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