Why do lakes lying in granite basins tend to become acidified by acid rain more readily than lakes lying in limestone basins?
Dissolved carbonates from the limestone tend to neutralize the acid.
Lakes lying in granite basins tend to become acidified by acid rain more readily than lakes lying in limestone basins due to the difference in the composition of their respective bedrocks.
When it comes to acid rain, the primary factor that determines a lake's susceptibility to acidification is the bedrock composition of the surrounding area. Granite, a common type of igneous rock, is composed mainly of quartz, feldspar, and mica. These minerals are considered to be acidic. As a result, when acid rain falls on a granite basin, the acidic components in the rainwater interact with the minerals in the granite, causing the release of acidic ions, such as hydrogen ions. These acidic ions then make their way into the lake, leading to the acidification of its water.
On the other hand, limestone is a sedimentary rock primarily composed of calcium carbonate. Calcium carbonate acts as a natural buffer against acidification since it has the ability to neutralize acidic substances. When acid rain interacts with limestone, it undergoes a process called neutralization, in which the acid in the rain reacts with the calcium carbonate in the limestone, resulting in the formation of non-acidic compounds like water and carbon dioxide.
Therefore, lakes lying in limestone basins are less prone to acidification as the limestone acts as a buffer, reducing the impact of acid rain by neutralizing the acidity of the rainwater.
In summary, the differing composition of granite and limestone bedrocks is the reason why lakes lying in granite basins tend to become more acidified by acid rain compared to lakes lying in limestone basins.