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Mineral Resources > Online Spatial Data > Geology > by state > Georgia Geology

Geologic units in Effingham county, Georgia

Holocene Shoreline Complex - marsh and lagoonal facies (Holocene) at surface, covers < 0.1 % of this area

Holocene Shoreline Complex - marsh and lagoonal facies

Lithology: unconsolidated deposit

Chenier plain and deltas of Suwannee & Chattahoochie Rivers (Holocene) at surface, covers < 0.1 % of this area

Chenier plain and deltas of Suwannee & Chattahoochie Rivers

Lithology: unconsolidated deposit

Floyd Shale; Hartselle Sandstone member (Mississippian) at surface, covers 0.7 % of this area

Hartselle Sandstone member (Mh) in Floyd County

Lithology: sandstone

Wicomico Shoreline Complex - barrier island facies (Pleistocene) at surface, covers 8 % of this area

Wicomico Shoreline Complex - barrier island facies

Lithology: beach sand

Wicomico Shoreline Complex - marsh and lagoonal facies (Pleistocene) at surface, covers 28 % of this area

Wicomico Shoreline Complex - marsh and lagoonal facies

Lithology: unconsolidated deposit

Tidal Marsh (Quaternary) at surface, covers < 0.1 % of this area

Tidal Marsh: Peat and muck deposits along tidal margins of esturaries and back bays. Deposits range from a few feet to 60+ feet deep. Locally include silt and fine sand and clay as levees on tidal channels. At depth peaty material may be accumulated from fresh water plants. Peat at the surface dominated by spartina and other salt tolerant species.

Lithology: peat; silt; sand; clay or mud

Neogene undifferentiated (Neogene) at surface, covers 0.3 % of this area

Neogene undifferentiated, includes Altamaha Grit (Dall, 1892); Citronelle Formation (Matson & Berry, 1916); and "Hawthorn Formation" (Cooke, 1939). (*) - outcrops of indurated sandstone and claystone

Lithology: sandstone; claystone

Penholoway shoreline complex - marsh and lagoonal facies (Pleistocene) at surface, covers 23 % of this area

Penholoway shoreline complex - marsh and lagoonal facies

Lithology: unconsolidated deposit

Alluvial Valley Swamp (Quaternary) at surface, covers 0.9 % of this area

Alluvial Valley Swamp: Unconformable on all underlying units, fluvial sand and gravel at base, grading upwards into fine sands and silts, local peat. May be overrun with recent sediments from forest cutting and agriculture.

Lithology: sand; gravel; silt; peat

Pleistocene-Pliocene sands and gravels (Pleistocene-Pliocene) at surface, covers 18 % of this area

Pleistocene-Pliocene sands and gravels, includes, in part, Sunderland, Coharie, and Brandywine "Formations" of Cooke, 1939

Lithology: sand; gravel

Talbot shoreline complex - marsh and lagoonal facies (Pleistocene) at surface, covers 2 % of this area

Talbot shoreline complex - marsh and lagoonal facies

Lithology: unconsolidated deposit

Pamlico shoreline complex - marsh and lagoonal facies (Pleistocene) at surface, covers < 0.1 % of this area

Pamlico shoreline complex - marsh and lagoonal facies

Lithology: unconsolidated deposit

Stream alluvium (Quaternary) at surface, covers 16 % of this area

Stream alluvium and undifferentiated terrace deposits

Lithology: alluvium; alluvial terrace

Penholoway shoreline complex - barrier island facies (Pleistocene) at surface, covers 3 % of this area

Penholoway shoreline complex - barrier island facies

Lithology: beach sand