Surficial Geology Waterville Quadrangle, Maine
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Surficial Geology SURFICIAL GEOLOGY OF MAINE Surficial geologic mapping of the Waterville quadrangle was conducted by Thomas K. Weddle and Sydney D. Eckert during the 2015 field season. Funding for this work was provided by the U. S. Geological Survey STATEMAP program and the Maine Geological Survey, Department of Agriculture, Conservation and Forestry. SOURCES OF MAP INFORMATION Waterville Quadrangle, Maine Open-File No. 16-8 2016 Digital cartography by Amber T. H. Whittaker State Geologist Robert G. Marvinney Cartographic design by Christian H. Halsted Surficial geologic mapping by Thomas K. Weddle and Sydney D. Eckert Address: 93 State House Station, Augusta, Maine 04333 Telephone: 207-287-2801 E-mail: [email protected] Home page: www.maine.gov/dacf/mgs/ Maine Geological Survey 1 0 1 0.5 Mile 1 0 1 0.5 Kilometer 1000 0 1000 2000 3000 4000 5000 6000 7000 Feet Maine Hinckley Clinton Waterville Fairfield Belgrade Norridgewock Rome Vassalboro China Lake CONTOUR INTERVAL 10 FEET ___Continental glaciers like the ice sheet now covering Antarctica probably extended across Maine several times during the Pleistocene Epoch, between about 2.5 million and 11,700 years ago. The slow- moving ice superficially changed the landscape as it scraped over mountains and valleys (Figure 1), eroding and transporting boulders and other rock debris for miles (Figure 2 ). The sediments that cover much of Maine are largely the product of glaciation. Glacial ice deposited some of these materials, while others washed into the sea or accumulated in meltwater streams and lakes as the ice receded. Earlier stream patterns were disrupted, creating hundreds of ponds and lakes across the state. The map at left shows the pattern of glacial sediments in this quadrangle. ___The most recent "Ice Age" in Maine began about 30,000 years ago, when an ice sheet spread southward over New England (Stone and Borns, 1986). During its peak, the ice was several thousand feet thick and covered the highest mountains in the state. The weight of this huge glacier actually caused the land surface to sink hundreds of feet. Rock debris frozen into the base of the glacier abraded the bedrock surface over which the ice flowed. The grooves and fine scratches (striations) resulting from this scraping process are often seen on freshly exposed bedrock, and they are important indicators of the direction of ice movement (Figure 3). Erosion and sediment deposition by the ice sheet combined to give a streamlined shape to many hills, with their long dimension parallel to the direction of ice flow. Some of these hills (drumlins) are composed of dense glacial sediment (till) plastered under great pressure beneath the ice. ___A warming climate forced the ice sheet to start receding as early as 21,000 calendar years ago, soon after it reached its southernmost position on Long Island (Ridge, 2004). The edge of the glacier withdrew from the continental shelf east of Long Island and reached the present position of the Maine coast by about 16,000 years ago (Borns and others, 2004). Even though the weight of the ice was removed from the land surface, the Earth's crust did not immediately spring back to its normal level. As a result, the sea flooded much of southern Maine as the glacier retreated to the northwest. Ocean waters extended far up the Kennebec and Penobscot valleys, reaching present elevations of up to 420 feet in the central part of the state. ___Great quantities of sediment washed out of the melting ice and into the sea, which was in contact with the receding glacier margin. Sand and gravel accumulated as deltas (Figure 4) and submarine fans where streams discharged along the ice front, while the finer silt and clay dispersed across the ocean floor. The shells of clams, mussels, and other invertebrates are found in the glacial-marine clay that blankets lowland areas of southern Maine. Ages of these fossils tell us that ocean waters covered parts of Maine until about 13,000 years ago. The land rebounded as the weight of the ice sheet was removed, forcing the sea to retreat. ___Meltwater streams deposited sand and gravel in tunnels within the ice. These deposits remained as ridges (eskers) when the surrounding ice disappeared (Figure 5). Maine's esker systems can be traced for up to 100 miles, and are among the longest in the country. ___Other sand and gravel deposits formed as mounds (kames) and terraces adjacent to melting ice, or as outwash in valleys in front of the glacier. Many of these water-laid deposits are well layered, in contrast to the chaotic mixture of boulders and sediment of all sizes (till) that was released from dirty ice without subsequent reworking. Ridges consisting of till or washed sediments (moraines) were constructed along the ice margin in places where the glacier was still actively flowing and conveying rock debris to its terminus. Moraine ridges are abundant in the zone of former marine submergence, where they are useful indicators of the pattern of ice retreat (Figure 6). ___The last remnants of glacial ice probably were gone from Maine by 12,000 years ago. Large sand dunes accumulated in late-glacial time as winds picked up outwash sand and blew it onto the east sides of river valleys, such as the Androscoggin and Saco valleys ( Figure 7). The modern stream network became established soon after deglaciation, and organic deposits began to form in peat bogs, marshes, and swamps. Tundra vegetation bordering the ice sheet was replaced by changing forest communities as the climate warmed (Davis and Jacobson, 1985). Geologic processes are by no means dormant today, however, since rivers and wave action modify the land (Figure 8), and worldwide sea level is gradually rising against Maine's coast. References Borns, H. W., Jr., Doner, L. A., Dorion, C. C., Jacobson, G. L., Jr., Kaplan, M. R., Kreutz, K. J., Lowell, T. V., Thompson, W. B., and Weddle, T. K., 2004, The deglaciation of Maine, U.S.A., in Ehlers, J., and Gibbard, P. L., eds., Quaternary Glaciations Extent and Chronology, Part II: North America: Amsterdam, Elsevier, p. 89-109. Davis, R. B., and Jacobson, G. L., Jr., 1985, Late-glacial and early Holocene landscapes in northern New England and adjacent areas of Canada: Quaternary Research, v. 23, p. 341-368. Ridge, J. C., 2004, The Quaternary glaciation of western New England with correlations to surrounding areas, in Ehlers, J., and Gibbard, P. L., eds., Quaternary Glaciations Extent and Chronology, Part II: North America: Amsterdam, Elsevier, p. 169-199. Stone, B. D., and Borns, H. W., Jr., 1986, Pleistocene glacial and interglacial stratigraphy of New England, Long Island, and adjacent Georges Bank and Gulf of Maine, in Sibrava, V., Bowen, D. Q., and Richmond, G. M. (editors), Quaternary glaciations in the northern hemisphere: Quaternary Science Reviews, v. 5, p. 39-52. 1:24,000 SCALE Base map features from Maine Office of GIS - 1:24,000 USGS contour lines, E911 roads, 1:24,000 National Hydrography Dataset, USGS GNIS placenames and 1:24,000 political boundaries. Map projection Universal Transverse Mercator, North American Datum, 1927. The use of industry, firm, or local government names on this map is for location purposes only and does not impute responsibility for any present or potential effects on the natural resources. Approximate Mean Declination, 2015 16.5 o W (not to scale) True North Magnetic North o Funding for the preparation of this map was provided in part by the U.S. Geological Survey STATEMAP Program, Cooperative Agreement No. G15AC00181. Figure 7: Sand dune in Wayne. This and other "deserts" in Maine formed as windstorms in late-glacial time blew sand out of valleys, often depositing it as dune fields on hillsides downwind. Some dunes were reactivated in historical time when grazing animals stripped the vegetation cover. Figure 8: Songo River delta and Songo Beach, Sebago Lake State Park, Naples. These deposits are typical of geological features formed in Maine since the Ice Age. Figure 5: Esker cutting across Kezar Five Ponds, Waterford. The ridge consists of sand and gravel deposited by meltwater flowing in a tunnel beneath glacial ice. Figure 6: Aerial view of moraine ridges in blueberry field, Sedgwick (note dirt road in upper right for scale). Each bouldery ridge marks a position of the retreating glacier margin. The ice receded from right to left. Figure 3: Granite ledge in Westbrook, showing polished and grooved surface resulting from glacial abrasion. The grooves and shape of the ledge indicate ice flow toward the southeast. Figure 4: Glaciomarine delta in Franklin, formed by sand and gravel washing into the ocean from the glacier margin. The flat delta top marks approximate former sea level. Kettle hole in foreground was left by melting of ice. Figure 1: "The Bubbles" and Jordan Pond in Acadia National Park. These hills and valleys were sculpted by glacial erosion. The pond was dammed behind a moraine ridge during retreat of the ice sheet. Figure 2: Daggett's Rock in Phillips. This is the largest known glacially transported boulder in Maine. It is about 100 feet long and estimated to weigh 8,000 tons. Note: The first letter of each map unit indicates the general age of the unit: H = Holocene (postglacial deposit; formed during the last 11,700 years). Q = Quaternary (deposit of uncertain age; usually late-glacial and/or postglacial). P = Pleistocene (deposit formed during glacial to late-glacial time, prior to 11,700 yr B.P. [years before present]). Artificial fill - Variable mixtures of earth, rock, and/or man-made materials used as fill for roads. Usually shown only where large enough to affect the contour pattern on the topographic map. af Presumpscot Formation - Glaciomarine silt, clay, and sand deposited on the late-glacial sea floor. This map unit commonly overlies the irregular surface of glacial till in a complex manner, so it is likely to include areas of till exposed at the ground surface. Pp Stream alluvium - Sand, gravel, and silt deposited on flood plains. May include organic wetland deposits or underlie some of the mapped wetland areas along streams. Ha Stream terrace - Fluvially deposited sand, silt, gravel, and occasional muck on terraces cut into glacial deposits. Hst Wetland deposits - Peat, muck, silt, and clay in poorly drained areas. Map unit may also include some alluvial sediments along stream valleys. Hw USES OF SURFICIAL GEOLOGY MAPS ___A surficial geology map shows all the loose materials such as till (commonly called hardpan), sand and gravel, or clay, which overlie solid ledge (bedrock). Bedrock outcrops and areas of abundant bedrock outcrops are shown on the map, but varieties of the bedrock are not distinguished (refer to bedrock geology map). Most of the surficial materials are deposits formed by glacial and deglacial processes during the last stage of continental glaciation, which began about 25,000 years ago. The remainder of the surficial deposits are the products of postglacial geologic processes, such as river floodplains, or are attributed to human activity, such as fill or other land-modifying features. ___The map shows the areal distribution of the different types of glacial features, deposits, and landforms as described in the map explanation. Features such as striations and moraines can be used to reconstruct the movement and position of the glacier and its margin, especially as the ice sheet melted. Other ancient features include shorelines and deposits of glacial lakes or the glacial sea, now long gone from the state. This glacial geologic history of the quadrangle is useful to the larger understanding of past earth climate, and how our region of the world underwent recent geologically significant climatic and environmental changes. We may then be able to use this knowledge in anticipation of future similar changes for long-term planning efforts, such as coastal development or waste disposal. ___Surficial geology maps are often best used in conjunction with related maps such as surficial materials maps or significant sand and gravel aquifer maps for anyone wanting to know what lies beneath the land surface. For example, these maps may aid in the search for water supplies, or economically important deposits such as sand and gravel for aggregate or clay for bricks or pottery. Environmental issues such as the location of a suitable landfill site or the possible spread of contaminants are directly related to surficial geology. Construction projects such as locating new roads, excavating foundations, or siting new homes may be better planned with a good knowledge of the surficial geology of the site. Andersen, B. G., 1973, Report on Quaternary field mapping in the Waldoboro area: unpublished reconnaissance field maps and handwritten report, archived at the Maine Geological Survey. Jong, R. S., 1980, Small push moraines in central coastal Maine: M. S. thesis, Ohio University, 75 p. REFERENCES Weddle, Thomas K., 2016, Surficial materials of the Waterville 7.5' quadrangle, Maine: Maine Geological Survey, Open-File Map 16-7, scale 1:24,000. Neil, Craig D. (compiler), Locke, Daniel B. (mapper), 2000, Significant sand and gravel aquifers in the Waterville quadrangle, Maine: Maine Geological Survey, Open-File Map 00-30, scale 1:24,000. Thompson, Woodrow B., 2015, Surficial geology handbook for southern Maine: Maine Geological Survey, Bulletin 44, 97 p. Thompson, W. B., and Borns, H. W., Jr., 1985, Surficial geologic map of Maine: Maine Geological Survey, scale 1:500,000. SOURCES OF RELATED INFORMATION Axis of esker - Alignment of symbols shows trend of esker. Chevrons point in direction of former glacial meltwater flow. >>>>> Contact - Boundary between map units. Most contacts are approximately located and therefore indicated by dashed lines. Former marine shoreline - Subtle erosional scarp parallel to contours below the marine limit, formed by shoreline erosion during falling sea level. Interpreted from lidar imagery. Marine limit - Approximate elevation of high stand of sea level at approximately 13,000 years before the present. Disturbed earth - Areas where original topography has been altered by excavation. Glacial striation - Arrow shows ice-flow direction(s) inferred from striations on bedrock. Dot marks point of observation. Number is azimuth (in degrees) of flow direction. At site where two sets of striations are present and relative ages could be determined, the flagged arrow indicates the older flow direction. 115 A C E 135 180 Esker deposits - Ridges of sand and gravel deposited by glacial meltwater streams in subglacial tunnels. Borrow pit symbols indicate depletion of the esker system deposit. Pge Till - Loose to very compact, poorly sorted, massive to weakly stratified mixture of sand, silt, and gravel-size rock debris deposited by glacial ice. Locally includes lenses of waterlaid sand and gravel. Pt Thin drift - Areas with ruled pattern indicate areas where outcrops are common and/or surficial sediments are generally less than 10 feet thick (mapped partly from aerial photos). Fluted landform - Narrow ridge shaped by flow of glacial ice. Symbol indicates length and direction of the ridge crest. È Borrow pit, active p Borrow pit, inactive q
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Surficial Geology
SURFICIAL GEOLOGY OF MAINE
S urficial geologic mapping of th e W aterville quadrangle w as conducted byTh omas K. W eddle and S ydney D. Eckert during th e 2015 field season. Fundingfor th is w ork w as provided by th e U. S. Geological S urvey STATEMAP programand th e Maine Geological S urvey, Department of Agriculture, Conservation andForestry.
SOURCES OF MAP INFORMATION
Waterville Quadrangle, Maine
Open-File No. 16-82016
Digital cartography byAmber T. H. Whittaker State Geologist
Robert G. Marvinney Cartographic design byChristian H. Halsted
Surficial geologic mapping byThomas K. Weddle and Sydney D. Eckert
Address: 93 State House Station, Augusta, Maine 04333Telephone: 207-287-2801 E-mail: [email protected] page: www.maine.gov/dacf/mgs/
Maine Geological Survey
1 0 10.5 Mile
1 0 10.5 Kilometer
1000 0 1000 2000 3000 4000 5000 6000 7000FeetMaine
Hinckley Clinton
W aterville Fairfield
Belgrade
Norridgew ock
R ome
V assalboro Ch inaL ake
CONTOUR INTER V AL 10 FEET
___Continental glaciers like th e ice sh eet now covering Antarcticaprobably extended across Maine several times during th e PleistoceneEpoch , betw een about 2.5 million and 11,700 years ago. Th e slow -moving ice superficially ch anged th e landscape as it scraped overmountains and valleys (Figure 1), eroding and transporting bouldersand oth er rock debris for miles (Figure 2). Th e sediments th at covermuch of Maine are largely th e product of glaciation. Glacial icedeposited some of th ese materials, w h ile oth ers w ash ed into th e sea oraccumulated in meltw ater streams and lakes as th e ice receded. Earlierstream patterns w ere disrupted, creating h undreds of ponds and lakesacross th e state. Th e map at left sh ow s th e pattern of glacial sedimentsin th is quadrangle.___Th e most recent "Ice Age" in Maine began about 30,000 years ago,w h en an ice sh eet spread south w ard over New England (S tone andBorns, 1986). During its peak, th e ice w as several th ousand feet th ickand covered th e h igh est mountains in th e state. Th e w eigh t of th is h ugeglacier actually caused th e land surface to sink h undreds of feet. R ockdebris frozen into th e base of th e glacier abraded th e bedrock surfaceover w h ich th e ice flow ed. Th e grooves and fine scratch es (striations)resulting from th is scraping process are often seen on fresh ly exposedbedrock, and th ey are important indicators of th e direction of icemovement (Figure 3). Erosion and sediment deposition by th e icesh eet combined to give a streamlined sh ape to many h ills, w ith th eirlong dimension parallel to th e direction of ice flow . S ome of th ese h ills(drumlins) are composed of dense glacial sediment (till) plasteredunder great pressure beneath th e ice.___A w arming climate forced th e ice sh eet to start receding as early as21,000 calendar years ago, soon after it reach ed its south ernmostposition on Long Island (R idge, 2004). Th e edge of th e glacierw ith drew from th e continental sh elf east of L ong Island and reach edth e present position of th e Maine coast by about 16,000 years ago(Borns and oth ers, 2004). Even th ough th e w eigh t of th e ice w asremoved from th e land surface, th e Earth 's crust did not immediatelyspring back to its normal level. As a result, th e sea flooded much ofsouth ern Maine as th e glacier retreated to th e north w est. Ocean w atersextended far up th e Kennebec and Penobscot valleys, reach ing presentelevations of up to 420 feet in th e central part of th e state.___Great quantities of sediment w ash ed out of th e melting ice and intoth e sea, w h ich w as in contact w ith th e receding glacier margin. S andand gravel accumulated as deltas (Figure 4) and submarine fans w h erestreams disch arged along th e ice front, w h ile th e finer silt and claydispersed across th e ocean floor. Th e sh ells of clams, mussels, andoth er invertebrates are found in th e glacial-marine clay th at blanketslow land areas of south ern Maine. Ages of th ese fossils tell us th atocean w aters covered parts of Maine until about 13,000 years ago. Th eland rebounded as th e w eigh t of th e ice sh eet w as removed, forcing th esea to retreat.
___Meltw ater streams deposited sand and gravel in tunnels w ith in th eice. Th ese deposits remained as ridges (eskers) w h en th e surroundingice disappeared (Figure 5). Maine's esker systems can be traced for upto 100 miles, and are among th e longest in th e country.___Oth er sand and gravel deposits formed as mounds (kames) andterraces adjacent to melting ice, or as outw ash in valleys in front of th eglacier. Many of th ese w ater-laid deposits are w ell layered, in contrastto th e ch aotic mixture of boulders and sediment of all sizes (till) th atw as released from dirty ice w ith out subsequent rew orking. R idgesconsisting of till or w ash ed sediments (moraines) w ere constructedalong th e ice margin in places w h ere th e glacier w as still activelyflow ing and conveying rock debris to its terminus. Moraine ridges areabundant in th e zone of former marine submergence, w h ere th ey areuseful indicators of th e pattern of ice retreat (Figure 6).___Th e last remnants of glacial ice probably w ere gone from Maine by12,000 years ago. L arge sand dunes accumulated in late-glacial time asw inds picked up outw ash sand and blew it onto th e east sides of rivervalleys, such as th e Androscoggin and S aco valleys (Figure 7). Th emodern stream netw ork became establish ed soon after deglaciation,and organic deposits began to form in peat bogs, marsh es, and sw amps.Tundra vegetation bordering th e ice sh eet w as replaced by ch angingforest communities as th e climate w armed (Davis and Jacobson, 1985).Geologic processes are by no means dormant today, h ow ever, sincerivers and w ave action modify th e land (Figure 8), and w orldw ide sealevel is gradually rising against Maine's coast.
References
Borns, H. W ., Jr., Doner, L. A., Dorion, C. C., Jacobson, G. L., Jr.,Kaplan, M. R ., Kreutz, K. J., L ow ell, T. V ., Th ompson, W . B., andW eddle, T. K., 2004, Th e deglaciation of Maine, U.S .A.,in Ehlers, J.,and Gibbard, P. L., eds., Q uaternary Glaciations – Extent andCh ronology, Part II: North America: Amsterdam, Elsevier, p. 89-109.Davis, R . B., and Jacobson, G. L., Jr., 1985, L ate-glacial and earlyHolocene landscapes in north ern New England and adjacent areas ofCanada: Q uaternary R esearch, v. 23, p. 341-368.
R idge, J. C., 2004, Th e Q uaternary glaciation of w estern New Englandw ith correlations to surrounding areas,in Ehlers, J., and Gibbard, P. L.,eds., Q uaternary Glaciations – Extent and Ch ronology, Part II: NorthAmerica: Amsterdam, Elsevier, p. 169-199.
S tone, B. D., and Borns, H. W ., Jr., 1986, Pleistocene glacial andinterglacial stratigraph y of New England, Long Island, and adjacentGeorges Bank and Gulf of Maine, in S ibrava, V ., Bow en, D. Q ., andR ich mond, G. M. (editors), Q uaternary glaciations in th e north ernh emisph ere: Q uaternary S cience R eview s, v. 5, p. 39-52.
1:24,000SCALE Base map features from Maine Office of GIS - 1:24,000 USGS contourlines, E911 roads, 1:24,000 National Hydrograph y Dataset, USGSGNIS placenames and 1:24,000 political boundaries. Map projectionUniversal Transverse Mercator, North American Datum, 1927.Th e use of industry, firm, or local government names on th is map is forlocation purposes only and does not impute responsibility for anypresent or potential effects on th e natural resources.
Approximate MeanDeclination, 201516.5o W (not to scale)
True North
Magnetic North
Funding for the preparation of this map was provided in part by the U.S. Geological SurveySTATEMAP Program, Cooperative Agreement No. G15AC00181.
Figure 7: S and dune in W ayne. Th is and oth er "deserts" in Maineformed as w indstorms in late-glacial time blew sand out of valleys,often depositing it as dune fields on h illsides dow nw ind. S ome dunesw ere reactivated in h istorical time w h en grazing animals stripped th evegetation cover.
Figure 8: S ongo R iver delta and S ongo Beach , S ebago L ake S tatePark, Naples. Th ese deposits are typical of geological features formedin Maine since th e Ice Age.
Figure 5: Esker cutting across Kezar Five Ponds, W aterford. Th eridge consists of sand and gravel deposited by meltw ater flow ing in atunnel beneath glacial ice.
Figure 6: Aerial view of moraine ridges in blueberry field, S edgw ick(note dirt road in upper righ t for scale). Each bouldery ridge marks aposition of th e retreating glacier margin. Th e ice receded from righ t toleft.
Figure 3: Granite ledge in W estbrook, sh ow ing polish ed and groovedsurface resulting from glacial abrasion. Th e grooves and sh ape of th eledge indicate ice flow tow ard th e south east.
Figure 4: Glaciomarine delta in Franklin, formed by sand and gravelw ash ing into th e ocean from th e glacier margin. Th e flat delta topmarks approximate former sea level. Kettle h ole in foreground w as leftby melting of ice.
Figure 1: "Th e Bubbles" and Jordan Pond in Acadia National Park.Th ese h ills and valleys w ere sculpted by glacial erosion. Th e pond w asdammed beh ind a moraine ridge during retreat of th e ice sh eet.
Figure 2: Daggett's R ock in Ph illips. Th is is th e largest know nglacially transported boulder in Maine. It is about 100 feet long andestimated to w eigh 8,000 tons.
Note: Th e first letter of each map unit indicates th e general age of th e unit:H= Holocene (postglacial deposit; formed during th e last 11,700 years).Q= Q uaternary (deposit of uncertain age; usually late-glacial and/or postglacial).P = Pleistocene (deposit formed during glacial to late-glacial time, prior to 11,700 yr B.P. [years beforepresent]).
Artificial fill - V ariable mixtures of earth , rock, and/or man-made materials used as fill forroads. Usually sh ow n only w h ere large enough to affect th e contour pattern on th e topograph icmap.
af
Presumpscot Formation - Glaciomarine silt, clay, and sand deposited on th e late-glacial seafloor. Th is map unit commonly overlies th e irregular surface of glacial till in a complexmanner, so it is likely to include areas of till exposed at th e ground surface.
Pp
Stream alluvium - S and, gravel, and silt deposited on flood plains. May include organicw etland deposits or underlie some of th e mapped w etland areas along streams.Ha
Stream terrace - Fluvially deposited sand, silt, gravel, and occasional muck on terraces cutinto glacial deposits.Hst
Wetland deposits - Peat, muck, silt, and clay in poorly drained areas. Map unit may alsoinclude some alluvial sediments along stream valleys.Hw
USES OF SURFICIAL GEOLOGY MAPS___A surficial geology map sh ow s all th e loose materials such as till (commonly called h ardpan), sandand gravel, or clay, w h ich overlie solid ledge (bedrock). Bedrock outcrops and areas of abundantbedrock outcrops are sh ow n on th e map, but varieties of th e bedrock are not distinguish ed (refer tobedrock geology map). Most of th e surficial materials are deposits formed by glacial and deglacialprocesses during th e last stage of continental glaciation, w h ich began about 25,000 years ago. Th eremainder of th e surficial deposits are th e products of postglacial geologic processes, such as riverfloodplains, or are attributed to h uman activity, such as fill or oth er land-modifying features.___Th e map sh ow s th e areal distribution of th e different types of glacial features, deposits, andlandforms as described in th e map explanation. Features such as striations and moraines can be used toreconstruct th e movement and position of th e glacier and its margin, especially as th e ice sh eet melted.Oth er ancient features include sh orelines and deposits of glacial lakes or th e glacial sea, now long gonefrom th e state. Th is glacial geologic h istory of th e quadrangle is useful to th e larger understanding ofpast earth climate, and h ow our region of th e w orld underw ent recent geologically significant climaticand environmental ch anges. W e may th en be able to use th is know ledge in anticipation of future similarch anges for long-term planning efforts, such as coastal development or w aste disposal.___S urficial geology maps are often best used in conjunction w ith related maps such as surficialmaterials maps or significant sand and gravel aquifer maps for anyone w anting to know w h at liesbeneath th e land surface. For example, th ese maps may aid in th e search for w ater supplies, oreconomically important deposits such as sand and gravel for aggregate or clay for bricks or pottery.Environmental issues such as th e location of a suitable landfill site or th e possible spread ofcontaminants are directly related to surficial geology. Construction projects such as locating new roads,excavating foundations, or siting new h omes may be better planned w ith a good know ledge of th esurficial geology of th e site.
Andersen, B. G., 1973, R eport on Q uaternary field mapping in th e W aldoboro area: unpublish edreconnaissance field maps and h andw ritten report, arch ived at th e Maine Geological S urvey.Jong, R . S., 1980, Small push moraines in central coastal Maine: M. S. th esis, Oh io University, 75 p.
REFERENCES
W eddle, Th omas K., 2016, S urficial materials of th e W aterville 7.5' quadrangle, Maine: MaineGeological S urvey, Open-File Map 16-7, scale 1:24,000.
Neil, Craig D. (compiler), Locke, Daniel B. (mapper), 2000, S ignificant sand and gravel aquifers in th eW aterville quadrangle, Maine: Maine Geological S urvey, Open-File Map 00-30, scale 1:24,000.
Th ompson, W oodrow B., 2015, S urficial geology h andbook for south ern Maine: Maine GeologicalS urvey, Bulletin 44, 97 p.
Th ompson, W . B., and Borns, H. W ., Jr., 1985, S urficial geologic map of Maine: Maine GeologicalS urvey, scale 1:500,000.
SOURCES OF RELATED INFORMATION
Axis of esker - Alignment of symbols sh ow s trend of esker. Ch evrons point in direction offormer glacial meltw ater flow .
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Contact - Boundary betw een map units. Most contacts are approximately located andth erefore indicated by dash ed lines.
Former marine shoreline - S ubtle erosional scarp parallel to contours below th e marine limit,formed by sh oreline erosion during falling sea level. Interpreted from lidar imagery.
Marine limit - Approximate elevation of h igh stand of sea level at approximately 13,000 yearsbefore th e present.
Disturbed earth- Areas w h ere original topograph y h as been altered by excavation.
Glacial striation- Arrow sh ow s ice-flow direction(s) inferred from striations on bedrock. Dotmarks point of observation. Number is azimuth (in degrees) of flow direction. At site w h eretw o sets of striations are present and relative ages could be determined, th e flagged arrowindicates th e older flow direction.
115
135180
Esker deposits - R idges of sand and gravel deposited by glacial meltw ater streams insubglacial tunnels. Borrow pit symbols indicate depletion of th e esker system deposit.Pge
Till - Loose to very compact, poorly sorted, massive to w eakly stratified mixture of sand, silt,and gravel-size rock debris deposited by glacial ice. Locally includes lenses of w aterlaid sandand gravel.
Pt
Thin drift - Areas w ith ruled pattern indicate areas w h ere outcrops are common and/orsurficial sediments are generally less th an 10 feet th ick (mapped partly from aerial ph otos).
Fluted landform - Narrow ridge sh aped by flow of glacial ice. S ymbol indicates length anddirection of th e ridge crest.
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Borrow pit, active
Borrow pit, inactive
