Eureka Sound Formation

Eureka Sound Formation
Stratigraphic range: Paleogene
Type Formation
Location
Region Nunavut
Country Canada
This is a map of the Canadian Territory of Nunavut

The Eureka Sound Formation is a geologic formation found in the Canadian Territory of Nunavut on Ellesmere Island, which is part of the Canadian Arctic Archipelago. The Eureka Sound Formation is Tertiary in age. [1]

History

During the early Tertiary period, marine beds began forming in the Eureka Sound Formation within an area that was previously thought to be almost exclusively non-marine. [1] This discovery indicates that this region of the Arctic had been mild, temperate, and ice-free during the early to middle Eocene , despite being well above the Arctic Circle. As of May 2014, this discovery had been restricted to the easternmost regions of the Canadian Arctic on Ellesmere Island.[2] Because the Eureka Sound Formation contains the largest accumulation of Arctic Paleogene deposits, studying its marine deposits is key in gaining a better understanding of the early Tertiary history of the Arctic Ocean.[1]

Fossils

Some fossils discovered in the Eureka Sound Formation were Paleogene land vertebrates that include fish, turtles, and several types of mammals.[3] Other types of fossils found were reptilian species and several types of birds. [4] Fresh water molluscs were also found. [5]

Sediments and Geology

On Southern Ellesmere Island, the Eureka Sound Formation is up to 480 meters thick and consists of a sequence of prediminantly non-marine sandstones, mudstones, coal and minor siltstones. Sandstone petrography and heavy mineral analyses indicate that the Eureka Sound sediments were derived mainly from Precambrian granulite-grade metamorphic rocks of the Canadian Shield located to the southeast of the Formation.[6] Another finding states that significant anounts of the rocks of the Eureka Sound Formation on Western Ellesmere Island are marine in origin. [5]

See also

References

  1. 1 2 3 "Circular, Volumes 905-917".
  2. ↑ "First Record of Eocene Bony Fishes and Crocodyliforms from Canada's Western Arctic.".
  3. ↑ Dawson, Mary R.; West, Robert M.; Langston, Wann; Hutchison, J. Howard (May 21, 1976). "Paleogene Terrestrial Vertebrates: Northernmost Occurrence, Ellesmere Island, Canada". Science. 192 (4241): 781–782. doi:10.1126/science.192.4241.781. ISSN 0036-8075. PMID 17777182. Retrieved May 7, 2015.
  4. ↑ "Eocene lower vertebrates from Ellesmere Island, Canadian Arctic Archipelago".
  5. 1 2 "Paleontologic Evidence of Marine Sediments in the Eureka Sound Formation of Ellesmere Island, Arctic Archipelago, N.W.T., Canada". www.nrcresearchpress.com. Retrieved 2015-05-07.
  6. ↑ "AAPG Datapages/Archives: The Eureka Sound Formation, Southern Ellesmere Island". archives.datapages.com. Retrieved 2015-05-07.


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