Self-study
P1
Discovered in 1993, the site known as Ukhaa Tolgod, in the Gobi desert of Mongolia, is one of the world's best sources of fossils from the Late Cretaceous period, which ended about 65 million years ago. ███ █████████ ███████ ███ ██████ ███████ ████ ████ █████ █████████ ████████ ██████████ ████ ████ █ ███████████ ███████ ███ ███████████████ ████ ██████████ ███
Phenomenon ·
Well preserved fossils
How did they form?
Hypothesis ·
Sandstorm buried the animals
Hypothesis wrong ·
New evidence calls sandstorm hypothesis into question
P2
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Details of Phenomenon ·
Three different types of sandstone at the site
1st Type ·
Well-defined structure
Consistent with sandstorm hypothesis...
2nd Type ·
Tilt and layering
Also consistent with sandstorm hypothesis...
3rd Type ·
No layering; contains large pebbles
Inconsistent with sandstorm hypothesis because the pebbles are too large to have been windblown. This is the type that contains all of the vertebrate skeletal fossils.
P3
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Alternate Hypothesis ·
Sand avalanche caused fossils
Avalanche trapped animals in its path, resulting in the pristine quality of the remains.
P4
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Phenomenon ·
Avalanche / sandslides
What caused them?
Hypothesis ·
Unclear; clay played a role
Unclear but likely clay and rain played a role.
Evidence ·
Modern sand dunes
Implications of hypothesis ·
Sandslide hypothesis suggests area was not sterile desert
Passage Style
Critique or debate
Phenomenon-hypothesis (RC)
25.
The information in the passage ████ █████ ██ ██████ █████ ███ ██ ███ █████████ ██████████
a
What kinds of ███████ █████████ ███ ████ ██████ ██ ███ ███ ██ ███ ████ ██████████ ███████
We don’t get any information about different kinds of mammals.
b
What kind of █████████ ██ █████████ █████ ██████ ██ █████ ███████
Although we get a description of 3 kinds of sandstone in P2, the author never indicates what kind of sandstone is currently being formed.
c
Have fossilized plants ████ ████ █████ ██ █████████ ██ ███ ████ ███████
The author never mentions fossilized plants or anything that could be taken to refer to fossilized plants.
d
Have scientists found ██████████ █████████ ██ ███████ ████ ████ ██████ ██ ██████ ██████████ █████████ █████ ████ ██ █████ ███████
The author never mentions fossilized skeletons found in places besides Ukhaa Tolgod.
e
Are present-day sand █████ ████ ███████ ██ ███████ ████████ ███████████ ███████████