Surficial Geology of the Biddeford Pool 7.5' Quadrangle, Maine

DEPART MENT OF CONSER VA TION Maine Geo logi cal Sur vey Rob ert G. Marv in ney, State Ge olo gist

OPEN- FILE NO. 99-110

Ti tle: Sur fic ial Ge ol ogy of the Bid de ford Pool 7.5- minute Quad ran gle, York County, Maine

Author: Carol T. Hildreth

Date: 1999

Fi nan cial Sup port: Funding for the prepara tion of this report was provided in part by the U.S. Geo logi cal Sur vey Co op era tive Geo logi cal Map ping (CO GEO- MAP) Pro gram, Co op era tive Agree ment No. 14-08-0001-A0432.

As so ci ated Maps: Surfic ial geol ogy of the Biddeford Pool quad rangle, Open- File 99-79 Sur fic ial ma te ri als of the Biddeford Pool quad ran gle, Open- File 99-43

Con tents: 10 p. report Maine Geo logi cal Sur vey Open- File 99-110

Surficial Geology of the Biddeford Pool 7.5-minute Quadrangle, York County, Maine

Carol T. Hil dreth 135 Wash ing ton Street Hol lis ton, Mas sa chu setts 01746

IN TRO DUC TION

The Bidde ford and Bidde ford Pool 7.5-minute quadran - gles com prise an area of about 55 square miles (142 km2) along the coast of southwest ern Maine, within the Seaboard Lowland physio graphic province , about 15 miles south of Portland. Alti - tudes range from sea level to about 200 feet (61 m) above sea level. The drain age patter n is dominate d by the Bid deford pluton (Fig ure 1), a large oval-shape d bioti te granit e mass that in - truded the surround ing Precambrian-Sil urian meta sedim enta ry rocks of the Kitter y and Berwick Form ati ons about 354 mil lion years ago during the Missis sipian Peri od (Hussey, 1985). The Saco River skirts the north east edge of the pluton, and some of its minor tribu tar ies drain the northwest edge and northern part. The Ken nebunk River flanks the south ern edge, and some of its tribu tar ies, includ ing Goff Mill Brook, drain the south ern part. (NOTE: No major stream lies along the plutoni c contac t; per- haps there is a contact-m etamorphic horn fels border zone in the metasedi men tary rocks that is equally re sis tant to weath er ing and erosion as the mar ginal phase of the pluton itsel f.) The cen- tral and east ern part of the pluton is drained by several small rivers and brooks, all of which enter the Atlan ti c Ocean via Goose fare Bay (Fig ure 1), where a bar rier is land of sandy beach and dune de posit s has formed across the mouths of their estu ar - ies. The stream pat tern over the plu ton it self is re marka bly rec ti- Fig ure 1. Bid de ford quad ran gle (out lined), show ing re la tion ship of linear , refle cting two major roughly right-angle joint drain age pat tern to bed rock struc ture (from Hussey, 1985). sets—northeas t and northwest trending. The joint patter n is very obvi ous on air photos, espe cia lly in areas of abundant out crop, but the pat tern is not obvi ous on the topographi c map becaus e the 20-foot contour inter val is too large to show the many disti nct, the northwest block and appar ent horizon tal southwest displac e- closely spaced, par allel bedrock ridges and poorly drained val - ment of the southeas t block, though the actual movem ent is un- leys throughout the areas of abundant out crop (by far the major known. Note also in Figure 1 that the fault trace is uncer tai n and char acter istic of the land sur face in this area). shown as a dashed line near the southern end of the pluton. Paral lel to the northeast-tre nding joint set, a 60-foot es- Drain age off this es carp ment fol lows the gen eral rec ti lin ear pat - carpm ent that roughly bisec ts the pluton re flects a mapped fault tern, ex cept near its south ern end where sev eral tribu tary streams (Hussey, l985) that has appar ent rela tive upward displac em ent of have a pronounced change in course to south-southwe st just be-

1 C. T. Hildreth low the scarp (inste ad of a right-angle bend to a southwest direc - GLACIATION tion, which is what would be expect ed); this course change may re flect a change in the over all joint pat tern near the fault, or a South west ern Maine proba bly ex pe ri enced sev eral ad- change in the fault di recti on, or movem ent along the fault, or any vances of the Lauren ti de conti nental ice sheet during the Pleis to- com bi na tion thereof. cene Ice Age, but vir tu ally all evidence in this area for pre vious The landsca pe north of the Saco River in the Bidde ford gla cia tions was obliter ated dur ing the last gla cia tion (late Wis - quadran gle is prim aril y a broad, sandy plain drained eastward to consi nan) when the conti nental glacie r advance d from the north- the At lan tic by Goosefare Brook; the shore there is char acter ized west across the area to a term inal posi ti on on the conti nental by a clas sic Holo cene sandy beach complex that stretches for shelf. Gla cial ero sion within this area is mainly no tice able as miles north ward as “Old Or chard Beach.” glacia l stria tions on freshly exposed bedrock surface s; some The Bidde ford Pool quadran gle contai ns many rock is - ramp and pluck topog ra phy on bedrock knobs, includ ing a few lands, the largest two of which are connect ed to the mainland by roche mou ton née and small- scale crag- and- tail features in con - two sandy tom bolos—Fletcher Neck and Hills Beach—which juncti on with the striati ons, defi nitely record southeas t move- enclos e a shallow tidal pool that is pres ently open to the sea only ment of the ice. It should be noted that gla cial stria tions weather through a deep narrow channel be tween the two rock islands rapidl y and survive for a very short time (gener all y only a few (Hul mes, 1981). years) af ter ex po sure to sur face ele ments in this cli mate; those There is some indi ca ti on that part of the glacia l and pregla - along the shore of the Saco River and At lanti c Ocean are on bed- cial Saco River may have fol lowed a more south erly course bef - rock expo sures recent ly stripped of overly ing surface sedi ments ore enter ing the sea, as inferred from the distri buti on of by storm wave acti on. Most others were found on re cently exca - melt water depos it s (Caldwell and others, 1985). One such vated bedrock surface s in borrow pits. Gener all y, the striati ons course could have been into the lower Kennebunk River, around indi cat e a south to southeas t di recti on of ice flow; some varia- the northwest nose of the Bidde ford pluton (see Figure 1). This tions can be at tributed to local defle cti on of the ice flow around thought invit es further inves ti gati on beyond the scope of this re - irregu lar iti es of the bedrock topog ra phy . At least four local iti es port. Also, during re-em ergence of the coastli ne in postgla cia l had two sets of in ter sect ing stria tions—(1) in the West Brook time, part of the Saco may have flowed briefly along an aban - valley , east of downtown Bidde ford (135° stria tions are older doned channel( ?) that begins at its upstre am end along the cur- than 169- 183°); (2) in a borrow pit betwee n the Bidde ford City rent shore of the Saco betwee n Jordan Point and St. Francis Line and Beaver Pond (153-158° stria tions are older than 165- Col lege, thence southeas t landward of Hills Beach into Back 175°); (3) along the shore south of East Point in the Bidde ford Bay and The Pool. The sur face of the Pre sumpscot marine clay Pool quadran gle (133-137° stria tions are older than 158- 152°); in The Pool is 15 to 20 feet be low sea level and deepens to the and (4) in a house founda ti on exca va ti on on South Road next to south of Fletcher Neck (Hul mes, 1979, 1981), where there ap- the Maine Turnpike where age rela ti ons of the striati ons were not pears to be an offshore subm arine channel. The present author clear. Where age re lations be tween two sets on the same outcrop proposes that, in downcut ti ng its channel through gla ciomarine are clear, the younger stria tions rep re sent a more south erly (in sedi ments, the an ces tral Saco en coun tered the bed rock at the places, even south west erly) ice flow direc tion. How ever, this northern end of this abandoned channel and was thereby di- does not mean that all southerl y or southwest erly stria tions are of verted easterly into its cur rent course. the same age, nor does this meager set of measure ments con sti- tute suf ficie nt data to pos tulat e any thing greater than a minor sec ondary pulse of ice flow in a slightly dif ferent di recti on from the earli er flow at the same site. Even though some previous PREVIOUS WORK work ers in ter preted some features in the Ken nebunk area as evi - dence of a glacia l readvance , the contro versy is ongo ing (Smith, Early work on the surfic ial geol ogy in southwest ern Maine, 1981). includ ing the Bid deford and Bidde ford Pool area, was done gen- Af ter reach ing its ter mi nal po si tion on the con ti nen tal er ally at a recon nais sance level and at a smaller scale (Bloom, shelf, the late Wisconsi nan ice sheet be gan to recede be tween 1960, 1963; Smith, 1977a-c). Subsur face data was collec ted as 17,000 and 15,000 years ago, re treating across the Gulf of Maine part of a basic data set (Pres cott and Drake, 1962) and signifi cant to an offshore posi ti on roughly paral lel to the pres ent coast line sand and gravel aqui fers were mapped (Tolm an and Lanctot , about 14,000 years ago (Smith, 1985). Shells col lected from gla- 1985). Publi cati ons on the glacia l geol ogy of the southwest ern ciomarine sedi ments appar entl y deform ed by ice shove in Ken- Maine coastal zone include Smith (1984, 1985), Stuiver and nebunk, just to the southwest , were radio car bon dated at 13,200 Borns (1975), Thompson (1979, 1982), and Thompson and yr B.P. (Smith, 1985). Thus, the ice sheet term inus must have Borns (1985). The Holocene stra tigraphy of the Bidde ford Pool been in the Bidde ford area about that time, al though some work- area was studied in detai l by Hulm es (1979, 1980, 1981). The ers feel that ice had re treated far in land from the coast by 13,000 Soil Survey of York County (Na tional Coop era ti ve Soil Survey , yr B.P. based on other evidence (Thompson and Borns, 1985). 1982) greatly fa cili tated field work. Ad di tional data may clar ify the pic ture, even tu ally. (NOTE:

2 Surficial Geology of the Biddeford Pool Quadrangle, Maine

Figure 2. Gen er al ized gla cial stra tigra phy for the south ern Maine coastal zone (from Thomp son and Smith, 1988).

Some fos sil shells were collected in a pit near Beacon Cor ner in Maine is depict ed in Figure 2 (Smith, 1985). In the Bidde ford the Bidde ford quadran gle dur ing fieldwork for the present re- and Bidde ford Pool quadran gles , only distal glacial-m arine sedi- port, but have not yet been identi fied or dated.) ments (Pre sump scot For ma tion), proximal- distal glacial- marine “Two indi rect ef fects of gla cia tion had a very strong bear- sedi ments, and till are rec ognize d, but most of these sedi ments ing on the charac ter of ice retre at and the deposi ti on of the glacia l have been modifie d and some have been com pletely transform ed sedi ments in this porti on of the coastal zone. First, the great by wave and current acti on during marine offlap. Thus, areas weight of the Lauren ti de conti nental ice sheet depress ed the that are pre dominantl y sand and gravel which may have been crust be neath the gla cier sig nificantly be low its pres ent level origi nally de pos ited di rectly from gla cial melt wa ter have been throughout the region. Secondly , as glacie rs expanded world - re worked and ex hibit many char ac ter is tics of ma rine shore line wide, water was trapped on land as ice, caus ing sea level to be or nearshore de posit s and are therefore mapped as such (Pms and low ered by sev eral hun dred feet. Later, as the ice be gan to melt Pmn). The succes sion of surfic ial depos it s (Holocene and Pleis - and retreat, wa ter was re turned to the ocean and sea level rose tocene ) in the Bidde ford area is given on the corre la ti on chart imme di ate ly. At the same time, the crust be gan slowly to re - showing the relati ve ages of the map units (Figure 3). bound to its original level. The inter acti on of these ef fects re- Till (map unit Pt) oc curs throughout the Bidde ford area; its sulted in sub mer gence of the en tire Maine coastal zone for a thickness is vari able, as is its com posi ti on. Although various ge- peri od of several hundred years follow ing the retre at of the ice” netic types have been found throughout Maine, only the general (Smith, l999). Within the Bidde ford area, marine subm er gence lodgem ent till was observe d here. Lodgem ent till was depos it ed reached an es tim ated 190 feet (58 m) above pres ent sea level beneat h the ice sheet and forms a blanket de posit over the under - (Clinch and O'Toole, 1999a,b). Boulder ac cum ula ti ons around ly ing bedrock; it is inferred to under li e younger depos it s the sides of the 200+ foot a.s.l. standpipe hill south of Five Points throughout the area (Figure 2). In most expo sures this till is typi - in downtown Bidde ford suggest the presence of a shore line at cally a com pact boulder- pebble silt-clay . about that level here. Only a few scat tered spots in the quadran - Dis tal glacial-m arine sedim ents of the Pre sumpscot For - gle reach barely above the 200-foot contour , so nearly the enti re mati on (Pp) and sandy marine sedi ments depos it ed during the re- area was subm erged during the maxim um marine transgres sion. gression of the sea (Pmrs) “oc cur as a dis conti nuous cover up to 50 m thick throughout the area of late-glac ial marine subm er - GLACIAL AND POSTGLACIAL DEPOSITS gence. The general distri buti on of the marine sedi ments was origi nally mapped by Goldthwait (1949), and the sedim ents The gen er ally accepted con cept of the suc ces sion of Pleis - were de scribed in de tail and given form ati onal status by Bloom to cene (Late Wis consi nan) gla cial de pos its in south west ern (1960). The marine clay and silt (Pp) is the type Pre sumpscot

3 C. T. Hildreth

Form ati on descri bed by Bloom. It has a gra dati onal contac t with 140+ feet, based on terrace s and de posi ti onal feature s within the overly ing sandy fa cies of the marine sedi ments (unit Pmrs), these depos it s -- es pecia lly those observe d in borrow pits west of which is a regres sive deposit” (Smith, 1999). The sand-sil t sur- Blue Star Mem oria l Highway in Bidde ford. A cobble-pebble - face mate rial that char acter izes the Pmrs unit is gen er ally only boulder gravel ridge at 160+ feet along Proctor Road is also in- 1-3 feet thick, but may be as much as 10 feet thick in places (Na- ter preted as a beach ridge of this stand. Pms2 rep re sents de pos its tional Coop era ti ve Soil Survey , 1982). Where present, the Pmrs as so ciated with a sea- level stand of 120- feet a.s.l., based on lag unit is found overly ing the clay- silt Pp unit, but the former is not boulder depos it s along West St., and depo si ti onal and erosiona l every where present and may be older at one site than some of the ter races at that level around West and Dungeon Brooks and clay- silt de pos ited at an other site; thus, these are time- tribu tar ies of the Lit tle and Bat son Riv ers. Pms3 rep re sents de - transgressive units. The clay- silt facies of the Pre sumpscot For - posit s asso ci ate d with sea-leve l stands of 60+ and 80+ feet, mati on gener all y overli es till and can be found overly ing, under - based on well-sorte d sand and gravel depos it s and re lated scarps ly ing, and in ter tongu ing with proximal- distal gla cial ma rine at these ele vati ons. Fossil marine shells were dredged up from de pos its, in clud ing the Pleis to cene ma rine shore line de pos its marine clays be low sand and gravel of Pms2 at Beacon Cor ner, a (Pms), as seen in borrow pits at Bea con Cor ner and Oak Ridge. lag boul der hori zon was found in pits northeas t of Adam s Cor- “Strati fied depos it s of sand and gravel that both under li e ner, a cobble-boulder beach ridge dominate s the unit along New- and in ter tongue with the Pre sump scot For ma tion are con sid ered town Road, and a pocket of marine clay was found within the to be subaqueous outwash sedim ents (Smith, 1982, 1985; Oak Ridge pits. (As noted previ ously , the cores of some of these Thompson, 1982). These mate ri als are not exposed at the depos it s may be proxim al glacia l depos it s, but I saw no une - ground surface in the study area, and thus are not shown on the quivocal evidence of that). Pms4 (mapped only in the Bidde ford geologi c map, but they form an exten sive blanket of depos it s be- Pool quad ran gle) rep re sents de pos its as so ci ated with a sea- level neath the younger marine sedi ments. Many ex posures of these stand of 40- feet a.s.l., based on an upli fted beach ridge in the mate ri als in nearby ar eas of south west ern Maine display a va ri - golf course at Bidde ford Pool village . Some depos it s mapped as ety of dis tinctly flu vial pri mary struc tures” (Smith, 1999). Pmrs in the Bidde ford quadran gle may be long in the Pms4 unit, The surface s of both the till and subaqueous outwash sedi- but I did not noti ce any shore line fea tures near this eleva ti on ments have been substa nti ally re worked by waves and current s there. in ar eas below the marine limit to form nearshore marine depos - De pos its of Holo cene age are gen er ally as so ci ated with its (Pmn). Nearshore marine depos it s include a wide vari ety of modern streams, wet lands, and marine shoreli nes. Along the mate ri als , from reworked till and clay to sand and gravel, that coast line they in clude salt marsh (Hwsm), marine shore line form a gener all y thin blanket over bedrock. Such depos it s above (beach) (Hms), and dune (Hd) depos it s. A few small thin dune the 120- foot contour are include d in Pmn1, whereas those below depos it s cover saltwa ter marsh de posit s along the Saco and Bat - this eleva tion are mapped as Pmn2; this boundary corre sponds son Rivers. One elongate sand ridge whose crest eleva ti on is roughly with the edge of the fault scarp and a mapped 120-foot about 180 feet a.s.l. is inter preted to be a dune de posit; it is marine shoreli ne, based on beach depos it s and de posi ti onal and lumped with the Holocene dunes on the modern coastli ne, but ero sional ter races of Pms2. This was a sim ple Pmn subdi vi sion may have formed when sea level stood near it while Pms1 depos - to make because of the co in cidence of the shore line fea tures with its were accu m ulat ing. Freshwa ter marsh (Hwfm) and swamp the scarp, but the contour inter val of the base map is too great for (Hws) depos it s are found scatter ed throughout the area. These further “meaning ful” subdi vi sion of this type of deposit in the and the salt marshes are char acter ized by ac cu mu lations of de - map area. cayed organic matter . Some are un der lain by peat, in which case The units mapped as Pms1-4 may have originall y been de- the de posit is further classi fie d as to thickness and ash content of posit ed as proxim al glacia l depos it s; for exam ple, the fan-shape d the peat (see map expla na ti on). Allu vial depos it s (Ha) of vari- sand and gravel depos it s that spread southeas tward down West able thickness and com posi ti on under li e the floodplai ns of most Street and Proctor Road may have been marine outwash fans modern streams; it should be noted that swamp depos it s and allu - (proxim al glacial- marine sedim ents of Figure 2), but these de- vial depos it s are coin ci dent along many stretches of the stream posit s have been so well re worked by wave and current acti on floodplai ns in this area. that ex po sures in them con sis tently re veal sedi men tary fea tures Moors Brook has cut a channel as much as 20 feet deep charac ter isti c of marine shoreli nes, such as openwork gravel in through clay-sil t depos it s of the Presum pscot Form ati on; the re- appar ent beach ridges, lag boulder terrace s and hori zons, and de- sult ing banks are nearly ver ti cal in places and landsli des (Hlsd) po si tional di rec tions more com pati ble with ma rine shore line have devel oped in a few places where the steep banks have been pro cesses than with gla cial meltwa ter flow di rec tions in this recent ly under cut by the brook. area. Pms depos it s are predom inantl y sand and gravel repre sent - Fi nally, where the sur face con sists of sub stan tial ar ti fi cial ing shal low ma rine and/or ma rine shore line de pos its as so ci ated mate ri als used by man to fill depres sions , both man-m ade and with parti cular sea-leve l stands mapped on the basis of erosiona l natu ral, or where the sur face has been so al tered by con struc tion and/or de po sitional fea tures at scat tered sites in the area. Pms1 so as to obliter ate the natu ral land scape, that area has been rep re sents de pos its as so ci ated with sea- level stands of 160+ and mapped as “af”.

4 Surficial Geology of the Biddeford Pool Quadrangle, Maine

have de veloped beaches of vari ous types, includ ing “clean” gravel to classi cal sandy beaches backed by dunes, which shel ter the stream estu ar ies where saltm arsh depos its (some of which are greater that 5 feet thick) form within the zone of tidal fluc tua - tion. The present shoreli ne configu ra ti on was proba bly estab - lished by about 1,000 yr B.P., based on a radio car bon date for rel ict salt marsh recently ex posed in the beach face at Fletcher's Neck (Vibra core 3, Secti on A-A', Bidde ford Pool quadran gle) , indi cat ing a rela tively slow (18 cm/yr) landward migra ti on of that beach spit (Hulm es, 1981). Evidence in the study area for a postgla cia l lower sea level include s the appar ent erosion channel in the Pre sumpscot Form ati on below Holocene tidal delta depos - its in The Pool (See discus sion on same in Intro duc ti on and Hul - Figure 3. Pro vi sional rela tive ages of map units for Bidde ford and Bid - mes, 1980, 1981). de ford Pool quad ran gles. Modern streams have built floodplai ns that are graded to the pres ent po sition of sea level, and fresh wa ter wet land ar eas con tinue to ac cu mu late de pos its of or ganic mat ter (in clud ing peat) and fine-grai ned sedim ents. Evi dence of modern erosion DEGLACIAL AND HOLOCENE HISTORY was pre sented in the dis cussion on expo sures of gla cial stria tions in the in tro duc tion. The Pre sump scot For ma tion, which con sists pre domi- nantly of rock flour, was car ried by glacial meltwa ters and de - pos ited in a ma rine es tu ar ine en vi ron ment (Bloom, 1960) that REFERENCES CITED in cluded prac tically the en tire study area, as the maxim um sub - mer gence in the Bidde ford area was around 190+ feet eleva ti on. Bloom, A. L., 1960, Late Pleisto cene changes of sea level in southwest ern Maine: Maine Geologi cal Survey, 140 p. As the con tinen tal ice sheet re treated north west ward, the land Bloom, A. L., 1963, Late Pleisto cene fluctua tions of sea level and post glacial began to rebound isosta ti cally and relati ve sea level be gan to fall. crustal rebound in coastal Maine: American Jour nal of Science, v. 261, p. Meltwa ter streams con tin ued to carry sedi ment to the sea as sea 862- 879. level fell. “With pro gres sive low er ing of sea level, mate ri als de - Caldwell , D. W., Han son, L. S., and Thomp son,W. B., 1985, Styles of degla cia - tion in cen tral Maine, in Borns, H. W., Jr., La Salle, P., and Thompson , W. pos ited dur ing ear lier stages of gla cia tion and de gla cia tion B. (eds.), Late Pleisto cene history of northeast ern New England and ad - passed through the wave zone, were eroded, and shed sandy ja cent Que bec: Geo logi cal So ci ety of Amer ica, Special Pa per 197, p. sedi ment (Pmrs) over the silt and clay (Pp) depos it ed when sea 45- 58. level was higher. Sandy to silty sedim ents eroded from till de- Clinch, J. M., and O'Toole, P. B., 1999a, Surfic ial ge ology of the York Harbor quadran gle, Maine: Maine Geologi cal Survey, Open- File Map 99-107. posit s (Pmn) form a veneer over till and bedrock in some parts of Clinch, J. M., and O'Toole, P. B., 1999b, Surfic ial ge ology of the York Harbor the study area. Short-ter m pauses in the low ering of relati ve sea 7.5-minute quadran gle, Maine: Maine Geologi cal Survey, Open- File level al lowed for greater erosion at certai n ele vati ons, produc ing Report 99- 138, 6 p. wave- cut scarps and ac cu mu lations of beach sedim ents (Pms). Goldthwait , L., 1949, Clay Survey - 1948: Maine Development Commission, Report of the State Geolo gist, 1947-1948, p. 63- 69. Sev eral of these pauses oc curred be tween the time of maxi mum Hulm es, L. J., 1979, Origin of the Hills Beach/Fletcher Neck tom bolo system , subm er gence and offlap to the posi ti on of present sea level. Par- Bidde ford, Maine: Am. Assoc. Petrol. Geol., Bull., v. 63, p. 571. ticu larly prominent stands of sea level are re corded at ele va tions Hulm es, L. J., 1980, Holocene stra tigraphy and geom orphol ogy of the Hills of 220-, 200+, 190+, 140+, 100+, 80+, 60+, 40-, and 20+ ft” Beach/Fletcher Neck tombolo sys tem, Bid de ford, Maine: M. S. the sis, Uni ver sity of Dela ware, 92 p. (Smith, 1999) in nearby coastal areas . Some of these still stands Hulm es, L.J., 1981, Holocene stra tigraphy and geo morphol ogy of the Hills were identi fied in the Bidde ford area and Pms depos it s were sub- Beach/Fletcher Neck tombolo sys tem, Bid de ford, Maine, in Leonard, di vided ac cord ingly. Some stream ter races are graded to these J. E., and Maur neyer, E. (eds.), Coastal and near shore pro cesses of the same levels and so are include d in the corre spond ing depos it s. west ern Atlan tic: North east ern Geol ogy, v. 3, p. 197-201. Hussey, A. M., II, 1985, Bedrock ge ology of the Bath and Port land 2° map There is some evi dence that the land emerged iso statically sheets, Maine: Maine Geologi cal Survey, Open- File Report 85- 87, 82 p., “un til areas sea ward of the pres ent coast line were a minim um of 2 plates, scale 1:250,000. 11 m (35 ft) above pres ent sea level at that time. Weath ered sur - National Coop era tive Soil Sur vey, 1982, Soil survey of York County, Maine: faces and tree stumps (now sub merged) date this emer gence to U.S. De part ment of Agri cul ture , 143 p., 66 sheets, scale 1:20,000. Pres cott, G. C., and Drake, J. A., 1962, Re cords of se lected wells, test holes, and be at least 4,000 years B.P.” (Hulm es, 1981). “Relative sea level springs in southwest ern Maine: U. S. Geologi cal Survey, Maine Basic on the coast of Maine has been rising since 4,200 years ago as re- Data Re port No. 1, Ground wa ter Series—South west ern area, 35 p. corded by radiocarbon-date d stumps. Tide gauge rec ords indi - Smith, G. W., 1977a, Recon nais sance surfic ial ge ology of the Bidde ford quad- cate this subm er gence is conti nuing” (Hulm es, 1981, p.198), due ran gle, Maine: Maine Geo logi cal Sur vey, Open- File Map 77- 10, scale 1:62,500. pri mar ily to eustatic sea level rise. Coastal marine pro cesses

5 C. T. Hildreth

Smith, G. W., 1977b, Recon nais sance surfic ial ge ology of the Kennebunk quad- Smith, G. W., 1999, Surfic ial ge ology of the Portsm outh 7.5- minute quad rangle, ran gle, Maine: Maine Geo logi cal Sur vey, Open- File Map 77- 13, scale York County, Maine: Maine Geologi cal Survey, Open- File Report 99- 1:62,500. 127, 5 p. Smith, G. W., 1977c, Recon nais sance surfic ial ge ology of the Port land quadran - Stuiver, M., and Borns, H. W., Jr., 1975, Late Qua ter nary marine in va sion in gle, Maine: Maine Geo logi cal Sur vey, Open- File Map 77- 16, scale Maine—its chro nol ogy and as so ci ated crus tal move ment: Geo logi cal 1:62,500. Soci ety of America, Bulletin, v. 86, p. 99-104. Smith, G. W., 1981, The Kennebunk glacial advance -- A reap prai sal: Geol ogy, Thomp son, W. B., 1979, Surfic ial ge ology handbook for coastal Maine: Maine v. 9, p. 250-253. Geo logi cal Sur vey, 68 p. Smith, G. W., 1982, End mo raines and the patter n of last ice retre at from centra l Thomp son, W. B., 1982, Reces sion of the late Wisconsi nan ice sheet in coastal and south coastal Maine, in Lar son, G. J., and Stone, B. D. (eds.), Late Maine, in Lar son, G. J. and Stone, B. D. (eds.), Late Wis consi nan gla cia - Wis consinan glacia tion of New England: Kendall/ Hunt Pub. Co., Du- tion of New England: Kendall/ Hunt Pub. Co., Dubuque, p. 211-228. buque, p. 195-209. Thomp son, W. B., and Borns, H. W., Jr., 1985, Till stratigr aphy and Late Wis- Smith, G. W., 1984, Glaciom arine sedim ents and facies asso cia tions, southern consinan degla cia tion of southern Maine -- A review: Geogra phie Phy - York County, Maine, in Hanson, L. S. (ed.), Geol ogy of the coastal low - sique et Quater naire, v. 39, no. 2, p.199-214. lands, Boston MA to Kennebunk, ME: New England In ter colle giate Thomp son, W. B., and Smith, G. W., 1988, Pleisto cene stra tigraphy of the Geo logi cal Con fer ence , p. 352- 369. Augusta and Waldo boro ar eas, Maine: Maine Geologi cal Survey, Smith, G. W., 1985, Chronol ogy of Late Wisconsi nan degla cia tion of coastal Bulletin 27, 36 p. Maine, in Borns, H. W., Jr., La Salle, P., and Thompson , W. B. (eds.), Late Tolm an, A. L., and Lanctot, E. M., 1985, Hydrogeo logic data for signifi cant sand Pleis to cene his tory of north east ern New Eng land and ad ja cent Que bec: and gravel aqui fers in parts of York and Cum berland Counties , Maine: Geo logi cal So ci ety of Amer ica, Special Pa per 197, p. 29- 44. Maine Geologi cal Survey, Open- File Map 85- 93, scale 1:50,000.

AP PEN DIX A. ED ITED CORE LOG DE SCRIP TIONS AND IN TER PRE TA TIONS. (from Hulme 1980, Ap pendix A)

VI BRA CORE 1. Flood- tidal delta - 510 cm VI BRA CORE 2. Flood- tidal delta - 498 cm Depth (cm) De scrip tion In ter pre ta tion Depth (cm) De scrip tion In ter pre ta tion

0 - 40 Slip pery mud, Spar tina Marsh 0 - 40 Sandy mud with Spar tina al ter ni flora Marsh al ter ni flora rhizom es Sharp contact Sharp contact 40 - 65 Sand (2.0f); de crease in Chan nel sand 40 - 85 Moder atel y sorted sand 2.0f organic Marsh organic content to 10% content 30 - 50%; Spar tina al ter ni flora rhi zomes de crease down- 65 - 130 No organ ics - sharp in crease Edge of flood- tidal delta ward to 0%; sand fines downwar d in mica; bet ter sorted; 2.5f coars ens into mud downwar d to 2.0f 85 - 130 Silt and sand (3.0f); scat tered Marsh Sharp contact rhi zomes 130 - 320 Silt layer; layers of silt and or ganic Tidal pool muds and 130 - 200 Clean, well- sorted sand 3.0 to 2.5f Tidal- delta sands matter inter spersed with sand, wood sands; some sands fragm ents; sorting and grain size vary washed in through 200 - 267 Minor lay ers of silt, mica or gan ics Tidal- delta sands 1.5 to 2.5f; bio tur ba tion through out tidal in let in clean sand 2.0 to 2.5f Abrupt contact Sharp contact 320 - 350 Clean, mod er ately well- sorted sand Tidal delta sand washed 267 - 400 Sandy silt; dis creet sand layers, but Tidal pool muds and 1.5f in through tidal inlet may be some re working of sand into sands 350 - 510 Inter bedded silty sands and sandy Tidal pool muds and mud by or ganism s silts; very mi caceous; organic lay ers; sands 400 - 468 Lami nated sand; shell frag ments Tidal-delta sands pos si ble bio tur ba tion; shell frag ments 468 - 476 Cross- bedded sands with mud drape; Tidal- delta sands scat tered through out slip face 476 - 498 Silty sands; some organ ics Tidal pool

6 Surficial Geology of the Biddeford Pool Quadrangle, Maine

AP PENDIX A. CONTIN UED.

VI BRA CORE 3. Beach face - Fletcher Neck. Exposed relict marsh - 230 cm VI BRA CORE 6. Back bar rier - Hills Beach - 387 cm Depth (cm) De scrip tion In ter pre ta tion Depth (cm) De scrip tion In ter pre ta tion

0 - 70 Dark brown sandy mud; Spar tina Rel ict marsh C14 date 0 - 80 Sandy mud; plant rhizom es; shell Marsh alter ni flor a rhizom es 985 ± 80 yr B.P. and wood frag ments 70 - 90 Transi tion into cleaner sand 1.5f 80 - 100 Mud; or gan ics mi nor Tidal pool 90 - 230 Clean sand with some pebbles and Bar rier sands 100 - 360 Clean, well- sorted sand lay ers 2.5 to Washover sands mixing granules; variation in color and 3.5f with gray clay layers with tidal pool sorting; 1.5 to 2.0f 360 - 387 Compacted gray clay; mi nor sand Presum pscot Form ation lenses

VI BRA CORE 3A. Beach face - Fletcher Neck. 30 meters south west of vi - bracore 3 - 180 cm VIBRA CORE 7. Marsh on tip of lobe on west ern side of Pool - 210 cm Depth (cm) De scrip tion In ter pre ta tion Depth (cm) De scrip tion In ter pre ta tion

0 - 48 Sandy mud grading into sand Marsh 0 - 86 Dark brown sandy mud; Spar tina Marsh 48 - 180 Well-sorte d and rounded sand 1.5 to Bar rier sands al ter ni flora; few small pebbles 2.0f; coarse lens - 0.5f 86 - 136 Fine sand - dark brown, coated with Tidal pool muds and or gan ics; wood frag ments sands 136 - 163 Sand to silt; abundant mica Tidal pool VIBRA CORE 4. Edge of marsh be hind Fletcher Neck - 255 cm 163 - 176 Well-sorte d sand 3.0f Depth (cm) De scrip tion In ter pre ta tion 176 - 194 Coarse granules and pebbles Washed down from ad ja cent high lands 0 - 28 Dark brown mud with Spar tina Marsh 194 - 210 Com pacted coarse sand; very poorly High land sands al ter ni flora sorted; num erous large pebbles 28 - 110 Sand with orange-brown mottling Washover sands (oxida tion ?); sorting and grain size de crease down ward; mod er ately well- sorted 1.5f at 40 cm; poor sorting VI BRA CORE 8. Tidal flats in Pool - 464 cm 2.5f at 110 cm; mud content in creases Depth (cm) De scrip tion In ter pre ta tion with depth 110 - 210 Muddy sand; oc casional mud lens; Tidal pool muds and 0 - 415 Sandy mud to mud; whole shell and 8 Tidal pool muds and wood fragm ents sands cm long pebble together ; abundant sands mica; or gan ics scat tered through out; 210 - 220 Transi tion - more sand, less mud; oc ca sional sand lenses orange- brown mot tling 415 - 464 Very com pacted gray clay; orange- Presum pscot Form ation 220 - 233 Sand, poor sorting .5 to 1.5f Washover sand brown mottling (oxidixed) 233 - 255 Muddy sand with organ ics Tidal pool

VI BRA CORE 9. Tidal flats behind Fletcher Neck - 509 cm VI BRA CORE 5. Beach face - Hills Beach - 521 cm Depth (cm) De scrip tion In ter pre ta tion Depth (cm) De scrip tion In ter pre ta tion 0 - 509 Sandy mud to mud throughout; Tidal pool muds with 0 - 24 Moder atel y sorted sand 2.5f Bar rier sands abundant mica; organ ics and shell washover sands fragm ents throughout; sand lay ers at 24 - 38 Coarse, poorly sorted sand 0 to 1.0f; ridge slipface (?); pebbles 80 - 110 158 - 180 2.0f 38 - 57 Same sand matri x with wood From pa per mills (?); 372 - 380 1.5 to 2.0f frag ments in lay ers Seen on pres ent beach face 400 - 404 2.5f 438 - 490 1.0 to 2.0f 57 - 182 Sand 1.0 to 1.5f; some organic 494 - 509 1.5f mot tling 182 - 238 Minor clay lenses in sand Pos si ble Pre sump scot For ma tion con tact 238 - 521 Com pacted gray clay with light to Pre sump scot For ma tion heavy mottling throughout

7 C. T. Hildreth

AP PENDIX A. CONTIN UED.

VI BRA CORE 10. Fring ing marsh on western side of Pool - 374 cm VI BRA CORE 13. Mean der ing tidal creek behind Hills Beach - 140 cm. Depth (cm) De scrip tion In ter pre ta tion Depth (cm) De scrip tion In ter pre ta tion

0 - 30 Sandy mud; heavy rhizom es Marsh 0 - 20 Sand -0.5f; large pebbles (8 cm); Tidal channel sands Spar tina al ter ni flora grades down into pebble layer 30 - 54 Sand 2.0f with scat tered large peb bles Washed down from 20 - 32 Sand 1.5 to 2.0f with mud matrix Tidal channel sands ad ja cent high lands with slack wa ter fines 54 - 86 Sandy mud Tidal pool 32 - 37 Clean sand lens 2.0f Washover (?) 86 - 100 Gray mud/clay 37 - 43 Sand with organic mottling; Tidal channel sand with 100 -174 Sand with shells; mud content wood fragm ents organ ics from beach or in creases down ward; large wood chan nel frag ments 43 - 75 Clean sands with mud lenses 174 - 194 Rock frag ments, pebbles, granules in Washed down from Sharp contact mud; twigs high lands 75 - 90 Clean sands 1.0 to 1.5f 194 - 266 Mud to clay Tidal pool 90 - 140 Com pacted clay; pebbles at bottom Pre sump scot For ma tion 266 - 324 Sandy mud; scatter ed pebbles Tidal pool 324 - 374 Clean sand; oxi dized, 1.5f; Washed down; pebbles large an gu lar peb bles same as found in sam ple VI BRA CORE 14. Beach face Hills Beach - 129 cm.. from ad ja cent high lands Depth (cm) De scrip tion In ter pre ta tion

0 - 129 Sand - varied sorting and grain size Bar rier sands VI BRA CORE 11. Near wave- cut scarp, fringing marsh - 135 cm. .5 to 2.5f; slipface 39 to 46 cm; peb bles Depth (cm) De scrip tion In ter pre ta tion

0 - 18 Sandy mud; Spar tina al ter ni flora; Marsh with some large an gu lar peb bles through out washed down sedi ments .5 to 2 cm VI BRA CORE 15. Tidal flats on east/west tran sect be hind flood- tidal delta - 468 cm. 18 - 26 Muddy sand; de creasing rhi zomes Marsh Depth (cm) De scrip tion In ter pre ta tion 26 - 41 Pebble layer; muddy sand matri x; Washed down very poorly sorted 0 - 9 Sand; shell fragm ents Tidal delta sands 57 - 88 Brown to orange-brown (oxidized) 9 - 31 Mud with some shell fragm ents and Tidal pool sand; poorly sorted or gan ics 81 - 135 Com pacted clay; oxi da tion Pre sump scot For ma tion 31 - 247 Mot tled (bio tur bated) sand with Tidal delta sands vary ing mud content (0 to 5%) 247 - 290 Dark gray muds and sandy mud Tidal pool VI BRA CORE 12. Fring ing marsh, near vibra core 11 - 186 cm 290 - 335 Orange- brown (oxi dized) sand; Tidal pool nu mer ous shell frag ments; mi nor Depth (cm) De scrip tion In ter pre ta tion mud lenses 0 - 55 Dark brown mud; Spar tina Marsh 335 - 468 Dark brown sandy mud; some shell Tidal pool al ter ni flora rhizom es fragm ents; sand lens 55 - 96 Muddy sand; scatter ed rhi zomes Marsh 96 - 122 Green- gray clay; sharp lens Tidal pool 122 - 175 Sand 2.5 to 3.0f Washed down VI BRA CORE 16. Fring ing marsh, northwest edge of Pool - 180 cm 175 - 185 Com pacted sandy mud Tidal pool Depth (cm) De scrip tion In ter pre ta tion

0 - 70 Dark brown mud with Spar tina Marsh al ter ni flora 70 - 180 Com pacted clay; some oxida tion; Pre sump scot For ma tion sand lenses; minor plant mate ria l near bottom

8 Surficial Geology of the Biddeford Pool Quadrangle, Maine

AP PENDIX A. CONTIN UED.

VI BRA CORE 17. Tidal chan nel near Hills Beach - 685 cm. VI BRA CORE 21. Fring ing marsh, Fletcher Neck near vi bracore 4 - 537 cm Depth (cm) De scrip tion In ter pre ta tion Depth (cm) De scrip tion In ter pre ta tion

0 - 14 Sand 1.5f mod er ately well- sorted Chan nel sands 0 - 20 Mud with Spar tina al ter ni flora Marsh 14 - 31 Gray sandy mud with biotur bated Tidal pool 20 - 124 Moder atel y sorted sand 1.5 to 2.0f Bar rier washover brown sands 124 - 240 Sandy mud; minor lenses of organ ics Tidal pool 31 - 48 Very fine sand coated with or gan ics; Tidal pool/channel with mica, and sand; minor shell slip face frag ments 48 - 444 Al ter nat ing lay ers of mud/clay and Tidal pool with 240 - 537 Lay ers of mud and silt; or ganics; Tidal pool with sand 2.5 to 3.0f bio tur ba tion washovers shell frag ments; sev eral layers of sand storm washovers with heavy concen tra tions of shells 444 - 685 Compacted greenish- gray clay with Presum pscot Form ation organic mottling and poorly-sorte d sand lenses; 2 sand lay ers biotur bated VI BRA CORE 22. Basket Island tom bolo Depth (cm) De scrip tion In ter pre ta tion VI BRA CORE 18. Beach face, Fletcher Neck - 134 cm 0 - 217 No core re cov ered Barrier- type sands Depth (cm) De scrip tion In ter pre ta tion 0 - 134 Clean sand 1.0 to 1.5f pebbles Bar rier sands

VI BRA CORE 23. Spit betwee n Basket and Stage Island - 243 cm VI BRA CORE 19. Tidal creek be hind Fletcher Neck - 94 cm. Depth (cm) De scrip tion In ter pre ta tion

Depth (cm) De scrip tion In ter pre ta tion 0 - 217 Sand 1.5f with scat tered shell Barrier- type sands frag ments; sev eral wood frag ment 0 - 17 Muddy sand with Spartina Marsh layers; some large pebbles near bot tom al ter ni flora; some pebbles 17 - 48 Sharp con tact with clean sand Washover 48 - 86 Sandy mud; shell and wood fragm ents Tidal pool VIBRA CORE 24. Shoal in front of flood- tidal delta - 158 cm 86 - 94 Or ganic ma te rial (Spar tina Possi ble old marsh (?) al ter ni flora?) Depth (cm) De scrip tion In ter pre ta tion

0 - 158 Sand 1.0 to 1.5f; mod er ately to Tidal delta/chan nel sands VI BRA CORE 20. Flood- tidal delta near vibra core 1 -647 cm poorly-sorte d; some shell fragm ents; lay ers of wood fragm ents; Depth (cm) De scrip tion In ter pre ta tion no struc tures 0 - 76 Sandy mud; Spar tina al ter ni flora Marsh 76 - 284 Sand; no rhizom es; wood fragm ents Tidal delta throughout; abundant mica; some “DUTCH” CORE D-1. Above wave- cut scarp, fringing marsh - 47 cm oxi da tion Depth (cm) De scrip tion In ter pre ta tion 284 - 448 Thin lenses of muddy sand and Tidal pool sandy mud 0 - 13 Divot rem oved - grasses in sand High marsh/dune 448 - 475 Sand 2.0f; scat tered shell frag ments; Tidal pool vege ta tion some wood fragm ents 13 - 47 Poorly- sorted sand and pebbles Same mate rial as on 475 - 585 Alter nating lenses of mud and sandy Tidal pool ad ja cent hill side and on mud; some shell frag ments; scat tered marsh edge rhizom es; wood fragm ent layer 585 - 647 Com pacted blue- gray clay Pre sump scot For ma tion

9 C. T. Hildreth

AP PENDIX A. CONTIN UED.

CORE D-2. On north ern end of marsh lobe - 65 cm CORE D-7. Oppo site D-6. - 83 cm Depth (cm) De scrip tion In ter pre ta tion Depth (cm) De scrip tion In ter pre ta tion

0 - 25 Divot rem oved - mud with Spar tina Marsh 0 - 19 Mud with Spar tina al ter ni flora Marsh al ter ni flora 19 - 41 Mud with Spar tina al ter ni flora Marsh 25 - 42 Black mud with Spar tina al ter ni flora Marsh with in creasing sand con tent Sharp contact down ward 42 - 65 Poorly sorted pebbly sand Same as Core D-1 41 - 83 Sand 1.0 to 2.0f rhizom es gone; Tidal channel sands some wood fragm ents at base; muddy matri x

CORE D-3. Small creek, west side behind Hills Beach - 100 cm Depth (cm) De scrip tion In ter pre ta tion CORE D-8. Back- barrier marsh, southern end behind Fletcher Neck - 36 cm 0 - 8 Soupy brown mud Marsh Depth (cm) De scrip tion In ter pre ta tion 8 - 78 Com pacted brown mud with Marsh Spar tina al ter ni flora 0 - 36 Sand 2.0f with minor amounts of silt Marsh on washover through out and Spar tina al ter ni flora 78 - 100 Compacted blue clay Presum pscot Form ation rhi zomes also visible along banks of tidal creek at low water , approx. 1 m be low marsh sur face CORE D-9, D-10, D-11, D-12. Washover lobe behind Fletcher Neck. Depth (cm) De scrip tion In ter pre ta tion

CORE D-4. Just north of D-3 - 200 cm 0 - 60 Soupy muds with Spar tina Marsh al ter ni flora Depth (cm) De scrip tion In ter pre ta tion 60 - 70 Sand Washover sands 0 - 145 Mud with some sand; Spar tina Marsh al ter ni flora rhi zomes de creas ing to 0% at 140 cm CORE D-13. Marsh behind Fletcher Neck, approx. 30 meter s from MLW. 145 - 153 Sharp con tact with silty sand Chan nel sands 153 - 184 Fairly clean sand 2.0f Chan nel sands Depth (cm) De scrip tion In ter pre ta tion 184 - 192 Clean sand 2.0f Chan nel sands 0 - 30 Soupy marsh mud Marsh; same as D-9 192 - 200 Mud and sand mixed Chan nel sands through D-12 30 - 35 Clean sand Washover sands

CORE D-5. East side of creek behind Hills Beach, oppo site D-4 - 200 cm CORE D-14. Marsh behind Fletcher Neck, approx. at MLW Depth (cm) De scrip tion In ter pre ta tion Depth (cm) De scrip tion In ter pre ta tion 0 - 173 Brown mud with Spar tina al ter ni flora Marsh 0 - 80 Soupy mud Marsh; same as above 173 - 200 Sand 1.5 to 2.0f with fine (mud/clay) Chan nel sands ma trix 80 - Clean sand Washover sands

CORE D-6. East side of creek behind Hills Beach, just north of D-5 - 81 cm Depth (cm) De scrip tion In ter pre ta tion

0 - 20 Divot rem oved - mud with Spar tina Marsh al ter ni flora 20 - 71 Mud with Spar tina al ter ni flora Marsh 71 -76 Grada tional in crease in sand; no rhi zomes 76 - 81 Sand 2.0 to 2.50 with minor silt Tidal channel sands ma trix