Bainbridge, Ga., and of Alum Bluff, Fla. 247 



The often sandy clays overlying the Chipola of this red clay 

 hill region from Bainbridge southward are undoubtedly to a 

 considerable extent perezonal material, becoming coarser to- 

 wards the unfossiliferous Chattahoochee embay ment of Chipola 

 times. What this means will be better understood when it is 

 learned that in Florida the Chipola also ends above in a mass 

 of perezonal sands, the feather edge of the much thicker north- 

 ern deposits. These perezonal sands, moreover at Alum Bluff, 

 contain in places frequent impressions of palmetto and many 

 dicotyledonous leaves, showing a great Gulf ward extension of 

 continental land before the deposition of the Chesapeake. 

 This may account in part for the fact that while the Chipola 

 has been found farther north, the Chesapeake can be traced 

 only a short distance north of Alum Bluff. 



Previous publications with reference to the position of the 

 leaf remains, if correctly understood, are entirely erroneous. At 

 Alum Bluff tlie Chipola rises only a few feet above the river's 

 edge under ordinary conditions of water level. Below they 

 consist of a strongly calcareous sandy formation, calcareous 

 chie:ffy on account of its abundant shell remains ; becoming a 

 loose sand layer above as soon as the fossils practically disap- 

 pear. This upper sandy portion may be almost structureless 

 and contain a few gasteropods and oyster shells, or it may be 

 strongly cross-bedded, when it is likely to contain trunks 

 with more or less of the leaves of palmetto palms, or they 

 may be finely interbedcled with thin more clayey layers, when 

 they are more apt to contain the best specimens of the dicoty- 

 ledonous leaves. In the few localities studied the cross-bedded 

 sands lie over the evenly bedded leaf layers last mentioned, 

 and the stray oyster shells are found some distance away hori- 

 zontally, at various levels. These formations all evidently 

 form a unit and signify simply that towards the close of the 

 Chipola a considerable area was added to the land and the 

 effects are recognized as far south as Alum Bluff in the form 

 of land, plant containing deposits. (It will be remembered 

 that earlier in this paper the writer notes the similar observa- 

 tion of Dall when he states that towards the upper part of the 

 equivalent Orthaulax bed a land shell fauna comes in). Above 

 these leaf-bearing sands at Alum Bluff the Chesapeake forma- 

 tion is found. 



To every one familiar with Southern geology it is evident 

 that Tertiary rivers here have given rise to great perezonal 

 deposits. Stratigraphically the Altamaha grits some distance 

 south of central Georgia and the Grand Gulf group of the 

 Mississippi embayment should represent such perezonal depos- 

 its for the entire Miocene, since they rest directly upon the 

 Eocene. Only recently has an attempt been made to subdivide 



