Cross Cutting Geology Definition
Cross-sectional relationships can be seen mapped, megascopically and microscopically. In other words, these relationships have different scales. For example, a cross-sectional cartographic relationship may look like a big mistake when dissecting the landscape on a large map. Megascopic transverse relationships are features such as magmatic, as mentioned above, that would be seen on an outcrop or in a limited geographical area. Microscopic cross-sectional relationships are those that need to be examined by magnification or other in-depth examination. For example, the penetration into a fossil shell by the drilling action of a drilling organization is an example of such a relationship. Cross-sectional relationships are a principle of geology that states that the geological feature that intersects another is the younger of the two features. It is a relative dating technique in geology. It was first developed by the Danish geological pioneer Nicholas Steno in Dissertationis prodromus (1669) and later formulated by James Hutton in Theory of the Earth (1795) and embellished by Charles Lyell in Principles of Geology (1830). Transversal relationships can be composed.
For example, if a defect was cut by a nonconformance and that nonconformance was cut through a dike. On the basis of such composite transverse relationships, it can be determined that the defect is older than the deviation, which in turn is older than the dike. With such justification, the sequence of geological events can be better understood. The photo shows a very good example of transversal relationships. The light gray penetration is located in Sweden. It is cut by a white penetration (pegmatite), which is cut by a black penetration (diabase). Since the black intrusion is whole (not cut by an intrusion), it is the youngest. The white penetration is the second youngest because it is cut through the black penetration but cuts into the light gray penetration. The light gray penetration is the oldest because: it is cut by the white penetration and the black penetration. The law of transversal relations, described by the Scotsman James Hutton (1726 – 1997), states that if a defect or other rocky body cuts through another rocky body, it must be younger than the rock through which it cuts and moves. A cross-sectional relationship is the principle in geology with respect to intersecting layers.
from the simple principle of transversal relations, the relative age of all units can be deduced. There are several basic types of cross-sectional relationships: Cross-sectional relationships can also be used in conjunction with radiometric age dating to determine an age group for geological materials that cannot be directly dated by radiometric techniques. For example, if a sedimentary layer containing a fossil of interest is delimited at the top and bottom by conformities, with the lower gap cutting dike A and the upper gap cutting dike B (which permeates the layer in question), this method can be used. A radiometric age date of the crystals in dam A indicates the maximum age date of the layer in question, and the crystals of dam B also indicate the minimum age date. This provides an age group or range of possible age groups for the stratum in question. James Hutton`s observations of uniformitarianism also serve as the basis for another important geological principle called transversal relationships, a technique used in relative age dating. In short, an intrusive rocky body is younger than the rocks it penetrates. For example, Salisbury Crag, an important Edinburgh landmark known to Hutton, owes its relief to a thick leaf of resistant basalt. Hutton showed from the overheated contacts below and above and from the places where basalt actually penetrated into the beds below and above that the thick basalt body was not just a river that had formed one after the other.
On the contrary, it was penetrated into the surrounding sedimentary rocks as hot magma long after deposition (Eicher 1976). Other similar relationships include faults younger than the rock layers they cut and erosion surfaces younger than the rocks they erode. Part of a series of articles entitled Fundamental Geological Principles. As you can see in this image, the fossil remains of living things are present at certain intervals in the rock layers and exist in a discrete period of time. In this case, using the law of superposition, would the age of the unit of rock A be older or younger than the age of the unit of rock B? In the image above, an igneous rock dam cuts through three layers of previously deposited sedimentary rocks. In this case, is the dike the oldest, oldest or youngest rock layer? The law of inclusions was also described by James Hutton and states that if a rock body (rock B) contained fragments of another rock body (rock A), it must be younger than the rock fragments it contains. The invading rock (rock A) had to be there first to deliver the fragments. The law of superposition meant that the Coconino sandstone is older than the Toroweap formation and younger than the hermit shale, as seen in the image above. As this was the diagram of geological times, the law of superposition meant that the Jurassic period was older than the Cretaceous and younger than the Triassic. Beginning in the 1600s, with a revival of scientific research, early geologists began to study the rock layers that were evident in the countryside. Their first observations eventually turned out to be true and were described as principles.
Four of these principles are important for understanding the geological time map. Our editors will review what you have submitted and decide if you want to review the article. A geological object cannot be modified until it exists, which means that the change in the object must be younger than the object itself. Nicolaus Steno, Danish anatomist, geologist and priest (1636 – 1686), observed the changes in a sequence of rock layers while working in the mountains of Italy.