Chapter HB

BIOSTRATIGRAPHY, HANNA AND CARBON

BASINS

By D.J. Nichols

in U.S. Geological Survey Professional Paper 1625-A

U.S. Department of the Interior

U.S. Geological Survey
HB-ii

Contents

Biostratigraphy....................................................................................................HB-1

References ..........................................................................................................HB-2

Figures

HB-1. Biostratigraphic reference sections in the Hanna and Carbon Basins.

HB-2. Occurrences of Momipites and Caryapollenites pollen and the

definition of palynostratigraphic zones P1-P6.

HB-3. Palynostratigraphic zones of the Paleocene rocks in the Hanna and

Carbon Basins.
HB-1

BIOSTRATIGRAPHY

• The most common fossils in coal and coal-bearing rocks are pollen grains

and spores. Thus, biostratigraphy based on pollen and spores

(palynostratigraphy) has been used to determine the age of the coal beds

and coal zones in the Hanna and Carbon Basins.

• Palynostratigraphy in the Hanna and Carbon Basins is based on regional

palynological studies using reference sections in both basins (fig. HB-1).

The reference sections include outcrops and coal mines.

• Two formations, the Ferris and the Hanna, are included in the

exceptionally thick section of sedimentary rocks in these basins. The

Paleocene part of this interval is divided into six palynostratigraphic

zones (fig. HB-2) based on occurrences of fossil pollen and spores.

• Economic coal beds are present in the Paleocene parts of the Ferris and

Hanna Formations in the Hanna and Carbon Basins (fig. HB-3).
HB-2

REFERENCES

Nichols, D.J., 1996, Palynological zonation of the Paleocene of Rocky

Mountain intermontane basins [abs.]: Geological Society of America,

1996 Annual Meeting, Abstracts with Programs, v. 28, no. 7, p. 372.

Nichols, D.J., and Ott, H.L., 1978, Biostratigraphy and evolution of the

Momipites-Caryapollenites lineage in the early Tertiary in the Wind

River Basin, Wyoming: Palynology, v. 2, p. 93-112.
Figure HB-1. Biostratigraphic reference sections in the 

Hanna and Carbon Basins.

Biostratigraphic age determination 

of the Paleocene coal beds of the 

Hanna and Carbon Basins is based 

on palynologic analyses of samples 

from selected outcrops and mines. 

Approximate locations of sample 

localities are indicated by red dots.

Hanna Basin

Carbon Basin
Figure HB-2. Occurrences of Momipites and Caryapollenites 

pollen and the definition of palynostratigraphic zones P1-P6. 

L, M, and U designate lower, middle, and upper Paleocene.

P1

P2

P3

P4

P5

P6

U

M

L

M. inaequalis

M. leffingwellii

M. waltmanensis

M. wyomingensis

M. actinus

M. anellus

M. triorbicularis

M. ventifluminis

C. wodehousei

C. veripites
Hanna

Formation

(part)

Figure HB-3. Palynostratigraphic zones of the Paleocene rocks 

in the Hanna and Carbon Basins.

The palynostratigraphic zonation 

for the Hanna and Carbon Basins is 

based on ranges of fossil pollen and 

spores analyzed in samples from 

coal beds and associated outcrops. 

Economically important coal beds

are present in the upper part of 

the Ferris Formation and the upper 

part of the Hanna Formation. Ferris

Formation

(part)

P1

P2

P3

P4

P5

P6

300 m

Hanna Nos.

77-79, 81 

Ferris Nos. 

23, 25 

Ferris Nos. 

31, 50, 65