Maps available from MDEQ

(JACKSON, Miss.) – What types of rocks are in my neighborhood?  Where are mineral resources located?  How does geology shape the hills and valleys of Mississippi?  What are the oldest and youngest rocks in Mississippi?

The answers to these questions and more can be found on the Mississippi Department of Environmental Quality (MDEQ)’s website at

MDEQ’s Office of Geology is promoting its geologic map resources by recognizing national Geologic Map Day on October 18.  Geologic maps of the State of Mississippi, many of the counties, and 133 individual quadrangles may be viewed on the agency’s website and are available for free download in PDF format.

“Our systematic program of detailed surface geologic mapping has produced 133 geologic quadrangle maps (and growing) that are being used for environmental analyses, exploration for mineral resources, and engineering applications,” said Michael Bograd, State Geologist and director of the MDEQ Office of Geology.

What are your questions about geologic maps?   As an example:  What are the oldest and youngest rocks in Mississippi?

The answer is found on the state geologic map:$File/MS_Geology1969.pdf?OpenElement

And the answer is that the oldest rocks at the surface in Mississippi are the Chattanooga Shale and Devonian Limestone.  This outcrop is depicted by a small patch of dark purple in northern Tishomingo County.  This unit is at the bottom of the explanation, or legend.  The rocks of the stratigraphic column get younger as you go up.  In the legend, Alluvium, the youngest geologic formation (actually sediments) in the state, is at the top of the list.  If you look at the geologic units in the legend one by one, starting at the bottom, and locate the same units on the map, you will see that the oldest rocks are in northeastern Mississippi and the rocks get progressively younger as you move to the west and the south.

To search for more answers, go to the Mississippi Department of Environmental Quality website:, scroll down to the Office of Geology link, and start exploring.

The List of Publications provides links to free downloads of many publications.  The county geologic reports are found in the list of Bulletins, and the geologic quadrangles are found under Open-File Reports.

A poster size Geologic Map of Mississippi printed at the scale of 1:500,000 is available at the Map and Publication Sales Office at 700 North State Street, Jackson.  It measures 35.5 by 46 inches and sells for $7.00.  Call 601-961-5523 for information about postage and handling charges if ordering by mail.

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