Rocks
Two kids are walking a creek bank, they hope to find some fossils along the way. What kinds of rocks should they look for?
Sedimentary Rocks (Sandstone, Shale, Limestone)
Shale is being exposed. What kind of environment might have once existed?
Swamp
What do we call the scale that measures time?
Geological Time Scale
What is an index fossil?
Fossils that provide evidence for the age of rock layers.
1. Lived for a SHORT period of time 2. Lived in many places around the world
How does shale form?
Shale forms from sediments (clay and silt) settling in a basin and compacting together over time.
Sandstone is layered ON TOP of Limestone. What can it be said about the environments?
An ocean turned into a desert.
Where are newer layers formed?
On top of older layers.
Yes or No.
If you buried a hamster in your backyard, would that hamster become fossilized?
No.
What rock(s) form from cementation?
Sandstone
Students find some pieces of white sandy rock in a creek. They drip hydrochloric acid on that rock. The rock does not fizz. Did a chemical reaction and melting form the rocks in the creek?
No.
To a geologist, the most important use of index fossils is?
To determine the age of the rock.
What are reasons for gaps in the fossils record? Yes or No.
There were periods of time when no organisms died.
No.
Why is uniformitarianism an important principle to consider when making inferences about how Earth's geology has changed over millions of years?
If we observe a process shaping earth today, we can assume the same process shaped earth in the past and will shape in it in the future.
Yes or No
Do rock layers always form horizontally?
Yes.
Geological time is described in eras and periods. Those segments of time are based on _____.
1. Significant evolutionary events in Earth's history.
2. The number of layers of rock that can be counted in 10 meters of a rock column.
1.
The Grand Canyon Fossils were found in which era?
Paleozoic.
Do scientists think that new rocks are still forming today? How does uniformitarianism help scientists answer the first question?
Today we see evidence of rock formation like volcanoes erupting, sediments layering, but it is almost impossible for use to observe directly. If rocks were not forming today, the earth's surface would be smooth. Uniformitarianism helps explain this.
Yes or No.
An entire basin can become tilted.
Yes.
What era do we live in?
Cenozoic era.
What are reasons for gaps in the fossils record? Yes or No.
Many organisms have structures that can be fossilized.
Yes.