18E: The Statenville Formation
Middle Miocene
About 14 million years old
By Thurman Thurman
A Mystery of Terrestrial Miocene Fossils
The literature suggests that along the Alapaha River just west of Statenville, Miocene fossils are easily collected; they are not.
In Section 18A of this website we looked at the Miocene fossils Michael Voorhies collected and reported from Statenville, Georgia in 1974; 200 shark teeth, teeth from multiple terrestrial mammals, turtle, and even rhino remains. Fossils that dated to between 13 and 16 million years old. They were once housed at the University of Georgia Geology Department but have since been lost. So, there are historic and scientific reasons for revisiting, and perhaps expanding on Voorhies 1974 research.
The literature suggests that along the Alapaha River just west of Statenville, Miocene fossils are easily collected; they are not.
In Section 18A of this website we looked at the Miocene fossils Michael Voorhies collected and reported from Statenville, Georgia in 1974; 200 shark teeth, teeth from multiple terrestrial mammals, turtle, and even rhino remains. Fossils that dated to between 13 and 16 million years old. They were once housed at the University of Georgia Geology Department but have since been lost. So, there are historic and scientific reasons for revisiting, and perhaps expanding on Voorhies 1974 research.
When dealing with the vast Miocene epoch, which span 23.0 to 5.3 million years ago researchers usually turn to fossil dating by NALMA; North American Land Mammal Age. This breaks large blocks of time into more manageable chucks by correlating what other species are known to have existed at any point and time. NALMA actually extends from the Cretaceous to the present. But for our purposes here, we look at its breakdown of the Miocene.
NALMA dating through the Miocene (MYA=Million Years Ago)
- Hemphillian; 10.3 MYA to 4.9 MYA
- Clarendonian; 13.6 MYA to 10.3 MYA
- Barstovian; 15.97 MYA to 13.6 MYA
- Hemingfordian; 20.43 MYA to 15.97 MYA
- Arikareean; 30.8 MYA to 20.43 MYA
- Geringian; 30.8 MYA to 26.3 MYA
- Monroecreekian; 26.3 MYA to 24.8 MYA
- Harrisonian; 24.8 MYA to 20.43 MYA
Statenville’s fossils date to NALMA’s Barstovian Age.
As far as the Southeast goes, only Florida has a well explored Miocene record but it tends to run in the 5 to 10 million year old range (Hemphillian Age). Georgia’s seems a bit older.
Statenville is the county seat of Echols County, Georgia. It is about 18 air miles southeast of Valdosta and about 5.75 miles north of the Georgia/Florida line.
Voorhies reported “Except for the rhinoceros remains, all fossils were obtained from a small exposure about 15 yards long at the mouth of the small tributary that enters the river approximately 150 yards north (upstream) of the Georgia Highway 94 bridge at the western city limits of Statenville.”
Furthermore, Kyle Keller, the musician and amateur paleontologist, reported multiple horse teeth and petrified wood from the area. He and Hank Josey explored further and recovered additional mammal teeth, petrified wood and a coral fragment.
Furthermore, Kyle Keller, the musician and amateur paleontologist, reported multiple horse teeth and petrified wood from the area. He and Hank Josey explored further and recovered additional mammal teeth, petrified wood and a coral fragment.
The author has a bit of field experience… The 30/April/2022 drive from Warner Robins to Statenville was 2.5 hours each way. I was onsite at 9am on a Saturday morning and spent three hours prospecting, screening, observing and referencing Voorhies report.
For all that effort, I found one single trace fossil, a burrow cast which 1966 researchers attributed to the mud shrimp Callinassa.
For all that effort, I found one single trace fossil, a burrow cast which 1966 researchers attributed to the mud shrimp Callinassa.
Frustrated, but not defeated, I returned home to expand my research.
I’m not alone. In 1988 Paul Huddlestun reported; “The Statenville Formation is very sparsely fossiliferous.” And further down in his text he reports; “Most beds and many sections of the Statenville Formation, however, are barren of visible fossils.”
Clearly, there are gaps which need to be filled in the literature on hand.
I’m not alone. In 1988 Paul Huddlestun reported; “The Statenville Formation is very sparsely fossiliferous.” And further down in his text he reports; “Most beds and many sections of the Statenville Formation, however, are barren of visible fossils.”
Clearly, there are gaps which need to be filled in the literature on hand.
Visiting a site helps you understand it. Voorhies had good descriptions of what he observed, he was referencing and expanding on a detailed 1966 field trip report by Harold Kelly (H. K.) Brooks.
Standing amid the stratigraphy and reading the descriptions allows you to see what they saw and touch the same exposures.
It was immediately clear that Voorhies had at least one mistake in his text; or perhaps conditions had changed in the last 48 years. At any rate, there was no small tributary feeding into the Alapaha River 150 yard north of the Highway 94 bridge. Troublesome Creek feeds into it 350 yards north of the bridge. But about 230 yards north of the bridge, on the river’s east bank, the literature suggest that there’s an earthen dam.
Standing amid the stratigraphy and reading the descriptions allows you to see what they saw and touch the same exposures.
It was immediately clear that Voorhies had at least one mistake in his text; or perhaps conditions had changed in the last 48 years. At any rate, there was no small tributary feeding into the Alapaha River 150 yard north of the Highway 94 bridge. Troublesome Creek feeds into it 350 yards north of the bridge. But about 230 yards north of the bridge, on the river’s east bank, the literature suggest that there’s an earthen dam.
As this Google Earth image shows, Highway 94 bridges the Alapaha River in an east-west direction. The Alapaha River flows southward. There’s a boat ramp and parking lot on the west bank of the river and a cemetery on the east bank. The elevation at the boat ramp parking lot is about 100 feet above sea level. The elevation at the center of the cemetery is about 125 feet above sea level. Just north of the cemetery there’s a gentle hillcrest which is a promontory over a flood area. The highest point in the immediate area stands 148 feet above sea level.
The Alapaha River is one of Georgia’s smaller rivers and was on the low side when I visited. I watched two powered jon boats launch from the boat ramp, they could maneuver comfortably but a boat much larger would have to move very carefully. The current was quick, but the water was smooth and quiet.
The Alapaha River is one of Georgia’s smaller rivers and was on the low side when I visited. I watched two powered jon boats launch from the boat ramp, they could maneuver comfortably but a boat much larger would have to move very carefully. The current was quick, but the water was smooth and quiet.
Brooks (1966)
“Outcrops to be studied at this stop are located on the east bank of the Alapaha River and in a small tributary creek at an earthen dam north of the cemetery on the property of Mr. Dick Davis.” Then, on the next page. “Almost the entire section is fossiliferous, containing both vertebrate and invertebrate remains. (Bed 6)”
“During periods of minimum flow on the Alapaha, commonly late October to mid-November, one can stand in the channel on hard thin-bedded limestone layers which dip 10° to 12° southeast. They are, however, part of a sequence of large crossbeds which are truncated by unconsolidated Pleistocene (?) quartz sand, all of which are well exposed in the east bank of the river directly upstream of the GA 94 bridge.”
“Outcrops to be studied at this stop are located on the east bank of the Alapaha River and in a small tributary creek at an earthen dam north of the cemetery on the property of Mr. Dick Davis.” Then, on the next page. “Almost the entire section is fossiliferous, containing both vertebrate and invertebrate remains. (Bed 6)”
“During periods of minimum flow on the Alapaha, commonly late October to mid-November, one can stand in the channel on hard thin-bedded limestone layers which dip 10° to 12° southeast. They are, however, part of a sequence of large crossbeds which are truncated by unconsolidated Pleistocene (?) quartz sand, all of which are well exposed in the east bank of the river directly upstream of the GA 94 bridge.”
Bed Description Thickness in feet
8 Soil, sandy 1.5
7 Sand & clay, pure clay beds to 6” thick, weathered. 1.5
6 Sand, yellowish gray to grayish orange, moderate amounts of 6.0
clay matrix, oblate spheroidal quartz pebbles to 10mm dia-
meter, irregular clay laminae, emphasizing cross-bedding, dip
southward; moderate to abundant phosphate particles, dark
brown to very pale yellowish brown, granule to pebble size,
displaying typical highly polished porcelain-like luster;
fossiliferous, containing large terrestrial tortoise, shark, skate
and ray teeth.
5 Clay, greenish clay, weathered to grayish orange and moderate yel- 6.0
lowish brown, and sand, grayish orange to moderate yellowish
brown, equal proportions, thinly bedded ¼ to ½ inch thick, hor-
izontal; minor amounts of phosphate particles.
4 Clay, greenish grey, pure, semi-consolidated, thins sand stringers 1.6
separating beds ¾ to 2” thick; abundant blue quartz grains and
black and green phosphate particles in sand partings; occasion-
al very poorly preserved barnacle fragments.
3 Sand, grayish orange to moderate yellowish brown, medium to 2.0
coarse, with granules and an occasional pebble; coarse particles
medium to well rounded; phosphatic particles nearly black,
weathering to cream and white, medium to coarse; irregular, pure
clay partings, gray, weathering to moderate yellowish brown,
bedding horizontal; fossiliferous, with abundant poorly preserved
compartmental and opercular plates of a small species of Balanus,
a barnacle.
2 Sand, weathered light brown, medium to coarse, occasional quartz 4
pebbles are mostly oblate spheroids, coarse particles are well
rounded, crossbedded, complex, with most sets dipping southward;
phosphate patrticles abundant; clayey sand partings present, but
much less evident than in underlying bed, fossiliferous with shark
teeth and burrows of Callinassa sp., a shrimp, this porous unit is
highly weathered in outcrop.
1 Sand, greenish gray to medium dark gray, coarse to medium, 7.7
occasional pebbles to 10 mm, coarse particles well rounded to
sub-rounded, 2% to 5% bluish quartz grains, slightly calcareous,
black phosphate particles, weathering to orange and brown,
10% to 20%. Major sets of beds 4” to 8” thick, dipping south-
ward 5° to 10°, supplemental cross bedding within major
sets dipping 15° to 30°; crossbedding evident due to fine sandy
partings, light olive green, ¼ to ½ inch thick, cemented with
dolomite, and containing rounded pebble and cobble clasts
of same material; horizontal dolomitized sandy parting at top
of this unit is 0” to 4” thick, ands contains rounded clasts up
to 90mm diameter. Burrows of Callinassa sp are common.
Total thickness (Brooks 1966) 30.0ft
8 Soil, sandy 1.5
7 Sand & clay, pure clay beds to 6” thick, weathered. 1.5
6 Sand, yellowish gray to grayish orange, moderate amounts of 6.0
clay matrix, oblate spheroidal quartz pebbles to 10mm dia-
meter, irregular clay laminae, emphasizing cross-bedding, dip
southward; moderate to abundant phosphate particles, dark
brown to very pale yellowish brown, granule to pebble size,
displaying typical highly polished porcelain-like luster;
fossiliferous, containing large terrestrial tortoise, shark, skate
and ray teeth.
5 Clay, greenish clay, weathered to grayish orange and moderate yel- 6.0
lowish brown, and sand, grayish orange to moderate yellowish
brown, equal proportions, thinly bedded ¼ to ½ inch thick, hor-
izontal; minor amounts of phosphate particles.
4 Clay, greenish grey, pure, semi-consolidated, thins sand stringers 1.6
separating beds ¾ to 2” thick; abundant blue quartz grains and
black and green phosphate particles in sand partings; occasion-
al very poorly preserved barnacle fragments.
3 Sand, grayish orange to moderate yellowish brown, medium to 2.0
coarse, with granules and an occasional pebble; coarse particles
medium to well rounded; phosphatic particles nearly black,
weathering to cream and white, medium to coarse; irregular, pure
clay partings, gray, weathering to moderate yellowish brown,
bedding horizontal; fossiliferous, with abundant poorly preserved
compartmental and opercular plates of a small species of Balanus,
a barnacle.
2 Sand, weathered light brown, medium to coarse, occasional quartz 4
pebbles are mostly oblate spheroids, coarse particles are well
rounded, crossbedded, complex, with most sets dipping southward;
phosphate patrticles abundant; clayey sand partings present, but
much less evident than in underlying bed, fossiliferous with shark
teeth and burrows of Callinassa sp., a shrimp, this porous unit is
highly weathered in outcrop.
1 Sand, greenish gray to medium dark gray, coarse to medium, 7.7
occasional pebbles to 10 mm, coarse particles well rounded to
sub-rounded, 2% to 5% bluish quartz grains, slightly calcareous,
black phosphate particles, weathering to orange and brown,
10% to 20%. Major sets of beds 4” to 8” thick, dipping south-
ward 5° to 10°, supplemental cross bedding within major
sets dipping 15° to 30°; crossbedding evident due to fine sandy
partings, light olive green, ¼ to ½ inch thick, cemented with
dolomite, and containing rounded pebble and cobble clasts
of same material; horizontal dolomitized sandy parting at top
of this unit is 0” to 4” thick, ands contains rounded clasts up
to 90mm diameter. Burrows of Callinassa sp are common.
Total thickness (Brooks 1966) 30.0ft
When the author visited on 30/April/2022, two vertical feet of the angled, crossbedded sediments were above the river, so the river levels were low, but they get lower.
Brooks reported 5 beds that held fossils in 1966 field trip report
Bed 6; “fossiliferous, containing large terrestrial tortoise, shark, skate and ray teeth”
Bed 4; “very poorly preserved barnacle fragments.”
Bed 3; “fossiliferous, abundant poorly preserved… species of Balanus, a barnacle.”
Bed 2: “fossiliferous with shark teeth and burrows of Callinassa sp., a shrimp.”
Bed 1: “Burrows of Callinassa sp are common”
Brooks reported 5 beds that held fossils in 1966 field trip report
Bed 6; “fossiliferous, containing large terrestrial tortoise, shark, skate and ray teeth”
Bed 4; “very poorly preserved barnacle fragments.”
Bed 3; “fossiliferous, abundant poorly preserved… species of Balanus, a barnacle.”
Bed 2: “fossiliferous with shark teeth and burrows of Callinassa sp., a shrimp.”
Bed 1: “Burrows of Callinassa sp are common”
Voorhies (1974)
Voorhies in 1974 seems very specific in his description of the beds, but this is misleading.
Again, Voorhies reported in 1974 that all the fossils he collected except the rhino material came from “…a small exposure about 15 yards long at the mouth of the small tributary that enters the river approximately 150 yards north of the Georgia Highway 94…”
Bed 1
“Brooks’ Bed 1…small black phosphorite pebbles and some small shark teeth were found in this unit…”
Bed 2
“All fossils in the Statenville local fauna except from the rhinocerous, were collected from a phosphorite pebble lens at the base of unit number 2 (Bed 2).
Bed 6
“A layer of fine gray sand with a few with a few phosphorite pebbles at the base (Brooks Bed 6) overlies the preceding strata, possibly disconformably although no evidence of profound erosion was observed. The rhinoceros bones were collected for near the top of this unit which measures about 6 feet in thickness.”
Voorhies in 1974 seems very specific in his description of the beds, but this is misleading.
Again, Voorhies reported in 1974 that all the fossils he collected except the rhino material came from “…a small exposure about 15 yards long at the mouth of the small tributary that enters the river approximately 150 yards north of the Georgia Highway 94…”
Bed 1
“Brooks’ Bed 1…small black phosphorite pebbles and some small shark teeth were found in this unit…”
Bed 2
“All fossils in the Statenville local fauna except from the rhinocerous, were collected from a phosphorite pebble lens at the base of unit number 2 (Bed 2).
Bed 6
“A layer of fine gray sand with a few with a few phosphorite pebbles at the base (Brooks Bed 6) overlies the preceding strata, possibly disconformably although no evidence of profound erosion was observed. The rhinoceros bones were collected for near the top of this unit which measures about 6 feet in thickness.”
Voorhies Continues
Preservation of the Fossils
“The collection exists almost entirely of isolated teeth of mammals and fish. Except for the associated rhinoceros bones, the fossils all show signs of transportation – abrasion and breakage – although very few are badly rounded.”
“The rhinoceros bones were collected in fine grained sediment and show no evidence of transportation.”
“The color of the teeth range from black and gray through tans and browns, much like the range in colors in the phosphate pebbles associated with them. Because the color changes do not appear to correlate with either taxonomy or degree of abrasion and because several colors often occur within a single fossil, color does not appear to provide a useful criterion for distinguishing fossils of different chronological or environmental provinces.”
Preservation of the Fossils
“The collection exists almost entirely of isolated teeth of mammals and fish. Except for the associated rhinoceros bones, the fossils all show signs of transportation – abrasion and breakage – although very few are badly rounded.”
“The rhinoceros bones were collected in fine grained sediment and show no evidence of transportation.”
“The color of the teeth range from black and gray through tans and browns, much like the range in colors in the phosphate pebbles associated with them. Because the color changes do not appear to correlate with either taxonomy or degree of abrasion and because several colors often occur within a single fossil, color does not appear to provide a useful criterion for distinguishing fossils of different chronological or environmental provinces.”
“Although some of the fossils may be reworked there is no biostratigraphic evidence of heterochronity and reworking need not be invoked to account for the presence of both marine and terrestrial fossils in the same bed, particularly in such deltaic/estuarine sediments as those in Statenville.”
“Preservation of several complete and unabraided bones of a single rhinoceros in the fine- grained sandstone at the top of the Statenville exposure suggest a different mode of origin from that of the principal fossil concentration in the phosphorite pebble zone. Although the rhinocerous bones were not articulated they were not widely scattered indicating that no significant transportation had occurred after disarticulation. Perhaps the remains represented a bloated carcass that floated down from the adjacent mainland and then sank in relatively quiet water where it was buried by fine sand and silt before much scattering occurred.”
“Preservation of several complete and unabraided bones of a single rhinoceros in the fine- grained sandstone at the top of the Statenville exposure suggest a different mode of origin from that of the principal fossil concentration in the phosphorite pebble zone. Although the rhinocerous bones were not articulated they were not widely scattered indicating that no significant transportation had occurred after disarticulation. Perhaps the remains represented a bloated carcass that floated down from the adjacent mainland and then sank in relatively quiet water where it was buried by fine sand and silt before much scattering occurred.”
“A sample of sediment enclosing the rhinoceros was submitted to Dr. E. A. Stanley for micro-faunal analysis. Dr. Stanley reports (oral communication) that no calcareous microfossils or pollen could be found in the sample but that hystricosphaerids are present. Hystricosphaerids, so far as is known (1966), are restricted to strata deposited in marine or brackish waters. (Hystricosphaerids have since been reassigned.)
Invertebrates
Voorhies 1974
Mega-invertebrate fossils appear to be rare in the cross-bedded clastics at Statenville. Occasional obscure molds and some barnacle plates were observed. Burrows of the Ophimorpha type are fairly common in the sands below the principal bone-bearing horizon. These are regarded as indicators of litoral and shallow neritic marine environment. In the fossiliferous phosphoritic pebble horizon, sinuous, ramifying burrows about one inch in diameter and up to a yard long were observed to penetrate the sediment in a more-or-less horizontal orientation. They resemble the burrows of the shrimp Upogebia affinis investigated by Frey and Howard (1969) in tidal stream deposits on Sapelo Island, Georgia. These burrows lack the pelletoid wall structure typical of Ophiomorpha.
Voorhies 1974
Mega-invertebrate fossils appear to be rare in the cross-bedded clastics at Statenville. Occasional obscure molds and some barnacle plates were observed. Burrows of the Ophimorpha type are fairly common in the sands below the principal bone-bearing horizon. These are regarded as indicators of litoral and shallow neritic marine environment. In the fossiliferous phosphoritic pebble horizon, sinuous, ramifying burrows about one inch in diameter and up to a yard long were observed to penetrate the sediment in a more-or-less horizontal orientation. They resemble the burrows of the shrimp Upogebia affinis investigated by Frey and Howard (1969) in tidal stream deposits on Sapelo Island, Georgia. These burrows lack the pelletoid wall structure typical of Ophiomorpha.
Tredford, Hunter 1984
Marine & Nonmarine Vertebrates
In the wake of Voorhies 1974 Echols County Paper, Richard Tredford and Muriel Hunter published a 1984 review of Miocene vertebrates of the southeastern Coastal Plain. They were cross referencing coastal land vertebrates recovered from marine sediments with mollusks, foraminifera, and diatoms with planktonic foraminiferal zones in an effort to increase dating accuracy. They reviewed and discussed the Statenville finds. (*)
“Echols County, Georgia (Statenville Local Fauna; Voorhies, 1974) represent an early phase of the late Barstovian on the bases of their contained horses species of "Merychippus", Calippus and Cormohipparion which compare most closely with forms from the lower part of the Valentine Formation of Nebraska (early late Barstovian). The terrestrial vertebrate remains are associated with estuarine sharks and rays and occur at 30-50 m above sea level. This assemblage apparently represents a fauna coeval with a depositional phase within the medial Miocene transgression.”
While Tredford and Hunter agree with Voorhies’ Merychippus identification they expand the list to three different genre of horse in the Statenville deposits; Merychippus, Calippus and Cormohipparion.
Marine & Nonmarine Vertebrates
In the wake of Voorhies 1974 Echols County Paper, Richard Tredford and Muriel Hunter published a 1984 review of Miocene vertebrates of the southeastern Coastal Plain. They were cross referencing coastal land vertebrates recovered from marine sediments with mollusks, foraminifera, and diatoms with planktonic foraminiferal zones in an effort to increase dating accuracy. They reviewed and discussed the Statenville finds. (*)
“Echols County, Georgia (Statenville Local Fauna; Voorhies, 1974) represent an early phase of the late Barstovian on the bases of their contained horses species of "Merychippus", Calippus and Cormohipparion which compare most closely with forms from the lower part of the Valentine Formation of Nebraska (early late Barstovian). The terrestrial vertebrate remains are associated with estuarine sharks and rays and occur at 30-50 m above sea level. This assemblage apparently represents a fauna coeval with a depositional phase within the medial Miocene transgression.”
While Tredford and Hunter agree with Voorhies’ Merychippus identification they expand the list to three different genre of horse in the Statenville deposits; Merychippus, Calippus and Cormohipparion.
Huddlestun 1988
The Statenville Formation is very sparsely fossiliferous. Molds and casts of mollusks occur locally in moderate frequency in the dolomitic beds. Fossils with calcitic shells, such as scallops, oysters, and barnacles are very rare. Voorhies (1974b) reported a meager assemblage of vertebrate fossils from the type locality of the formation. Vertebrate fossil debris, such as small fish teeth and bones, is not rare in the phosphatic beds of the formation, and the trace fossil Ophiomorpha nodosa is locally common in sand beds on both the Alapaha and Suwannee Rivers. Most beds and many sections of the Statenville Formation, however, are barren of visible fossils.
The Statenville Formation is very sparsely fossiliferous. Molds and casts of mollusks occur locally in moderate frequency in the dolomitic beds. Fossils with calcitic shells, such as scallops, oysters, and barnacles are very rare. Voorhies (1974b) reported a meager assemblage of vertebrate fossils from the type locality of the formation. Vertebrate fossil debris, such as small fish teeth and bones, is not rare in the phosphatic beds of the formation, and the trace fossil Ophiomorpha nodosa is locally common in sand beds on both the Alapaha and Suwannee Rivers. Most beds and many sections of the Statenville Formation, however, are barren of visible fossils.
All that said...
There's more going on.
Kyler Keller, the intrepid musician and fossil hunter, kept reporting to Hank Josey and I that there was more going on in Statenville that was reported in the literature. He was kayaking and walking the water, screening for samples and recovering horse teeth, shark teeth, and petrified wood, and from the river during low levels.
In October 2016 Hank Josey loaded his kayak and went down to join Kyle for a day on the water. They created this photo record.
There's more going on.
Kyler Keller, the intrepid musician and fossil hunter, kept reporting to Hank Josey and I that there was more going on in Statenville that was reported in the literature. He was kayaking and walking the water, screening for samples and recovering horse teeth, shark teeth, and petrified wood, and from the river during low levels.
In October 2016 Hank Josey loaded his kayak and went down to join Kyle for a day on the water. They created this photo record.
Clearly more work needs to be done in Statenville.
References
Brooks, H. K.; Gremillion, L. Ray; Olson, Norman K.; Puni, S. Harbans; Geology Of The Miocene And Pliocene Series; Atlantic Coastal Plain Geological Association & Southeastern Geological Society; Guidebook, Annual Field Conference, November, 1966
Voorhies, Michael R.; Late Miocene Terrestrial Mammals Echols County, Georgia Published in Southeastern Geology, 1974B
Tedford, Richard H. & Hunter, Muriel E.; Miocene Marine-Nonmarine Correlations, Atlantic and Gulf Coast Plains, North America; Palaeogeography, Palaeoclimatology, Palaeoecology, 47 (1984): 129-151
Huddlestun, Paul, F.; A Revision of the Lithostratigraphic Units of the Coastal Plain of Georgia. The Miocene Through Holocene, Bulletin 104, Georgia Geologic Survey, 1988