Stress, The geothermal gradient, Folding and faulting and how horizontally-directed plate motions cause vertical uplift are the main reasons for rocks deformation. When
sedimentary rocks deform, deformation causes some structures to form, many of them are traps for oil accumulation known as structural traps.so we will discuss these structures then we will show which one can form a trap.
Break, transport then rest is the right description of these three geological events. Rocks are broken down and chemically dissolved through weathering .this occurs when rocks are subjected to the atmosphere and ocean bottom. Rivers, wind, waves, gravity (landslides), and glaciers transport and deposit these sediments in a process called erosion. If both weathering and erosion stops for a period of time then starts again forming new layers of sedimentary rocks, the buried erosional or non-depositional surface separating two rock masses or strata of different ages is called unconformity surface.
Unconformity comes in variety of ways. Disconformity occurs between sedimentary rocks whereas Nonconformity occurs between sedimentary and igneous or metamorphic rocks. Angular unconformity is an ancient erosional surface in which the sedimentary rock layers below the unconformity are tilted at an angle to the layers above the unconformity. Blended unconformity is a type of disconformity or nonconformity with no distinct separation plane or contact, sometimes consisting of soils, paleosols, or beds of pebbles derived from the underlying rock. A paraconformity is a type of unconformity in which strata are parallel; there is no apparent erosion and the unconformity surface resembles a simple bedding plane.
Anticlines and synclines are the up and down folds that usually occur together and are caused by compressional stress. IF they are exposed to weathering and erosion, for anticlines older rocks will appear, on the contrary, younger rocks will appear for synclines. Most anticlines and synclines are not level and are tilted with respect to the surface of the earth. These are called plunging anticlines and plunging synclines.to understand this; imagine it as a quarter of a ball with which you can trap a rat against the wall.
Dome is an anticlinal uplift that has no distinct trend. Basin is a synclinal depression that has no distinct trend.to understand this; imagine a dome as half of a ball with which you can trap a rat against the ground. Before a dome is eroded down, it forms a hill but if the dome is eroded, it leaves a characteristic bull’s eye pattern on the surface.
It represents sedimentary rocks dipping uniformly in one direction meaning that we have a zone of steeper dip within an otherwise horizontal or gently-dipping sequence.
The structures formed by the brittle fracturing of rocks are known variously as joints and faults.
A joint is a fracture in the rocks with no movement of one side relative to the other.
A fault is a break in the rocks along which one side has moved relative to the other.
You can differentiate between them as follows: