Angular Unconformity - an unconformity in which the older strata dip at a different angle than the younger strata.

Basalt - any fine crystalline black igneous rock.

Beds - the smallest division of a series of layered sedimentary rocks.

Breccia - a sedimentary rock consisting of variable sized angular, particles that are transported a short distance to the site of deposition. These particles may be transported by streams or mudflows.

Cephalopods - a marine invertebrate characterized by a head surrounded by tentacles.

Clasts - the particles that are transported to the site of deposition and deposited to form sedimentary rock.

Coal Seam - an accumulation of vegetable matter that is buried and compressed into a black to brown rock like material and results in a layer of coal.

Conglomerate - rounded, water worn, fragments of rock of varying sizes that is cemented together into a rock.

Crinoids - a type of echinoiderm (spiny skin organism) consisting of a cup or "head" numerous radiating arms, on an elongated jointed stem and a root like structure that attached to the ocean bottom.

Cross Bedded - an arrangement of very thin beds that slope at an angle to the main bedding planes.

Cut and Fill - a structure resulting from the erosion of a channel by a stream and subsequent deposition to fill the channel.

Eocene Epoch - a time interval of the geologic time scale that represents the time from 57 to 36 million years ago.

Formation - a unit or rock with well defined upper and lower boundaries that is unique and mappable.

Fossil - the remains of traces of animals and plants which have been preserved by natural processes in the earth's crust.

Gastropods - snails, usually with a coiled calcareous shell.

Geologic Units - a recognized body of rock material that is mappable. An example would be a formation.

Hydraulic Mining - a method of mining in which a bank of gold bearing gravel is washed away by a powerful jet of water and carried into the sluices where the gold separated from the gravel by its specific gravity.

Marble - a metamorphic rock composed of calcite. Essentially a metamorphosed limestone.

Metamorphic Rocks - Rocks that have been transformed in response to profound changes of temperature, pressure, and chemical environment without ever melting.

Mud Cracks - polygonal cracks that occur during the drying of mud.

Pelecypods - a division of mollusks, commonly called clams.

Phyllite - a clay bearing rock with a silky sheen that has been subjected to a low grade of metamorphism.

Quartzite - is a metamorphic rock that results from the metamorphism (heat and pressure) of the sedimentary rock quartz sandstone.

Sandstone - a sedimentary rock consisting of rock and mineral particles ranging in size from 1/16 to 2 mm in diameter.

Sedimentary Rocks - rocks formed by the settling of particles in water or air. These accumulations result in layers and bedding.

Triassic Period - a period of time that began 245 million years ago and ending 208 million years ago.

Unconformity - a surface of erosion or non-deposition that separates younger strata from older rocks. This usually occur during periods of uplift or falls in sea level.

Volcanic Ash - volcanic ejection from a volcanic explosion that is transported through the air and subsequently accumulates as layers on the earth's surface.

Volcanic mud flow - also known as a lahar, a sedimentary rock of limited distribution resulting from pyroclastic material on a volcanic slope becoming saturated with water and begins to flow down hills as a viscous mass of volcanic debris.