Which one of the following is NOT a palaeoclimatic geological indicato

Which one of the following is NOT a palaeoclimatic geological indicator ?

Lacustrine deposits
Ice sheets and ice cores
Evaporite deposits
Sedimentary deposits
This question was previously asked in
UPSC CAPF – 2019
The correct answer is D) Sedimentary deposits. While many types of sedimentary deposits are excellent palaeoclimatic indicators (such as lacustrine deposits, evaporites, tills, coal seams, etc.), the term “Sedimentary deposits” itself is too general. Not all sedimentary deposits provide clear palaeoclimate information, and it is the specific characteristics or type of sedimentary deposit that makes it an indicator, unlike the other options which represent specific types of deposits known to be valuable palaeoclimate proxies.
– Palaeoclimatic geological indicators are geological features, structures, or deposits that contain evidence about past climate conditions.
– Lacustrine deposits (lake sediments) often preserve pollen, microfossils, and sediment layers that reflect changes in precipitation, temperature, and vegetation.
– Ice sheets and ice cores contain trapped gases, isotopes, and impurities that provide high-resolution records of past atmospheric composition and temperature.
– Evaporite deposits (e.g., salt, gypsum) form in environments with high evaporation rates, indicating arid or semi-arid conditions.
– Sedimentary deposits encompass a vast range of rocks and unconsolidated sediments formed by deposition. While climate influences many sedimentary processes and products, some sedimentary deposits are formed primarily by tectonic or erosional processes without a strong, direct, or easily interpretable climate signal. The term is too broad to be a specific indicator type in the same way as the others listed.
Specific types of sedimentary rocks like glacial till (indicating past glaciation), coal (indicating warm, humid, swampy conditions), loess (wind-blown silt indicating arid/semi-arid conditions), and certain marine sediments are indeed used as palaeoclimate indicators. However, “Sedimentary deposits” as a general category is not a specific indicator type itself.
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