Question

On a geologic map, different rocks are represented by symbols of letters, such as Png or Zwr. What does the first letter always stand for in these symbols?

Answer 1

The actually mean ages. 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. Here's a reading you can follow: http://geology.about.com/od/maps/ss/How-To-Read-A-Geologic-Map_6.htm

Answer 2

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