Alluvium – Unconsolidated gravel, sand, and finer rock debris deposited principally by running water. Found locally on the floors of canyons and valleys.
Anticline – a fold in layered rock, convex upward, with older rocks toward the core.
Basement Complex – the surface beneath which sedimentary rocks are not found; the igneous, metamorphic, granitized, or highly deformed rock underlying sedimentary rocks.
Bedding Plane – the dividing plane that separates each layer in a sedimentary or stratified rock from layers below and above it.
Coast Ranges Orogeny – A time, mostly during the late Pliocene, of major deformation (mostly mountain building and faulting), metamorphism, and volcanic activity in the Coast Ranges in California.
Disconformity – an unconformity in which the beds above and below an erosion surface are concordant. These mark breaks in the geologic timeline.
Facies – an assemblage or association of mineral, rock, or fossil features reflecting the environment and conditions of origin of the rock.
Headward Erosion – the lengthening of a valley or gully, or of a stream, by erosion at the valley head
Orogeny – period of intense mountain building by way of folding, thrusting, or volcanism
Perennial – flowing year round, as opposed to Intermittent, flowing seasonally
Syncline – a downward fold in layered rock, primarily sedimentary rocks, caused by compression forces ; opposite of an Anticline
Terrace – Step-like landform consisting of a flat tread and a steep riser, commonly of fluvial (river), lacrustine (lake), or marine origin.
Thrust Fault or Zone – Gently inclined reverse fault along which one block is thrust over the other.