A Detailed Economic Investigation of Geochemical and Aeromagnetic Anomalies North Central Maine
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A DETAILED ECONOMIC INVESTIGATION OF GEOCHEMICAL AND AEROMAGNETIC ANOMALIES NORTH CENTRAL MAINE By W.F.Stickney, R.S.Young, LA.Wing Edited By R.G.Doyle - Special Economic Series No.A Maine Geological Survey Robert G. Doyle State Geologist Department of Economic Development Augusta, Maine March, 1965 TABLE OF CONTENTS FOREWORD by Robert G. Doyle l PART I GEOLOGY by Webster F. Stickney INTRODUCTION 4 ACKNOWLEDGEMENTS 6 PREVIOUS WORK 7 GENERAL GEOLOGY 8 LITHOLOGIC DESCRIPTIONS AREA I 10 Silurian 11 Siluro-Devonian 11 Devonian 12 Plutonic Rocks 14 LITHOLOGIC DESCRIPTIONS AREA II 16 Devonian 17 Plutonic Rocks 19 METAMORPHISM 24 STR.UCTURE 28 PART II GEOPHYSICS by Robert S. Young INTRODUCTION 31 EXPLORATION PROGRAM 32 Prospect #1 B Pond Grid 34 Prospect #2 Crawford Pond Traverse 37 Prospect #3 Boardway Ponds Prospect 39 Prospect #4 Baker Pond Traverse 42 Prospect #5 Horseshoe Pond West Traverse 43 Prospect #6 Horseshoe Pond East Grid 44 Prospect #7 Scammon Ridge Grid 45 Prospect #8 Barren Mountain Traverses 48 TABLE OF CONTENTS CONT 1 D: PART II GEOPHYSICS CONT'D: Prospect # 9 White Brook Anomaly lJ.9 Prospect #10 Hay Brook Grid 50 Prospect #11 Gulf Hagas Grid 52 Prospect #12 Chairback Mountain Anomaly 54- Prospect #13 Wangan Brook Anomaly 56 Prospect #llJ. Katahdin Iron Works 57 Prospect #15 Little Squaw Mountain Prospect 60 Prospect #16 Big Squaw Pond Grid 64 Prospect #17 Moorers Bog Prospect 66 Prospect #18 Chase Stream Area 67 AFMAG SURVEYS 73 PART III GEOCHEMISTRY by Lawrence Ao Wing INTRODUCTION 76 PREVIOUS WORK 76 METHODS 77 SAMPLE DENSITY AND INTERPRETATION 78 RESULTS 80 REFERENCES i-iii INDEX OF PLATES AND FIGURES Following Page Figure l Index Map of limits of area of exploration 4 Plate l Geologic Map 5 Plate 2 Prospect Location Map 6 Plate 3 nBn Pond Grid - Magnetics 34 Plate lj. Crawford Pond Traverse - Magnetics & AFMAG Data. 37 Plate 5 Boardway Ponds Prospect - Geology 39 Plate 6 Horseshoe Pond East - Geology-Geochemical Values Magnetic-Self Potential Profiles 43 Plate 7 Scammon Ridge - Magnetic Survey 45 Plate 8 Scammon Ridge - Self-Potential Survey 46 Plate 9 Barren Mtn. Prospect - Geology-Geophysics- Geochem Values . 48 Plate 10 Hay Brook Anomaly - Geochemical Data-Geology 50 Plate 11 Gulf Hagas Grid - Culture-Geology- Geochem Values . 52 Plate 12 Gulf Hagas Grid - Self-Potential Survey 53 Plate 13 Chairback Mountain Geochemistry 54 Figure 2 Wangan Brook Geochemical Locations 56 Plate llJ. Katahdin Iron Works - Geophysical Data, Line IT Q!T 57 Plate 15 Katahdin Iron Works - Geophysical Data, Line lW 58 Plate 16 Little Squaw Grid - Culture-Geology 60 Plate 17 Little Squaw Grid - Magnetics 61 Plate 18 Little Squaw Grid - Self Potential Survey 62 Plate 19 Big Squaw Pond Grid - Culture-Geology 63 Plate 20 Big Squaw Pond Grid - Magnetics 64 Plate 21 Big Squaw Pond Grid - Self Potential Survey. 64 Plate 22 Moore 1 s Bog Prospect Area - Geology-Geochem Self Potential Surveys - Magnetics . 66 Plate 23 Chase Stream Geochemistry 67 Plate 2LJ. Chase Stream - Location of AFMAG Stations 68 Plate 25 Chase Stream - AFMAG Data 70 Geochemical Sheet, Part III, in Pocket FOREWORD The principle objective of the Maine Geological Survey after its organization as a full-time Agency in 1956 has been the promotion and development of the mineral resources of the State. Of the several projects which have been undertaken by the Survey to reach this objective, the present series of Economic Evaluations has met with the most success. It is not a common practice for a State Agency of this type to enter the field of mineral exploration, even in first phase work. At the outset, however, with the publication of Economic Study Series #1 (Penobscot County) it was recognized and noted that the specific problems for conducting explo ration in Maine that were being encountered by mining companies had hindered successful exploration work. The geologists initially involved in these four Economic Studies had gained experience in the State in previous work and it was felt that if the State Survey could underwrite the cost of experimental techniques in exploration several hurdles might be overcome. The editor and his colleagues feel that the recent history of successes in mineral explor ation in Maine have justified the program in Maine. This present report will be the last in a series of four areal economic evaluations. Like its predecessors, results presented herein run the whole gamut of target interest; but the information does provide an accurate representation of the type of targets and environment which are found within the subject area. -1- The editor wishes to acknowledge the unique contribution so un- stintingly provided by field directors of the various programs, To Dr. Robert S. Young, Chief Geologist, University of Virginia; Mr, Lawrence A. Wing, Chief Geochemist, James W, Sewall Company; and to Mr. W. F. Stickney of the Survey staff and geologic coordinator, the editor offers his grateful thanks and appreciation. Appreciation and acknowledgment should be extended to all of the field assistants who supported the program since 1959; and to the geologic mapping parties from the USGS staff, as well as the many geologists who made contributions to our effort in their work for private industry and universities. With the present high level of exploration activity in Maine and northern New England, it would be presumptuous for this Agency to continue conducting exploration reconnaissance in the nature of the present economic studies. The Maine Geological Survey will, however, continue the economically oriented topical studies in both areas of interest and mineral commodities where such needs arise. The bulk of the effort of the Survey for the next several years will be directed toward detailed geologic mapping especially in areas of economic interest. Robert G. Doyle Editor -2- PART I GEOLOGY By Webster Fo Stickney -3-· 71° 67° 47° 45° Figure 1. Index map showing the limits of the area of exploration within the State of Maine. P-Portland, A-Augusta, B-Bangor, C-Caribou. INTR.OOUCTION Du.ring the summe:r: field. sea.sc1ns of 1962 through 19611 a reecmna.is~ sance geologic mapping progra.m W3.s condn.o::ed by the. Maine Geolog.ica.l Survey to complement a :r.'egi.ona1 s t:re ::i.m sE;d.i.ment geochem:ica.l and ground geophysical study of a. large port:i on of north centh:i.l JV!aine 0 The re~ sulting information was used principally to provide a geologic framewor~ for· geophysical e11aluati.cms in a.:i:ea.s of gt';oc.hem.ica.lly a:noma.lous dra.inage basins located by the stream sediment sa.mpling phase of the ove1·a.ll progra.mo The area of study (sc:e Plate 1) is geneJ::"a.Lly bound on the north by Potowad.jo Ridge 9 Ii:cst Roach Pond.) Moosehead Lake and Mis12:ry Ridgeo The southern slopes of Moxie Mountain 9 Foster R:idge a.nd l{ussel Muuntain 9 and the Piscata.guis River fo:r,m the approxima:t:E so1J.t:hern bo:rde:r o.f the: project area.o The western boundary is the ?0th meridi.::,.n 0 t:he ea.st line of limit is a north south line from Pernarlumc:ouk Lake" a.long ct-112 Pisca.ta.quis~ Penobscot County line to Bciyd La.fo2 ., I'he bounds inc1•H'l£~ the Sebec" St::bec 0 majo~r portions of the Moosehea.d L.;;..ke, First Rt•i:l.ch Porn:l 3 .Jo, Ma.ry Mounr:ai:n qi_1a.dranglc:s (sE£ location indt::X m.:s.p 3 I'iginec 1) 0 Tbis inc:ludE;s nea.:r:ly all ths southe:o::·n quarter of Piscataquis County ana. a. sma.11 portion of eastern Somer-se:t County D Jc,tal a:t20. is a.pp:r:cod.mate:l.y iq.oo sqcJ.a.re miles" This area was selected on the basis of several known geochemical anomalies and previous airborne magnetic data (Wing, 1959) (Boucot eto al., 1960) (Balsley and Kaiser, 1954) o The large massive sulfide deposit at I\atahdin Iron Works was also a contributing factor in selecting the study areao The western half of the area (Area I) was added to the original during the latter weeks of the 1964 field season to include several other known sulfide prospects, geochemical anomalies and eco nomically interesting environments in that regiono Because of the above mentioned plan changes and because of previous mapping work done, the area has been divided for ease of discussion into two parts, West - Area I and East - Area II" A line extending from Sugar Island in Moosehead Lake southeastward to Greenville and Abbot Village divides the project area into these two sections, as shown on Plate 2" A detailed mapping reconnaissance was made in Area II as little or no geologic work had been done there except for Philbrickys study of Onawa pluton and its contact aureole" The writer made only cursory examination of a few of the l.ithologic units in Area I as time did not permit a complete reconnaissance of this half of the study area" The majority of the geologic information for the western half (Area I) has been compiled from published and unpublished work contributed to the Maine Geological Survey by various workers in the area" LEGEND FOR GEOLOGIC MAP ~ook fm. ~l~eslpelites and minor quartzites ~> !) a Capens fm., Whiskey quartzite and equivalent rocks ess-Dpl o~ Quartzites and minor ~ 0 slatesr::::-:-1 ~~ [§] ~ ~ ~r Limy sandstone Limy argillites Granite, quartz monzonite and granodiorite ~ ~ l:~~one, sandy limestone, limy Diorite and pyroxene-hornblende [u~rtz,te and greenstone (Sg) granodiorite ~ Ult ramafic rock ; Gabbro, norite and troctolite ~ Felsite porphyry ~ ~ joto~ ~ "Pinstriped" quartzites and phyllite Tomhegan fm.