Eramosa Karst is a provincially-significant Earth
Science Area of
Natural and Scientific Interest in Ontario, Canada, located in
Creek, a constituent community of the City of
immediately south of the Niagara
It exhibits sixteen different karstic
geological features, of which seven are provincially significant,
and is considered to be the best example of karst topography found
in Ontario. The area is composed of parcels of land that are
provincially, municipally and privately owned. It received ANSI-ES
designation on February 13
In October 2006, Ontario donated 73 ha of land to the Hamilton Conservation
to create a new conservation area
, followed by another
donation of 3.1 ha in April 2007. The City of Hamilton has also
contributed in June 2007 by transferring 1.6 ha. The area opened to
the public on June 20, 2008.
The area is crossed by the Eramosa Escarpment. It is
morphologically similar to the Niagara Escarpent, as both are
composed of the Lockport Formation dolostones
. However, the Eramosa Escarpment is
much smaller in height (no more than 10 metres); its crest is only
occasionally defined by cliffs, which are no higher than 3 metres.
Most of the bedrock
is buried by till
The area exhibits a great concentration of various karstic
These tubular cavities, a few millimeters to a few centimitres in
diameter, conduct water from the surface to the karst bedrock
Dolines (or sinkholes
) are mostly found in
its suffosion form. Suffosion dolines are depressions formed above
caves and smaller cavities in unconsolidated sediments. Many of
such dolines in the Eramosa Karst are formed by a combination of
soil piping and erosion of the glacially-deposited sediments,
overlying the bedrock.
Entrance of Pottruff Cave.
These features are created when a cave's bedrock roof collapses.
Pottruff Cave's entrance is an example of such a formation.
Streams flowing through the area have formed different varieties of
valleys that are typical of a karstic landscape. Blind valleys are
formed when a stream sinks underground. As there is no farther
surface flow, a valley ends abruptly. A half-blind valley is
similar, except that a surface flow is occasionally present
downstream of the sinkpoint. Dry valleys were formed prior to the
development of underground stream passages, representing a former
route of springs before they were diverted by sinkholes. Depending
on the stage of evolution, these valleys may or may not have
Five dissolutional caves, large enough for human entry, have been
identified within the area. Nexus Cave is the largest. Measuring
335 metres in length, it is the 10th longest cave in Ontario.
The ANSI status of the area does not imply automatic protection.
The conservation area's boundaries roughly correspond to the Core
Area of the ANSI. However, the Feeder Area, where the streams
originate, is managed by the Ontario Realty Corporation, which
intends to sell it for residential development. Local scientists
and politicians urge the Ontario government to abandon its plans
and incorporate these lands into the conservation area, arguing
that geological and biological diversity of Eramosa Karst will be
severely diminished, should the development take place.
planned to connect the conservation area to Felker's Falls, Mount Albion Conservation Area, and Bruce Trail via the 10 kilometre East Mountain
Furthermore, a link to Olmstead Cave, located in
a Hamilton park, is considered.