Question

Spiti Shale was deposited during the _____ time.

• A. Palaeozoic
• B. Mesozoic
• C. Cenozoic
• D. Proterozoic

Answer 1

The Correct Option is B

The question asks about the geological time period during which the Spiti Shale was deposited. To solve this, we need to understand the geological time scales and when significant deposits were formed.

The Spiti Shale is a significant geological formation found in the Spiti region of Himachal Pradesh, India. It is known for its fossil content, particularly marine invertebrates. Geological studies and fossil records from these formations suggest their deposition during the Mesozoic era.

Let's consider the options provided:

• Palaeozoic: This era occurred before the Mesozoic and is characterized by the evolution of early life forms, but it does not correspond with the Spiti Shale deposition period.
• Mesozoic: Known as the "Age of Reptiles," this era spans from around 252 to 66 million years ago and includes the Triassic, Jurassic, and Cretaceous periods. The Spiti Shale was deposited during this era, more specifically in the Jurassic period, due to the presence of marine fossils typical of that time.
• Cenozoic: This era follows the Mesozoic and is known as the "Age of Mammals," but it is not when the Spiti Shale was deposited.
• Proterozoic: This is an earlier era within the Precambrian supereon and does not align with the time frame of Spiti Shale deposition.

By understanding these eras and their characteristics, it is clear that the correct answer is Mesozoic. Thus, the Spiti Shale was deposited during the Mesozoic era.