Leon County Pleistocene coastal terraces
Encyclopedia
Leon County Pleistocene coastal terraces and shorelines were the geologic result of warming and cooling periods in what is now Leon County, Florida
during the Pleistocene epoch.
s and shorelines were named by various geologists, verified and mapped by the USGS. Each glacial retreat caused sea level to rise less than the previous warming event, giving an extremely accurate depiction of the appearance of Florida. Leon County was studied in detail by C. W. Hendry and C. Sproul in 1966.
MacNeil's high Pliocene
terrace. Deposits are found between 97 to 65.5 meters (320—215 feet). During the interstadial period of late Pliocene to early Pleistocene epoch, the Hazelhurst terrace and shoreline was created in many counties east to west. Gadsden
in particular had a very large land mass not only created by rising and lowering sea levels, but from depositions from the Apalachicola River
on Gadsden's west side. Leon County remained completely submerged.
in North Carolina
. It is associated with a Pre-Illinoian interglacial, most probably the disused Yarmouthian interglacial and was the third rise in sea level during the Early Pleistocene glacial retreat and left behind dry land in the form of six distinct islands. The Coharie is defined by sediments at 65 to 52 meters (215-170 feet) above current mean sea level. In Florida the Coharie is included with the Sunderland terrace in USGS mapping.
One ancient island appeared in the extreme northwest portion of the county near the junction of Meridian Road and County Road 12. The second island was located in the general vicinity of U.S. 319 and Sunnyhill Road just south of the Florida/Georgia
border. The third of the northern islands of the Coharie was located in extreme northeast portion of the county and overlapping the county line between Leon and Jefferson County
.
To the south lay 3 more islands. The first was located generally north and near Elinor Klapp-Phipps Park
and surrounding area. The second and largest covered the area where most of Tallahassee is today. It extended from near Interstate 10
in the north to the capitol complex in the south, to just east of State Road 263. The third island was to the west and encompassed an area near Arvah Branch including I-10, U.S. 90, and north to Miccosukee Road.
. It includes deposits of the Sunderland terrace assigned by Cooke. It is associated with a Pre-Illinoian interglacial (Yarmouthian) and was the third rise in sea level during the Early Pleistocene glacial retreat. The Okefenokee is defined by sediments at 52 to 30.5 meters (170—100 feet) above current mean sea level. The dry land mass left behind can best be described as an oddly shaped peninsula
overlaying the islands of the Coharie as well as added land that is connected to adjacent peninsulas in other counties.
During the forming of the Okefenokee, the Ochlockonee River
began to take shape as did rivers in other counties in Florida. The large inlet in the northeastern part of the county left the land capable of supporting a more recognizable Lake Iamonia. Eastern Leon had a large inlet reaching as far as the northeastern portion of the county. The Cody Scarp
is the remnant of the Okefenokee. What would become Lake Lafayette is a Pleistocene river delta with the lake's eastern section accessing the sea.
in St. Mary's County, Maryland and Charles County, Maryland
. The Wicomico is associated with the Sangamonian interglacial
between 75,000 and 125,000 years ago. and was the fourth rise in sea level during the Early Pleistocene glacial retreat. The Wicomico is defined by sediments located at 30.5 to 21 meters (100-70 feet) above current mean sea level. The Wicomico is well developed in northeastern and extreme northwestern Florida. At this time the county is mostly dry except for the southern coastline. The Cody Scarp
is a shoreline of the Wicomico as well as the aforementioned Okefenokee. The Ocklochonee River empties in to a large, wide estuary or inlet leading to the sea. The ground for what will be the Tallahassee Regional Airport
remains underwater.
and is associated with the Sangamonian interglacial. The Penholoway is defined by sediments located at 21 to 13 meters (70-42 feet) above current mean sea level. The seaward boundary is generally better defined than the landward boundary. In Leon County, the Penholoway is a reduction of the Wicomico.
. The Talbot is associated with the Sangamonian interglacial. The Talbot is defined by sediments located at 12 to 7.5 meters (42-25 feet) above current mean sea level. In Leon County the Talbot existed along the Leon/Wakulla County
line. The Talbot is not well developed in Florida as it is in Maryland and other states. However, within Florida, the Talbot is better developed in Leon as well as Bay County
, Wakulla
, and Walton County
.
Leon County, Florida
Leon County is a county located in the state of Florida, named after the Spanish explorer Juan Ponce de León. At the 2010 Census, the population was 275,487. The county seat of Leon County is Tallahassee which also serves as the state capital. The county seat is home to two of Florida's major...
during the Pleistocene epoch.
Overview
Repeated growth and retreat of the North American glacial sheet resulted in fluctuations of sea level over several thousand years. Florida submerged and emerged several times leaving behind established terraces assigned by mineral deposits and maximum sea level relative to the current mean sea level. These marine terraceMarine terrace
A marine terrace, coastal terrace, raised beach or perched coastline is a relatively flat, horizontal or gently inclined surface of marine origin, mostly an old abrasion platform which has been lifted out of the sphere of wave activity . Thus it lies above or under the current sea level, depending...
s and shorelines were named by various geologists, verified and mapped by the USGS. Each glacial retreat caused sea level to rise less than the previous warming event, giving an extremely accurate depiction of the appearance of Florida. Leon County was studied in detail by C. W. Hendry and C. Sproul in 1966.
Hazelhurst
The Hazelhurst terrace and shoreline (formerly the Brandywine) was assigned by C. W. Cooke and includes Vernon's Coastwise delta plain andMacNeil's high Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
terrace. Deposits are found between 97 to 65.5 meters (320—215 feet). During the interstadial period of late Pliocene to early Pleistocene epoch, the Hazelhurst terrace and shoreline was created in many counties east to west. Gadsden
Gadsden County, Florida
Gadsden County is a county located in the panhandle of the U.S. state of Florida. As of the 2000 census, the population was 45,087. The U.S. Census Bureau 2005 estimate for the county is 46,428 . Its county seat is Quincy, Florida. Gadsden County is the only predominantly African-American...
in particular had a very large land mass not only created by rising and lowering sea levels, but from depositions from the Apalachicola River
Apalachicola River
The Apalachicola River is a river, approximately 112 mi long in the State of Florida. This river's large watershed, known as the ACF River Basin for short, drains an area of approximately into the Gulf of Mexico. The distance to its farthest headstream in northeast Georgia is approximately 500...
on Gadsden's west side. Leon County remained completely submerged.
Coharie
The Coharie terrace and shoreline was applied by C. W. Cook in 1931 and was named for the Great Coharie Creek, a tributary of the Black RiverBlack River (North Carolina)
The Black River is a tributary of the Cape Fear River, approximately 50 mi long, in southeastern North Carolina in the United States....
in North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
. It is associated with a Pre-Illinoian interglacial, most probably the disused Yarmouthian interglacial and was the third rise in sea level during the Early Pleistocene glacial retreat and left behind dry land in the form of six distinct islands. The Coharie is defined by sediments at 65 to 52 meters (215-170 feet) above current mean sea level. In Florida the Coharie is included with the Sunderland terrace in USGS mapping.
One ancient island appeared in the extreme northwest portion of the county near the junction of Meridian Road and County Road 12. The second island was located in the general vicinity of U.S. 319 and Sunnyhill Road just south of the Florida/Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
border. The third of the northern islands of the Coharie was located in extreme northeast portion of the county and overlapping the county line between Leon and Jefferson County
Jefferson County, Florida
Jefferson County is a county located in the U.S. state of Florida. As of 2000, the population is 12,902. The U.S. Census Bureau 2005 estimate for the county is 14,490 . Its county seat is Monticello, Florida....
.
To the south lay 3 more islands. The first was located generally north and near Elinor Klapp-Phipps Park
Elinor Klapp-Phipps Park
Elinor Klapp-Phipps Park is an open natural park located in northern Tallahassee, Florida, United States and operated by the City Of Tallahassee...
and surrounding area. The second and largest covered the area where most of Tallahassee is today. It extended from near Interstate 10
Interstate 10
Interstate 10 is the fourth-longest Interstate Highway in the United States, after I-90, I-80, and I-40. It is the southernmost east–west, coast-to-coast Interstate Highway, although I-4 and I-8 are further south. It stretches from the Pacific Ocean at State Route 1 in Santa Monica,...
in the north to the capitol complex in the south, to just east of State Road 263. The third island was to the west and encompassed an area near Arvah Branch including I-10, U.S. 90, and north to Miccosukee Road.
Okefenokee
The Okefenokee terrace and shoreline was assigned by MacNeil in 1950 and named after Okefenokee SwampOkefenokee Swamp
The Okefenokee Swamp is a shallow, 438,000 acre , peat-filled wetland straddling the Georgia–Florida border in the United States. A majority of the swamp is in Georgia and protected by the Okefenokee National Wildlife Refuge and the Okefenokee Wilderness. The Okefenokee Swamp is considered to be...
. It includes deposits of the Sunderland terrace assigned by Cooke. It is associated with a Pre-Illinoian interglacial (Yarmouthian) and was the third rise in sea level during the Early Pleistocene glacial retreat. The Okefenokee is defined by sediments at 52 to 30.5 meters (170—100 feet) above current mean sea level. The dry land mass left behind can best be described as an oddly shaped peninsula
Peninsula
A peninsula is a piece of land that is bordered by water on three sides but connected to mainland. In many Germanic and Celtic languages and also in Baltic, Slavic and Hungarian, peninsulas are called "half-islands"....
overlaying the islands of the Coharie as well as added land that is connected to adjacent peninsulas in other counties.
During the forming of the Okefenokee, the Ochlockonee River
Ochlockonee River
The Ochlockonee River is a fast running river originating in Georgia and flowing for before terminating in Florida.- Background :The Ochlockonee originates south of the town of Sylvester in Worth County in southwest Georgia emptying into Ochlockonee Bay, then into Apalachee Bay, in Florida...
began to take shape as did rivers in other counties in Florida. The large inlet in the northeastern part of the county left the land capable of supporting a more recognizable Lake Iamonia. Eastern Leon had a large inlet reaching as far as the northeastern portion of the county. The Cody Scarp
Cody Scarp
The Cody Scarp or escarpment is located in north and north central Florida USA. It is a relict scarp and ancient persistent topographical feature formed from an ancient early Pleistocene shorelines of ~1.8 million to 10,000 years BP during interglacial periods...
is the remnant of the Okefenokee. What would become Lake Lafayette is a Pleistocene river delta with the lake's eastern section accessing the sea.
Wicomico
The Wicomico terrace and shoreline was assigned by Cooke and is named for the Wicomico RiverWicomico River
The Wicomico River is the name of two rivers in Maryland in the United States:*The Wicomico River , in Wicomico County, Maryland, on the eastern shore of the Chesapeake Bay...
in St. Mary's County, Maryland and Charles County, Maryland
Charles County, Maryland
Charles County is a county in the south central portion of the U.S. state of Maryland.As of 2010, the population was 146,551. Its county seat is La Plata. This county was named for Charles Calvert , third Baron Baltimore....
. The Wicomico is associated with the Sangamonian interglacial
Sangamonian Stage
The Sangamonian Stage, also known as the Sangamon interglacial, is the name used by Quaternary geologists to designate the last interglacial period in North America from 125,000—75,000 years ago, a period of...
between 75,000 and 125,000 years ago. and was the fourth rise in sea level during the Early Pleistocene glacial retreat. The Wicomico is defined by sediments located at 30.5 to 21 meters (100-70 feet) above current mean sea level. The Wicomico is well developed in northeastern and extreme northwestern Florida. At this time the county is mostly dry except for the southern coastline. The Cody Scarp
Cody Scarp
The Cody Scarp or escarpment is located in north and north central Florida USA. It is a relict scarp and ancient persistent topographical feature formed from an ancient early Pleistocene shorelines of ~1.8 million to 10,000 years BP during interglacial periods...
is a shoreline of the Wicomico as well as the aforementioned Okefenokee. The Ocklochonee River empties in to a large, wide estuary or inlet leading to the sea. The ground for what will be the Tallahassee Regional Airport
Tallahassee Regional Airport
Tallahassee Regional Airport is a city-owned public-use airport located four nautical miles southwest of the central business district of Tallahassee, a city in Leon County, Florida, United States.- History :...
remains underwater.
Penholoway
The Penholoway terrace and shoreline was assigned by Cooke and named after Penholoway Creek in Wayne County, GeorgiaWayne County, Georgia
Wayne County is a county located in the U.S. state of Georgia. As of 2000, the population was 26,565. The 2007 Census Estimate showed a population of 29,046. The county seat is Jesup.-History:...
and is associated with the Sangamonian interglacial. The Penholoway is defined by sediments located at 21 to 13 meters (70-42 feet) above current mean sea level. The seaward boundary is generally better defined than the landward boundary. In Leon County, the Penholoway is a reduction of the Wicomico.
Talbot
The Talbot terrace and shoreline was assigned by Cooke and named for Talbot County, MarylandTalbot County, Maryland
-2010:Whereas according to the 2010 U.S. Census Bureau:*81.4% White*12.8% Black*0.2% Native American*1.2% Asian*0.1% Native Hawaiian or Pacific Islander*1.6% Two or more races*2.7% Other races*5.5% Hispanic or Latino -2000:...
. The Talbot is associated with the Sangamonian interglacial. The Talbot is defined by sediments located at 12 to 7.5 meters (42-25 feet) above current mean sea level. In Leon County the Talbot existed along the Leon/Wakulla County
Wakulla County, Florida
Wakulla County is a county located in the U.S. state of Florida. As of 2000, the population was 22,863. The U.S. Census Bureau 2005 estimate for the county was 28,212 people...
line. The Talbot is not well developed in Florida as it is in Maryland and other states. However, within Florida, the Talbot is better developed in Leon as well as Bay County
Bay County, Florida
Bay County is a county located in the U.S. state of Florida. The U.S. Census Bureau 2006 estimate for the county is 163,505 . Its county seat is Panama City, Florida. The county is best known for its white sand beaches and crystal blue water, where large pods of dolphins swim year-round...
, Wakulla
Wakulla County, Florida
Wakulla County is a county located in the U.S. state of Florida. As of 2000, the population was 22,863. The U.S. Census Bureau 2005 estimate for the county was 28,212 people...
, and Walton County
Walton County, Florida
Walton County is a county located in the state of Florida. As of 2000, the population was 40,601. The U.S. Census Bureau 2005 estimate for the county is 50,324. Its county seat is DeFuniak Springs, Florida. The county is home to the highest natural point in Florida: Britton Hill, at .- History...
.