368 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 28, 



in portions of the sedimentary masses, and alter by its solvent power 

 the constituent materials ; or the heated water might be converted 

 into steam, or generate permanent gases, which might derange or 

 alter the suspended material in various ways. If the sediment had 

 not reached the bottom, but formed a freely suspended mud-cloud 

 in mid- ocean, the effect of the interposed bed of fluid mud impeding 

 the upward progress of heat from the lower region would be neces- 

 sarily to increase the heat of the water below the mud, and thus 

 place the sediment between the upward pressure of the heated water 

 and the downward pressure of the overlying water. The ocean above 

 would cease to derive its usual supply of heat from below, and be- 

 come climatally altered. The now consolidated mud-bed would of 

 its own weight either sink bodily down, and take different positions 

 according to its consistency and the form of the ocean-bottom, or it 

 would be contorted and broken through from the effect of the accu- 

 mulated heat below. In tracing the results of this upward pressure 

 and bursting, the author observed that on the enormously thick and 

 partially consolidated stratified mass one or more weak points would 

 admit of the formation of elevated domes, and that from the burst- 

 ing of one of these domes, in a sea of much greater length than 

 breadth, a vast wave would be propagated through the plastic matter, 

 which would advance and be followed by others less perhaps in de- 

 gree. As the original wave advanced, the diminishing depth of the 

 ocean would cause the head of the wave to advance with greater 

 speed than its base, impeded by friction on the ocean-floor, and give 

 it its advancing form and a steeper declivity in front than on its hind 

 side ; this might be carried so far that the foremost wave might even 

 double itself over, and yet, owing to the plasticity of the mass, there 

 might be no breach of continuity. To the transmission of such im- 

 pulses through semi-consolidated strata, the author refers for an ex- 

 planation of the overlapping and inversion of strata seen in the Ap- 

 palachian and other mountain-ranges. 



The paper concluded with remarks on the indications of the age, 

 and causes influencing the structure of deposits, such as cleavage, 

 &c., in connexion with the foregoing observations on sedimentary 

 formations, and as illustrating, with them, some of the consequences 

 of several physical causes which act through vast intervals of time 

 upon the strata forming the crust of the earth. 



