^iittts ot f literal ||itssurf in 
i}^t §ristoI gistrut: an (Estimate 
aiib a Suggestion* 
By PROFESSOR C. LLOYD MORGAN, F.R.S. 
HE effects of lateral pressure are threefold : first the arch- 
1 iiig or troughing of the stratified deposits into domes or 
basins ; secondly, the local dislocation of the strata wherever 
overthrust or reversed faults occur ; and thirdly, the rearrange- 
ment of the constituent materials under compression, with a 
tendency to a thickening of the beds at the summits of the 
domes and the bottoms of the basins, and a thinning of the 
beds in the intervening limbs of the anticlines and synclines. 
When any or all of these effects occur the net result is that the 
area subjected to lateral pressure has suffered a diminution 
of horizontal extent. The edges of any given superficies of 
originally flat-lying deposits are thrust closer together when 
the strata are thrown into anticlinal and synclinal folds. And 
the measure of the folding, faulting, and rearrangement of 
constituents is also a measure of the diminution in horizontal 
extent of the area in question. 
148 
