A) Every Pb2+ atom detected in the zircon sample must be the result of radioactive decay, while some Pb2+ atoms found in sphene could have been incorporated during its formation.
Explanation:
The reason why the geochemist will prefer to use the ziron which takes the 4+ cation would be because, every Pb2+ atom detected in the zircon sample must be the result of radioactive decay, while some Pb2+ atoms found in sphene could have been incorporated during its formation.
✓ The Pb 2+ produced the daughter isotopes of the radioactive decays.
✓ To properly date the rock sample, any external source of the daughter isotopes should be eradicated.
✓ This will help to establish a fair ratio between the parent and daughter isotopes in order to track the decay rate.
✓ This is why the Zircon would be preferred to the Sphene.
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Answer:
Marginal information includes the topographical sheet number, its location, grid references, its extent in degrees and minutes, scale, the districts covered, etc. Marginal information is classified in to : Extra Marginal Information - Serial Number, name of the State, District and other general information.
Explanation:
Answer:
The correct answer is option A. convergent evolution.
Explanation:
Convergent evolution occurs when there are <u>two organisms that have similar characteristics or traits</u>, but there is no recent ancestor from which they have evolved.
That is, each species developed its own characteristic and did not inherit it from a common ancestor. This happens because depending on the habitat, the species have to <u>develop the same solution to a problem that presents itself, even if they are of different species.
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An example of this is sharks and dolphins. They are <u>physically very similar</u>, both have soft skin and fins that serve to chase their prey.
But if we look better, <u>the shark is oviparous</u>, while the <u>dolphin is mammal.</u>
<u>The shark is a killer carnivore while the dolphin is a friendlier animal.
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The explanation of their similarity is due to the fact that the last ancestor they shared lived about 290 million years ago, that is, it was not recent. Then both animals were forced to <u>evolve differently.
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Homology is called to those organisms that have structural similarities because they share the inheritance of a common ancestor.
And it is called analogy to similar characteristics but that do not come from a common ancestor.
Answer:
a. fumarole -- 1. a vent from which steam escapes
b. geyser -- 4. an eruption of hot water and steam
c. hot spring -- 2. ground water has come into contact with hot rocks and risen to the surface
d. travertine -- 3. massive deposits of calcium carbonate around a hot spring
Explanation:
- A fumarole is opening of the crust and has emitted streams and gases like the carbon dioxide, and the sulfur dioxide, and hydrogen chloride, and hydrogen sulfide.
- The streams are formed by the boiling of the superheated water and its pressure falls when it reaches the ground surface.
- A geyser is a spring that is characterized by the discharge of the water ejected turbulently and is accompanied by a stream and exists at a few places on earth.
- A hot spring is a hydrothermal vent that is made by the emergence of the geothermally heated groundwater that rises form the earth crust.
- A travertine is a terrestrial sedimentary rock that is formed by the precipitation of the carbonate materials form the solution to the ground surface and a geothermally heated ground spring.
"Longitudinal waves" is the wave among the following choices given in the question that <span>cause the matter to move perpendicular to the direction in which the wave is traveling. The correct option among the two options that are given in the question is the first option. I hope that this answer has come to your help.</span>