Chapter 10 Online Study Guide

Limestone is a sedimentary rock because it is formed from the accumulation and compaction of sediments such as shells, coral, and other organic materials. Sedimentary rocks are formed through the process of weathering, erosion, deposition, and lithification. Granite, anthracite, and slate are not sedimentary rocks. Granite is an igneous rock formed from the cooling and solidification of molten magma. Anthracite is a metamorphic rock formed from the transformation of bituminous coal under high heat and pressure. Slate is also a metamorphic rock formed from the alteration of shale or mudstone. Therefore, the correct answer is limestone.

In 1980, Mount St. Helens erupted. This volcanic eruption was one of the most significant and destructive in the history of the United States. It resulted in the loss of many lives and caused extensive damage to the surrounding area. The eruption also led to the formation of a large crater at the summit of the volcano. The event had a lasting impact on the region's landscape and ecosystems.

A mineral is a naturally occurring solid substance. It is formed through geological processes and has a specific chemical composition and crystal structure. Minerals can be found in rocks, but they can also occur on their own. Sedimentary, metamorphic, and igneous rocks are composed of minerals, but they are not minerals themselves. Therefore, the correct answer is mineral.

Granite is an igneous rock because it is formed from the cooling and solidification of molten materials, such as magma or lava. It is composed mainly of quartz, feldspar, and mica minerals. Granite is typically coarse-grained and has a granular texture. It is commonly found in continental crust and is often used in construction and as a decorative stone.

Subsoil is the layer of soil beneath the topsoil, which is rich in organic matter and nutrients. It is typically denser and contains less organic material than the topsoil. In this question, option B is considered subsoil because it is the layer beneath the topsoil. Options A, C, and D are not subsoil as they do not represent the layer beneath the topsoil.

Loam is considered the best type of soil for growing most crops because it has a balanced mixture of sand, silt, and clay. This composition allows for good drainage while retaining enough moisture and nutrients for plant growth. Loam also has a good structure, allowing roots to penetrate easily and access water and nutrients. Overall, loam provides an ideal environment for plant roots to grow, resulting in healthy and productive crops.

Convergent faults occur when two tectonic plates collide and are forced together. This collision can result in the formation of mountain ranges and deep trenches. The force and pressure from the converging plates cause the Earth's crust to fold and buckle, creating uplifted areas that eventually form mountains. Additionally, the collision can also cause one plate to be forced beneath the other, forming deep ocean trenches. Therefore, the correct answer is convergent.

Mantle plumes refer to the phenomenon where mantle rock flows slowly upward in a column, similar to how it would flow up an umbrella through the handle and then spread out in all directions. This process is responsible for volcanic activity and the formation of hotspots on the Earth's surface. As the mantle rock rises, it can cause the formation of magma conduits, which are channels through which magma can flow to the surface, resulting in volcanic upwellings. The term "chimney effect" is not an accurate description of this specific process.

The San Andreas Fault exhibits a transform fault. Transform faults occur when two tectonic plates slide past each other horizontally. The San Andreas Fault is a prominent example of this type of fault, as it marks the boundary between the Pacific Plate and the North American Plate. The movement along this fault has caused numerous earthquakes in California.

Frost wedging is the most important agent of mechanical weathering because it occurs when water seeps into cracks in rocks, freezes, and expands, causing the rocks to break apart. This process is particularly effective in cold climates with frequent freeze-thaw cycles. As the water freezes and expands, it exerts pressure on the surrounding rock, causing it to fracture and break. Over time, this repeated freeze-thaw action can lead to the disintegration of rocks into smaller pieces. Therefore, frost wedging is a significant contributor to the breakdown and erosion of rocks, making it the most important agent of mechanical weathering.

The core of the Earth is very hot and made mostly of iron. It is the innermost layer of the Earth, located beneath the mantle. The core is divided into two parts: the outer core and the inner core. The outer core is liquid, while the inner core is solid. The high temperature in the core is due to the heat generated by the decay of radioactive elements and the residual heat from the formation of the Earth. The iron content in the core gives it its density and magnetic properties.