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Home Camp I: Dragon Creek,
Camp II: Blackwelder Mtns,
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Our first field camp this season was one we had actually visited previously. During the 1996 Expedition, this camp had been chosen to sample the excellent exposure of Strand Fiord Basalt located upstream. One idle afternoon while John and Rory were walking along the tundra, Rory literally tripped over a rock that turned out to contain a champsosaur femur. Champsosaurs are non-migratory, ectothermic extinct reptiles similar to extant crocodiles. They do not carry with them the climatological ambiguity that dinosaurs do (whether or not dinosaurs are ecto- or endothermic, and therefore able to survive prolong exposure to freezing temperatures, remains in question), and their presence at a 72.5° N paleolatitude approximately 90 million years ago therefore indicates that the coldest month mean temperature did not fall below approximately 5.5° C. The Middle Cretaceous polar paleoclimate is analogous to Florida's present climate. Furthermore, the champsosaurs were found in rocks immediately above 1.5 km thick subaerial-erupted flood basalt. This thick volcanic stratigraphic section is associated with the large igneous province (LIP) of Strand Fiord Basalt. LIPs were common and globally distributed in the Cretaceous and are considered the primary source for the amplified carbon dioxide levels characteristic of the Cretaceous. For more information regarding this significant discovery, please refer to articles and links at Arctic Fossils.
Our goal in returning to Dragon Creek was to collect a more complete
fossil assemblage. We collected numerous additional champsosaur
bones, hard and soft shelled turtles, numerous fish scales and vertebrae,
and mesosequoia flora, with which we will try to describe a more complete
paleoecological description of the environment in which these organisms
lived. Once our cataloging and analysis is complete, samples
are returned to Canada where they are displayed and stored at the Royal
Tyrrell Museum of Paleontology in Drumheller, Alberta.
| We had waited for several days in Resolute Bay and nearly another at Eureka Weather Station for the weather to clear enough for us to get onto Axel Heiberg. There was a short interval of respective calm, and we slipped onto the island just as the weather started to turn poor again. Here Matt P. and Santo wait by our gear while John examines the tundra in the background. The fog was coming in quickly, forming the thick white blanket in the background, and we were wondering if the rest of our team and gear was going to make in it on time. |
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| The weather cleared the next morning, as shown in this picture of Camp I. |  |
| This is the view from our tents, looking south across Dragon Creek at the Kanguk Formation, a thick Late Cretaceous shale. The rock is strongly banded from the numerous and continuous bentonite beds characteristic to the formation. Bentonite is volcanic tuff, or ash. It holds water well, so you often find it in varying colors as a slippery clay- or Play-Do-like substance. The bentonites here were staining ochres and yellows. |  |
| Here is a view of camp and Dragon Creek from Dragon Mountain. If you look closely, you will see four yellow dots just right of bottom-center: that's camp. We were camped on Kanguk shale, which weathered easily into mud and formed broad, flat valleys penned in by high ridges held up by the Strand Fiord Basalt. |  |
| The champsosaurs and other fossils came from a thin (~4 m) silty-sandstone bed, visible in this picture as the strong, outcropping bed just above Santo, Rory, and the Matts. The rock on this side of the river was tenacious, and consequently it often refused to break. We were nonetheless able to collect several teeth, mandibles, and articulated vertebrae from this site. |  |
| Another view of the bed exposure on the south side of Dragon Creek. Immediately downsection (to the left) is the top of the Strand Fiord Basalt. |  |
| This is a view of the north side of Dragon Creek and the champsosaur bed. The sun shined on this side of the river a lot more than on the other, thereby contributing significantly to the amount of freeze-thaw action there. Extensive fracturing allowed us to excavate a lot of rock, shown by the concave shape of the outcrop. Several complete turtles and partially articulated vertebrae were extracted here. |  |
| Here, on our first day of field work, John (foreground) briefs the students (from left: Santo, Matt F., Allyson, and Matt P.) on the site geology and what were are looking for. Although the skies had cleared, it was still a chilly day in the Arctic. |  |
| After collecting several hundred pounds of rock came the task of choosing which fossils would earn a trip back to the US. Here Rory and Allyson pause from wrapping and cataloging fossils for a smile break. |
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| Arctic travel takes various forms. Here Matt F. clings to slippery Strand Fiord Basalt hoping to keep his feet dry and warm. |  |
| Upstream from camp, Dragon Creek sliced through the Strand Fiord Basalt creating this small canyon, the site of the 1996 core sampling. |  |
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