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Grande Cache Dinosaur Tracksite
Grande Cache, Near
Statement of Significance
Description of Historic Place
Located in the former Smoky River Coal Mine, approximately 20 km north of Grande Cache, the Grande Cache Dinosaur Tracksite is the only large-scale exposure of dinosaur tracks known in Canada.
The designation of the Grande Cache Dinosaur Tracksite includes portions of 11 sections of land within the former Smoky River Coal Mine. The designation includes the trackways, view planes and buffer zones around the trackways.
Map showing location of the Grande Cache Dinosaur Tracksite and an aerial photo (inset) showing the areas nominated for designation (pink) and the location of known dinosaur trackways. See Appendix A for a detailed version of the aerial photo.
Heritage Value
The heritage value/significance of the Grande Cache Dinosaur Tracksite lies in its representation of information about dinosaur biology and behaviour not available from skeletal remains. Through the study of dinosaur trackways we can learn how dinosaurs moved, how they interacted with their environment and with other dinosaurs.
Dinosaur footprints were first discovered at South Pit Lake during the late 1980's by staff at the former Smoky River Coal Mine as coal-mining operations exposed the rocks in which the tracks were preserved. In total, over 20 tracksites have been discovered within the coal mine.
The trackways are all located on steeply angled (between 40º and 60º) footwalls exposed during open pit mining activities. Some of the footwalls are over 60 meters high and nearly a kilometer long. There has been some slope failures resulting in the partial or complete loss of some trackways but in many cases new trackways are revealed with each slope failure.
The tracksites can be accessed via mine haul roads that wind through the mine. In some cases the tracksites occur adjacent to the haul road (e.g. W1 Sites) and in other instances the tracksites are located over 100 meters from the haul road across easily traversed terrain.
The Grande Cache dinosaur tracks are known from the Lower Cretaceous Gladstone and Gates formations (approximately 90 mya). The only other vertebrate-bearing deposit of this age in Alberta is located in the Crowsnest Pass and to-date it has only yielded a small amount of unidentifiable dinosaur bone.
The Grande Cache dinosaur tracks were made by several species of dinosaurs, including several types of theropods (meat-eating dinosaurs), ankylosaurs (armoured dinosaurs) and several species of birds. Estimates suggest that there are well over 10,000 footprints (in fact, over 10,00 footprints have been counted at the W3 Main Site alone) within the mine site. This diversity and abundance is not seen elsewhere in Canada and is rivaled by only a few sites from around the world.
The Grande Cache Dinosaur Tracksite allows us to compare the Lower Cretaceous faunas of this area with those in other parts of the world. Ankylosaurs were the most common dinosaur in the Grande Cache area during this period. Footprint sites in Utah demonstrate that sauropods (which are not known from Grande Cache) dominated the Lower Creteceous environments. The Peace River Canyon appears to have had a very similar dinosaur fauna to Grande Cache except that the dominant dinosaur track maker in the Peace River Canyon, ornithopods (bipedal, plant-eaters), are not known from the Grande Cache area. This evidence has allowed researchers to divide North America into three faunal zones, each based on a unique assemblage of dinosaurs.
For these reasons, many experts consider this site to be one of the most important dinosaur tracksites in the world.
There is also an abundance of fossilized plant material (petrified stumps, log impressions and leaf impressions) preserved at several of the sites (both as backfill and in situ) and at one site (9 Mine Lower East Limb Pit) there is a deposit containing the remains of a rare bivalve. Not only do these fossils tell us about the environment in which the dinosaurs lived, but also provide information on fossils from an otherwise poorly represented time in Alberta's pre-history.
Character-Defining Elements
W3 Sites (W3 Bird, W3 Main, W3 Extension and W3 Corner):
Location: Near No. 12 Mine haul road
UTM Coordinates (NAD27): W3 Corner - 11U 350298 5990010
W3 Extension - 11U 350410 5989965
W3 Main - 11U 350736 5989712
W3 Bird - 11U 350829 5989665
Description of Sites: Tetrapodosaurus borealis (large quadrapedal [four-footed] dinosaur - ankylosaur), Irenesauripus mclearni (large bipedal [two-footed] carnivorous dinosaur - allosaurid), Columbosauripus ungulatus (medium bipedal carnivorous dinosaur), Gypsichnites pascensis (medium bipedal carnivorous(?) dinosaur), Irenichnites gracilis (small bipedal carnivorous dinosaur - ornothomimid), Aquatilavipes ichnospecies (several footprint taxa of avian affinity, ranging in size from just over 2cm to just over 10cm).
These track sites are continuous along a 600m long portion of a footwall that in most areas exceed 50 meters in height. The footprints occur as natural moulds (i.e. they are impressions as opposed to infillings or natural casts) and many lengthy trackway (sequences of footprints made by individual animals) are present. The footprints of bipedal animals are dominant over those of the quadrapeds.
Characteristics of Site: The footwall displaying the track sites is at an angle exceeding 60º in some places. The track sites were exposed as a result of surface coal-mining operations. There is no significant vegetation in the area between the access road and the footwall. Before backfill and reclamation operations the base of the original footwall was located over 30 meters below its present level. The site is easily accessed from a main haul road if the access road is maintained. The tracksites are less that 150 meters from the point of access and can be reached by walking over the level but rocky backfill area.
These sites have also produced an impressive amount of fossil plants specimens (gingkoes, ferns, conifers, cycads and others) from the talus and backfill material in front of the footwall.
Significance of the W3 Sites: The W3 sites have a large diversity of footprint types and there are no other tracksites known in Canada (and few places in the world) where one can view so many footprints (est. 10 000 for W3 Main alone) at one site.
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W2 Site:
Location: Near No. 12 Mine haul road
UTM Coordinates (NAD27): 11U 351260 5989309
Description of Site: Tetrapodosaurus borealis (large quadrapedal dinosaur - ankylosaur), Irenesauripus mclearni (large bipedal carnivorous dinosaur - allosaurid), Columbosauripus ungulatus (medium bipedal carnivorous dinosaur), Gypsichnites pascensis (medium bipedal carnivorous(?) dinosaur).
The tracksite is about 150-200 meters long and about 10-15 meters high. The footprints occur as natural moulds (depressions) with many lengthy trackways present. The footprints of quadrapedal animals are overwhelmingly dominant over those of bipeds.
Characteristics of Site: The site is at an angle of approximately 60º. The tracksites were exposed as a result of surface coal-mining operations. There is no significant vegetation other than grass in the area between the access road and the footwall. Before backfilling and reclamation operations the base of the original footwall was located over 30 meters below its present level. The site can be accessed by foot from the main haul road near a run out lane. This site is about 200-250 meters from the point of access. A level backfilled and reclaimed area in front of the footwall can be reached by walking over partially unconsolidated and rocky backfill that can contain crevasses and other pitfalls.
This site has also produced a large amount of fossil plant specimens (gingkoes, ferns, conifers, cycads and others) from the talus and backfill material in front of the footwall.
Significance of the W2 site: The W2 site has nearly as great a diversity of vertebrate footprints as the W3 sites. This is the only site in the world that shows herding behaviour of ankylosaurs (Tetrapodosaurus borealis). There are estimated to be over 1500 footprints at this site.
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W1 Sites (W1a, W1b & W1c):
Location: Near No. 12 Mine haul road
UTM Coordinates (NAD27): W1a - 11U 352445 5988694
W1b - 11U 352269 5988820
W1c - 11U 351669 5989169
Description of Sites: Tetrapodosaurus borealis (large quadrapedal dinosaur - ankylosaur) exclusively. These tracksites occur along a 200m long portion of footwall that in most areas exceeds 50 meters in height. The footprints occur as natural moulds and some short trackways are present, although the number of footprints is so great (dinoturbated) that the individual trackways are difficult to recognize. There is some in situ tree stumps from small to medium size with radiating root systems but these may be difficult to see from a distance.
Characteristics of Site: The footwall displaying the tracksites is at an angle of approximately 60º. There is no vegetation as the footwall is right next to a main haul road, making this site easily accessible. There is a site nearby to the southeast where impressions of fallen logs (Torrens Member of the Gates Formation) are visible on a high footwall. There are no other significant fossils in the area.
Significance of W1 Sites: Such a profusion of ankylosaur footprints also supports an interpretation of gregarious behaviour for which there is no other footprint evidence anywhere else in the world. There are perhaps 300+ footprints at these sites.
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9 Mine Lower East Limb Pit:
Location: Near the No. 9 Mine haul road
UTM Coordinates (NAD27): 11U 358078 5988959
Description of Site: Tetrapodosaurus borealis (large quadrapedal dinosaur - ankylosaur) exclusively. This relatively small tracksite is only about 25-30 meters across and perhaps 20 meters high. Its most notable feature is a single T. borealis trackway that was excavated by staff of the Royal Tyrrell Museum of Palaeontology in the early 1990's. There are a few other T. borealis trackways present but are not visible under any but the most favourable lighting conditions. The footprints occur as natural moulds and there are some in situ tree stumps present as well.
Characteristics of Site: The footwall displaying this tracksite is at an angle of approximately 40º. There is no vegetation and the footwall is right next to the corner of a main haul road making this site easily accessible.
Significance of the 9 Mine Lower East Limb Pit Tracksite: This is one of the first tracksites discovered in this area and it was largely excavated with considerable skill and effort by Royal Tyrrell Museum staff. The single trackway is quite visible and is quite striking. Photographs and trackway maps have appeared in several scientific papers and popular publications. There are approximately 100+ footprints at this site.
Further up the road towards the 9 Mine Extension sites and Centre Limb Pit there is an area in the ditch where a scientifically important bivalve layer is exposed. The shells are light to dark grey and some annual rings are evident. Dr. Paul Johnston (Curator of Invertebrates at the Royal Tyrrell Museum of Palaeontology) has confirmed the significance of this bivalve site and has provided the following information: The bivalves belong to the genus Murraya sp. which has only been found in surface exposures here and in Ft. McMurray where the type material was collected. The bivalves at Grande Cache may be the same taxon as those found at Ft. McMurray but it is possible that they represent something new. Murraya taxa are a bit of a palaeontological enigma as their relation to other bivalve groups is currently unresolved. At Grande Cache the Murraya sp. layer is continuous over a large area.
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Centre Limb Pit
Location: Near the No. 9 Mine haul road
UTM Coordinates (NAD27): 11U 357326 5989079
Description of Site: Tetrapodosaurus borealis (large quadrapedal dinosaur - ankylosaur) exclusively. This tracksite is fairly small although it is located in very impressive surroundings (on the side of an excavated anticline fold axis). There are only a few short trackways present and the footprints are natural moulds.
Characteristics of Site: The footwall displaying this tracksite is at a nearly 90º angle. There is no vegetation. This site is very accessible from the main 9 Mine haul road. The most impressive feature of this site is not the footprints but the excavated anticline whose long fold axis leads to a high wall with very visible layers of folded strata. The limbs of the fold axis plunge on each side into deep pools of water and are very picturesque.
Significance of Centre Limb Pit Tracksite: This is a recently discovered tracksite and its most impressive feature is the surrounding geology rather than the footprints. There are less than one hundred footprints known from this site but further research may be necessary to be sure the inventory of footprints from this site is complete.
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9 Mine West Extension Sites (9 Mine West Extension a & b and 9 Mine West Extension Fold Axis, Mine Dump)
Location: End of the No. 9 Mine haul road
UTM Coordinates (NAD27): 9 Mine West Ext. a - 11U 354245 5989655
9 Mine West Ext. b - 11U 354589 5989655
9 Mine West Fold Axis - 11U 354243 5990109
Mine Dump - 11U 355487 5989047
Description of Sites: Footprints of Tetrapodosaurus borealis type, found in situ and in talus debris on the fold axis and south-facing slope of the anticline limb.
Characteristics of Site: Several tracksites are found along a large, exposed anticline which is quite a visible landmark in the area (visible from 12 Mine haul road along E2 Pit-W3 anticline limb. In situ trackways occur high up on the steep anticline limb (9 Mine West Extension a and b tracksites) but one (9 Mine West Extension Fold Axis) occurs on a horizontal horizon. Additional research is needed to be sure of the extent of these tracksites as well as to find out how many footprints and footprint types are present.
Significance of the 9 Mine Extension Sites: Numerous Tetrapodosaurus borealis footprint casts are present in large talus piles, easily numbering in the hundreds. The in situ footprints that have been found to date number approximately 40-50 but the walls have not been more than cursorily surveyed.
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South Pit Lake Site
Location: Just off of the haul road parallel to Sheep Creek. It is near Beaverdam Road and the switchbacks to the 12 Mine haul roads.
UTM Coordinates (NAD27): 11U 355833 5987770
Description of Site: Irenichnites gracilis (small theropod), Gypsichnites pascensis (small theropod and Tetrapodosaurus borealis (ankylosaur) footprints. Footprints are found in situ or on small to large talus blocks.
Characteristics of Site: There were several in situ theropod (meat-eating dinosaur) footprints on a steep slope adjacent to a large body of water surrounded by steep slopes on three sides. Many large theropod footprint slabs had been discovered in talus debris in the area, including rare occurrences of theropod footprints showing dew claw and hind leg impressions.
Significance of South Pit Lake: The very first track site discovered in this area. The footprint finds from here were reported to the Royal Tyrrell Museum of Palaeontology in 1989. The Royal Tyrrell Museum sent the first of several expeditions to this area to collect superb footprint slabs that were spawling off of the slopes. It has been almost ten years since any researcher has visited this site because, until recently, this area had been occupied by an explosives compound.
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Location
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Grande Cache, Near |
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Recognition
| Recognition Authority: |
Province of Alberta |
| Designation Status: |
Provincial Historic Resource |
| Date of Designation: |
2006/04/21 |
Historical Information
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Additional Information
| Object Number: |
4665-1333 |
| Designation File: |
DES 2085 |
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| Data Source: |
Alberta Culture and Community Spirit, Historic Resources Management Branch, Old St. Stephen's College, 8820 - 112 Street, Edmonton, AB T6G 2P8 (File: Des. 2085) |
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