geology

9 articles · All tags

• What Is a River Delta and How Does It Form?
  A river delta is new land built where a river slows on entering a sea or lake, drops its sediment, and splits into channels that push the coastline outward.
• What Killed the Dinosaurs? The Chicxulub Impact
  The Chicxulub impact, about 66 million years ago off the Yucatán coast, triggered the mass extinction that ended the non-avian dinosaurs and most other species.
• How Are Caves and Karst Landscapes Formed?
  Caves and karst form when slightly acidic groundwater dissolves limestone along cracks, enlarging them over thousands of years into passages and sinkholes.
• Meandering Rivers and Oxbow Lakes: How They Form and Change
  A meandering river forms looping bends because its fastest flow erodes the outside of each curve, and an oxbow lake forms when a flood cuts through a loop neck.
• Volcanoes: How They Erupt
  Volcanoes explained: why magma rises and erupts, what makes eruptions explosive or gentle, and how volcanoes build mountains, islands, and new crust over time.
• The Mariana Trench
  The deepest place on Earth: a subduction trench reaching 10,935 meters at Challenger Deep, with its own fauna, chemistry, and a handful of human visitors.
• Fossilization
  The rare sequence of processes that preserves remains or traces of ancient organisms in the rock record.
• The Rock Cycle
  The model describing how igneous, sedimentary, and metamorphic rocks form and transform over geological time.
• Plate Tectonics
  The theory that Earth's outer shell consists of moving plates whose interactions build mountains, open oceans, and trigger earthquakes and volcanoes.