1-24 
THE TERTIARY GEOLOGY OF THE 
formh (F. Uoceroidea), Namla Iwvh, MijoconcJm, WohoXAy M. incnrva, and Pecten 
MudUonina. 
Maryland. 
With respect to the Tertiary geology of this State we have very much more 
precise information than in the case of Delaware, although it must be confessed that 
a great deal still remains to be accomplished before an even approximately accurate 
delineation of boundary lines can be presented. This applies more particularly to 
the region of the East Shore, where the geological work done has been of a decidedly 
unsiitisfactory character — a character that unfortunately only too well distinguishes 
the exploration of a very considerable portion of the Atlantic border. It is lamentable 
to find in the report of a survey published as late as I860,* that work had not yet 
proceeded sufficiently far to permit of the subdivision of the Tertiary series into its 
primary component members (Eocene, Miocene and Pliocene), and this thirty years 
aOer the publication of Conrad’s paper on the “Geology and Organic Remains of a 
Part of the Peninsula of Maryland ” ! f 
'I’he Cretaceo-Tertiary boundary line enters Kent County from Delaware at a point 
.situated a few miles north of Millington, bisects in a southw'esterly direction the 
peninsula formed between the northern head of Chesapeake Bay and Chester River, 
mid continues on the west shore from a point a little outside of Annapolis to the 
neighborhood of Fort M'ashington, on the Potomac, a few miles below the city of 
Mhishington. South of this line to about the Little Choptank in Dorchester County, 
the region is occupied by the older and middle Tertiary depo.sits; the rest of the State 
southward and southeastward, con.sisting of loamy clays and sands, is considered to be 
of post-Tertiary date. The combined Tertiary and post-Tertiary areas cover nearly 
one-half of the entire State. 
EocK.vK._The development of this formation on the East Shore has thus far not 
been afcurately traced, but it may be assumed that its southern boundary lies some- 
«l,nt hclwoe,, Cl, ester Itiver and Ccnlreville. Cliostertown and Millington doubtless 
10 Mt lin its area. Gn the West , Shore the formation has been more accurately 
Studied, at least from a paleontological standpoint, but even here the exact boundary 
me, separating it on the southeast from the adjoining Miocene, has never been 
accura e } ( e ned. It may be said to correspond in a general way with a X. E.-S. W. 
Pori S'" u" ™ Chesapeake, to the .nouth of 
consists of Hav”"’ 1" occupied by this formiition, which 
fossil remains * hi""' h "" sands, and, in some places, compact siliceous rocks, 
I, rr . f c abundant. „nl 
ompiisc number of forms, prominent by size, which are more or less distinctiveof 
1 Chemist, p. 43. 
