Which rock is harder? Shale, sandstone, or limestone? which one is softer?
What is it about sandstone, shale, and limestone that might cause the slopes and cliffs to form?
Please help me. thank you.
A clue to the first part is in the second part of the question. Which of the three types of rock forms sea arches? Do a Google search for Durdle Door. This must be the hardest rock.
What shepes of cliffs do you get from the three rocks? The hardest will form a near vertical cliff, while the softest will form a slope. Google "The Twelve Apostles" [there are only 8, there never were 12!], "Red Sandstone Cliff, south of Saltern Cove", "Burning Cliff".
Hope this helps.
To determine which rock is harder among shale, sandstone, and limestone, you would typically refer to the Mohs scale of mineral hardness. The Mohs scale is a qualitative scale that arranges minerals from 1 to 10 based on their scratch resistance.
The Mohs scale indicates that shale has a hardness of 2, sandstone has a hardness of 6-7, and limestone has a hardness of 3-4. Therefore, sandstone is the hardest among the three, while shale is the softest.
Now, regarding the formation of slopes and cliffs, each rock has distinct characteristics that contribute to their formation:
1. Sandstone: Sandstone is formed from sand-sized grains held together by natural cementing agents. It often has well-defined bedding planes, making it prone to the formation of cliffs and slopes due to its ability to erode unevenly along these planes.
2. Shale: Shale is composed mainly of fine-grained clay minerals. These clay minerals are often layered and compacted. Over time, shale formations can be easily eroded by water, leading to the formation of slopes and cliffs.
3. Limestone: Limestone is primarily composed of calcium carbonate. It can exhibit different levels of hardness depending on its purity. Limestone cliffs and slopes often form due to the dissolution of calcium carbonate by water. This occurs particularly in areas with underground caverns or where water flows over the limestone, gradually wearing it down.
In summary, sandstone is the hardest rock among the three options, while shale is the softest. The formation of slopes and cliffs can result from various factors, including the characteristics and composition of the rocks, as well as erosion processes over time.