221 



their valley sides. The thin Harroclsburg limestone being removed as 

 well as the upper Knobstone. the shaly slopes, weathering flat, became, 

 with the modifications mentioned above, the terraces of today. 



This subject will be further investigated in the near future. At that 

 time it is hoped that the origin of the terraces can be more definitely 

 determined. 



After the ponding of Bean Blossom Creek the tributaries silted up 

 their channels which became miniature estuaries. They then began to 

 form deltas in the lake and in the slack water regions. The western 

 tributaries, for example. Buck Creek, built their deltas in a direct line 

 toward the center of the lake. This demonstrates that the water in which 

 the delta was built was free from strong currents. The deltas of the 

 eastern tributaries swing westward, often forming an east and west bar, 

 now a ridge, thus indicating that these tributaries entered a swollen, 

 westerly-moving stream. The eastern deltas also attest that Bean Blos- 

 som Creek was not then ponded but was a slowly moving stream reach- 

 ing from bluff to bluff. When the estuaries were all filled and the deltas 

 had reached the level of the benches the tributaries spread their del)ris 

 over the benches as well, so that today it is hard to tell, so far as 

 topographical appearance goes, where the terraces leave off and the deltas 

 begin. Two of the most conspicuous deltas are those of Buck and Wolf 

 creeks. In writing about these Prof. Marsters says:* 



"Besides the portion of each creek, wriggling across the valley bottom, 

 there are ratheu long and narrow strips or delta-like accumulations simi- 

 lar in content to tlie benches already described, and extending from the 

 valley slope to Avithin a few yards of the Bean Blossom channel which 

 hugs the south slope of its valley. The surface does not attain the char- 

 acteristic flatness of the rimming benches, but is slightly irregular in 

 relief and increasingly so towards the slope to which it is attached. This 

 is especially true for the Buck Creek case, but not for the AVolf Creek. 

 The increasing irregularity may be in part due to the nearly complete 

 burial of a projecting spur, whose top is barely coated over with the 

 delta deposits now spread almost across the entire width of Bean Blos- 

 som; but it must be said that no outcrops of limestone or sandstone, such 

 as make the slopes of the valley, have been discovered within its limits. 

 On the other hand, the irregularity of relief may have I teen produced by 



'Loc. cit. p. 235. 



