Question

• .Define the terrestrial age of a meteorite and explain, in your own words, how this is determined. (About 200 words)

• b.If a meteorite were to be of Martian origin, explain where the oxygen isotope composition of this sample and other Martian samples would appear with respect to the terrestrial fractionation line (TFL) on a plot of ¹⁷O versus ¹⁸O (see Figure 9.16 in ISS). (2 sentences)

Answer 1

Meteorites are estimated by the decay of enduring radioactive isotopes of components that happen normally in rocks and minerals and that decay with half existences of 700 million to in excess of 100 billion years to stable isotopes of different components. These dating systems, which are immovably grounded in physics and are referred to on the whole as radiometric dating, are utilized to quantify the last time that the stone being dated was either liquefied or upset adequately to re-homogenize its radioactive components. This method is called isochron method.the minerals inside a rock are utilized to date it, and the line on the diagram is called an internal isochron. A similar rule can be applied in the event that one uses various rocks that shaped simultaneously and spot however had diverse initial 87Rb/86Sr proportions. The outcome is known whole-rock isochron. An isochron is vague in that it dates the time either when the minerals or rocks framed or when they were last warmed and the strontium isotopes in them rehomogenized. Thusly, other proof about a rocks or suite of rocks is expected to figure out what the isochron is really dating. On the off chance that the information focuses for minerals or rocks don't fall on a line, it shows that the framework has been upset and can't be utilized for dating. Shock is the most widely recognized reason for upset systems in shooting stars.

answer b

The little contrast between the O-isotopic mass fractionation lines of the Earth and Mars has been estimated exactly utilizing a laser fluorination framework. The exactness accomplished from the two example sets is better than ±0.014‰, with the counterbalance (Δ17O) among Mars and Earth estimated as +0.321‰. This outcome shows that all the Shergotty—Nakhla—Chassigny (SNC) shooting stars characterize a significant level of isotopic homogeneity, practically identical to that of crustal material on the Earth, demonstrating that these meteorites begin, unequivocally, from a solitary body, Mars. With its old age, shows that any underlying heterogeneity bestowed into Mars from the cloud was homogenized right off the bat in the arrangement history of the planet. There's also another explanation for varying Δ17O value- (1) experimental faults, (2) terrestrial weathering outcomes (3) existence of martian weathering outcomes.