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FGS 010692
OPEN FILE MAP SERIES No 3
R22E
FLORIDA GEOLOGICAL SURVEY
DEPARTMENT OF NATURAL RESOURCES
R26F
R27E
R28E
GEORGIA
SCALE
Qph
-N-
I
FERNANDINA
BEACH
Qu
-C ~
cc
0
LU
(0
The geologic map of Nasau County, Florida wa developed a a
-I-
Sgeology depitean often parse data base Aa generalrule if
the undifferentiated sediments were less than 20 feet thick, the
underlying recogniableformation wa mapped
--I-
poorly preserved mollusk mold n be een in expo ure The
S unconformablyoverlies theHawthornGroupandis overlain
Cypresshead was deposited in a shallow nearhore marine setting
Undifferentiated Quaternary ediments (Ou) are mapped in much
of the central and eastern portions ofthe county They are
-I'- ,, .. .
S ,, , .... ,
Pleistocene and Holocene coastal deposits (Oph) The sedimentsare
composed of sands, silts and clays that sometimes contain varying
percentage of organic matter The sand may contain mi and
r0} heavy minerals The sandsare poorly towell sorted depending on
the depositional environment These include beach, march and
Quaternary sand dunes (Od) form Amelia I land on the eastern
S Pleistocene and Holocene coastal deposits
REFERENCES
Huddlestun, PF, 1988 A reviion of the lthostratigraphic units
148p
(eds) Southeastern Geological Society Annual Field Trip
Guideboo, February 1 29,1988 pp 772
GEOLOGIC MAP OF
NASSAU COUNTY
FLORIDA
BY
T Scott, PG.# 99 and K. Campbell, PG.# 192
Preliminary field mapping by
J.D. Arthur and PA. Bond
1992
THIS IS AN INTERIM GEOLOGIC MAP
EDITING AND EDGE MATCHING HAVE
NOT BEEN COMPLETED. UPDATING
AND CORRECTING ARE CONTINUING.
WALTER SCHMIDT
STATE GEOLOGIST AND CHIEF
R27E 21
by
T. Scott, PG.# 99
R26E
R28E
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PAGE 1
Hilliard Andrews15l15l115l108l108l115l115l121l 108l108l95p95p95p121Al121Al17o5l17oLITTLEST. MARYSRIVER TIGER BASINCHESTER YULEE CARTOGRAPHY BY JIM JONEST 3 N T 2 N T 1 N T 1 SR 22 E R 23 E R 24 E R 25 E R 26 E R 27 E R 28 E R 29 E 82 05' 81 55' 81 45' 81 35' 81 25' 30 35' 30 45' T 4 N R 22 E82 05' R 23 E 81 55' R 24 E R 25 E 81 45' R 26 E R 27 E81 35' R 28 E 81 25' R 29 E T 2 S 30 25' T 2 S T 1 S30 25' T 1 N T 2 N 30 35' T 3 N 30 45' T 4 N FERNANDINA BEACH l15l15 A1Al301o200l l115 NASSAURIVERD U V A L C O U N T YD U V A L C O U N T YMARYSRIVERST.ATLANTIC OCEANC H A R L T O N C O U N T Y C A M D E N C O U N T YST.MARYSRIVERG E O R G I AG E O R G I A121l108l121l119l121l 119lA1AlA1Al107l 107l115l CALLAHAN SCALE4 MILES 3 2 1 0.5 0 6 KILOMETERS 5 4 3 2 1 0 N THIS IS AN INTERIM GEOLOGIC MAP. EDITING AND EDGE MATCHING HAVE NOT BEEN COMPLETED. UPDATING AND CORRECTING ARE CONTINUING. Tc FGS 010692 OPEN FILE MAP SERIES No. 3Qu Thcc STATE GEOLOGIST AND CHIEF URVEY WALTER SCHMIDTEST. 1907DLFORIA S 1992GOGELOLI CANASSAU COUNTYT. Scott, P.G.# 99 and K. Campbell, P.G.# 192GEOLOGIC MAP OFPreliminary eld mapping by J.D. Arthur and P.A. BondFLORIDABY (eds.) Southeastern Geological Society Annual Field Trip (Miocene) of Florida: Florida Geological Survey Bulletin 59, Scott, T.M., 1988a, The lithostratigraphy of the Hawthorn Group of the Coastal Plain of Georgia: Miocene through Holocene: Huddlestun, P.F., 1988, A revision of the lithostratigraphic units 10 percent heavy minerals. This unit lies on undierentiated the dunes may contain shell fragments. The sands often contain 5coast of Nassau County. The well sorted quartz sands comprising Quaternary sand dunes (Qd) form Amelia Island on the eastern Guidebook, February 19-29, 1988, pp. 70-72. peninsular Florida: in Pirkle, F.L., and Reynolds, J.G., Scott, T.M., 1988b, The Cypresshead Formation in northern Georgia Geologic Survey Bulletin 104, 162p. Pleistocene and Holocene coastal deposits. 148p. REFERENCESDEPARTMENT OF NATURAL RESOURCESQph Qd FLORIDA GEOLOGICAL SURVEYRiver, consist of interbedded carbonate (limestone and dolostone) the depositional environment. These include beach, marsh and heavy minerals. The sands are poorly to well sorted depending on percentages of organic matter. The sands may contain mica and composed of sands, silts and clays that sometimes contain varying Pleistocene and Holocene coastal deposits (Qph). The sediments are rivers and streams are sediments referred to as undierentiated Along the present day coast,the associated lagoons, coastal sediments were deposited under marine conditions although some the underlying Nashua Formation or the Hawthorn Group. These sediments are very thin and a very detailed geologic map would show Formation or Hawthorn Group sediments. In localized areas, these reworked Cypresshead Formation and lies unconformably(?) on Nashua limited numbers of fossils. This sediment package may contain composed of sands, clayey sands and clays occasionally containing of the central and eastern portions of the county. They are Undierentiated Quaternary sediments (Qu) are mapped in much Cypresshead was deposited in a shallow, nearshore, marine setting. unconformably by the sands of Trail Ridge in western-most Duval Formation, a variably shelly, clayey sand (Huddlestun, 1988). It Cypresshead Formation grades laterally down dip into the Nashua poorly preserved mollusk molds can be seen in exposures. The sections to olive gray in the subsurface. Occasionally, faint, grained sediments. Colors range from reddish-orange in exposed present in very minor amounts and is generally kaolinite. Mica sorted with common occurrences of quartz gravel. Clay is commonly sands ranging from ne to very coarse, usually moderately to well (Tc) (Scott, 1988b). The Cypresshead Formation consists of quartz of the county is late Tertiary, Late Pliocene Cypresshead Formation Overlying the Hawthorn Group sediments in the western portion containing abundant molds and casts of mollusks. The clays are and clay beds. The carbonates are slightly sandy and clayey, often undierentiated Quaternary sediments or Nashua Formation. lagoonal sediments which lie unconformably(?) on older, uvial reworking has occurred. county and thin surcial sands and soils elsewhere. The unconformably overlies the Hawthorn Group and is overlain often occurs in minor percentages, particularly in the ner silty and calcareous to dolomitic. 1988a). These sediments, which are exposed along the St. Marys of the Coosawhatchie Formation, Hawthorn Group (Thcc)(Scott, The oldest unit mapped in Nassau County is the Charlton Member the undierentiated sediments were less than 20 feet thick, the geology despite an often sparse data base. As a general rule, if were included in order to provide a more accurate picture of the lithostratigraphic units and informal units. Both types of units Community Aairs. The geology of the county was mapped utilizing Environmental Protection Agency (EPA) and the Florida Department of hazards. Funding for this eort was provided by the U. S. generalized base map to be utilized in predicting radon potential The geologic map of Nassau County, Florida was developed as a GEOLOGIC MAP OF NASSAU COUNTY, FLORIDAunderlying recognizable formation was mapped. topographic maps. Geologic units identied include formal well cuttings, cores, natural and man-made exposures and T. Scott, P.G.# 99 by
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