Lab 7, 9 - 11
Preservation of unaltered soft parts
-Freezing -Desiccation (mummification) -Insects being preserved in tree sap, resin, or amber
Sponge spicules
Composition is calcareous or siliceous. Significance: can accumulate to form chert. Environment: Live attached to the sea floor, most are marine.
What are lithodemic units?
Intrusive igneous rocks and highly deformed and metamorphosed rocks.
What is lithologic correlation?
Matching of formations to other nearby formations based on similarities in rock type.
Proifera
Sponges
Pinch out
The thinning out and disappearance over a distance of a formation
Mollusca, Scaphopoda
Tusk shells
Trace Fossils or Ichnofossils
-Tracks = produced by the feet of walking animals -Trackways = a continuous series of tracks made by one animal -Trails = produced by a warm or arthropod as it drags its body or tail across the ground -Burrows = excavations of an animal made into soft sediment -Borings = Holes made into a firm material -Coprolites = fossilized feces -Gastroliths = stones in the gizzards of birds or stomachs of reptiles. -Bite marks = made by a predatory animal on its prey -Root marks = produced by plants -Stromatolites = laminated, mound-like structures formed by colonies of sediment trapping cyanobacteria.
What is a stratigraphic section?
A sequence of layered rock in the order they were deposited.
What is a disconformity?
An irregular erosional surface that truncates flat lying sedimentary rocks.
What are steinkerns?
Another name for internal molds
Charophytes
Another type of green algae aka stoneworts Composition: Calcium carbonate Significance: closest living relatives to the ancestors of land plants. Can be a contributor to lake sediment. Environment: mostly inhabit quiet fresh to brackish (low salinity) water.
Mollusca, Cephalopda, Coleoidea
Belemenites, Squid, Cuttlefish, Octopus
Comparing Bivalves and Brachiopods: 3.) In which does the plane of symmetry pass between the valves?
Bivalves
Comparing Bivalves and Brachiopods: 4.) In which are the valves the same size but mirror images of each other?
Bivalves
Comparing Bivalves and Brachiopods: 1.) In which does the plane of symmetry cut through the center of the valves?
Brachiopods
Comparing Bivalves and Brachiopods: 2.) In which are the valves to different sizes?
Brachiopods
Mollusca
Clams, Oysters, Snails, Slugs, Squids, Octopus, and Cuttlefish
Which is not a coelenterate?
Class Asteroidea
Plant pollen and spores
Composition is organic material (Sporopollenin) Environment: Most commonly found in freshwater deposits.
Coralline Algae
Composition: Calcite, some with high magnesium calcite. Significance: The oldest identified multicellular eukaryote was a type of red algae. Important to reef construction, and can be used as an indicator of water depth and temperature. Environment: Mostly marine in warm, tropical waters
Calcareous algae
Composition: aragonite (calcium carbonate) Significance: Contributors to lime muds and other carbonate sediments. Environment: Marine, tropical to subtropical.
Cnidaria (Anthozoa)
Corals and Sea Anemones
Cnidaria
Corals, Jellyfish, Sea Anemones
What does diachronous mean?
Cut across time lines.
Walther's Law
Facies that were once laterally adjacent will shift so that the deposits of one environment come to overlie those of an adjacent environment.
Corals are plants.
False
Chemical Alteration - Permineralization
Filling of tiny holes in wood, shell, or bone by the precipitation or deposition of minerals from solution.
What are the fundamental units of stratigraphy?
Formations
What is an angular unconformity?
Forms when rock is deposited in horizontal layers and the layers are folded or tilted.
Hemichordata
Graptolites
Archaeplastida
Have plastids with chlorophyll, and they are photosynthetic. Belonging to this group are plants, green algae, charophytes, and re algae.
Internal molds
Imprints of the inside of shells in the rock.
External Mold
Imprints of the outside of a shell in rock.
Arthropoda
Insects, Spiders, Shrimp, Crab, Lobster, Barnacles, Ostracodes, Trilobites, Eurypterids
What are formations?
Lithologically homogeneous, distinct and different from adjacent rock units above and below, and traceable from place to place across the countryside.
Brachiopoda
Means "arm foot"
Bryozoa
Means "moss animal"
Mollusca, Monoplacophora
Means "one plate"
Chemical Alteration - Replacement
Molecule by molecule substitution of another mineral. Generally fossils that should be calcareous undergo this process and are filled with silica or pyrite
Clams, oysters, snails, and squid belong to this phylum:
Mollusca
Chemical Alteration - Recrystallization
Mollusks made of aragonite being recrystallized into calcite.
Mollusca, Cephalopoda, Coleoidea subclasses
Neocoleoidea: Octopus, Squids, Cuttlefish Teuthida: Squid Octopoda: Octopus
What is a Paraconformity?
Nondeposition separating two parallel units of sedimentary rock.
Four types of unconformities
Paraconformity, Disconformity, Angular Unconformity, and a Nonconformity.
Ostracodes
Resemble tiny kidney beans. Composition is calcareous but some are organic. Environment: Marine and nonmarine, most are benthic (bottom dwellers).
Foraminifera
Shell Composition of calcite or aragonite. Significance: Source of carbonate sediment Environment: Marine only
Dinoflagellates
Shell Composition of original material (sporopollenin) Significance: Cause red tides and secrete paralytic shellfish poison. Environment: Marine and nonmarine or freshwater
Radiolaria
Shell Composition of silica Significance: Constituent of chery Environment: Marine only
Coccolithophores
Shell composition of calcite. Significance: Base of the marine food chain. Major constituent of chalk. Environment: Marine Only
Diatoms
Shell composition of silica. Significance: Integral part of the food chain and a major constituent of diatomite. Environment: Both marine and nonmarine
Chromalveolata
Single celled protists with plastids. Belonging to this group are diatoms, dinoflagellates, and coccolithophores.
Rhizaria
Single celled protists with pseudopods. Belonging to this microfossil group are foraminifera and radiolaria
Conodonts
Small toothlike hard parts from an extinct animal (Cambrian to the Late Triassic). Composition is phosphate. Significance: Their color is a good indicator of the temperature to which the enclosing rock has been subjected. The darker it is, the higher the temperature to which the rocks have been heated. Environment: Were marine and free swimming
Mollusca (Cephalopoda)
Squid, Octopus, Nautilus, and Cuttlefish
Echinodermata
Starfish, Sea Urchins, Sand Dollara, Crinoids, and Balstoids.
What is the fundamental lithodemic unit?
The Lithodeme.
What is the smallest lithostratigraphic rock unit?
The bed
Transgressive Sequence
The facies is becoming finer grained over time. This also represents a sea level rise. The sequence is as follows: Limestone Shale Siltstone Sandstone
Regressive Sequence
The facies is becoming more coarse over time. This also represents a sea level drop. The sequence is as follows: Sandstone Siltstone Shale Limestone
Members
These are subdivisions within formations
Virtually all lithostratigraphic units are what?
They are time transgressive or diachronous.
Opisthokonta
This microfossil group includes multicellular organisms such as animals and fungi, as well as various groups of protists. Belonging to this group are sponge spicules, ostracodes, and conodonts.
Which is not an echinoderm?
ammonoid
Trilobites belong to this phylum:
arthropoda
Which is not a mollusc?
brachiopod
The plane of symmetry passes through the center of the shells or valves of this group:
brachiopoda
Mollusca (Bivalvia)
clams, oysters, scallops, mussels, rudists
Scleractinian corals belong to this phylum:
cnidaria
If you found a microfossil that looked like a very tiny button or disk in marine sediments, you would have a (an):
coccolith
Which microfossil group requires an electron microscope to see it?
coccolith
The calcite disks that make up the stem of a crinoid are called:
columnals
If you found a microfossil made of phosphate that looks like a row of teeth, you would have a(an):
conodont
Which microfossil group is extinct?
conodont
Microfossils are useful for:
determining the age of sedimentary rocks interpreting depositional environment biostratigraphic correlation
Name a plant-like protist made of silica.
diatom
Which microfossil group of organisms causes red tides
dinoflagellates
Which microfossil group of organisms secretes paralytic shellfish poisoning?
dinoflagellates
Crinoids belong to this phylum:
echinodermata
Which phylum has a 5-part symmetry?
echinodermata
Sand dollars belong to this group:
echinoidea
Crinoids (sea lilies) are plants.
false
Name an animal-like protist made of calcium carbonate.
foraminifera
The word "arthropod" means:
jointed foot
If you found a microfossil that consisted of two calcareous valves with a hinge, you would have a (an):
ostracode
Which microfossil group belongs to the Arthropods?
ostracode
Chemical Alteration - Carbonization
preserves plants or animals as a thin carbon film usually in fine grained sediments such as shale
Mollusca (Gastropoda)
snails and slugs
If you found microfossils which were made of silica with six radiating needle-like points, you would have a (an):
sponge spicule
Which type of plant fossil has the longest geologic range?
spores from algae, fungi, or mosses
Contour Intervals
the difference in elevation between any two contour lines on a topographic map.
Which three groups are extinct?
trilobites, tabulate corals, rugose corals
What is a nonconformity?
when the erosional surface separates older metamorphic or intrusive igneous rocks from younger sedimentary rocks