What geologic event caused the dry flat physical landscape of the prairie
A) tectonic plates under the earth shifted
B) glaciers in the arctic circle melted
C) wind storms in the midwest flattened the land
D) fires in the midwest scoured the soil
Well, I have to say, the prairie's flatness isn't because Mother Nature had too much fun with an iron and decided to give it a good pressing. The correct answer is A) tectonic plates under the earth shifting. But hey, can you imagine the chaos if the answer was actually D) fires in the Midwest scouring the soil? That would be one hot mess!
I think its D
Disagree.
Prairies are one of the most recently developed ecosystems in North America, formed after the period of Pleistocene glaciation. About 18,000 years ago, much of Illinois was covered by glaciers. As the glaciers melted, the land was covered at first with tundra type vegetation, then by spruce forests.
The correct answer is B) glaciers in the arctic circle melted.
During the Pleistocene epoch, around 2.6 million to 11,700 years ago, the prairies were covered by thick sheets of ice known as glaciers. As the glaciers melted, they deposited vast amounts of sediment, forming a flat physical landscape characteristic of the prairies.
The correct answer is A) tectonic plates under the earth shifted.
To understand why the prairie has a dry and flat physical landscape, we need to consider the geological processes that shaped the region. The prairie is characterized by extensive grasslands and a lack of significant elevation changes. This landscape is primarily a result of tectonic activity, specifically the shifting of tectonic plates.
Tectonic plates are enormous slabs of Earth's crust that float on the semi-fluid layer below. These plates interact with each other, causing various geologic events like earthquakes, volcanic eruptions, and the formation of mountain ranges. The prairie region was shaped by the gradual shifting of tectonic plates over millions of years.
During the Paleozoic era (about 541 to 252 million years ago), the prairie region experienced significant periods of subsidence and uplift caused by tectonic movements. Subsidence refers to the sinking of the Earth's crust, while uplift means the rising of the Earth's crust. These processes resulted in the creation of large basins and subsequent filling of these basins with sediment.
Over time, the sediments deposited in these basins were compacted and turned into rocks, primarily limestone and sandstone. These sedimentary rocks are relatively resistant to erosion, which contributed to the development of the prairie's flat landscape. The area's dryness is also influenced by the lack of significant relief features, which prevent moisture from getting trapped and lead to the region's arid climate.
In summary, the dry and flat physical landscape of the prairie is a result of tectonic plate movements that shaped the region, causing subsidence and uplift and leading to the formation of basins that were subsequently filled with sediment. This geological process, along with the erosion-resistant sedimentary rocks, contributed to the development of the prairie's unique features.