FOSSILS Flashcards
Body of sediment with distinctive
physical, chemical, and biological
attributes.
Sedimentary Facies
Sea level rises with respect to land wherein the shoreline migrates landward, as does the environment
Marine Transgression
What happens to facies during marine transgression?
Superposed on facies deposited in nearshore environments
True or False: rocks making up each facies in marine transgression become younger landward
True
The opposite of transgression where nearshore facies overlay offshore facies
Marine regression
True or False: rocks units in marine regression are older seaward
False
this law states that the facies seen in a conformable vertical
sequence will also replace one another
laterally
Walther’s Law (Johannes Walther)
What is Walther’s law used for?
to work out lateral relationships by easily observing vertical facies relationships
Does Walther’s law apply only to conformable sequences of rocks?
Yes
Scientific study of fossils
Paleontology
remains or traces of prehistoric organisms preserved commonly in sedimentary rocks
fossils
type of fossil recognized for having skeletal parts, shells, bones, and teeth
body fossils
type of fossil that indicates organic activity recognized by tracks, trails, burrows, nests, and feces (coprolite)
Trace Fossils
a type of fossil preservation wherein the original composition and structure are preserved
body fossils-unaltered remains
a type of fossil preservation wherein change in the composition/structure of original material is observed
body fossils-altered remains
a type of fossil preservation wherein any indication of organic activity such as tracks, trails, burrows, droppings, and nests are observed
trace fossils/ ichnofossils
a type of fossil preservation where a mold (the cavity with shape) is casted (mold is filled by minerals/sediments)
molds and casts
organisms are frozen in sediment
freezing
soft tissues are shriveled and organism is air dried
mummification (drying/dessication)
organisms are trapped and preserved in hardened tree resin
preservation in amber
organisms and their remains are preserved in asphaltlike substance at oil seeos
Preservation in Tar
minerals grow in pores and cavities
permineralization
change in crystal structure
recrystallization
a chemical compound replaces another
replacement
volatile elements from organic matter leaves a carbon film; common for leaves & insects
carbonization
how was Lyuba preserved?
Freezing
She’s a 40,000 year old frozen wooly mammoth known as the best preserved mammoth fossil in the world; she was found in Yamal Peninsula, Russia
Lyuba
another 40,000 year old frozen mammoth found in NE Siberia
Dima
True or False: Desiccation cannot preserve and organism’s skin and soft tissues
False
this is the tiny dinosaur whose tail was preserved in amber
Coelorosaurs
another term for tar pit
asphalt pit or asphalt lake
True or false: Tar pits are created due to petroleum leaking to the surface where lighter components vaporize and leave behind the thick asphalt
True
the process of turning living organic material into
stone.
petrification
happens when pores of organisms are permeated by mineral matter
permineralization
common minerals that form permineralized fossils
calcite, iron, and silica
takes place when water dissolves the original
hard parts and replaces them with mineral matter.
replacement
common minerals during replacement
calcite, silica, pyrite, and hematite
True or false: At its extreme, carbonization
reduces plants and animals to shiny black or
brown film.
true
This often has the fine detail
of the surface of the original organism.
external mold
forms when sand or
clay commonly fills such things as empty shells of snails
and clams
internal cast
the cavity duplicating the original inner surface of the organism
cast
type of trace fossil formed in soft sediments
burrows
type of trace fossils made by organisms in hard substrate
borings
stones found in stomachs
gastroliths
