Kaibab Limestone Toroweap Formation Coconino Sandstone. Hermit Shale. Redwall Limestone. Muav Limestone. Bright Angel Shale.

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Elfreda Dean
5 years ago
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1 ITHOSTRATIGRAPHY

2 Kaibab imestone Toroweap Formation Coconino Sandstone Hermit Shale Redwall imestone Muav imestone Bright Angel Shale Tapeats imestone Brahma Schist

3 These are the Paleogene rocks that occur along the Flint River between Montezuma and the dam at ake Blackshear. Paleocene Eocene Oligocene M Bridgeboro imestone Ocala imestone Clinchfield Sandstone isbon Formation Tallahatta Sandstone Hatchetigbee Formation Tuscahoma Sandstone Nanafalia Formation Clayton Formation Youngest Oldest

4 The Bridgeboro imestone was first recognized and described from a quarry near Bridgeboro, GA (southeast of Albany). It can be traced from Dublin, GA (near Macon) to the western part of Florida. The Ocala imestone was first recognized at Ocala, F (central part of the state). It can be traced from central Florida to near Macon, GA and westward to southeastern Mississippi. Paleocene Eocene Oligocene M Bridgeboro imestone Ocala imestone Clinchfield Sandstone isbon Formation Tallahatta Sandstone Hatchetigbee Formation Tuscahoma Sandstone Nanafalia Formation Clayton Formation The Clinchfield Sandstone was described at Clinchfield, GA (near Perry). It can be traced southwestward to near Albany, GA. The isbon Formation was described at isbon Bluff, A and can be traced eastward to near Americus and westward to ouisiana. In the Americus area it contains Sands, mudstones, and limestone. The limestone is less common west of here. The Tallahatta Sandstone was described in the Tallahatta Hills in western Alabama, and can be traced from the Flint River westward to Mississippi. The Hatchetigbee Formation was described from Hatchetigbee Bluff on the Tombigbee River in western Alabama. It comprises sand and clay, some of the clay a bit limy. It thins into both Mississippi and Georgia and is difficult to find near Americus. At Andersonville it is apparently missing (because of a disconformity). The Tuscahoma Sandstone was described near Tuscahoma, Alabama and stretches from western Georgia to Mississippi. The Nanafalia was described at Nanafalia Bluff on the Tombigbee, and can be traced from Georgia to Mississippi. It comprises mudstone and sandy mudstone. The kaolin mined at Andersonville is from the Nanafalia. The Clayton Formation (named for Clayton, A) is a complex mix of sandstones, mudstones, and limestones. Near the Flint it is mostly mudstone with oyster reefs. Near Cuthbert, GA and on the Chattahoochee it is almost all limestone, westward it becomes less lime. It extends from near here to western Tennessee and Arkansas.

5 All the units of rock on the preceding page are formations. This is the basic unit of lithostratigraphy. A formation is defined as a package of sedimentary rocks of a certain minimum thickness, and of an easily recognized character, and that can be easily distinguished from the formations above and below, and that can be traced or correlated over a considerable distance. The locations on the preceding page are the type sections. The rocks were first described there and their top and bottom contacts characterized. They are found (mostly) from Mississippi to Georgia with similar characteristics and always in the same vertical order. The type section is always the first part of the name of a formation. The second part may be descriptive of the rock (Bridgeboro imestone, for example) or just the word Formation if the rock type is variable (Clayton Formation, for example).

This is a picture of the Bridgeboro imestone at the type section (at Bridgeboro, GA). The people are standing on mining rubble. In-place rock starts at the girl s feet.

6 This is a picture of the Bridgeboro imestone at the type section (at Bridgeboro, GA). The people are standing on mining rubble. In-place rock starts at the girl s feet. The formation is at least twice as thick as what you see. Notice that it contains thinner beds than itself. Some are cherty (the blackish ones) some have very course algal fossils (behind the girl and near the top) and some are finer grained (above the chert). All are limestone (or silicified limestone). ook carefully near where the girl is and you ll see even thinner layers inside these. The Bridgeboro is a layer of limestone that contains even thinner layers. All formations are like this.

7 Paleocene Eocene Oligocene M Bridgeboro imestone Ocala imestone Clinchfield Sandstone isbon Formation Tallahatta Sandstone Hatchetigbee Formation Tuscahoma Sandstone Nanafalia Formation Clayton Formation

8 All the formations (except the Hatchetigbee) can be seen on a float trip down the Flint River from just north of Montezuma to the Dam, or in nearby quarries. (Some are covered by the waters of ake Blackshear and can only be seen at exceptionally low water levels.) Paleocene Eocene Oligocene? M Bridgeboro imestone Ocala imestone Clinchfield Sandstone isbon Formation Tallahatta Sandstone Hatchetigbee Formation Tuscahoma Sandstone Nanafalia Formation Clayton Formation Notice that they are encountered in superpositional order as you go downstream older farther north and progressively younger southward. (North is not up. When you look at the map you are looking straight down ). Why is this?

9 All the rocks dip generally southward at a very low angle roughly the angle of the continental shelf they were deposited on. (Most have marine organisms in them). 1-2 The older ones dip beneath the younger ones southward.

10 N (land surface) S Bridgeboro Ocala Clinchfield isbon Tallahatta Dips are greatly exaggerated! Hatchetigbee Tuscahoma Nanafalia Clayton

11 Dam GA Vet. St. Pk. Bridgeboro Ocala N. Spring Cr. Cir. Ocala Danville Bluff Ocala Clinchfield isbon Powerline Crossing Reeves anding Tallahatta Hatch.?? Tallahatta Andersonville Quarries Tallahatta Tuscahoma Montezuma Bluffs Nanafalia Clayton

12 WF George Dam Nanafalia Clayton Roaring Creek Tuscahoma Nanafalia Abbie Creek area Tallahatta Hatchetigbee The same pattern holds along the Chattahoochee River, but the sandstone between the isbon and Ocala looks different more like a sand at Moodys Branch, near Jackson, MS. They are in the same position, but look different. Tuscahoma Columbia, A isbon Tallahatta Andrews Dam Moodys Br. isbon S 84 Bridge Ocala Moodys Br. ake Seminole Bridgeboro Ocala

13 ODER TO NORTH YONGER TO SOTH

14 Paleocene Eocene Oligocene M Bridgeboro imestone Ocala imestone Moodys Br. Sandstone isbon Formation Tallahatta Sandstone Hatchetigbee Formation Tuscahoma Sandstone Nanafalia Formation Paleocene Eocene Oligocene M Bridgeboro imestone Ocala imestone Clinchfield Sandstone isbon Formation Tallahatta Sandstone Hatchetigbee Formation Tuscahoma Sandstone Nanafalia Formation Clayton Formation Clayton Formation

15 Paleocene Eocene Oligocene M Bridgeboro imestone Ocala imestone Moodys Br. Sandstone isbon Formation Tallahatta Sandstone Hatchetigbee Formation Tuscahoma Sandstone Nanafalia Formation Bridgeboro imestone Ocala imestone Clinchfield Sandstone isbon Formation Tallahatta Sandstone Hatchetigbee Formation Tuscahoma Sandstone Nanafalia Formation Clayton Formation Clayton Formation

Unconformities are depositional contacts that overlie rocks distinctly older than they are. They are often called gaps in the sedimentary record.

UNCONFORMITIES Unconformities are depositional contacts that overlie rocks distinctly older than they are. They are often called gaps in the sedimentary record. The contact represents time when no sediment