Search results
Results From The WOW.Com Content Network
In geology, interbedding occurs when beds (layers of rock) of a particular lithology lie between or alternate with beds of a different lithology. [1] For example, sedimentary rocks may be interbedded if there were sea level variations in their sedimentary depositional environment .
In geology, a bed is a layer of sediment, sedimentary rock, or volcanic rock "bounded above and below by more or less well-defined bedding surfaces". [1] A bedding surface or bedding plane is respectively a curved surface or plane that visibly separates each successive bed (of the same or different lithology) from the preceding or following bed.
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
For example, when mixed sandstone and mudstone sequences are folded during very-low to low grade metamorphism, cleavage forms parallel to the fold axial plane, particularly in the clay-rich parts of the sequence. In folded alternations of sandstone and mudstone the cleavage has a fan-like arrangement, divergent in the mudstone layers and ...
In geology, a rock's fabric describes the spatial and geometric configuration of all the elements that make it up. [ 1 ] [ 2 ] In sedimentary rocks , the fabric developed depends on the depositional environment and can provide information on current directions at the time of deposition.
[11] [12] Marianas Trench is an example of a deep slab, thereby creating the deepest trench in the world established by a steep slab angle. [13] Slab breakoff occurs during a collision between oceanic and continental lithosphere, [ 14 ] allowing for a slab tear; an example of slab breakoff occurs within the Himalayan subduction zone.
For example: well-rounded, and well-sorted sand that is mostly composed of quartz grains is commonly found in beach environments, far from the source of the sediment. Poorly sorted and angular sediment that is composed of a diversity of minerals is more commonly found in rivers, near the source of the sediment. [ 8 ]
In geology, a sill is a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or along the direction of foliation in metamorphic rock. A sill is a concordant intrusive sheet , meaning that it does not cut across preexisting rock beds.