Steno's Laws

What is the principle of superposition?

• The youngest layer is on top and the oldest is on the bottom.

• The principle of superposition is the idea that in an undisturbed sequence of rock layers, the oldest layer will be on top and the youngest layer on the bottom.

• The principle of superposition is based on the idea that in an undisturbed sequence of sedimentary rock layers, the oldest layer is at the bottom and the youngest layer is at the top.

• The principle of superposition states that all rock layers were originally horizontal.

Explain the concept of original horizontality.

• Original horizontality refers to the folding of rock layers.

• It is the concept of rocks being formed in irregular shapes.

• Sedimentary rocks are deposited in vertical layers.

• Sedimentary rocks are deposited in horizontal layers.

How are cross-cutting relationships used in relative dating?

• By studying the fossils found in the rock layers

• By determining the sequence of events and identifying which rock layers are older or younger based on their interactions with each other.

• By analyzing the chemical composition of the rock layers

• By measuring the absolute age of the rock layers

What are unconformities and how do they form?

• Unconformities are the result of tectonic plate movement and they form when new sediment is deposited on top of older rock layers.

• Unconformities are the result of weathering and they form when sediment is transported by wind or water.

• Unconformities are gaps in the rock record caused by erosion or non-deposition, and they form when there is a period of uplift and erosion before new sediment is deposited.

• Unconformities are caused by volcanic activity and they form when lava solidifies into rock.

Define index fossil and explain its significance in relative dating.

• A fossil that only exists in one specific location

• A fossil that is not useful for dating rock layers

• A fossil that is found in a rock layer younger than the layer it is in

• A fossil of a widely distributed organism that lived during a specific period and can be used to date the rock layer in which it is found.

What is the Mesozoic Era known for in terms of geological history?

• Era of volcanic eruptions and earthquakes

• Era of ice age and glaciation

• Era of extreme heat and desertification

• Dominance of dinosaurs and development of flowering plants

Explain the concept of the geological time scale.

• A scale used to measure the hardness of different types of rocks

• A way to determine the age of fossils based on their size

• A method of measuring the depth of the Earth's crust

• A system of chronological dating that relates geological strata to time

How does the principle of superposition help in understanding the relative age of rock layers?

• It has no impact on understanding the relative age of rock layers

• It only works for sedimentary rocks, not igneous or metamorphic rocks

• It helps in understanding the relative age of rock layers by allowing geologists to determine the sequence of events and the relative ages of the rock layers based on their positions.

• It is not a reliable method for determining the relative age of rock layers

Why are index fossils important in determining the relative age of rock layers?

• Index fossils are too rare to be useful in determining the relative age of rock layers

• Index fossils are only found in one location and cannot be used to correlate rock layers

• Index fossils help in correlating rock layers from different locations.

• Index fossils are not important in determining the relative age of rock layers

Describe the significance of unconformities in understanding geological history.

• Unconformities only occur in recent geological formations

• Unconformities indicate continuous and uninterrupted geological record

• Unconformities are irrelevant in understanding geological history

• Unconformities provide evidence of gaps in the geological record and help understand the timing of events and Earth's history.