Guidebook for the 32Nd Annual Field Conference of Pennsylvania

GUIDEBOOK - 32nJ f itfJ Conft>itnct Of Ptnn~~f v4ni4 Gtof o~t~t~ East Stroudsburg, Pa . September 29 and 30, 1967 ... - -..: ... 'kmied, $/atu {}~ SWUte4f - p~ q~,gWUJelf r .J:.::~: ...;,;.· .. Guidebook for·the 32nd Annual Field Conference of Pennsylvania Geologists ' -~ GEOLOGY IN TIIE REGION OF TIIE DELAWARE TO LEHIGH WATER GAPS September 29 and 30, 1967 ! ' I Hosts: U. S. Geological Survey and Pennsylvania Geological Survey Tl ' J -~ _: By Jack B. Epstein and Anita G. Epstein U. S. Geological Survey, Beltsville, Md., and Washington, D. C. i .::..1I t --, . iI -J Cover Design: Jack B. Epstein Guidebook distributed by: Bureau of Topographic and Geologic Survey Depa rtrrent of En vi ronrrenta 1 Resources Harrisburg, Pennsylvania 17120 --··' i Publication authorized by the Director, U. S. Geological Survey -CONTENTS I l- Introduction ..................................................... Early hist.ory •.•.••.• , • , ••••• , •• , ••••• , , , • , •••• , , • , • , •••• , • • • • • • • 4 Stratigraphy •.•. , ••••• , .•••••••••••• , • , ••••.••••• , , ••••• , • • • • • • • • • 13 Geographic and tectonic environments of deposition ••••••••••• 13 Structural geology .•.•.•••••••••••• , •••••••• , ••••••• , , • . • • • • • • • • • • 19 L,___ ; 25 ''nle Taconic orogeny in eastern Pennsylvania ...................... r , ....., ! 32 Geomorphology .. .. .. .. .. .. .. .. Glac ia 1 geology •••••••••••••••••••••••••••••••••••••••••••••.• • • • • 34 .. -.'' 37 i.Ui...1 Road log--First day .............................................. 38 Stop 1 ....................................................... 46 Stop 2 ........................................................ 50 Stop 3 ....................................................... Stop 4 . , • ,· ..•.•..••••• , •. ,,.,,, •.•• ,,., ••••••• , ••• , •• ,, •• , •. , 53 57 Stop 5 ...................... " . .. ...................... 62 Stop 6 .................................... -· ................. 66 Road log--Second day ............................................. 66 Stop l ........................................................ ' , 69 Stop 2 ........................................................ 76 ' ___ _J" Stop 3 ......•.•..........•........•....•••.• ........ ....... 76 Stop 4 ...................................... ............. 79 Stop 5 ························································· 81 Stop.6 ....................................................... 85 References cited ................................................. 90 ............. ' ............................ l: .• .I Reprint (Epstein, 1966) iii I I J ILLUSTRATIONS ... Page Figure 1. Index map of eastern Pennsylva~ia ................... 3 2. Generalized geologic map of field-trip area . .. 5 . _J 3. Phys iograp hie diagram of field-trip area ............ 6 4. Stratigraphic section of Shawangunk Conglomerate, Bloomsburg Red Beds, and Poxono Island Formation rt of White (1882) in field-trip area • • . • • . • • • • • • • • • 15 fJ 5. Stratigraphic section of Poxono Island Formation J of White (1882) through Buttermilk Falls Limestone of Willard (1938) in field-trip area ........................................ •..... 17 6. Geologic structure section in eastern part of field-trip area •.••••.•.••• ,· ..•..•••••••..•••.• '.i• 23 7. Geologic structure section in western part of field-trip area •..•.••.••.•••••.••.••••••••••.••. 24 J 8. Stereographic projections of cleavage .••••.•••••••• 30 9. Geologic section through Blue Mountain east of Little Gap .................................. " .... 33 10. Diagrammatic sketch of Wisconsin glacier in Lake Sciota •••.•••.••••.•.•.•••••••••••••.•.•••.•• 36 11. Topographic map and geologic section of esker and delta, stop 1, first day ...................... 39 12. -Diagrammatic geologic section through Stony Ridge at Little Gap .............................. 43 13.. Diagrammatic geologic section of Penn Big Bed Slate Company quarry, stop 2, first day •••••••.••• 46 iv 1,, U'.·· ··. I I -..:.-· Page i -~ 49 ' Figure 1/~. Geologic section east of Lehigh Gap •••••••·····~·· r .-·~ j ' 15. Diagrammatic geologic section through the -L• Shawangunk-Martinsburg contact at Lehigh Gap, stop 3, first day • • • • • . • . • • . • • • • • • • • • . • • • • . 49 16. Diagrammatic sketch of hedding and cleavages -L_J in Shawangunk Cong1d111erate, stop 3, first day 51 ' r I 17. Diagrammatic sketch of normal fault in Shawangunk I _,1_: Conglomerate, stop 3, first day ................ .. 51 :; ·, -~ ! _G,.,;1 18. Diagrammatic sketch of wedges and bedding-plane ·dips in Bloomsburg Red Beds, stop 4, first day 54 n.. , ~ 19. Geologic section through Blue Mountain near Pennsylvania Turnpike Extension .•.•.•••.•••••.••• 54 20. Columnar section at stop 5, fir.st day ............. 58 21. Geologic map and section at stop 5, first day 59 22. Diagranm1atic sketch of cascade folds, stop 5, fi.rs t day . • . • . • . • • • . 60 j 23. Sketch of view north of Cherry Ridge . .. .. .. .. .. .. 61 I \ .;, .. -1 2li·.. Stratigraphic column at stop 6, first day .. .. • . • .. 63 25. Geologic section at stop 6, first day 64 -~ 26. Diagrmmnatic sketch of overturned anticline at stop 6, first day .....••.............•.•.•.••.••• 64 27. Sketcl1 of biohermul <rnd nonbiohermal facies in Coeymans Formation, stop 2, second day • • • . • • . • 70 28. Geologic section at Tocks Island damsite ••.••.. , • • 71 29. Ceo logic section through Godfrey Ridge, stop 4, second day ....................................... 77 v Page Figure 30. Diagrammatic geologic section showing fanning of cleavage in Port Ewen Shale, stop 4, second day- •.•••••••••••••••••••••••••••••••••••.•••••••• 78 J 31. Geologic map of.Delaware Water Gap area, stop 6, }1 second day •••••••••.••.•.••••.•••..• _, • • . • . • • • . • . • 82 ·U P_··.Ll TABLES n.·. Page .y Table 1. Description of rock units in Kittatinny Mountain r].._·· and Godfrey Ridge ................................ 10 •\:- 2. Description of rock units in Blue Mountain and 1 Cherry, Chestnut, and Stony Ridges • • • • • • • • • • • • • • 12 - 3. Li thotec tonic uni ts • • . • . • . • • • • • • • • • • • • • • • • • • • • . • • • 20 J j I.: ts"] f i ..J. vi J u 1 INTRODUCTION ;,,; This field conference will demonstrate the interrelationship of r-·: -U the stratigraphy, structure, geomorphology, glacial geology, and eco~omic geology of Middle Ordovician through part of the Middle Devonian strata ,r7' i. 1 _)\ and overlying surficial deposits in the area between the Delaware and Lehigh Rivers in eastern Pennsylvania. Rocks north and south of this area were seen on two previous fi~ld trips,. The 26th Field Conference of Pennsylvania Geologists, in 1961, dealt with the rocks.in the Great Valley and Reading Prong to the south. The 28th Field Conference concerned the geology north and west of Stroudsburg, Pa., and included rocks generally younger than Lower Devonian. r11:_':1 .l;;:Y Data for this field trip have been gathered by (1) nearly completed bedrock and surficial mapping of all or parts of eight 7lii-minute quadrangles by J. B. Epstein, U. S. Geological Survey (Stroudsburg, East Stroudsburg, Portland, Saylorsburg, Wind Gap, Kunkletown, Palmerton, and Lehighton-- the last five being done in cooperation with the Pennsylvania Geological. Survey), and (2) stratigraphic studies of Upper Silurian and Lower Devonian rocks of northeastern Pennsylvania, New Jersey, and southeastern- I I --,;.-J most New York by Epstein and others (1967). In addition, we have benefited from discussions and exchange of data with several coworkers, including A. A. Drake, Jr., U. s. Geological Survey, and J. D. Glaeser, J. F. Wietrzychowski, and W. D. Seven of the Pennsylvania Geological Survey. D. G. Parrillo and A. J. Depman of the U. S. Army Corps of Engineers have supplied the ?ata concerning the engineering geology of the Tocks Island damsite which will be discussed at stop 2, second day. They have also made available cores from the damsfte which will be seen at the lunch stop on the second day. D. W. Kohls supplied the road-log description of The ! I •1....i \ 2 .j New Jersey Zinc Company operations at Palmerton. Much of the work is still incomplete, and some of the conclusions presented in this guidebook should be regarded as tentative. We will examine the probable facies relationships and correlations __.' between rocks in the eastern and western sections of the area and consider the environmental conditions under which these strata were deposited. The rock stratigraphic units have been grouped into four successive lithofacies, r "·1··i".. .; each of which displays a different style of d~formation. Folds produced in these rocks are disharmonic, and it is believed that each rock sequence is set off from sequences above and below by a decollement, or zone of r1 detachment. Movement was northwest into the Appalachian basin, primarily l..1 by gravitational sliding, aided by direct~d tectonic forces. The contact u between the Shawangunk Conglomerate of Silurian age and Martinsburg " Formation of Ordovician age, believed by most workers to be an angular unconformity, may also be one zone of detachment. The deformational effects of the Middle to Late Ordovician Taconic orogeny may not be as J intense in this area as some geologists believe. rt Y. Erosion of the folded heterogeneous bedrock in this part of the Appalachians has produced linear ridges and valleys. This topography had a profound effect on the manner of retreat of the Pleistocene glaciers. ... ·.··]'.· We shall demonstrate that during the Wisconsin Glaciation a moraine-dammed

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