Review: Theory Of Continental Drift And Plate Tectonics

Alfred Wegener is the correct answer because he proposed the theory of continental drift. He suggested that the Earth's continents were once joined together in a single landmass called Pangaea, and over time, they gradually moved apart to their current positions. Wegener's theory was based on various pieces of evidence, including the fit of the continents, similarities in rock formations and fossils across different continents, and the presence of ancient glacial deposits in regions that are now located near the equator. Despite initial skepticism, his theory laid the foundation for the modern understanding of plate tectonics.

Pangea is the correct answer because it was the name of the super-continent that existed around 300 million years ago. Pangea was a massive landmass that contained all of Earth's continents before they started to drift apart. This theory is supported by geological evidence such as the matching shapes of coastlines and similar rock formations found on different continents.

There are three types of plate boundaries: convergent, divergent, and transform. Convergent boundaries occur when two plates collide, causing one plate to be forced beneath the other. Divergent boundaries occur when two plates move away from each other, creating new crust. Transform boundaries occur when two plates slide past each other horizontally. Therefore, the correct answer is 3.

Sea-floor spreading is a geological process that occurs at divergent boundaries, where tectonic plates move away from each other. As the plates separate, magma rises from the mantle, creating new oceanic crust. This process results in the formation of mid-ocean ridges and the spreading of the sea floor. Therefore, sea-floor spreading is applied at divergent boundaries.

The correct answer is 200 million years. This is the estimated time it took for the continents to move and form their current positions on Earth's surface. This process is known as continental drift or plate tectonics, which involves the slow movement of Earth's tectonic plates over millions of years. Through this process, the continents have shifted and collided, forming the continents as we know them today.

Tectonic plates occupy the lithosphere, which is the outermost layer of the Earth. The lithosphere is made up of the crust and the uppermost part of the mantle. It is divided into several large and small plates that float on the semi-fluid asthenosphere beneath them. These plates interact with each other, causing geological phenomena such as earthquakes, volcanic activity, and the formation of mountains.

The Himalayas were created as a result of convergent boundaries. Convergent boundaries occur when two tectonic plates collide, causing one plate to be forced beneath the other in a process called subduction. In the case of the Himalayas, the Indian Plate collided with the Eurasian Plate, leading to the uplift and formation of the mountain range. This collision continues to this day, causing the Himalayas to grow taller each year. Therefore, the correct answer is convergent.

Convergent boundaries have three sub-types: oceanic-continental convergence, oceanic-oceanic convergence, and continental-continental convergence. In these boundaries, tectonic plates move towards each other, leading to the formation of mountains, volcanic activity, and earthquakes. The collision of plates can result in the subduction of one plate beneath another or the uplifting of crustal material. Therefore, convergent boundaries are characterized by intense geological activity and the creation of various landforms.

There have been 15 MAJOR plates discovered.