Stratigraphy of the Bois Blanc Formation in New York GEOLOGICAL SURVEY PROFESSIONAL PAPER 584-A Stratigraphy of the Bois Blanc Formation in New York By WILLIAM A. OLIVER, ]R. STRATIGRAPHY AND PALEONTOLOGY OF THE BOIS BLANC FORMATION IN NEW YORK GEOLOGICAL SURVEY PROFESSIONAL PAPER 584-A Description of a little-known limestone formation of Early Devonian age in western New York UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1967 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 45 cents (paper cover) CONTENTS Page Page Abstract___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ A 1 Descriptive stratigraphy ____________________________ _ A5 Introduction_______________________________________ 1 Localities _________________________________________ _ 6 Previouswork______________________________________ 1 References cited ___________________________________ _ 7 Schoharie Formation____________________________ 1 Bois Blanc Formation___________________________ 2 ILLUSTRATIONS Page PLATE 1. Map showing Bois Blanc outcrops in western New York and the Niagara Peninsula of Ontario ____ . _ __ __ _ _ _ _ In pocket FIGURE 1. Correlation of the Bois Blanc and Onondaga Formations of western New York with formations in southwestern Ontario and eastern New York ________ --------------______________________________________________ A2 2. Index map showing areas and localities in Michigan, southwestern Ontario, and New York ____________ ·-·-__ 3 3. Chart showing earlier interpretation of Onondaga-Detroit River correlations _______ . ___ . _________ . _ __ __ _ _ __ _ _ 4 4. Columnar section of Bois Blanc and Onondaga Formations near Buffalo, N. Y _______________ ------------ -- -- 4 5. Columnar sections showing lithic sequences at base of Bois Blanc and Onondaga Formations________ __ _ _ _ _ __ __ 6 III STRATIGRAPHY AND PALEONTOLOGY OF THE BOIS BLANC FORMATION IN NEW YORK STRATIGRAPHY OF THE BOIS BLANC FORMATION IN NEW YORK By wILLIAM: A. OLIVER, JR. ABSTRACT is misleading. The Schoharie and Onondaga Forma­ The Bois Blanc Formation, thickest and most widespread in tions are clearly defined rock units. Their type sections the Michigan Basin, extends eastward to western New York in central and eastern New York define two informal where it is thin and discontinuous beneath the Onondaga time-rock units. These two units with a third, lower Limestone. unit form the Onesquethaw Stage in the standard New Historically, Bois Blanc rocks have been included in the Onondaga Limestone or have not been recognized in Ontario and York section (fig. 1). Present evidence indicates that New York. Recent studies show the Bois Blanc to be Schoharie the Lower-Middle Devonian boundary is between the (late Early Devonian) in age and to be separated from the over­ Schoharie and Onondaga. lying Onondaga Limestone and Detroit River Group by a dis­ The purpose of this paper is to describe the Bois conformity that is probably widespread. Blanc Formation of Schoharie age in western New The Bois Blanc and Schoharie Formations contain brachiopods and corals that are distinctly different from underlying and over­ York and adjacent Ontario where it underlies the lying faunas. The Schoharie-Bois Blanc fauna is widespread Onondaga Limestone. A historical review of both in a province that covers most of eastern North America. Schoharie and Bois Blanc usage precedes the descrip­ tion of the Bois Blanc. INTRODUCTION PREVIOUS WORK The lower boundary of the Onondaga Limestone is clearly defined in central and eastern New York (fig. 1) SCHOHARIE 'FORlYIATION where the Edgecli:ff Men1ber either disconformably over­ The Schoharie Formation and Onondaga Limestone lies Oriskany or older rocks or rests on the Schoharie :have been recognized as distinct lithologic units since the Formation of distinctly different lithology. In the early New York surveys. Early workers, perhaps un­ Niagara Peninsula of southwestern Ontario, and locally critically, accepted them as successive unit$, :the 'Onon- in western New York, the Edgecli:ff Member is underlain daga overlying the Schoharie.· · , by older limestone that has comn1only been included in Detailed restudy of the Schoharie began with several the Onondaga. The subEdgecli:ff limestone in these areal reports of the New York State Museum (Ruede­ areas if? lithologically distinct and is separated from the mann, 1930, p. 60-61; Goldring, 1931, p~ ·384; 1935, p. Edgecli:ff by a disconformity. 136; 1943, p. 212) and culminated with ·a redescription Farther west, in the Michigan Basin, limestones simi­ and analysis of the whole formation by GOldring and lar to those underlying the Edgecli:ff underlie the De­ Flower (1942). In the works cited; Ruedemann and troit River Formation or Group and are termed the Goldring described the Schoharie-Onondaga contact as· Bois Blanc Formation. The subEdgecli:ff limestone is 1ithologically gTadational and suggested that the laterally continuous with the Bois Blanc and should be Schoharie was a basal sandy facies of the Onondaga, included in that formation. although it is not clear whether they meant that the The Schoharie-Bois Blanc and Onondaga-Detroit Schoharie Formation was the time equivalent of a part River intervals contain distinct faunas that have long of the Onondaga farther west or merely that deposition been accepted as useful time-rock indices, recognizable was continuous from one to the other. Goldring and over the eastern half of North America. In literature Flower (1942, p. 691) noted that the gradation could be these have been referred to as "lower" and "upper Onon­ due to the reworking of Schoharie clastics into the in­ daga," or "Schoharie" and "Onondaga," respectively. itial Onondaga deposit. Because "lower Onondaga" has never included any part Chadwick ( 1944, p. 93, 153) provided a dissenting of the Onondaga Limestone in its type area, this usage voice in the Schoharie-Onondaga relationship question. 271-458-67-2 Al A2 STRATIGRAPHY AND PALEONTOLOGY OF THE BOIS BLANC FORMATION IN NEW YORK Helderberg area, London-Woodstock Buffalo area, New York Series area, Ontario Ontario-New York eastern New York stages Hamilton Group Cazenovia Delaware Limestone Hamilton Group "Columbus" Limestone Middle Devonian Onondaga Limestone Onondaga Limestone Detroit River Group Onesquethaw Schoharie Formation Carlisle Center Formation Esopus Shale Lower Devonian Oriskany Sandstone Deerpark ,Helderberg Group Helderberg Rondout Limestone Cayuga Upper Silurian Akron and Bertie Formations Akron and Bertie Formations Cobleskill Limestone FIGURE 1.-Correlation of the Bois Blanc and Onondaga Formations of western New York with formations in southwestern Ontario and eastern New York. He described a glauconite bed separating the two forma­ Schoharie, and the recent New York Devonian correla­ tions locally and considered this to indicate an tion chart (Rickard, 1964) followed this interpretation. unconformity. The interpretation of the Schoharie as a clastic facies BOIS BLANC FORMATION of the Onondaga was clearly stated at least as far back The Bois Blanc Formation, as here recognized, ex­ as 1902 (Clarke, 1902, p. 667-668) but was given re­ tends :from the Michigan Basin to western New York newed emphasis by the works of Ruedemann, Goldring, across southwestern Ontario (fig. 2). The Findlay arch and Goldring and Flower cited above. This work and (Eardley, 1951, p. 36-37, fig. 1, p. 29) roughly bisects faunal studies discussed below certainly influenced southwestern Ontario and serves as a convenient divid­ Cooper and others (1942, p. 1748,1756, 1774, 1779-1780) ing line between Michigan Basin and New York se­ to refer to the Schoharie and equivalent formations as quences. West of the arch, the Bois Blanc is overlain "lower Onondaga." On their correlation chart, these by the Detroit River Formation or Group; east of the authors clearly indicated the Schoharie Formation to be arch, it is overlain by the Onondaga Limestone in the the time equivalent of the lower part of the Onondaga Niagara Peninsula of Ontario and in western New York. Limestone in New York areas west of the known limits The Bois Blanc is best developed within the Michigan of the Schoharie. Basin and only the thin eastern part of the formation Oliver (1954, 1956) redescribed the Onondaga Lime­ stone in eastern New York and accepted the Schoharie extends over the arch to New York. as a facies of the lowest part of the formation. Later, Stauffer ( 1915) described the Devonian limestone however, he suggested that the lowest member of the sequence in southwestern Ontario. For the Niagara Onondaga was time parallel and everywhere younger Peninsula he gave the following generalized section (in than units containing the Schoharie fauna (Oliver, 1960, descending order) : 1963). Johnsen and Southard ( 1962) came to the same 5. Very cherty gray limestone with meager fauna. conclusion in the most recently published study of the 4. Cherty, bluish black compact limestone with corals. STRATIGRAPHY A3 \ \. ''----.--, \"'v,.. \ \ ... -- ) --'- / '60ttawa ) 0 N T A R I 0 /~-~-----T·· ,' \ / ' ) \ ~ 0 Syraeu,. \ ---r---- INDIANA i PENNSYLVANIA OHIO 0 100 200 MILES ~--~~--L---------~ FIGURE 2.-Index map of areas and localities in Michigan, southwestern Ontario, and New York. The outcrop patterns of the Bois Blanc Formation in western New York and the Schoharie Formation in