What is letter symbols in geological map?

The letter symbols signify the name and age of the rock units in an area. The first letter refers to the geologic age, as shown above. The other letters refer to the formation name or the rock type.

What do the numbers on a geologic map mean?

If you imagine a random sheet of newspaper lying on that street, lineation is the printing on it, and the arrow shows the direction it reads. The number represents the plunge or the dip angle in that direction. The full documentation of geologic map symbols is specified by the Federal Geographic Data Committee. 06.

How do you read a geological map?

A geologic map shows the geological features of a region (see figure 4 for an example). Rock units are color-coded and identified in a key. Faults and folds are also shown on geologic maps. The geology is superimposed on a topographic map to give a more complete view of the geology of the region.

What information is shown on geologic maps?

Geologic maps represent the distribution of different types of rock and surficial deposits, as well as locations of geologic structures such as faults and folds. Geologic maps are the primary source of information for various aspects of land-use planning, including the siting of buildings and transportation systems.

What do colors represent on a geologic map?

Geologic maps use color to represent various types of geologic features or units (a particular type of rock with a known age range). Geologic units are indicated by colors that can range from yellows and reds to purples and browns. Not only are geologic units assigned a color but also a set of letters.

What are strike and dip symbols?

Geologists use a special symbol called strike and dip to represent inclined beds (Figure 2). Strike and dip map symbols look like the capital letter T, with a short trunk and extra-wide top line. The short trunk represents the dip and the top line represents the strike.