleys in East Africa.
An intrusion is the
replacement of some part of the original stratigraphic profile with younger material.
Magma can intrude from below, while erosion can
remove parts of the original deposition that are later infilled by younger deposits.
Erosion of all sorts is both
friend and foe to paleoanthropologists.
Erosion exposes
long-buried sediments, the fossils therein, and also destroys those fossils and their contexts as they erode to the surface.
biostratigraphy, a second relative dating technique
builds on basic stratigraphic analysis, based on faunal correlation.
Using the principles of stratigraphy, geologists can
make correlated stratigraphic maps covering broad geological time scales.
paleomagnetism, a third relative dating technique
The Earth has a magnetic field which is produced by electric currents in its iron-rich molten outer core
Body fossils are the
preserved remains of organisms, like bones or shells,
Principles of stratigraphy
Superposition
Original horizontality
Original continuity
Relative dating techniques –
Stratigraphy
Biostratigraphy
Paleomagnetism
Geologic structures/processes:
Strata (stratum)
Intrusion
Unconformity (due to erosion OR non-deposition)
Erosion
trace fossils are
evidence of past life, such as footprints or burrows, indicating activity rather than the organism itself.
