Historical:Blackriveran Stage

Chronostratigraphy: Paleozoic Erathem >>Ordovician System >>Champlainian Series >>Blackriveran Stage
Allostratigraphy: Tippecanoe Sequence

Authors

H. B. Willman and T. C. Buschbach

Name Origin

The Blackriveran Stage (Vanuxem, 1842, p. 38-45; Moore, 1949) is named for the Black River in New York State.

Stratigraphic Position

The Blackriveran Stage consists of the strata included in the Ancell and Platteville Groups, which are present throughout most of Illinois (fig. O-19)

Fig. O-19 -- Thickness of the Platteville Group.

Description

Many of the distinctive lithologic units of the Platteville in Illinois have been traced to the Black River region in New York (Templeton and Willman, 1963).

Fossils

Although the Ancell strata contain few fossils, the Platteville strata contain many that are characteristic of Blackriveran strata in New York (fig. O-5).

Fig. O-5 -- Typical Ordovician fossils

References

MOORE, R. C., 1949, Introduction to historical geology: McGraw-Hill Book Co.. Inc., New York, 582 p.
TEMPLETON, J. S., and H. B. WILLMAN, 1963, Champlainian Series (Middle Ordovician) in Illinois: Illinois State Geological Survey Bulletin 89, 260 p.
VANUXEM, LARDNER, 1842, Geology of New York, part 3, comprising the survey of the third geological district: Albany, 306 p.

ISGS Codes

Stratigraphic Code	Geo Unit Designation
7840	--