A Natural Resource Management Guide for the County of Morris A ...

Glossary
BASALT Fine grained, dark colored, volcanic rock; dominant rock of Hook Mountain and Long Hill.
BEDROCK Solid rock below soil and rock fragments, sometimes exposed at surface.
CONGLOMERATE Pebbles or cobbles embedded in a fine-grained matrix of sand or silt. Reddish
Greenpond conglomerate was a frequent choice for foundations for the county's historic homes.
CONSOLIDATED SEDIMENTS Sediments compressed and/or cemented together into a rock.
DOLOMITE Crystalline calcium magnesium carbonate; a metamorphosed limestone. Common in the
Highlands.
GNEISS A coarse grained, metamorphic rock commonly composed of bands of mineral components,
which may include quartz, feldspar, mica, and hornblende. A dominant rock type of the Highlands.
GRANITE A coarse grained, igneous rock composed primarily of quartz and feldspar. Common in the
Highlands.
IGNEOUS ROCK One of three basic rock types formed by the cooling and solidification of lava.
MARBLE A recrystallized and metamorphosed limestone or dolomite.
METAMORPHIC ROCK One of three basic types of rock formed as the result of temperature, pressure,
shearing stress, or chemical activity, drastically changing the integrity of pre-existing rock.
QUARTZ A very common crystalline mineral, an oxide of silicon. Common in the Highlands.
SEDIMENTARY ROCK One of three basic types of rock formed by the consolidation and cementing of
loose sediments, such as sand, silt, or gravel.
SHALE A fine-grained sedimentary rock consisting of tightly packed sediments less than 1/16mm in
diameter. Most shales were formed from mud deposited on lake bottoms, along rivers, or in oceans.
SLATE A very fine grained rock, derived by the metamorphosis of rocks such as shale or volcanic ash.
TILL Rocky material (clay, sand, gravel, stones, boulders) picked up by glacial ice and deposited
elsewhere. Specific characteristics depend upon parent material. Most glacial till in Morris County derives
from Highlands rocks. Till may be stratified (sorted into layers according to the size of rock particles) or
mixed (unsorted and poorly stratified).
UNCONSOLIDATED SEDIMENTS Loose clay, sand, and gravel sediments.
A Natural Resource Management Guide
for the County of Morris 23