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 (part of a man-made berm?) may also feed this system during periods of high run-off. Water run-off in the system may be fed by an artificial pond held up by a small dam upstream of this entrance cave.
The Cardinal Creek Karst site incorporates features which are probably Holocene in age (they were formed in the last 10 000 years), and which are covered by the “Postglacial and Holocene Events Environment” and, more significantly, the “Karst Landforms Processes and Environments” as outlined and described in the Earth Science Framework (Davidson 1981). There is some discussion that the karst may have been inherited during the Holocene, suggesting that the system was formed during an earlier time. Bedrock Geology: The bedrock exposed at the site consists of the Middle Ordovician Bobcaygeon Formation of the Ottawa Group (Johnson et al. 1992). It is made up of pure, fossiliferous, coarsegrained, massive to thick-bedded limestone, with thin shale partings (Photo 3). The Bobcaygeon Formation was laid down in a shallow, marine, inland sea environment. Important joint sets, roughly east-west in orientation, occur within the bedrock that are utilized by underground water in the development of the karst system. The bedrock is generally buried beneath up to 20 metres of insoluble, glaciomarine silt and clay. 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 sinkholes (also known as dolines). These features occur mainly in the clay plain south of Watters Road. In addition, Buck (pers.com. 2008) noted the presence of a “breakdown collapse” structure which is not known to be present in other karst systems of the province. These occur in the main cave section of the system south of Watters Road. He indicates that this feature consists of a large suffosion doline above the central portion 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. There are a number of examples of large collapse dolines over collapsed cave roofs (e.g., Bonnechere Cave, Ottawa River Caves, Dewdney’s Caves, Puzzle Lake Cave, possibly Warsaw Caves, etc), but this may be the only such site where the surface expression is entirely within overburden, with no bedrock exposed. The closest example of such a feature is Tyendinaga Cave, which is a straight passage terminating in breakdown at either end. 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 form a grid pattern of limestone cavities. These caves probably focus groundwater into springs which exit, among other places, along the banks of Cardinal Creek north of Watters Road. None of the other core features in themselves are notably representative, as they commonly occur frequently in other karst systems, including in protected areas of the province (e.g., the Eramosa Karst site and many Bruce Peninsula sites). The karst features of the site are well-described by Beaupre and Schroeder 1991). A sketch diagram is presented showing the character of the main cave system south of Watters Road. This map (Figure 2) is not to scale. Location ID #CM0009
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