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Our Bonnechere history is written on stone,
wood, paper and the hearts of those who love the Bonnechere valley. The stone
records include fossils. A fossil (the word is from the Latin fossilis, meaning
"dug up") is an impression, or the actual remains of an animal or plant
preserved in rock.
 Our major fossils are from
the Ordovician time period, a time when North America was drifting away from
the equator and the outlines of billions of small animals and plants were
preserved in the sedimentary rock formed in the seas that covered much of this
landscape. The Ordovician geologic period was first described by Charles
Lapworth in 1879 based on rocks located in the original lands of the Ordovices
and was named after them.
The study of fossils is called palaeontology.
Palaeontologists are able to describe much of the geological history of a
region from fossil remains.
The museum has a collection of fossils and encourages people
to find their own samples by holding fossils hunts which grow more popular
every year. Donated fossils are welcome and enhance our collection.
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Bonnechere
Museum’s Fossil Collection
 Graptolites
These narrow skeletal-like creatures lived nearly 400
million years ago. They floated on the surface of the ocean forming fragile,
often branching skeletons. Typically Graptolites were only between
½ and 4 inches long. In the rock they look very much like pencil
marks.
Crinoids
The Crinoids’ soft body was protected by several hard
plates which formed in a bowl-like shape. From this came tentacle-like
arms, which were used to gather food. It was fixed to the sea floor by a
long flexible stem consisting of many discs. Once the crinoid died, the
discs were scattered over the sea floor, and we find many examples of these in
some limestone.
Trilobites
Trilobites are related to crabs, spiders and insects we see
today. They were aquatic creatures that had fragmented bodies with
multiple limbs. Most fossils of Trilobites are only about an inch long
but when they were one of the dominant species in the Cambrian and Ordovician
periods, they reached more than eighteen inches long.
Cephalopods
There are many different species of cephalopods. Some
have long straight shells and others are intricately coiled and
decorated. Cephalopods are related to modern-day squids and
cuttlefish. One of the most common fossils found in limestone in Ontario
is the straight-shelled species (closely resembling the squid). During
the Ordovician period it was one of the most dominant invertebrates and it
sometimes reached over four feet in length.
 Gastropods
Found in both fresh and salt water, gastropods are commonly
known as snails. Many fossils of freshwater gastropods can be found in
sands and gravels.
Pelecypods
Also known as clams, pelecypods can be found all over the
world. Pelecypods date back as early as the Cambrian period and live in
both fresh and salt water.
Brachiopods
Brachiopods resemble clams but are actually unrelated.
These animals have been found in rocks dating back as far as 700 million
years. Brachiopods were very abundant before the time of the dinosaurs,
but have declined since. A species of Brachiopod we still have today is
the Lingula, found in mudflats. It has changed very little in the last
100 million years.
Resource: R.R.H. Lemon, Fossils In
Ontario
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Fossils: Four Questions And
Answers
What Are Fossils? Fossils are the remains or
impressions of animals and plants which lived in prehistoric times. In Ontario,
we have some of the richest fossil bearing rocks in the world, providing fossil
hunters with countless examples of the type created by animal impressions.
Where Do Fossils Come From?During the Ordovician,
Silurian, and Devonian periods (350 to 450 million years ago), most of Ontario
was under water. More recently, during the Pleistocene Period (10,000 to
1,000,000 years ago) giant glaciers were advancing and retreating over the
entire Bonnechere Valley. These conditions allowed many species of early
animals, especially water dwellers, to live and die in our area.
How Are Fossils Formed? When an ancient creature,
such as a trilobite, died, it floated down to the sea bottom, where was
gradually covered with sand, silt and other organic material. Over hundreds of
years, the layers above the dead creature gradually deepened, although water
could still reach it. As the layers turned to rock, a chemical reaction between
the animal’s shell and the minerals carried in the water caused the shell
to be replaced, molecule by molecule, with calcite or silica. After this
replacement process had been going on for about 100,000 years, the original
shell had been completely carried away by water, and in its place was an exact
replica in stone. Once the surrounding layers turned to stone, the fossil lay
preserved, awaiting discovery by fossil hunters.
Where Can I See Some Of These Fossils? Bonnechere
Museum’s has a collection of fossils, which you can view and learn from.
However, the “fossil hunts” conducted from the museum every summer
are an opportunity to apply what you have learned about fossils. Travelling
with other fossil hunters, you, yourself, can discover real
Ordovician fossils.
Resource: R.R.H. Lemon, Fossils In Ontario
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The Ordovician Period (490 to 443 Million
Years Ago)
The Ordovician period began approximately 490 million years
ago, with the end of the Cambrian, and ended around 443 million years ago, with
the beginning of the Silurian.
The Ordovician is best known for the presence of its diverse
marine invertebrates, including graptolites, trilobites, brachiopods, and the
conodonts (early vertebrates). A typical marine community consisted of these
animals, plus red and green algae, primitive fish, cephalopods, corals,
crinoids, and gastropods.
From the Early to Middle Ordovician, the earth experienced a
milder climate in which the weather was warm and the atmosphere contained a lot
of moisture. During the Late Ordovician, massive glaciers formed causing
shallow seas to drain and sea levels to drop. This likely caused the mass
extinctions that characterize the end of the Ordovician, in which 60% of all
marine invertebrate genera and 25% of all families went extinct.
The name Ordovician. The name Ordo-vic-
probably means "those fighting with a hammer".
The Ordovices were a Celtic tribe living in
the British Islands, before the Roman invasion of Britain. Its tribal lands
were located in Wales between the Silures to the south and the Deceangli to the
north-east. The Ordovices were conquered by the Roman governor Gnaeus Julius
Agricola in AD 77/78.
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Geologic Time
 Geologic Time is
subdivided into a number of categories.
Eons are divided into...
Eras which are divided into...
Periods and subperiods which are divided into...
Epochs. (Epochal subdivisions are referred to as "ages")
MYA = millions of years ago
THE PRESENT IS THE KEY TO THE PAST
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Natural History of The Bonnechere
Valley
Source: Clyde Kennedy, The Upper Ottawa
Valley
Glaciation and climate change shaped the Bonnechere Valley.
The weight of mile-thick ice compressed the land, pushing it towards the
earth’s crust and below the existing sea level. When the Wisconsin glacier
receded, the land gradually rose, but not before the Atlantic Ocean swept in
from the east, flooding the Ottawa Valley and the lower Bonnechere Valley,
creating a branch of the ocean known as the Champlain Sea which lasted from
about 11,000 to 9,500 years ago.
The rising land ended the drainage of the Great Lakes into
the Ottawa Valley and caused the Champlain Sea to recede. The in-flooding
deposited the flat clay sea bed which today’s Highway 60 follows. These
same gray clays, which turn reddish-orange when baked, are used in the
manufacture of brick and drainage tiles at Arnprior, Renfrew, Pembroke and
various other communities.
As you approach Eganville from the east, the land valley
becomes more hummocky and hilly. Here, Highway 60 courses along glacial tills
and moraines (piles of rock left behind by melting glaciers) which, although
nearby, were not likely flooded by the Champlain Sea. This stretch of road
travels to the edge of, and briefly into, the adjacent Snake River watershed
and along the fault lines which confine the north side of the watershed to a
narrow band.
Near Golden Lake, Highway 60 drops down into a huge glacial
spillway where an enormous river once flowed through the graben, (an elongate
crustal block that is relatively depressed (downdropped) between two fault
systems) depositing sands and gravels across the flat land.
According to Clyde Kennedy in The Upper Ottawa Valley,
“Most of the surface rocks in Renfrew and Pontiac counties are Precambrian
in age; the region lies within the area termed the Canadian Shield. These very
ancient rocks included the dolomite from which magnesium is extracted near
Haley’s; the crystalline limestone quarries that supplied some lime kilns,
such as the Biederman quarry near Lake Dore; the crystalline limestone host
rock at the Black Donald graphite mine; and the great outcrops of crystalline
limestone at Calumet Falls and Portage du Fort.
A large part of the Upper Ottawa Valley, which lies within
the Grenville Province of the Canadian Shield, is underlaid by gneisses, with
large bodies of granite, syenite and other igneous rocks. The age of some of
the Precambrian rocks is about one billion years; some rocks of the Shield
north of the Ottawa River basin have been dated at about two and a half billion
years.
Faults, breaks in the earth’s crust, caused some
limestone covered areas to be dropped down and thus protected from erosion.
Outliers of limestones may be seen in the Pembroke area; at the northwesterly
end of Muskrat Lake near Meath (this outlier also covers much of Stafford
Township); along the southerly shore of Lake Dore and extending in a
four-mile-wide band past Mink Lake to a point five miles northeast of Douglas,
along the Bonnechere River from five miles downstream from Douglas through the
Fourth Chute (where the Bonnechere Caves were formed by erosion of the
limestone) and beyond Eganville to Golden Lake village; on the northwest side
of Lake Clear; in a large part of Westmeath Township – the
‘peninsula’ portion, enclosed by the great bend of the Ottawa River;
and in the Braeside, Sand Point, Lochwinnoch areas.
In the Ordovician limestones are a variety of fossils,
including sponges, corals, brachiopods, pelecypods (clam type), gastropods
(snail type) cephalopods (the squid is a modern cephalopod), and crinoids
(animals that were thought to be plants – crinoids live in the
Mediterranean Sea today). Fossils may be seen in the limestones in several
places in the Valley, including the Eganville area and the Bonnechere Caves at
the Fourth Chute on the Bonnechere River.”
Today, while the larger Ottawa and Madawaska are noted for
their white water, the Bonnechere is known for its smooth water, allowing
scenic canoe and boat rides, although springtime freshets allow white water
activities too.
Stretching 145km (90mi), from near McAskill Lake in
Algonquin Park to the Ottawa River at Castleford, the Bonnechere River
drains 2400 square kilometres (935 square miles) — an area larger than
Prince Edward Island.
Over the centuries, the Bonnechere (often pronounced locally
as the bone-chur) has been a conduit for transportation, as an access route to
the pineries, for its square timber drives and later log drives. It spawned
sawmills and grist mills, carding mills, and was a powerhouse of energy for
mill wheels as well as hydro generators. (Currently, Eganville is served by a
generator located right down town.) It became a route along which settlements
grew, and farmlands extended from its banks and tributary streams, a source of
both food and recreation for residents and travellers. The productive soils and
enticing landscape of the Bonnechere Valley watershed (the area of land which
feeds the river) were among the first logged, settled and farmed in Renfrew
County.
Life along the Bonnechere sprang up at several locations
simultaneously, although usually related to logging or its supporting trades
and supply lines - including dam building, farming, general store items,
blacksmithing, as well as housing, health and family care, education and
worship.
The owners of the logging companies were called
timber-makers and several acquired the name of “King”; for example,
Alexander McDonell was known as the King of the four rivers because of his
association with the Madawaska, the Bonnechere, the Indian and the Mississippi;
John Egan was called the King of the Ottawa Valley because of his extensive
holdings and political influence, and James Bonfield was known as King of the
Bonnechere because of his sustained logging in its reaches.
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