Oil is formed when organic materials are buried under sedimentary rock; anoxic conditions and intense pressure cause a gradual transformation in petroleum. Most of the components of oil are small algae and zooplankton, although some larger animals like dinosaurs are also in the mix. This process takes hundreds of thousands of years.Know More
Oil formation requires a combination of several factors. Scientists refer to petroleum as a fossil fuel because it is derived from prehistoric organisms. Plants and animals settle below land and sea along with sand and silt. These remains are gradually covered by sedimentary rock buildup, which creates heat and pressure. These conditions turn anoxic, meaning that there is a lack of dissolved oxygen in the system.
Heat and pressure first turn the organic matter into kerogen, a waxy material. As heat and pressure increase, the kerogen undergoes the process of catagenesis, which transforms the material into liquid and gaseous hydrocarbons.
In order for oil to form, the mixture must achieve a temperature that geologists refer to as the "oil window." Otherwise, it remains in its kerogen state.
Over time, the oil travels upward through pores in the rock. Some seeps out onto the Earth's surface, but most remains stuck in barriers. Underground traps of oil are called reservoirs. People extract oil from reservoirs through drilling.Learn More
Onyx is a type of agate known as chalcedony, formed by intergrowths of silica minerals. The chert form of quartz is also used to make onyx jewelry items.Full Answer >
Visible light is created when electrons that are located inside atoms return to their ground state after being in an excited state, according to the University of Hartford. Light is radiant energy, meaning it is electromagnetic radiation that can be seen with the human eye.Full Answer >
While no one knows for certain how the Earth formed, scientists theorize that it formed over 4 million years ago after the sun went through its initial formation, gravity began to draw heavy particles together into a planet and solar winds blew away lighter gases. These heavy particles became the core of the planet. As the mass continued to grow, heavier particles sank to the center, according to Space.com.Full Answer >
Eskers are narrow ridges of fine sediment and gravel formed by subglacial rivers. Eskers remain long after glaciers retreat, sometimes running for several miles and standing over hundreds of feet tall.Full Answer >