194 PHYSIOGRAPHY, GEOLOGY AND MINERAL RESOURCES

Battle Ground, in Monmouth county, New Jersey, extends from New
Jersey southward across Delaware into Maryland, but is much less
extensively or typically developed in the state of Maryland than to
the northward, although some of its characteristic features are still
prominent. The Monmouth formation lies to the east of the Matawan
deposits above described and forms a narrow belt crossing Cecil, Kent,
Anne Arundel and portions of Prince George's counties, but gradually
disappears beyond the valley of the Patuxent as a result of the trans-
gression of the Eocene deposits.

Upon the eastern shore of Maryland we find the three subdivisions
of the Monmouth formation which characterize the New Jersey de-
posits represented, viz.: the basal red sands (Mount Laurel sands),
overlain by a well defined marl bed (Navesink marl), and this in turn
capped by slightly glauconitic red sands (Redbank sands); but upon
the western shore of Maryland the differentiation of the Monmouth
formation into these several parts is no longer possible, the formation
being represented by fine pinkish sands, which are sparingly glau-
conitic and which show no constant separation into lithologic zones.
The deposits have a thickness of about 75 feet upon the eastern shore,
but do not exceed 50 feet in Anne Arundel county, and gradually
decline in thickness until their final disappearance beyond the Patux-
ent valley.

The fossils of the Monmouth formation are not strikingly different
from those of the Matawan formation, although there are many which
are distinctive; while at the same time the more characteristic forms
of the Matawan formation are not found in the Monmouth. The
deposits are of undoubted upper Cretaceous age.

THE RANCOCAS FORMATION. —The Rancocas formation, so called
from its typical occurrence in the valley of Rancocas creek in southern
New Jersey, is well developed upon the eastern shore of Maryland,
where it forms a broad belt across Cecil and Kent counties to the east
of the Monmouth formation, and is the direct southward extension of
similar deposits in New Jersey and Delaware. On the western side
of the Chesapeake Bay it is found in only a few isolated patches in the
extreme eastern portion of Anne Arundel county near the mouths of
the Severn and Magothy rivers.