’ 3 
: Pores) acca d 
Arr. XXXIV.—Geology of South Alabama ; by C. 8. i.» 
; Mobile. se, otk 
Or the three sa included in the tertiary system, the up- — 
per, m iddle and lower,—or agreeably to the nomenclature of Mr. 
Lyell, rhe pliocene, ‘miocely and eocene—only the last has been 
found with certainty to exist in Alabama ; and even this appears 
to be limited to the older portion of the series. For certain de- 
posits of this formation, which occur in the Carolinas and Flori ma 
contain fossils specifically distinct from those of the Ae 
beds, and which evince that the former pPomtities embrace a newer | 
part of the series | 
The geographical limits of the formation, on the north, may | 
be defined by an imaginary line passing between the Upper and 
Lower Peach-tree landings, on the Alabama river; through Mos- 
cow on the Tombecbee, thence by the Suearnochee creek, 
through Kemper and Carrol counties, Miss., to Arkansas state, 
id to Natchitoches on the Red river. On the south, the last 
of the coralline white limestone beds disappear beneath the 4 
ng sands and clays near the junction of the Alabama and 
Tombecbee rivers. And on the Mississippi the equivalents of 
these beds terminate near its junction with the Red river, forming 
a zone about sixty miles in width. : 
The surface of this region is generally very uneven, consisting 
principally of the white limestone beds, which have been furrow- 
ed out into detached precipitous masses, laying bare, in many 
instances, the subsequent strata, and the whole i is often covered 
by more recent deposits of sand and cla 
The following is the order of the eocene series of Alabama. 
' a ae Clay bed. 
a: a an shells. : d 
4. Clay bed with oysters. | 4 
eh. play arenaceous limestone. Section of the Claiborne 
: “ bluff. 
The best natural section of foes: beds occurs at Claiborne, 
and may be regarded as normal deposits. This cliff which is 
nearly two hundred feet in height, includes the entire series of 
the formation with the exception of a few strata at the.two eX- 
mes. 
~ The basal bed of the cliff which may be seen here at extreme | 
low water, is a sandy deposit, partially developed at this locality, i 
but in other places it exhibits very decided characteristics, as an | 
important part of the group. We have identified its existence 
