Ancient Flood Buried Keezhadi, Forcing Abandonment 1,155 Years Ago

सही उत्तर: B

Statement 1 is correct. OSL dating relies on the principle that certain minerals (like quartz and feldspar) accumulate energy from environmental radiation over time. When exposed to light or heat, this stored energy is released as luminescence, effectively resetting the 'geological clock'. Statement 2 is correct. OSL dating has a broad range, typically from a few decades to several hundred thousand years, making it suitable for Quaternary geology and archaeology. Statement 3 is incorrect. The recent study used OSL dating to determine the *burial and abandonment* period (around 1,155 years ago) due to a flood, not the initial habitation. The habitation period is much older (Sangam Age, 3rd BCE to 3rd CE).

सही उत्तर: B

Statement 1 is incorrect. Keezhadi belongs to the Sangam Age (roughly 3rd century BCE to 3rd century CE), which is much later than the mature and late Harappan phases of the Indus Valley Civilization (c. 2600-1900 BCE). Statement 2 is correct. Keezhadi's sophisticated urban structures, pottery, and inscriptions have indeed pushed back the timeline of urbanisation in South India, demonstrating a thriving urban culture during the Sangam Age. Statement 3 is incorrect. While Roman trade links with South India during the Sangam Age are well-documented (e.g., Arikamedu), the primary significance of Keezhadi lies in its indigenous Dravidian urban characteristics, not necessarily a unique blend of Roman architectural styles. Evidence of Roman artifacts like rouletted ware and amphora shards has been found, indicating trade, but not a direct architectural blend.

सही उत्तर: B

Statement 1 is incorrect. While environmental changes, including shifts in monsoon patterns, droughts, and possibly some localized floods, are considered major factors in the decline of the Harappan civilization, it's generally understood as a complex process involving multiple factors over time, not a single catastrophic flood event across the entire civilization. Statement 2 is correct, as per the news article. OSL dating indicates a powerful flood around 1,155 years ago caused the abandonment of Keezhadi. Statement 3 is correct. Archaeological research at various Harappan sites, including Kalibangan (Ghaghra-Hakra river system) and Lothal (Bhogavo river, a tributary of Sabarmati), has shown that changes in river hydrology, including drying up of rivers or shifts in their courses, played a crucial role in the rise and decline of these settlements.