Exogenous Process

Exogenous Process


a geological process caused by sources of energy exterior to the earth’s surface, chiefly solar radiation, in combination with the force of gravity.

Exogenous processes occur at or near the surface of the earth’s crust and are the mechanical and physicochemical interactions of the crust with the hydrosphere and atmosphere. They include weathering and the geological action of wind (eolian processes, deflation), flowing surface and groundwaters (erosion, denudation), lakes and swamps, the waters of the seas and oceans (abrasion), and glaciers (exaration). The most important manifestations of exogenous processes on the earth’s surface are the disintegration of rocks and chemical transformation of their constituent minerals (physical, chemical, and organic weathering), the removal and transport of the resulting loosened and soluble products by water, wind, and glaciers, and the deposition (accumulation) of these products in the form of sediments on land or at the bottom of water basins and their gradual transformation into sedimentary rocks (sedimentogenesis, diagenesis, catagenesis).

Exogenous processes, together with endogenous processes, contribute to the shaping of the earth’s relief and the formation of sedimentary rocks and associated ore deposits. Thus, for example, ores of aluminum (bauxites), iron, nickel, and other minerals form under conditions of weathering and sedimentation. The selective deposition of minerals by flowing waters results in the formation of gold and diamond placers. Combustible minerals form under conditions favorable to the accumulation of organic matter and sedimentary strata rich in such matter.


Iakushova, A. F. Dinamicheskaia geologiia. Moscow, 1970.
Gorshkov, G. P., and A. F. Iakushova. Obshchaia geologiia, 3rd ed. Moscow, 1973.
Obshchaia geologiia. Moscow, 1974.


References in periodicals archive ?
Then the wind speed and wind power at time t can be modeled, respectively, as the following nonlinear autoregressive exogenous process:
Rogers and Monsell explained the abrupt disappearance of the residual switch cost in the first trial as an exogenous process triggered by the stimulus associated with the task, which eliminates the remaining or residual switch cost (i.e.
Hence, I need to introduce an additional source of variation to break this link, which I do by making the match efficiency parameter an exogenous process. I choose not to include consumption since my focus is on the labor market aspects of the model; nor do I use data on, for instance, the hiring rate, q([[theta].sub.t]), since the model implies that it is a log-linear function of [u.sub.t] and [[upsilon].sub.t].
They study the properties of the yield curve when inflation is an exogenous process and compare this with the yield curve when inflation is endogenous and determined through an interest rate (Taylor) rule.
One question that this experiment was designed to address, then, was whether the exogenous process of attention capture would operate in the case of bilateral cues when one was more salient than the other.
It is also assumed that reduction in barriers is an exogenous process, as demonstrated by the one-to-one relationship between property rights in this period and the next period (third quadrant).
We assume that the fundamental exogenous process that drives the economy is a 7 x 1 vector process {[[Epsilon].sub.t]} of serially uncorrelated shocks, with a covariance matrix equal to the identity matrix.
Future development of statistical procedures that explicitly accommodate a serially correlated disturbance term may produce tests that distinguish delayed density dependence from second-order effects resulting from autocorrelation in an exogenous process. Using current methodologies, however, diagnosis of the underlying causes of dynamics from single-species population censuses is at best tenuous and may be impossible.
So the monitoring and gathering of information about the status and trends of this and other exogenous processes, posing a real threat, is an urgent task [4].
The filling of residual mining pits with water will lead to creation of large water surfaces with maximum water depths up to 170 meters, where majority of factors and conditions initiating exogenous processes will be present.
Of particular interest is the criticism of one author that the model does not at all represent the process of paradigm change during revolutionary science, a period characterized by "sudden, idiosyncratic, discrete, and exogenous processes" altogether different from normal science (Barlas, 1992, p.