What is Summit Accordance?

Summer accordances can exist where structural planes were once exposed by erosion.
Summer accordances can exist where structural planes were once exposed by erosion.

Summit Accordance is also known as gipfelflur and they have two different explanations regarding how they came into existence. The first explanation is thought to be the remnants of the old erosion surfaces and could either be pediplain or Peneplain. The second explanation is explained as a product of regular patterns of dissection which constrain the summits to almost the same elevation. The summit accordance in the western part of the US lies at approximately 1,969 feet above the present timberline. There is also a variant explanation to the erosion surface theory, which argues that the summit level represents an interglacial alp slope related to the higher timberline than the present one.

Continuous Erosion Surfaces

The Earth’s hills and mountains were formed due to movements of the different tectonic plates and climate change which facilitates erosion. These processes lead to the adjustments of the height and shape of hills and mountains playing a significant role in the leveling of the heights of these geographical features resulting in summit accordance. The exposed structural planes to erosions are majorly what leads to the leveling of the hills. Contrary to what most people believe, it is the destructive forces of erosion impacting on the tectonics that leads to the altering of the shapes of hills. It is this finding that has made geologists conclude that the subtle movements caused by erosion contribute significantly to the emergence of summit accordance in different parts of the world.


Isostasy is a concept that explains the gravitational equilibrium between the mantle and the crust, which explains why the crust float on elevations that depend on the density and thickness. The concept of isostasy is used to explain the different topographical features on the earth’s surface. Whenever a particular area of the crust reaches a state of isostasy, then it is in isostatic equilibrium. In other words, isostasy work on the principle of buoyancy where an object floats on the fluid and exerts a force that is equal to the weight of the fluid displaced. Isostasy on a geological scale is observed when the crust or lithosphere exert stress on the mantle or the asthenosphere and over a long time or the geological time, flow laterally so that adjustments in height accommodate the load. One major example of an Isostasy action is the Greenland which is normally below sea level. Through this process, specific hills might change in their height or shape hence resulting in summit accordance. Therefore, isostasy controls the heights of specific mountain masses, where small mountains may be uplifted, and large mountains may be dragged down.

Structural Planes Alterations

Summit accordance is also derived from structural planes that have been exposed by erosion. Structural planes are part of structural geology, which features 3-dimensional distribution of rocks in relation to their deformational histories. Therefore, understanding the structural planes of a specific area in relation to the regionally prevalent pattern of rock deformation will give a clear understanding of summit surfaces resulting from rifting, mountain building, and plate tectonics.


More in Environment