THE UNIVERSITY OF ILLINOIS LIBRARY ftflB fill rJP' The person charging this material is re- sponsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for disciplinary action and may result in dismissal from the University. To renew call Telephone Center, 333-8400 UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN BUILDING USE ONjJfc jUN ±21980 JUN 1 2 1980 man 3 1 190' m L161—O-10% Digitized by the Internet Archive in 2013 http://archive.org/details/correlationofedgOOross HE CORRELATION OF THE EDGEWOOD AND SEXTON CREEK FORMATIONS OF THE ALEXANDRIAN SERIES IN MISSOURI, ILLINOIS, IOWA AND EASTERN WISCONSIN BY CLARENCE SAMUEL ROSS A. B. University of Illinois, 1913. THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of MASTER OF ARTS IN GEOLOGY IN THE GRADUATE SCHOOL OF THE UNIVERSITY OF ILLINOIS m R73 UNIVERSITY OF ILLINOIS THE GRADUATE SCHOOL JTJME 3 igi b I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPER- VISION BY Clarence Samuel P.o.ss _ _ ENTITLED THB! flfmttBT.ATTON QJ THE BDflEWOOD AND SEXTON CRBBR FOBWATIONa...QJ... THE ALEXANDRIAN SERIES IS MISSOURI, TLT.TNOTR, IOWA AND EASTERN WISCONSIN BE ACCEPTED AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE degree OF MASTER OE_ARIS_. , (S^ . ^^^^ In Charge of Thesis /) // JjL £lAJir~l/ C^i Head of Department Recommendation concurred in :* Committee on Final Examination* ^Required for doctor's degree but not for master's. UIUC J 313 SB CONTENTS. Pa^e I. INTRODUCTION 1 II. EARLIER STUDIES AND INTERPRETATION OF STRATA 2 III. GENERAL STRAT I ORA PI 1 1 C RELATIONS 9 IV. THE EDGEWOOD FORMATION IN ILLINOIS AND MISSOURI 10 Detailed Sections 12 Section of strata exposed one and one -half miles north of Thebes 12 Section In an abandoned quarry, onc-.'ourth mile southwest of Gale 13 Section of strata exposed along Noix Creel:, near Louisiana Missouri 14 Section of strata exposed one and one -half miles northeast of Ed^ewood, Missouri 15 Section of Charmahon Limestone exposed near Channahon , Illinois 15 Section of Essex Limestone near Essex, Illinois. 17 Section of strata at Winston , Illinois 17 Comparative Table of Fossils from the Edgewood Limestone 19 V. THE SSXTCM CREEK LIMESTONE IN THE ILLINOIS- MISSOURI REGION 24 Distribution of Strata 24 Pa^o . Detailed Sections cf the Sexton Creek Limestone 24 Section cf strata exposed one and one-half miles south of Thebes 26 Section of strata exposed in the east bank of Sexton Creek, one and one-half miles north of Gale 2o Section of strata exposed alone Daggetts Creek.. 28 Section of strata exposed one -"half mile above the mouth of Daggett s Creek 28 Section of strata exposed one-fourth mile east of Daggetts Creek .29 Section exposed two and one -half miles west of Grafton 29 Section of strata exposed in the south part of the village of Hamburg 30 Section of strata exposed three and one-half miles above Custer Park 31 Section of strata exposed three miles south of Channahon 32 Section of strata exposed three miles southwest of Channahon 32 Section cf strata exposed along Waubansia Creek, at Oswego 35 Section of strata exposed one-half mile south of Batavia 36 Section of strata exposed three-fourths of a mile south of St. Charles 36 Section of strata exposed two miles south Page of Elgin 37 Lithology of the Sexton Creek Limestone 38 Comparison of Sections 40 Comparative Table of Fossils from the Sexton Creek limestone 42 Comparative Table of Fossils from the Illinois, Ohio, and Kentucky Regions 47 VI. THE ALEXANDRIAN SERIES IN EASTERN fISOONSIN 56 Distribution 56 Physiography of the Region. 56 Description of the Mayville Limestone 59 Description of the Byron Limestone 61 Detailed sections 62 Outcrop near Eagle 62 Outcrop near Hartford 62 Sections of strata exposed south of Pewaukee Lake 63 Sections of strata exposed near Hayville 63 Section made at Neda 67 Section of rocks outcropping one-fourth mile north of Me da 67 Section of strata exposed one mile south of Oakfield 68 Sections of strata outcropping at Marblehead . 68 Section of strata exposed in an old quarry, one-half mile south of Peebles 69 . Page Outcrop of rocks south of Byron 72 Section of strata exposed at Brillion 72 Section of strata exposed at High Cliff 73 Section of strata exposed at Brick Yard 73 Section of strata exposed at G-reenleaf 73 Section of strata exposed at Cascade Falls 75 Comparison of Outcrops of the Alexandrian Series 77 Table of Fossils from the Mayville Limestone 80 VII. Correlations and General Conclusions S3 Correlations of . the . Edgewood Limestone 84 The Sexton Creek Limestone 85 VI I I. Summary 93 . 1 ^ INTRODUCTION The Alexandrian series comprise that portion of the Silurian system lying between the top of the Ordovician and the base of the Niagaran, . being composed of three formations in the Mississippi Valley; the Girardeau, the 3dgewood, and the Sexton Creek During the past three years a study of the Sexton Creek, and lidgewood formations of the Alexandrian series has been carried on by the writer. The first two summers the work was done in com- pany with Dr. T. 3. Savage, and while during the past summer Dr. Savage was in the field but a few days the work was done under his direction. The writer desires to acknowledge his great indebtedness to Dr. Savage for the opportunity to carry out this study, and for the constant help and advice that he has given. The papers of Prof. Charles Schuchert have furnished valuable data for correlat- tion, and the writer has also drawn from the work of Prof. T. C. Chamberlin^ The greater part of the Silurian rocks of the southern part of Illinois and all those in the northeastern part of the state of Illinois, and of eastern T.7isconsin have long been con- sidered to be of Niagaran age. The present study was begun in (1) Charles Schuchert: Bull. Geol. Soc. of Am. vol. 25, 1914, pp. 277-520 (2) T. C. Chamberlin: Geol of Wis. vol. II, 1873- 1S77, pp. 327-389 order to determine what part of the Silurian System could be cor- related with the earlier' Alexandrian series. The greater part of the rocks of Sexton Creek age in Illinois are undolomi tized and are quite dissimilar to the Niagara dolomites, from which the lithology of the Edgewood limestone is also usually quite distinct. In eastern Wisconsin there is a very close resemblance between the Niagaran rocks and the under- lying earlier Alexandrian limestones. In all of the Illinois region there is a well defined unconformity between the Alex- andrian and Iliagaran series, but in eastern Wisconsin no uncon- formity seems to be present at this horizon. The thickness of the limestone of the Alexandrian series of eastern Wisconsin is also much greater than the thickness of the corresponding series in Illinois. Because of these differences, and the evidences that two well defined regions of deposition are represented, it seems best to discuss the two regions separat ely , after which the necess- ary correlations between them will be made. EARLIER STUDIES AND INTERPRETATION OF STRATA . The name Alexandrian series was proposed by Dr. T. E. Savage in 1908 for that part of the Silurian column between the top of the Ordovician and the base of the Brassfield. In 1909 Dr. Savage included the Brassfield limestone and the Illinois (3) T.E. Savage: Am. Jour. Sci. vol t xxv, 1908, p, 454. (4) T. S. Savage: Am. Jour. Sci. vol. xxviii, Dec. 1909, pp. 509-519. formation of the same general age called the Sexton Creek, in the Alexandrian series. In 1857 Billings 5 proposed to place all of the strata of the Anticosti section, above what is now defined as the Char- leton formation in the Anticosti group. It has since been shown that this portion of the Anticosti section includes strata as low as the Richmond (Late Ordovician), and others as high as the Niagaran series. Billings therefore included too much in his Anticosti group, making it embrace rocks belonging to two dis- tinct systems. For this reason the new name Alexandrian was pro- posed to provide a place for those strata younger than the Rich- mond, and older than the earliest of the Niagaran formations of the Hew York section. 7 In 1855 ..r. G. C. Swallow , who was then state geologist of l^issouri, referred the rocks now known as the Edgewood in the Vicinity of Louisiana Missouri, to the Onondaga of the Devonian. In the same report Shumard described the limestones in the vicinity of Cape Girardeau, Missouri under the name Cape Girardeau limestone, and considered them the oldest Silurian rocks of the state In 1866 Worthen recognized the Girardeau .limestone in the vicinity of Thebes, Illinois, but referred it to the Cincinn- (5) E. Billings: Geol. Surv. of Canada, Report of Progress, 1857, p. 247. (6) Charles 5 cruchert: Bull. -Geol. Soc. of Am. vol.20, 1909, pp. 427-606. (7j G. C. Swallow: Geol Surv. of Missouri, Reports 1 and 2, 1855, p. 107. 2 ati group of the Ordovi cian. In this report Worthen correlated the gray limestone in the lower part of the bluffs of the Miss- issippi River in Pike and Calhoun counties, Illinois with the Niagar-n of the northern part of the state. On another page '.Vorthen referred as follows to the rocks in the vicinity of Thebes. "It would appear probable that no beds of undoubted Niagaran age were ever laid down in southern Illinois, but in their places these siliceous limestones, repre- senting in part the age of the Lower Ilelderberg limestones, and in part the Oriskany sandstones of the New York series, were deposited resting directly upon the Cincinnati group of the Lower Silurian." In a report on the geology of Alexander County, Illinois, published in 1868 Worthen 1^ again assigned the Girardeau lime- stone to the Lower Helderberg.