Plate Tectonics From Hypothesis to Theory Plate tectonics is a scientific theory that explains two centuries of often puzzling observations and hypotheses a bout our planet Earth. a The continents are drifting very slowl across the face of our planet Continental drift is a concept with a long history
Introduction: What Is an Igneous rock? Igneous rocks vary greatly. Some contain large mineral grains. Others contain grains so small they can barely be seen under a high power microscope. Igneous rocks also vary greatly in color. All igneous rocks are formed through the cooling and solidification of magma
Introduction: Weathering The Breakdown of Rock At the Earth's surface, rocks are exposed to the effects of weathering: the chemical alteration and mechanical breakdown of rock, when exposed to air, moisture, and organic matter. Weathering is an integral part of the rock cycle. Weathering converts rock to regolith