#3. You can determine the age of the Gabbro and Granite from the figure in quest
ID: 115160 • Letter: #
Question
#3. You can determine the age of the Gabbro and Granite from the figure in question #2 using U-235. Table 1.0 provides the results of laboratory isotopic analysis of samples. Using Formula 1.0, calculate the age of the Gabbro (Unit E) and Granite (Unit F) in years. The half-life of U-235 is approximately 700 million years. Show your work.
#3. You can determine the age of the Gabbro and Granite from the figure in question #2 using U-235. Table 1.0 provides the results of laboratory isotopic analysis of samples. Using Formula 1.0, calculate the age of the Gabbro (Unit E)and Granite(Unit F) in years. The half-life of U-235 is approximately 700 million years. Show your work Formula 1.0 Pi%= Pt/(Pt + Dt) Pi% = The percent of initial parent atoms remaining in the system Pts Number of Parent atoms today Dt = Number of Daughter atoms today Table 1.0 Rock Unit Unit E (Gabbro Unit F (Granite # of Daughter Atoms 2,750 # of Parent Atoms 2,750 550 A) What are the ages in millions of years of the Gabbro and Granite? B) What can you say about the ages of Unit D (Quartz Sandstone) and Unit A (Conglomerate)?Explanation / Answer
Rock unit E: initially, daughter atoms number would be zero. In first half life, both parent and daughter atoms will be same. That is from, 1:0, 1/2 : 1/2 will occur. Therefore, age of unit E is one half life. That is 700 million years. Rock unit F: Parent to daughter atoms: 1550:10850 1550/10850 = 0.14 =1/(50/7) =1/7 1:7 Now,half life 1 - 1:1 For half life 2- 1:3 For half life 3 - 1:7 Total number of half lives = 3 Therefore 3 x 700 = 2100 million years is the age of rock unit F Granite.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.