42 



APPENDIX TO THOMPSON'S VERMONT. 



GEOLOGY OF VERMONT. 



CHAMFLAIN ROCKS. 



POTSDAJI SANDSTONE. 



But they were by no means intended to 

 exhibit the entire results of each years' la- 

 bors, but merely to indicate the advance- 

 ment of the survey, and to furnish such 

 general information as would enable the 

 people of the state rightly to understand, 

 and duly to appreciate those results, when 

 they should be collected and systematised 

 in a Final Report. 



Before the close of the third year, for 

 which provision had been made by the act 

 of the legislature authorizing the survey, 

 the StateGeologist was appointed a Profes- 

 sor in the College at Amherst, Mass. Be- 

 lieving that the remaining iield labors, for 

 the completion of the survey, would be 

 finished during the next season, and that 

 he should derive much aid in the prepara- 

 tion of the Final Report, from the collections 

 and library at Amherst, he deemed it his 

 duty to accept the professorship ottered 

 him ; but he did it, with the expectation 

 that he would not be required to enter 

 fully upon the duties of the professorship, 

 until he had completed the survey and 

 prepared liis Final Report, and that our 

 legislature would make the appropriations 

 necessary for those purposes. 



At this time, only a part of the specimens, 

 collected from the various sections of the 

 state, had been trimmed, ticketed and sent 

 to the institutions for which they were de- 

 signed. The remainder, embracing those 

 Avhich had been ticketed for the state cabi- 

 net, Avere in the depot at Middlebury. 

 Anticipating legislative provision at the 

 next session, for'the completion of the work 

 as above mentioned, the State Geologist 

 directed his assistant, at Burlington, to 

 obtain, at that place, a suitable room, or 

 rooms, to serve as a depot for the tools, 

 fixtures and untrimmed specimens ; which 

 being done, the articles, amounting to 

 several tons, were forwarded from Middle- 

 bury and placed in it. In doing this, he 

 reserved the principal fossils and the speci- 

 mens ticketed for the state cabinet, which 

 he, soon afterwards, took with him to 

 Amherst, that they might be at hand, for 

 examination and reference, while preparing 

 his final Report. 



At the session of the legislature, in Oct. 

 1847, the subject of the survey was taken 

 up, but no appropriation Avas made, either 

 for its continuance, or for the preparation 

 of a Final Report. 



In 1848 the subject Avas again taken up, 

 but Avith no better success, and all that was 

 done in relation to it, Avas the passage of a 

 resolution, directing the Governor to employ 

 some person to get back into the state, the 

 materials and manuscripts, belonging to 

 the Survey, and place them in the charge 

 of th e State Librarian , at Montpelier. That 



duty the author of this Avork had the honor 

 of discharging, in the summer of 1849, and 

 his rejjort to the Governor, was published 

 in the Appendix of the House Journal, for 

 that year. Since 1840, the subject of the 

 Survey has, once or twice, been called up 

 in the legislature, but nothing further has 

 been done. The untrimmed and unticket- 

 ed specimens are lying, packed in boxes, 

 at Burlington, Avith a portion of the tools 

 and fixtures ; and the remamder are in 

 charge of the State Librai-ian at Montpelier, 

 and all these are fast losing their value. 



The Geological Survey of the state, having 

 been suspended before the examinations 

 were completed ; and the results of the 

 labors performed, having never been col- 

 lected together and systematically arrang- 

 ed, a full and satisfactory account of our 

 Geology cannot yet be expected ; and all 

 that Avill now be attempted, is a hasty 

 sketch of the general geological features of 

 the state. There are important scientific 

 questions, which an accurate knowledge of 

 the geology of Vei'mont would, doubtless, 

 very much aid in solving, but the acquisi- 

 tion of this knowledge will require much 

 additional patient investigation and re- 

 search ; and the discussion of these ques- 

 tions, would require more space than could 

 be afforded to the subject in this Appendix. 



Champlain Rocks. 



We shall begin our sketch of Vermont 

 Geology at the Avesteru border of the state, 

 and, proceeding eastwardly, give some 

 general account of the different rock-forma- 

 tions in their order. 



The rocks Avliich occupy the loAvest parts 

 of the valley of Lake Champlain belong to 

 that division of the Palteozoic rocks, denomi- 

 nated, by the NeAV York geologists, the 

 Champlain Group. Beginning with the 

 oldest and most westerly, these rocks are 

 arranged in the following order : 



1. Potsdam Sandstone. 



2. Calciferous Sandstone. 



3. Chazy, or Isle la Motte Limestone*. 



4. Trenton Limestone. 



•5. Utica Slate and Hudson River Shales. 



The Potsdam Sandstone is largely de- 

 veloped at several places on the west, or 

 NeAv York, side of Lake Cliamplain, but is 

 no where found in situ, Avithin the limits 

 of Vermont. The remarkable Chasm, 

 through Avhich the river Ausable passes, 

 near Port Kent, is in this rock. 



Calciferous Sa7idrock.-Th\s, the second 

 member of the Champlain group, appears 

 on the Vermont side of the lake, but very 

 sparingly. It is seen at the base of the 



* This division embraces the Chazy and Tird's eye 

 limestone, and Isle la Motte marble of the Kew York 

 Geologist. 



