GUIDEBOOK FOR FIELD TRIPS IN WESTERN NEW YORK MAY 4-6, 1956 TWENTY-EIGHTH ANNUAL MEETING NEW YORK STATE GEOLOGICAL ASSOCIATION AT THE UNIVERSITY OF ROCHESTER ROCHESTER, NEW YORK GUIDEBOOK Twenty-eighth Annual Meeting of the NEW YORK STATE GEOLOGICAL ASSOCIATION ***** Rochester, New York May 4-6, 1956 ***** Host Department of Geology and Geography The University of Rochester Prepared by the Staff of the Department, Assisted by Robert We Adams Paul T e Moyer Walter A. Anderson David R. Pefley Philip Cohen K. Norman Sachs Rufus E. Fulreader Paul R" Seaber Lewis Eo stover Multilith~ University of Rochester Print Shop ACKNOWIEDGMENTS Grateful thanks are extended to all those whose coopera­ tion made possible these field tripso Especially to be mentioned are the following8 Dro Harold L. Alling, Mr. Donald H. Campbell, the Wollensak Optical Company, and The University of Rochester, whose generous contributions toward expenses made possible a reduction in costs to individual trip participants; all owners of property visited on the field trips, for permission to enter their lands; Mr 0 Gordon Harvey, Chief Engineer and General Manager of Letchworth State Park, for assistance with arrangements in the park and for printed materials concerning the park; Easiman Kodak Company, for the guided tour of Kodak Park; Miss Marguerite Lyon and Mr. John Ro Van Ostrand, fo~ invaluable service in preparation of the guidebook. TABLE OF CONTENTS Introduction • e o 0 0 0 00000 •••••••••••••••••• 1 Part I - General geology A. Geomorphology 0 0 0 • • • • • • • .00000 ••••••• 2 Physiographic history 0 • • • · . 2 History of the Genesee River • • 0 • • • • • 5 Be Stratigraphic succession Ordovi cian System • • • • 0 • • • 0 • 0 9 Lower Silurian 0 • • • • • • 10 Middle Silurian • • . • • • 10 Upper Silurian 0 • • • • • • • • • • • • 17 Silurian depositional history •••••••••••••• 18 Silurian-Devonian hiatus ... • • • • • • • • 19 Lower or Middle Devonian • • • 21 Middle and Upper Devonian • • · . · . .· ." 26 Hamilton group and Tully formation •• 0 • • • • • 29 Genesee group e • • • • • • • • • • • • • • • • .. 0 39 Naples group .. 0 0 \) 0 0 8 0- • 0 00 • • 0 • 0 eo • 43 Formations above the Naples group • • • • • • • 0 • 45 Glacial geology .. • •• • • • • .0. 0 e • • • 47 Mendon Ponds Park • • • 0 • • • • • 0 eo III • 55 The Pinnacle Range e..... • • • • 0 • • 56 D. Economic geology Salina salt • • • • CI 0 .. • • 61 Clinton iron ore . • • G .. • 64 Oil and gas • o 0 • 0 • e 0 · . e 0 0 • 66 Ground water o I) • • • • • 0 · . 67 Part II - Itineraries Trip lA - Silurian stratigraphy; geomorphology ... • • • • • •• 69 Trip 18 - Glacial geology • • • • • • • • • • • ... 85 Trip Ie - Kodak Park tour 0 • • • • • • • • • • • • • • • • • •• 91 Trip 2 - Devonian stratigraphy; Genesee River history · . 93 Trip ]A - Hamilton stratigraphy and fossil collecting, locality 3 miles west of East Bethany • • . 103 Trip .3B - Silurian-Devonian contact relations, Oaks· Corners quarry 0 . 0 . 108 Trip 3C - Mineral collecting in Lockport· ·dolomite, · · · ·Penfield · · · · quarry . 0 0 . • • • · . • · · · · • • • .. · • ill Plates •• o • • • • • • • • • 0 • • • 0 • • • • • 114 References .. .. o (I (I e o 0 1111 • . .. · . · . · . · . • • 117 Aclmowledgments o (I 0 e 0 (I 0 0 e e eo. 0 · . ., . LIST OF MAPS AND DIAGRAMS Mapg Genesee River, pre-glacial and present courses •••••••••• 4 Block diagramg Portageville-Mt. Morris area 0 • • • • 6 Silurian formations east and west of Rochester • • • • • • • • • • G 12 Onondaga formation across New York State eo. • • • • • • • • • • • •• 22 Middle and Upper Devonian facies and faunas • • • • •• 28 Hamilton units~ Buffalo to Unadilla Valley. • • ••••••••• 32,33 Hamilton units, lithologic and faunal facies in Genesee Valley region 36 Genesee grouP3 facies relations 0.. 40 Naples group, facies relations • • • • • • 0 • • • • • • • • • •• 11 Map~ Terminal and recessional moraines in western New York • • • •• 18 Mapg Glacial features of Monroe County • • • • • • • • • • • • • • • •• 50 Mapg Glacial lakes Dawson and Iroquois • • • • • • • • • • 52 Block diagramg Rochester vicinity topography... • •• 0 • 0 • •• 57 Block diagramg origin of Pinnacle Range 0............... 60 Section of New York salt field • • • • • • • • • • • • 0 • • • • •• 62 Stratigraphic succession in Genesee Valley • • • • • • • • •• 68 Diagram~ bedrock-till relations, Rochester Gorge 0 ••••• 0 • • •• 71 Measured section~ Rochester Gorge ••• • ••••••••• 72,73 Mapg Route, Trip No" lA-I • • • •.• • • • • • • • • •• 74 Map g Route, Trip No" lA=2 • 6 • • • • • • • • • •• •• 80 Map: Route, Trip No" lB .. 0 0 • • • • • • • • • • •• 84 Map~ Route, Trip No o lB, stops 1 and 2 0 ••• • 0 • • • • •• 86 Map~Route~ Trip Noo lB» stops 3 and 4 & • • • • • • • •••• o. 88 Map~ Route, Trips Noo 2 and 3 . • • • • • • .• • • • •• 92 Diagram and stratigraphic section, Mte Morris Dam • • • 0 • • • • • •• 96 Map~ Route, Trip NO e 2, stops 2=1 • • • • • •• 0 • • • • 98 Stratigraphic section, Fall Brook G. • • • • • • • • • • • • • • • e e 100 Map and block diagram~ Area 3 miles west of East Bethany • • • 0 • • • 0 106 INTRODUCTION The area encompassing the field trip routes extends from the southern shore of Lake Onta1rio about 50 miles southward to the town of Portageville, livingston CountY$ which lies at the head of the upper gorge of the Genesee River, and from the longitude of Batavia in the west to that of Phelps, about 60 miles to the easto WithL~ this region are diverse geological features which have been the subject of the attention of some of New York's famous geologists from the days of the early surveys down to the presento The phases of the local geology which const.itute the principal objectives of these field trips are the i'o11owingg 10 The history of the Genesee River. The story of the Genesee, the largest northward flowing river in eastern North America, involves a long preglacial history including a major period of stream capture~ foJ.,lowed by dramatic glacial and postglacial events which resulted in conspicuous changes in river course and the carving of two spectacular gorges in the bedrock. 20 A survey of Silurian-Devonian stratigraphy in central western New York. Excellent exposures through some 3200 feet of sediments are provided where the Genesee cuts across the strike of belt after belt of gently inclined Middle Paleo­ zoic sediments as the river drops 850 feet in elevation. 3. Exposures near Batavia and Phelps, respectively to the east and west of Rochester. These provide, on the one hand, unmatched fossil collecting in strata of the Middle Devonian Hamilton group, and, on the other, an intimate view of dis­ conformable contact relations between the Upper Silurian and late Lower Devonian calcareous rocks. 4. The glacial history of the regiono Glacial features which can be seen include recessional mor~nes, kames, kettles, eskers, drumlins, and ancient lake shorelines a ' 5" Mineral colle cting in the Lockport dolomite 0 This Middle Silurian f orma­ tion in certain localities is replete with a variety of minerals characteristic of low temperature deposition in calcareous rocks" Part I of this guidebook provides a discussion of information pertinent to some of the major topics indicated above. The aim of this section is to present a background picture which will contribute to fuller appreciation of the geologic features to be seen in the fieldo This is supplemented by remarks in more detail at appropriate points in the itineraries for the individual trips, which constitute Part 110 r'" ~.' A chart showing the sequence of formations in the Genesee Valley will be found on page 680 2 .. PART I - GENERAL GEOLOGY A0 GEOMORPHOLOGY The area ll1 which the field trips are planned has maxiwJm dimensions of about 60 miles east-west and 50 miles north-south I' It reaches from the southern shore of Lake O:ntario a.cross a portion of the Central Lowlands physiographic province into the highlands of the Glaciated Allegheny Plateau section of the Appalachian Plateaus prO"lrince.. Throughout the area geologic phenomena recorded in observable features represent two widely separated phases of development: (1) the bedrock geology dating to the Middle Paleozoic and (2) the period of Pleistocene glaciati.on and post­ glacial developments.. The gap between these two is·bridged only by the obscure and not too spect2cular tectonic development of the area and by the more easily inter­ preted stages in the evolution of the surface of the land itselfo The area between Lake Ontar:l.o and the Allegheny Plateau is the far eastern attenuation of the great Central Lowlands province, which, as a whole, includes an area of over ha.lf a million square miles, comprising a part, or the entire portion, of the l&'1d wi thin sixteen states 0 Wi thin this large area the variation in es­ sential morphologic form is no greater than in the smaller physiographic provinces, lack of major distinctions being partly a result of the nearly flat-lying stratao The most dominating characteristic in the local area is the effect produced by glaciationo Similarly, if it were not for the glaciation in the northern part of -the Allegheny Plateau section, the glaciated and unglaciated portions of that section would probably not be considered distinct, since the extent of dissection and the ~ount of relief of both areas are comparable e Throughout the area to be visited, bedrock consists of Middle Paleozoic sedimentB-ry fOTlnations virtually 1L~deformed except for imposition of a regional southward dip wt.ich averages about 60