Answer:
A. In undisturbed rock layers, the youngest rocks are on the bottom.
C. If one rock contains pieces of another, the rock containing the pieces is older than the pieces.
Explanation:
Relative dating is a form of dating rocks in which past events in geologic records are put their proper order without necessarily knowing their absolute ages. There are several principles that helps in relative dating of rocks. These principles are:
- Principle of superposition of strata
- Law of original horizontality
- Principle of lateral continuity
- Principle of inclusion
- Principle of fossil and fauna succession
Option A and C are false statements of principle of superpositon of strata and principle of inclusion.
A. In undisturbed rock layers, the youngest rocks are on the bottom.
According to the principle of superpositon of strata, "the oldest sedimentary rock layers are usually at the bottom and the youngest on the top".
C. If one rock contains pieces of another, the rock containing the pieces is older than the pieces.
This is a false statement of principle of inclusion, the principle states that "inclusions found in a sedimentary rock are older than the rocks that contains them". Inclusions are fragments or pieces of other rocks that are found in a rock. These inclusion are believed to be older than the rocks they are found in.
Answer:
The magma that melts in the upper mantle and erupts at the mid-ocean ridge has a different composition (higher in Ca, Mg, Fe and relatively lower in Si and Al) than the composition of the magma (more Si, Al, Na, K rich in relative terms) that built the continents. Melting different degrees (2%, 5%, 30%) of a rock with a mantle-like composition generates magma of different Al, Si contents. Continents grow at their edges by partial melting of oceanic crust that is being subducted, generating magmas of a somewhat more Si, Al-rich composition than the subducting slab itself. The chemistry and physics of melting a mixture of minerals rather than one homogeneous substance has the wonderful outcome of creating two distinct types of crust:
Answer:
similar coastal rock formations. b)
Earthquakes produce P and S waves. The P waves are fast and of a higher frequency than S waves. P waves reach a point first and can pass through liquid media while S waves reach after and the lose much of their energy while passing liquid media. This is because S-waves are shear waves and require rigid/inelastic media for transmission.
During an earthquake, there is usually a shadow zone (where there is no destruction because S-waves did not reach) formed right above the epicenter of the earthquake. This is due to the fact that the S-waves were unable to transit through the liquid inner core of the earth before reaching the earth's surface. Only P-waves are registered in this shadow zone.
