Slag
         

Dictionary



Asthenosphere- Part of the upper mantle over which lithosphereic plates move; it has the consistancy of Silly Putty, and flows under pressure.

Basin- A large depression containing, or capable of receiving, sediment.

Bed- An individual layer of sedimentary rock. Bedding - the layered arrangement of sedimentary rocks.

Biogenic- Material produced by organisms or their activities

Brachiopods- Phlym of solitary, bilaterally symmetrical, unsegmented marine invertebrates with a bivalved shell and a complex feeding apparatus. Brachiopods range from the Cambrian all the way through to the Recent.

Carbonization- Decomposition of organic matter so that only a thin film of carbon remains, which may retain features of the original organism.

Coal- Combustible sedimentary rock containing >50% by weight of carbonaceous material and composed mainly of lithified plant remains

Continent- A large piece of land composed primarily of relatively low-density rocks such as granite.

Continental plates- plates- Individual pieces of lithosphere that move over the asthenosphere.

Cross stratification- cross bedding- Slanted parallel lines within sandstone beds produced by the migration of ripples and dunes. Individual sand grains, moving in response to water or wind, bounce up the back (up-current) side of the dune or ripple and come to rest on the protected front side of the bedform. This front side sits at the angle of repose of the sand. Variations in the rate of sediment accummulation layers results in development of a succession of planes parallel to the front face of the bedform.

Cyclothems- Sequence of sedimentary rocks characteristic of Pennsylvanian delta deposits; deposited during a single cycle of relative sea level rise and fall in a Pennsylvanian delta. In coal-bearing strata the sequence is sandstone, shale, fireclay, coal, and shale.

Delta- Triangular shaped sedimentary body, up to thousands of square kilomenters in area, where river systems interact with lake or ocean water. Sediment is deposited as the flow volume expands and channel flow becomes unconfined.

Deltaic- Refering to a delta system.

Dolostone- Rock made up of Calcium magnesium carbonate, a magnesium limestone.

Echinoderms- A phylum of marine invertebrates with a spiny calcite endoskeleton, a water vasular system and pentameral symmetry. The range started at the Cambrian and are found all the way to the Recent.

Elevation- Height above some base level, usually sea level.

Epicontinental- Meaning on a continent

Epicontinental sea- eperic sea- Shallow inland sea

Erosion- A process in which particles are detached from soil or rock and transported away by wind, ice, or water.

Floodplain- Low-lying area adjacent to a river that occasionally is covered with flood water.

Fluvial- River or stream

Fossil- Part or trace of an organism that is buried naturally and is preserved.

Gastropods- A class of the Phlym Mulluska in which the anterior part of the foot is developed into a head and a helically-coiled shell protects the organism. The range of Gastropods is from the Cambrian all the way through to the Recent.

Glacier- Mass of ice and snow which deforms and flows under its own weight if thick enough.

Igneous rock- Rock that has solidified from a molten or partially molten state.

Incursions- intrusions

Lifhification- Process of converting sediment to sedimentary rock.

Limestone- Rock that is made up of at least 50% calcium carbonate; may be partly or wholly of biogenic origin.

Lithosphere- Rigid "skin" of the Earth; made up of the crust and upper part of the mantle.

Margin- A border.

Marine- Pertaining to the sea.

Marker bed- A distinctive, easily recognizable sedimentary bed that can be used for determining where you are in a sequences of strata.

Meander scroll- The topography, comprising low, curved ridges of relatively coarse sediment parellel to a river channel, of exhumed point bars resulting from differential erosion of beds in a truncated epsilon cross-stratified complex.

Metamorphic rock- Rock that has been altered by pressure, heat, or chemical fluids or a combination of these agents.

Monocline- assymetric fold with one limb dipping at a lower angle than the other.

Oceanic crust- A thin young crust (approximately seven kilometers) of three layers; upermost layer is of sediments, pillow lavas underlain by dikes are the middle layer, gabbroic and underlying ultrabasic rock on the bottom layer.

Orogenic- Refering to orogeny (mountain building); process of creating a mountain belt by tectonic activity usually by collision of continental plates. Characterized by regional metamorphism, igneous activity and vertical movements.

Pangea- The supercontinent comprising all the continental crust in the late Paleozoic, which split into supercontinents Laurasia and Gondwanaland.

Plateau- Relatively flat tract of level high ground

Sandstone- A sedimentary rock with greater than twenty five percent by volume of sand, sediment between .625 and 2mm in diameter.

Sediment- Matter which may settle to the bottom of liquid and given the right conditions may come together to form sedimentary rock.

Sedimentary rock- Rock formed by the consolidation of sediment.

Shale- Sedimentary rock made from clay and/or silt; Shale can be split into thin, irregular sheets.

Slag- The unwanted remains from the production of steel; includes dirt, limestone, iron ore and/ or dolostone .

Strata- Any sedimentary layer or bed.

Subduction- Process of underthrusting an oceanic plate into the asthenosphere at a destructive plate margin.

Tectonic- Pertaining to a major Earth structure and its formation

Thrust fault- Compressional fault with a low dip angle.

Trace fossils- (boigenic sedimentary structure, ichnofossil) - Structure in sediment produced by the activity of an ancient organism. Includes tracks, trails, and burrows.

Topography- the shape of the land surface.

Turbidite- A dense, sediment-rich currentof water; forms when a mass of sediment is abruptly dumped into a body of water.