A. Small pieces of the Earth's crust. B. Large pieces of the Earth's crust that move slowly. C. Pieces of the moon. D. Pieces of the sun. 相关知识点: 试题来源: 解析 B。解析:文章中提到“Tectonic plates are large pieces of the Earth's crust that move slowly over time.”,即构造...
Over time, the scales and dynamics of hot asthenospheric upwelling versus lithospheric foundering + mantle return flow (bottom-up plume-driven ascent versus top-down plate subduction) evolved gradually, reflecting planetary cooling. These evolving plate-tectonic processes have accompanied the Earth's ...
Convection currents within the mantle take the continents on a conveyor-belt ride of oceanic crust that over millions of years takes them around the planet’s surface. Earth’s Tectonic Plates When the concept of seafloor spreading came along, scientists recognized that it was the mechanism to ...
Here are the 7 major tectonic plates of the world in a bit more detail. 1. Pacific Plate The Pacific major plate is the largest which underlies the Pacific Ocean. Specifically, it stretches all the way along the west coast of North America to the east coast of Japan and Indonesia. ...
Earth’s crustand upper mantle (to a depth of about 60 kilometers) are divided into about a dozen tectonic plates that fit together like the pieces of a jigsaw puzzle (Figure 2). In some places, such as the Atlantic Ocean, the plates are moving apart; in others, such as off the wes...
Most earthquakes are caused by the movements of tectonic plates. Sometimes, tectonic plates move very slowly — at the rate your fingernails grow — without causing the ground to shake. But sometimes, they get stuck against one another. Stress builds up until the pressure is too great, and th...
Plate tectonics describes seismic activity, volcanism, mountain building, and various other Earth processes in terms of the structure and mechanical behaviour of a small number of enormous rigid plates thought to constitute the outer part of the planet (i.e., the lithosphere). This all-...
In 1929 Holmes proposed an alternative mechanism—convection of the mantle—which remains today a serious candidate for the force driving the plates. Wegener’s ideas also were well received by geologists in the Southern Hemisphere. One of them, the South African Alexander Du Toit, remained an ...
reflecting the complex tectonic changes of the South China continent and the comprehensive influence of multi-phase tectonic-magmatic activities. The depth distribution of large granite bodies inferred from the density structure provides a basis for exploring deep tectonic-magmatic activities and their impa...
A new study says we may only have another 1.45 billion years to enjoy the dynamic action of Earth’s geologic engine.