Ch. 1] INTERRELATION OF FACTORS 17 



in degree of saturation, though microbial activity or the addition of 

 other substances, such as iron, manganese, or silica from submarine or 

 surface springs, may also influence the solubility relationships. The 

 oxidation-reduction potential, as mentioned above, is also a factor, 

 especially with respect to the development of red color in rocks (Tom- 

 linson, 1916). 



ENVIRONMENT 



Interrelation of Factors 



Deposition of sediments, as has been pointed out above, is influenced 

 very strongly by environment. An environment of deposition may be 

 considered an area in which the combined effect of the fundamental 

 factors of topography, temperature, water, organisms, and rates of 

 change of conditions are similar. Depending on the degree of simi- 

 larity of factors, subenvironments exist within general environments. 

 The ocean has many characteristics in common throughout the world, 

 but different parts vary. The Gulf of Mexico, for example, is quite 

 different from the Bay of Fundy. 



The fundamental factors that affect environment are interrelated. 

 Changes in one factor result in corresponding changes in other factors, 

 sometimes to a marked degree. The shape of the land influences pre- 

 cipitation and flow of water and its resulting effect upon erosion, trans- 

 portation, and deposition of debris. Topography affects the climate 

 and hence the activity of organisms. 



The distribution of water influences the shape of the ground by its 

 action on erosion and deposition; it affects the climate by its influence 

 upon precipitation, evaporation, and the transfer of heat from the 

 tropics toward the poles through the medium of oceanic circulation. 

 Moreover, the distribution of water influences the activity of organisms 

 by its effect upon food supply and distribution of oxygen and carbon 

 dioxide. 



Temperature profoundly influences all other factors, primarily be- 

 cause it is a source of energy. Climate is a direct result of the distri- 

 bution of temperature and precipitation. Wind and rain are closely 

 dependent upon temperature, and these two agents in turn profoundly 

 affect erosion, transportation, and deposition and thus the shape of the 

 land. Even diastrophism may be regarded as resulting from changes 

 in distribution of temperature within the earth. 



Living organisms and plants influence the configuration of land 

 because of their effect on erosion and on chemical action, which results 

 in changes of the shape of the land. Organisms affect the distribution 

 of water by transpiration and by increasing the infiltration of water 



