Which of the following is or are true?

Question

BlackTom AI · Accepted Answer

The question asks which statements are true. We are provided with two statements labeled b and c to evaluate.

Option b: During the Cretaceous period, the polar regions were probably dozens of degrees warmer than currently.
- This statement aligns with the well-established understanding of Cretaceous climate. During the Cretaceous, global temperatures were warmer, polar regions experienced substantially warmer conditions, and there is evidence of reduced polar ice and warmer surface temperatures. Paleoclimate data from marine sediments, plant and fossil records, and oxygen isotope analyses all support the view that polar areas were significantly warmer than today, though precise magnitudes vary by study. The phrase 'dozens of degrees warmer' is within the realm of current scholarly consensus about a much warmer Cretaceous climate, making this option plausible and commonly accepted in scientific discussions.

Option c: The Antarctic ice sheet was formed about 34 million years ago.
- This statement corresponds to the widely accepted geologic timeline for Antarctic glaciation. The onset of major Antarctic ice sheet formation is dated to around the Oligocene–Eocene transition, roughly 34 million years ago, marking a shift from a greenhouse world to a cooler state with permanent ice. This timing is supported by multiple stratigraphic and isotopic records, including microfossil assemblages and chemical proxies, indicating the establishment of a significant Antarctic ice mass at about that time. Therefore, this statement is considered true.

In summary, both statements b and c reflect well-supported aspects of paleoclimate evidence: a substantially warmer polar climate during the Cretaceous and the emergence of a substantial Antarctic ice sheet around 34 million years ago.

Dashboard QUIZ Multiple choice questions - Part 2

Which of the following is or are true?

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