Chapter 11 & 12 Test Earth Science

ARCHAEOPTERYX

a genus of bird-like dinosaurs that is transitional between non-avian feathered dinosaurs and modern birds.

BIRDS

a group of endothermic vertebrates, characterized by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton.

FJORD

a long, narrow, deep inlet of the sea between high cliffs, as in Norway and Iceland, typically formed by submergence of a glaciated valley.

MORAINE

a mass of rocks and sediment carried down and deposited by a glacier, typically as ridges at its edges or extremity.

CYANOBACTERIA

a phylum of bacteria that obtain their energy through photosynthesis, and are the only photosynthetic prokaryotes able to produce oxygen. The name "cyanobacteria" comes from the color of the bacteria (Greek: κυανός (kyanós) = blue).

CENOZOIC ERA

a span on the geologic time scale beginning about 65 million years ago following the Mesozoic era.

CONTINENTAL GLACIER

an ice sheet covering a considerable part of a continent

REPTILES

cold-blooded vertebrates. (Vertebrates have backbones.) They have dry skin covered with scales or bony plates and usually lay soft-shelled eggs.

PRINCIPLE OF SUPERPOSITION

law of superposition. Geology. a basic law of geochronology, stating that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it.

GLACIAL TILL

the rock and soil material that has been carried by a glacier as it moves and is left behind when the glacier melts or retreats.

CREVASSE

A deep crack in the brittle surface of a glacier

ANGIOSPERM

A flowering plant in which fruits contain the seeds.

INDEX FOSSIL

A fossil that is associated with a particular span o geologic time.

ALPINE GLACIER

A glacier confined to a mountain valley which in most instances had previously been a stream valley. Also known as a valley glacier.

GYMNOSPERM

A group of seed-bearing plants that includes conifers and Ginkgo. The term means "naked seed," a reference to the unenclosed condition of the seeds.

DESERT PAVEMENT

A layer of coarse pebbles and gravel created when wind removed the finer material.

ARETE

A narrow knifelike ridge separating two adjacent glaciated valleys.

LATERAL CONTINUITY

A principle which states that sedimentary beds originate as continuous layers that extend in all directions until they grade into a different type of sediment or thin out at the edge of sedimentary basin.

HORN

A pyramid like peak formed by glacial action in three or more cirques surrounding a mountain summit.

TARN

A small lake in a cirque.

MESOZOIC ERA

A span on the geologic time scale between the Paleozoic and Cenozoic eras from about 248 million to 65 million years ago.

PALEOZOIC ERA

A span on the geologic time scale between the eons of the Precambrian and Mesozoic era from about 540 million to 248 million years ago.

GLACIER

A thick mass of ice originating on land from the compacction and recrystallization of snow that shows evidence of past or present flow.

HANGING VALLEY

A tributary valley that enters a glacial trough at a considerable height above its floor.

DISCONFORMITY

A type of unconformity in which the beds above and below are parallel.

ABSOLUTE DATING

Absolute dating is the process of determining an age on a specified chronology in archaeology and geology.

WIND

Air flowing horizontally with respect to Earth's surface.

AMPHIBIANS

All amphibians begin their life in water with gills and tails. As they grow, they develop lungs and legs for their life on land. Frog. Amphibians are cold-blooded, which means that they are the same temperature as the air or water around them.

PRECAMBRIAN

All geologic time prior to Paleozoic era

CIRQUE

An amphitheater shaped basin at the head of a glaciated valley produced by frost wedging and plucking.

NONCONFORMITY

An unconformity in which older metamorphic or intrusive igneous rocks are overlain by younger sedimentary strata.

ANGULAR UNCONFORMITY

An unconformity in which the strata below dip at an angle different from that of the beds above.

INVERTEBRATES

Animals that neither possess nor develop a vertebral column.

CARBON DIOXIDE

Carbon dioxide is a colorless gas with a density about 50% higher than that of dry air. Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms.

LOESS

Deposits of windblown silt, lacking visible layers, generally buff-colored, and capable of maintaining a nearly vertical cliff.

DINOSAUR

Dinosaurs are a diverse group of reptiles of the clade Dinosauria that first appeared during the Triassic period.

FISH

Fish are the gill-bearing aquatic craniate animals that lack limbs with digits. They form a sister group to the tunicates, together forming the olfactores.

GLOSSOPTERIS

Glossopteris is the largest and best-known genus of the extinct order of seed ferns known as Glossopteridales. The genus Glossopteris refers only to leaves, within a framework of form genera used in paleobotany.

MAMMALS

Humans and all other animals that are warm-blooded vertebrates (vertebrates have backbones) with hair. They feed their young with milk and have a more well-developed brain than other types of animals.

AXIAL TILT

In astronomy, axial tilt is the angle between a planet's rotational axis at its north pole and a line perpendicular to the orbital plane of the planet. It is also called axial inclination or obliquity. The axial tilt of Earth is the cause of seasons like summer and winter on Earth.

SAND DUNES

In physical geography, a dune is a hill of loose sand built by aeolian processes (wind) or the flow of water. Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water.

RODINIA

Neoproterozoic supercontinent that was assembled 1.3-0.9 billion years ago and broke up 750-633 million years ago.

DESERT

On of the two types of dry climate; the driest of the dry climates. Also known as arid.

RELATIVE DATING

Placing rocks in their proper sequence or order to determine the chronological order of events.

30° LATTITUDE

The 30th parallel north is a circle of latitude that is 30 degrees north of the Earth's equatorial plane. It stands one-third of the way between the equator and the North Pole and crosses Africa, Asia, the Pacific Ocean, North America and the Atlantic Ocean. It is where most deserts are found.

MILANKOVITCH THEORY

The Milankovitch theory is an explanation of long term climate change.

UNIFORMITARIANISM

The concept that the processes that have shaped Earth in the geologic past are essentially the same as those operating today.

ORBITAL ECCENTRICITY

The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle.

ZONE OF WASTAGE

The part of a glacier beyond the zone of accumulation where all of the snow from the previous winter melts, as does some of the glacial ice.

ZONE OF ACCUMULATION

The part of a glacier characterized by snow accumulation and ice formation. Its outer limit is the snowline.

PRINCIPLE OF INCLUSIONS

The principle of inclusions states that inclusions found in other rocks (or formations) must be older than the rock that contain them.

PRINCIPLE OF LATERAL CONTINUITY

The principle of lateral continuity states that layers of sediment initially extend laterally in all directions; in other words, they are laterally continuous. As a result, rocks that are otherwise similar, but are now separated by a valley or other erosional feature, can be assumed to be originally continuous.

RADIOMETRIC DATING

The procedure of calculating the absolute ages of rocks and minerals that contain radioactive isotopes.

PANGEA

The proposed super continent that 200 million years ago began to break apart and form the present landmasses.

FOSSIL

The remains or traces of organism preserved from the geologic past.

U-SHAPED VALLEY

U-shaped valleys, trough valleys or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape, with steep, straight sides and a flat bottom.

CALVING

Wastage of a glacier that occurs when large pieces of ice break off into water.