214 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



publications of the Detroit THhune"^ secured a priority of over 10 

 months. The synoptical table of the rocks of the Lower Peninsula 

 published at this date, was almost identical with that reproduced 

 from the report on a subsequent page of this sketch. The following 

 vieAvs were embodied in the same digest : 



From the Potsdam sandstone to the close of the upper Helderbei'g period, 

 the geology of our State corresponds well with that of New York and other 

 Stiites. From the close of the Helderberg period, Michigan seems to have 

 had a history somewhat special to itself. We have here a basin which at very 

 remote periods was isolated from the seas which transported the sediments of 

 surrounding States. 



In this connection facts were cited pointing to the northern origin 

 of the sedimentary materials. 



Benefits. — Economically the most important discover}^ made dur- 

 ing the season of 1860 was the existence of a great gypsum formation 

 within an elevated ridge nearly parallel Avith the shore of Lake Huron, 

 and approaching nearest at a point about four miles south of Tawas. 

 This was identified with the gypsum formation west of Grand Rapids. 

 The inference was thus drawn that a continuous bed of gypseous ma- 

 terials underlaid all the central part of the Peninsula; and this opened 

 the way to new views respecting the origin of gypsum. This bed was 

 not actually exposed in this vicinity till some years afterAvard; and 

 in the meantime, it was maintained by men priding themselves as 

 " practical," in opposition to theorizing geologists, that the ridge con- 

 tained no gypsum, and that the only gypsum on the eastern slope of 

 the State was at Whitestone Point, six miles further south, at the 

 water level and beneath it. Llere, in 1841, several tracts had been en- 

 tered by McDonald, an Indian trader. " He and hundreds of others," 

 as tradition holds, " searched vigorously, but found nothing above 

 water." The deposit noAv brought to light has become one of thft 

 State's great resources. 



Publications. — The First Biennial Eeport of the Progress of the 

 Geological Survey was presented to the governor, and by him to the 

 legislature, on the 31st of December, 1860. Of this the legislature or- 

 dered printed 5.000 copies. To the State geologist for distribution 

 were allotted 500 copies, and to the assistant in zoology, 200 copies ; to 

 each member of the legislature one copy, and for distribution by the 

 legislature, 2,000 additional copies stitched in paper. The printing 

 and binding of the report were not completed until November 16, 1861. 

 It forms an octavo volume of 339 pages, and embraces observations 

 on the geology, zoology, and botany of the Lower Peninsula. An 

 "introduction" of 13 pages on the History of Geology in Michigan 



' It should 1)0 said that the Detroit Free Prcsn and the Detroit Advertiser pubUshed 

 quite extensive extracts and abstracts from the forthcoming report. 



