What is the depositional environment of the Burgess Shale?
Geological setting The fossil-bearing deposits of the Burgess Shale correlate to the Stephen Formation, a collection of slightly calcareous dark mudstones, about 508 million years old. The beds were deposited at the base of a cliff about 160 m tall, below the depth agitated by waves during storms.
Is Burgess Shale a sedimentary?
The widespread preservation of Burgess Shale-type assemblages of soft-bodied fossils during the Cambrian resulted from a combination of favorable sedimentary circumstances that acted to restrict the flow of oxidants into the early burial environment.
Where is the Burgess Shale formation found?
British Columbia’s Yoho National Park
The Burgess Shale is found in an area of the Canadian Rocky Mountains known as the Burgess Pass, and is located in British Columbia’s Yoho National Park.
What is the Burgess Shale and where is it located?
British ColumbiaBurgess Shale / Province
How was Burgess Shale formed?
Sediment flowing into the sea buried both dead and living animals. As more and more sediment accumulated, the organisms were compressed and fossilized. As this process repeated, the layers of fossils now found in the Burgess Shale were created.
What is special about the Burgess Shale?
These fossils merit special interest for several reasons: They were buried in an underwater avalanche of fine mud that preserved exceptionally fine details of the structure of their soft parts. Only hard parts are preserved in most other Cambrian deposits, obviously limiting information within the geologic record.
What type of rock is found in the Burgess Shale?
The Cambrian sedimentary formations of Yoho National Park consist of mudstone, deposited in deep ocean conditions, and limestone deposited in shallower-water. These formations are characterized by cycles of deposition which alternated between mudstone rocks in the lower portion and carbonates above.
Where is the Burgess Shale quarry located?
Yoho National Park
Burgess Shale Location Nestled high in the Canadian Rocky Mountains, the Burgess Shale is a record of one of the earliest marine ecosystems, giving a tantalizing glimpse of life as it was over 500 million years ago. The Burgess Shale is located in Yoho National Park, near the town of Field, BC.
What type of fossils does the Burgess Shale contain?
The soft-bodied organisms for which the Burgess Shale is famous are fossilized in the mudstone layers, which are between 2 and 170 millimetres (0.079 and 6.693 in) thick, averaging 30 millimetres (1.2 in), and have well-defined bases.
How was the Burgess Shale formed?
Why is the Burgess Shale significant?
More than half a billion years old, the fossils of the Burgess Shale preserve an intriguing glimpse of early life on Earth. They were first discovered in 1909 by Charles D. Walcott, then Secretary of the Smithsonian Institution.
What is the depositional mode of the shale?
Analysis of lithofacies and sedimentary structures indicated that the depositional mode of the shale was not only the suspension deposition under the low-energy hydrodynamic condition, but also the biogenic, storm, and bottom current depositions.
How was siliceous shale deposited in the Wufeng and longmaxi formation?
In the dysoxic/anoxic environment, the siliceous shale at the bottom of the Wufeng and Longmaxi Formation was deposited through the suspenion and biogenic process and was rich in organic matters.
What drives the formation of organic-rich shale?
Introduction The formation of organic-rich shale was controlled by depositional processes and environment condition.
What determines the redox condition during formation of organic shale?
The formation of organic-rich shale was controlled by sedimentary environment and preservation conditions of organic matters. Geochemical index was an effective method to reflect the redox condition during formation of black shale. Mo, U and V were regarded as the redox sensitive elements ( Calvert and Pedersen, 1993, Algeo and Maynard, 2004 ).