ANSWER:The KT boundary dates to 65 million years ago (when the dinosaurs disappeared).The KT boundary in Zumaia, Spain is sharprepresenting an abrupt change in the marine ecosystem.The KT boundary separates rock layers of the Cretaceous period from those of the Tertiary period.The KT boundary is a thin layer of clay found only in Gubbio, Italy. Show
Foraminifera above the boundary are larger and more diverse than those below.Foraminifera above the boundary are larger and less diverse than those below.Foraminifera above the boundary are smaller and more diverse than those below.Foraminifera above the boundary are smaller and less diverse than those below. CorrectThe geologic layers above (later than) the KT boundary show a sharp, dramatic reduction in diversity and size—a clue that something catastrophic happened.Part CIridium is a component of cosmic dust that rains down upon the earth at a constant rate. Why did Luis Alvarezsuggest measuring iridium levels in the KT boundary?CorrectPart DThe scientific community was slow to accept the asteroid impact hypothesis. Why?CorrectPart EWhich evidence is consistent with the asteroid impact hypothesis?Select all that apply. CorrectThe energy from an iridiumrich asteroid impact melted and transformed rock and ejected the material atvarying distances from the impact site. Altered rock forms like shocked quartz, spherules and tektites wereimportant clues in the search for the impact crater. 1. Which of the following statements about the K-T boundary are true? (Note: More than one answer is correct.)
Answers chosen: Attempts: 2. How do foraminifera found in rock layers above the K-T boundary compare to those in rock layers below?
Answers chosen: Attempts: 3. Iridium is a component of cosmic dust that rains down on Earth at a constant rate. Why did Dr. Luis Alvarez suggest measuring iridium levels across the K-T boundary?
Answers chosen: Attempts: 4. The scientific community was slow to accept the asteroid impact hypothesis. Why?
Answers chosen: Attempts: 5. Which evidence is consistent with the asteroid impact hypothesis? (Note: More than one answer is correct.)
Answers chosen: Attempts: 6. What was the critical piece of evidence that supported the hypothesis that an asteroid struck Earth about 65 million years ago?
Answers chosen: Attempts: 7. Which of the following effects of the asteroid impact would have caused large numbers of different species of animals and plants to die throughout the entire planet?
Answers chosen: Attempts: 8. Which characteristic was NOT advantageous for organisms in the million years after the catastrophic asteroid impact?
Answers chosen: Attempts: Which evidence is consistent with the asteroid impact hypothesis quizlet?Which evidence is consistent with the asteroid impact hypothesis? The energy from an iridium-rich asteroid impact melted and transformed rock and ejected the material at varying distances from the impact site.
What was the critical piece of evidence that supported the hypothesis that an asteroid?To test the hypothesis that an asteroid impact caused the K-T mass extinction, key evidence included impact ejecta, tsunami debris, and careful gravitational field measurements.
Which piece of evidence definitely showed that an asteroid had struck Earth?Which piece of evidence definitely showed that an asteroid had struck Earth? Explain your answer. The crater at Chicxulub was the smoking gun. Finding a crater that matched the age and size of the asteroid provided direct evidence for the impact.
What evidence led geologists to suggest that the mass extinction at the K PG boundary represents collision of an asteroid with the Earth?The impact hypothesis, also known as the Alvarez hypothesis, was bolstered by the discovery of the 180 km (112 mi) Chicxulub crater in the Gulf of Mexico's Yucatán Peninsula in the early 1990s, which provided conclusive evidence that the K–Pg boundary clay represented debris from an asteroid impact.
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