264 



SCIENCE. 



[N. S. Vol. XVI. No. 398. 



Approximately the grand movements 

 producing this fault may be fixed as be- 

 ginning in the Middle Tertiary period, 

 since Lower Tertiary rocks, consisting of 

 nummulitic limestone, are found on Mounts 

 Carmel, Ebal and Gerizim, and on some of 

 the heights in the vicinity of Jerusalem 

 and to the south of Hebron. 



The extensive post-Tertiary deposits of 

 silt extend as high as 750 feet above the 

 Dead sea, showing that up to a recent time 

 the water was 750 feet higher than now, 

 producing a lake several times larger than 

 the Dead sea, and extending southward 

 about forty miles beyond the Dead sea, in 

 which were deposited hundreds of feet of 

 fine sediment where side streams came in, 

 and one hundred feet or more over the en- 

 tire valley. In the wady Zuweiya, where 

 it enters the depression near the south end 

 of the Dead sea, one can see the fine 

 laminge of this sediment as it has gradually 

 accumulated to a depth of between 200 and 

 300 feet just below the 750-foot line, and 

 where it has been exposed by subsequent 

 erosion. 



The Jordan valley throughout all its 

 lower portion occupies a narrow gorge 

 which it has cut out of this sedimentary 

 deposit. The river is constantly under- 

 mining its banks, now on one side and now 

 on another, leaving, pretty generally, per- 

 pendicular walls of the sedimentary depos- 

 its separated from the river by a flood- 

 plain of varying width, averaging about a 

 quarter of a mile. As a consequence the 

 river is extremely muddy as it enters the 

 Dead sea. 



Notwithstanding the vigor of these ero- 

 sive agencies only a relatively small por- 

 tion of the sediment has been washed away, 

 and the Dead sea is still unfilled, which 

 is a witness to the recentness of its forma- 

 tion. The drainage basin of the Jordan 

 valley is more than 10,000 square miles in 



extent; while the immediate valley itself is 

 scarcely one fifteenth as large. All the 

 wash of this large drainage area finally 

 lodges in the valley. 



If we estimate the rate of erosion in the 

 drainage basin of the Jordan at one foot 

 in 2,000 years, the age of the Jordan fault 

 must be reckoned in tens of thousands of 

 years, rather than in hundreds of thou- 

 sands; thus confirming the shorter geolog- 

 ical chronology of the physicists. 



History of the Discoveries and Discussions 

 Concerning the Glacial Terraces in the 

 Upper Ohio and its Tributaries: G. 

 Fkedeeick Wriqht. 



Submerged Valleys in Sandusky Bay: E. 



L. MOSBLEY. 



Tilting of the earth's crust is causing a 

 depression of the land at the southwest ex- 

 tremity of Lake Erie as compared with the 

 outlet at Buffalo. The effect of this is 

 shown in the vicinity of Sandusky by the 

 extension of the water over the low ground 

 as evidenced by surveys, submerged 

 stumps, slack water in the lower course of 

 all the streams and submerged stalagmites 

 in the caves of Put-in bay. It is also 

 shown by the fact that from the mouth of 

 each stream entering Sandusky bay a val- 

 ley now filled with mud can be traced out 

 through the bay. These valleys show a rise 

 of the water of at least forty feet. 



Some Geological Notes in Honduras, Cen- 

 tral America: J. Francis Patch-Le 

 Baron. (Read by title.) 

 The main geological features of Hondu- 

 ras are volcanic, but of a former age. These 

 features are more pronounced on the Pacific 

 slope, but there are at present no live vol- 

 canoes in the Republic. 



The greater part of the stratified forma- 

 tions belong to the Permian. The charac- 

 teristic country rock in the departments of 



