Hagerman Fossil Beds National Monument
By: Emanuela Galateanu
Introduction
Hagerman Fossil Beds National Monument is a great place to be if you are interested
in seeing the many different kinds of animals and plants that lived there during
the Pliocene Epoch. There are museums and tours where visitors can take a look
in the past. There were modern flora and fauna, and plants also found in the
park. (http://usparks.about.com./library/miniplanner/blhagermannm.htm).
Location
Hagerman Fossil Beds National Monument is located in south-central Idaho near
the town of Hagerman, off US 30 (Figure 1).
Figure 1: Map of Idaho showing location of HAFO
from NPS http://www.nps.gov/hafo/information.htm.
History of Hagerman Fossil Beds National Monument
During the year of 1988 is when Hagerman Fossil Beds became a national monument
(Figure 2). Also during the year of 1988 is when the Hagerman horse became Idaho’s
state fossil. “The Monument is also one of three national park system
units containing a portion of the Oregon Trail National Historic Trail.”
(http://www.nps.gov/hafo/pphtml/nature.html)
Figure 2: This is a picture of a sign of the
Hagerman Fossil Beds National Monument.
From NPS http://www.nps.gov/hafo/information.htm.
Now as we are able to look in the past as to how it was back then with all the
fossils found, we can also see how the land looked before and after the excavation
took place (Figure 3 & 4).
Figure 3: Picture taken before the start of the excavation in 1988. From NPS.
Figure 4: This picture was taken a few years ago as to what the layers actually look like. From NPS.
Geology
During the Pliocene Epoch was when the Hagerman Fossil Beds were deposited.
The type of environment that deposited layers of sand, silt and clay was both
a fluvial (river) and flood plains that were around the edge of the ancient
Lake Idaho. In some places, the deposits were up to 600 feet thick (From NPS).
Stratigraphy & Environment
For the Stratigraphy of the Hagerman Fossil Beds National Monument there are
eight layers which include the silicic volcanic rocks, the Idaho Group and the
Snake River Group (Figure 5).
1) The first thing that was deposited was the Silicic Volcanic Rocks which these
came from the Idavada Volcanoes that filled the basal portion of the plain.
(http://www.nps.gov/hafo/landslides/chap2.htm).
(Figure 5)
Then around eleven million years ago is when the Idaho Group started to be deposited
on top of the Snake River Plains. In the Idaho Group there is:
2) “Banbury Basalt/Poisen Creek Formation, Chalk Hills Formation, Glenns
Ferry Formation, Tuana Gravel, Bruneaau Formation and the Black Mesa Gravel.
They are composed of clastic sedimentary lithologies and inter-bedded olivine
basalt flows, silicic volcanic ashes and basaltic pyroclastic material. Most
of the sediments are poorly consolidated and range in texture from clays to
gravels.” (http://www.nps.gov/hafo/landslides/chap2.htm).
(Figure 5)
3) “The Glenns Ferry Formation had four major environments that includes
sandy fluviatile, muddy flood plain, lacustrine, and valley border facies, but
only the fluciatile and the flood plain environments are being studied. The
climate was predominately humid but also semi-arid” (http://www.nps.gov/hafo/landslides/chap2.htm).
(Figure 5)
4) “The Tuana Gravel is composed of coarser grained sediments in the silt,
sand, and gravel fractions.” (http://www.nps.gov/hafo/landslides/chap2.htm).
“The Tuana Gravel is also composed of clastic deposits inter-bedded by
occasional basalt flows, silicic volcanic ash, and basaltic pyroclastic deposits
and most of the sediments are poorly consolidated and range in texture from
clays to gravels.” (http://www2.nature.nps.gov/geology/parks/hafo/index.cfm).
(Figure 5)
5) The Snake River Plain is a tectonic/volcanic feature in the northern portion
of the Basin and Range geologic region. Around 14 to 9 MA there were the Idavada
Volcanics in the southwestern and south-central Idaho that continued through
much of the Miocene and filled the basal portion of the western Snake River
Plain with silicic lavas, welded and vitric tuffs. (Figure 5)
Figure 5: “Sequence of upper Cenozoic rocks in the
western Snake River Plain, Owyhee Country, Idaho (modified from Malde, 1991)”
(http://www.nps.gov/hafo/landslides/chap2.htm).
Click here for the stratigraphic column in MSWord
or as a PDF file
Figure 6.
Figure 7.
Paleontology
During the end of the Pliocene Epoch, with an environment of grassy plains that
had ponds and forests, were found lots of animals such as: “mastodons,
saber-tooth cats, beavers, muskrats, otters, camels, antelope, deer, ground
sloths, hyena-like dogs, fish, frogs, snakes, waterfowl and much more.”
“More than 140 animal species of both vertebrates and invertebrates have
been found in hundreds of individual fossil sites; eight species are bound nowhere
else while forty-four species were found here first” (From NPS).
Most of the fossils that were deposited came from “wetlands, riparian,
and grassland savannas” (From NPS). The plants and animals found in the
rocks are dated around 3.5 million years ago, before the Ice Age. Here are some
of the earliest appearances of modern flora and fauna. With all of the fossils
found they are mostly embedded in the banks of the Snake River. The way that
we are able to see them in this day and age is from the Snake River’s
carving action as it is still in motion. (http://usparks.about.com/library/miniplanner/blhagermannm.htm)
Figure 8. stratigraphic range chart of ????
Conclusion
When ever you want to see something from the past or if you are in the area,
this would be a great place to stop for a few days and explore what happened
years ago.
References
About; 2006 About, INC., A part of The New York Times Company. Hagerman Fossil
Beds National Monument. (http://usparks.about.com/library/miniplanner/blhagermannm.htm).
Martin, S. ; 2006; personal communication from NPS.
General Geology; 7 May 1999. Hagerman Fossil Beds National Monument. (http://www.nps.gov/hafo/landslides/chap2.html).
National Park Service; 01/04/2005. Geology Field Notes Hagerman Fossil Beds
National Monument Idaho. (http://www2.nature.nps.gov/geology/parks/hafo/index.cfm).
National Park Service; No date. Hagerman Fossil Beds National Monument. (http://www.nps.gov/hafo/pphtm/nature.html).
National Park Service; May 27, 2005. Hagerman Fossil Beds National Monument.
(http://www.nps.gov/hafo/information.htm).
National Park Service; October 26, 2002. Hagerman Fossil Beds National Monument.
(http://www.nps.gov/hafor/paleontology.htm).