User:User85734/Cardinal Creek Karst

Cardinal Creek Karst

The Cardinal Creek Karst is a Karst located in the municipality of Ottawa, and is the 12th longest cave in Ontario with an estimated length of some 340 meters. It has been recognized by the Ministry of Natural Resources (Ontario) as an Earth Science Area of Natural and Scientific Interest in 2009 (ANSI-ES).

Karst Features
The main karst features which occur in the system at Cardinal Creek include karren (surface etching and pooling by waters), dry stream beds, sinks (all of which are impenetrable due to clayey plugs of sediment), springs (mainly impenetrable artesian types, some of which have been buried or otherwise impacted by slumping from upslope materials), and dolines. These features occur mainly in the clay plain south of Watters Road.

The Cardinal Creek Karst represents a karst tunnel valley system by which groundwater disappears beneath the surface into an entrance cave, and re-appears at several waterfalls along Cardinal Creek as springs, until it re-emerges at the foot of the system. Groundwater is partially controlled with a storm sewer, which directs runoff into the karst cave entrance. A natural dry channel, possibly man-made, may also feed this system during periods of high run-off. Water run-off in the system may be fed by an artificial pond help up by a small dam upstream of this entrance cave.

This karst is a complex system of caves and chambers with interconnected springs with notable occurrence of "breakdown collapse" features. The breakdown collapse features have not been reported elsewhere in the province of Ontario. These occur in the main cave system south of Watters Road. It consists of a large suffusion doline above the central part of the cave system, on the surface. Inside the cave, the breakdown is largely sealed by clay that has settled in from above creating an effective hydraulic constriction. On the surface, the dolines are entirely within overburden, with no bedrock exposed (insert picture).

The caves are transitory in shape and scale. The upstream caves consist of a group of short, straight small galleries with walls of collapsed limestone blocks and debris. The central portion of the caves consists of two, sub-parallel, horizontal galleries. Finally, the southern portion of the cave consists of a vadose maze, in which intersecting cavities from a grid pattern of limestone cavities.

The northern portion of the site, north of Watters Road, which has been excluded from the ANSI-SE designation is on a privately owned property.

The valley and springs portions of the site is of high scenic value.

Formation
The Cardinal Creek Karst site incorporates features which are probably Holocene in age (they were formed in the last 10,000 years). There is some discussion that the Karst may have been inherited during the Holocene, suggesting that the system was formed during an earlier time. The oldest sedimentary deposit in the valley is a thin- to discontinuous, stony, silty clay diamict (till) with erratic boulders of Paleozoic and Precambrian origins. It can be seen lying directly on top of the bedrock surface in the valley. It was likely modified once the Champlain Sea inundated the Ottawa River Valley. In some places it is absent; in others, it can be seen to overly directly on bedrock. Its presence suggests that it was deposited at the base of the glacial ice at a time when the karst was still forming, which in turn suggests that the karst may have been inherited; i.e., that it may be older than postglacial (i.e., preglacial or interglacial). After the last glaciation, once the Cardinal Creek cut through the surficial sediments down to bedrock, it opened up the cave entrances to the karst system.

The bedrock exposed at the site consists of the Middle Ordovician Bobcaygeon Formation of the Ottawa Group. It is made of pure, fossiliferous, coarse-grained, massive to think-bedded limestone, with thin shale partings (

insert photo). They are best exposed on the bedrock surfaces in the creek valley, at the base of the clay bluff just north of the Watters Road bridge, where it is overlain by glacial till.

Educational potential
Besides the presence of provincially significant karst features and systems, the Cardinal Creek Karst site is located in an urban area, and as such has excellent educational and recreational potential. It is a scenic, interesting landscape that is well worth preserving for public enjoyment and education. It is also a relatively large and complex cave with an estimated length of some 340 meters. There is still much to learn from the hydrology, geology and geomorphology of this cave, so there is potential for scientific study. The valley and springs portion of the site north of Watters Road is of high scenic value.

Detailed sensitivity
The site is not pristine. It has been impacted by human activities in the form of a culvert, an artificial berm, an abandoned water well, collapsed roof materials, and the burial of a spring have all been reported or noted in the past, in and around the cave system (undocumented). The construction of Watters Road and its corridor cut a wide swatch through the middle portion of the site, and are responsible for most of the observed impacts. In addition, steep banks of clay and silt have been eroded by foot traffic throughout the site. Natural slumping of the unstable clays and silts are also ongoing, and may be enhanced by foot traffic.

The small valley created by Cardinal Creek in post-Champlain Sea time has value as an indicator of the hydraulic function of the downstream end of the karst system. This area may be significantly impacted, both physically and functionally, by the construction along Watters Road. Despite its high scenic qualities, the geological valleys of the valley system north of Watters Road is considered to be locally significant.