92 Davis — 'Terraces of the Westjield River ^ Mass. 



14. Development of future meanders. — The river is evi- 

 dently tending to become more curved at its northward bend, 

 L, and its southward bend, Q. It was formerly less curved ; 

 and it was probably then that it ran into tlie strongly concave 

 reentrant, Y^ No immediately local cause is found for the 

 preservation of the low spur, Y, for no defending ledge is to 

 be seen at its apex ; but one may be there, buried in the flood 

 plain deposits ; the sandstone outcrops in the little island near 

 by and in the cusp F nearly opposite. It is possible that these 

 ledges held the river in the channel between them (on the 

 north side of the present island) while the river scoured out 

 the sharply concave reentrant, Y' ; and that, as the river in- 

 creased its curvature at L and Q, it withdrew from the curve 

 of Y'. Such a series of changes would not be inconsistent 

 with what is known of the development of river meanders. 

 Their greatest dimensions are attained only where the curves 

 are well organized, and such organization requires time for 

 its accomplishment. A limit is set to the size of the curves, 

 less by an equilibrium between current and bank than by the 

 abandonment of the curves when short cuts and cut-offs are 

 made. The river course is thereby made nearly straight 

 again, after which a new series of curves is gradually estab- 

 lished. The We^tfield river hereabouts is comparatively 

 straight to-day. Its course for several miles eastward from T 

 must be much less curved now than when the concave terrace 

 fronts were carved at various earlier dates. But a strong 

 curve is seen to-day at T^; the curves at L and Q are increas- 

 ing and their maximum curvature is not yet reached, and 

 hence it may be expected that another period of organized 

 meandering is approaching. The restraint of the ledges at JVl 

 will soon be avoided by the down-valley progress of the mean- 

 der T. The northward curving at L will be resisted by the 

 raih'oad. The southward curving at Q may be delayed by the 

 abundant fall of gravels from the truncated end of the spur ; 

 and indeed there are already some indications that the river 

 may bend southward into, the low flood plain west of the spur. 

 A stronger northward turn toward F would thus be induced 

 and a stronger southward turn might then follow farther east- 

 ward. The latter item in this series of changes would be 

 rnade more probable if the swinging river would again pass 

 the ledges at F on a southeastward course, as it did when 

 carving the up-valley side of Brown's spur. 



All these details are relatively trifling, yet they have a value 

 in that they unite in showing the competence of ordinary pro- 

 cesses, appropriate to a meandering, swinging and slowly de- 

 grading river, to produce even the most minute forms of our 

 terraces. There is no demand for an ancient river of great 



