What is a bedding plane in geography?
Definition of bedding plane. : the surface that separates each successive layer of a stratified rock from its preceeding layer : a depositional plane : a plane of stratification.
The term is generally applied to sedimentary strata, but may also be used for volcanic flows or ash layers. In a quarry, a bedding is a term used for a structure occurring in granite and similar massive rocks that allows them to split in well-defined planes horizontally or parallel to the land surface.
- A joint is a break (fracture) of natural origin in the continuity of either a layer or body of rock that lacks any visible or measurable movement parallel to the surface (plane) of the fracture. Although they can occur singly, they most frequently occur as joint sets and systems.
- Deep-seated igneous rocks often have joints approximately parallel to the surface, suggesting that they formed by expansion of the rock mass as overlying rocks were eroded away. Some joints in sedimentary rocks may have formed as the result of contraction during compaction and drying of the sediment.
- The Granite Source. Half Dome, like the other granite exposures in Yosemite, formed from so-called “intrusions” of magma—molten rock—that solidified underground to form massive granite bodies.
Cross-bedding is formed by the downstream migration of bedforms such as ripples or dunes in a flowing fluid. The fluid flow causes sand grains to saltate up the upstream ("stoss") side of the bedform and collect at the peak until the angle of repose is reached.
- Ripple marks come in two forms, symmetric, or wave formed ripples and asymmetric, or current ripples. Wave-formed ripple result from the to-and-fro motion of waves and have a symmetrical profile. Current ripple marks form in response to water or wind currents flowing in one direction and have asymmetric profiles.
- Sedimentary rocks are formed when sediment is deposited out of air, ice, wind, gravity, or water flows carrying the particles in suspension. This sediment is often formed when weathering and erosion break down a rock into loose material in a source area.
- In geology, lamination is a small-scale sequence of fine layers (laminae; singular: lamina) that occurs in sedimentary rocks.
Layering of rocks or sediment is also called stratification. A sequence of sedimentary layers stacked one atop the other is known as a stratigraphic section. And geologists sometimes refer to something formed in layers as a stratiform deposit.
- Nicolas Steno
- Geology. a basic law of geochronology, stating that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it.
- Sometimes magma pushes, or intrudes, into cracks in existing rocks. The principle of cross-cutting relationships states that an igneous intrusion is always younger than the rock it cuts across. ! Examine the igneous intrusion and the surrounding rock.
Updated: 28th November 2019