cooperative geologic project · geologic interpretation of sei&ddc data the geologic sections...
Post on 11-Jul-2020
9 Views
Preview:
TRANSCRIPT
c ot:unomveal th of Massachusetts Department of Publio Vi orks
y;. Fe Calla.han, Comraisdoner
u. s. Department or the Interior Geological Surve,y
W. E. Wrather, Dir ctor
. . - .) - ..J , . /
Cooperative Geologic Project
Geologic Interpretation of Seismic Data
Relocation Route 1, Cut, Stations 34-52
Copper Mine Road area and Northern Portion of Ba,.lard Estate
in Topsfield, Mass.
by
James E. Maynard, Geologist, u. s. Geological Surve.1
and
Rev. !).1"1.1el Lineha.n, s. J ., Seismologist, ·ueston Collet;e
5 pages or text 4 plates "
U S . GEOLOGICAL SURVEY MASS. DEPT. OF PUBLIC WORKS COOPERATIVE GEOLOGIC PROJECT
OPEN FILE REPORT
...:; •. • t .. .: . I t .
, ·· ~ of this report have been placed in open fi les for pub! c anspection at
·' (;EOLOG ICAL SU HVEY, El'\G il'\EEHING GEOLOG Y IIRA!';CH, nrvli.JRRAHY, F E DERAL WOHKS B'LD'G, WASHI:\GT ON, D. C.
' GEOLOG IC AL SURVEY . 100 NASHUA ST. , HOOM 802, BOSTON \!A ~SACH U:-i ETTS.
' ' ' o\C IJ USETTS DEPT. of P UBLIC WORKS, PHOJECT E:\GI NEER Seismic Series # ------
I t.() :\ASII UA ST., DOST0:'-1, ~JASSACH L'SETTS Release date:
Geologic Interpret~tion of Seismic Dnta
Relocation Route 1, Cut, Stations 34-52
Copper Mine Road area and Northern Portion of Ballard Estate
in Topsfield, Mass.
by
James E. Maynard, Geologist, u. s. Geological Survey e.nd
Rev. Daniel Linehan, s. J., Seismologist, Weston College
General Statement
Relocation of the NeVIburyport Turnpike, Route 1, in Topsfield, 1.1ass. •
will require a long relatively deep out between stations 34 and 52. In
order to obtain preliminary information on the depths to bedrock and on the
nature of the subsurface materials at this site, reconnaissance seismic work
was performed in October 1949. Because this reconnaissance work indicated
that bedrock rni~ht be relatively near the surface over an extensive area
where cuttings were to be made, a more detailed seismic study of the area
was made in November 1949. The results of both the reconnaissance and de-
tailed seismic work are included in this report. The work was done as part
of a cooperative program of the l:assachusetts Department of Public Works
and the u. s. Geological Survey.
Surface Geology
At this location the base line of the proposed road traverses an area
of moderate relief with many small irregular knobs and depressions. The
surface forllV3.tion ovar most of this area is fb.e wind-blown sand fro:n a few
- 1 -
inches up to a few feet 1n thiclme&s. This material ia underlain by till
that in many places c ontains numerous a:aall angule.r fragments or rook.
~ediuc to large boulders occur sporadically an the surface or the ground.
Some of the small depressions in the vicinity of the base line contain
stratified sand and are probably small kettles. Bedrock ia not exposed
along or in oloce vicinity to the base line.
The surface geology of the site and the surrounding area, and the sur-
faoe configuration of the location, suggest that most of the site ie underlain
at shallow depth by an irregular bedrock surface. The geology or the region
suggests that this bedrock is largely a tough, finely orystalline dark-colored
rook (u:elanite) with minor amounts of granite.
Seiacic Traverses
The plan of the seiamic traverses is shown on sheet 2. With the exception
of traverses GG-~, II-JJ, XX-YY, and C•D, the traverses for the more detailed
survey v;ere each approxi:aately 220 feet long. Traverses GG-Illi, 11-JJ. and
XX•YY were each 110 feet long, and traverse C•D was 345 feet long.
The shot points for each of the traverses were located as follawsa
A., station 50+60 B, • 47+30 al, .. 47+35 c, 70 feet to the right (east) of station 51+30 D, 70 • • • • • • • 47+85 nl. 70 " .. " .. .. .. .. 47+90 E, 60 • • • left (west) • • 50+30 F, 60 .. • • " • • • 47+00 Fl, 60 " • .. • " .. .. 47+05 G station 44+05 Gi, .. 44+00
H, 10 feet to the right (east) of station 44+60 I, 60 • • II lett (west) 11 • 43+76 Il, 60 • II • • • II .. 43+80 J, 60 • • II II • • • 40+50 K• station 40+70 GG, 55 feet to the right (east) 11 • 34+60 HH, 65 II • • left (west) • • 34+60 II, 55 • II • right (~at) " • 36+80 JJ, 65 • II • lett (west) 11 II 36+80 KK, 105 • • II • • • II 34+60 LL, 106 • • • • • • • 36+80 MM. 80 • • .. .. • • • 39+00 NN, 55 .. .. • II .. II II 39+00 00, station 39+00 pp, 25 feet to the • • II .. 41+15 QQ,, 35 • .. • right ( 86. '3t) • • 41+15 RR, 35 • II • II • II II 43+35 ss, 25 • • • left (west) • • 4~35 uu, 15 • • • II • .. .. 45+55 TT, 30 • • • right (east) • • 45+55 vv, 20 .. .. • • • • • 47+75 ww, 25 • II • left (west) " II 47+75 XX, 55 • • • right (east) • • 49+96 YY, 65 • • • left (west) • II 49+95
Depths to Bedrock
The approxiuAte depths to bedrock below the shot pointe area
A, 10 feet I 8 feet oo, 14 feet B, 1 • Ii, 8 • PP, 18 II
Bl, 8 • J, 8 • ~. 8 • c. 9 • K, 15 • RR• 1 • D, 8 • GG, 14 • ss. 4 II
nl, 8 • HH• 18 II uu, 8 • E, 8 • II, 9 II TT, 11 • F, 1 • JJ, 11 • vv, 8 • Fl, 8 • KK, 13 • ww, 10 • G~ 8 • LL, 14 • (minimum) XX, 10 • G ' 9 • m~. 12 • YY, 8 II
H, 5 • NN, 13 •
- 3-
The depth values to bedrock for shot pointe A to J inclusive are based
an an average till vqlooity of 2500 feet per second. a value that was
obtained when the shorter linea of the more detailed survew were rune The
value for shot point K represents accurate time-travel data. The till
velocities appear to range from 2500 to 3000 feet per second• using a till ~
velocity of 3000 fe t per second would yield depth values one to two feet
greater for the J. to J ahot pointe.
Geologic InterPretation of Sei&Ddc Data
The geologic sections aa interpreted from the surface geology. the
calculated depths to bedrock at the shot points. and the velocity curves are
sh own on 6heets 1 and 2.
The ~eneral contour of the bedrock surfaces. aa shown by sections A-B
to I-J inclusive. sheet 1. is based on good aeismio velocity data. However.
because the depth values at the shot points. as mentioned above. may be from
one to two feet deeper than those shown on the section. the bedrock profiles
~Y be one to two feet lower on the sections. The positions of the bedrock
surfaces on the geologic sections are shown by smooth curves. These curves
show only the :uajor configurations . for the detectors were too widely spaced
to pick up many small knobs, points and ridges.
Geologic sections GG-HH to XX-YY inclusive, sheet 2, show only the very
~eneralized broad configurations of the bedrock surface. Undoubtedly many
small ridges, knobs, pinnacles and depressions occur at altitudes above or
below those represented by the smooth curves. In the vicinity of shot
points LL the bedrock surface is represented by a dotted line; here the
bedrock surface is probably at a somewhat greater depth, but the velocity
data ·were too \.Ulcertain to ple.ce it more accurately. Indicated bedrock
velocities along the shorter (220 foot) tr~verses are appreciably l~er
(12.500 feet per second) than those along the longer (330 foot) traverses.
end are also lower than chould be expected for the kinds of rock involved•
such crystalline rocks commonly have seismic velocities of 15.000 to
16,000 feet per second. The apparently anomalous low velocities along the
shorter traverses suggest that the upper part of bedrock may be in an
appreciably 1;.ore shattered condition than the lower part. For the shorter
traverses, the upper part of the bedrock would tave greater influence an
determined apparent velocities than the deeper portion would have.
II
l 140
KK LL
HH -Q~M
NN
- -· ~z
uu
.... ~ ,.II.' ...:' ... Nf.A ...... ,. ·' " VIA " SAC>t t..: t • ·; "• f O.A~T Mf"-' l "'' J' C ti. r. w - ~.o ... ..
:: · .\~'1''-'rNT ~I ..... t lol ' t :...
l<l , f•
.... .. . \ ' [ ···- "' "'"'' .•
yy- E
=~~::~P=P====~======:.:~-s=~s~~~====~~~~::;.;:::==:~~~~w~w~====--~----~~.-~ ~--- -<>Jr -~- - ~- ---<>w--~- =:-<liJ _~_-c··~og_o ___ •• ___ .. -<-j.R!£RL·_G·· __ .G _____ ., -(-j.T.!.T __ •• ___ .,_s_s_. J"\l-v-'!1..:.'!1_.. •• I oo A -<>' .. -- . o,~ -GG -----H D D• --------. >.X
HH J J
.• oL T ·140 140
•oo-;:=-~ '!..:_~'!:!!-"'~ - l.oo 140· L---=:~-::::---~
Till V, 2500 fl./SIC.
~-------- ·· ····· loo· :o 100 I~
...... ...... -._-_--_------:,~,-~-V,-I!-~-OO~l:Clh«---------~-------__ ---'-_--_--__ ----------,,-.,-~-;;,;-;,~.--._c-1-ln_r< ______ ·--------------..J
60 0
B•<ln><t v. 11!000 ft/... I 8Nroc~ V, 1200C lt./Src. Bldt~Jd V. 12$00 11./-S.c B•d,od V, 12500 It /U~
-~ +60 ICC 110
60-l---------.-+-oo ' 100110
pp
~---·--··-- - ,----------r··. 0 100 20.,)
r·---- --· 220
·-r- . IOC
~ T ~--------------------------------------...!...-----m;VMOO.='="~-:-,------ -.---:::::.-==-..:::..-=--- - --~111 V.: 2$0011 / SH t- Till V, 2500-JOOO ff/src. __ - -- -- _ ~ :::-:::::--__
r------ ......!...''' v, ~o.:::~ ------------- ---- ..::._-::::::-=-~-------· ---100
60...,11------..-------- ,----r ·--440 500 •eo 700
~ ----- ·--r - - I-800 &SO 9')0 1', .,
'.c..:
1 •o ,.·f)O
I • ·10(,
~~ r J~~- .0 ~~~-----~-----------~=,~,_~~~2~=oo~,~,-/~-.--- ~--------------------- •oo
------------ ..!.:.!'...!:!_2~ !!.!!'"'-- -------------. ~
~ .. .
. '··J. . . :· ·
/lld'Wk v. 12000 I I./6K. ,.L 1310 s.,, ... v. 12000 fl./1 .. ----=--. ~60 1200 i7VV 2 1400 1$00 1 ~40
.~ . . ! J
PLAN OF-TRAVERSES
SCAl(: ·IINCH •lOO FE£T
l.etf""-ltttt' ~0 sllo.t poo"t:t ot t :uu o• ! •owe•Se\ ~ _, to Q P.W stQHons on bose fifth,
NOH Ootttcl port1on1 ol \t<:l•ons •Mhcote tn,onr;h.lllft sctsmlc doto
.--------------------------------------~ t>H ER PRETATIVE GEOLOGIC SECTIONS ALON G SE1SMIG ''lii"Jf RSES
TOPSFIELD---~ ---- RO Ui E _N_?._ I_
1---- RELOCATION RTE . I STAS. 34-52 {COPPER MINE ROAO AREA)
~~----------------~~-----------------·--.>V 'Ja.f'o t PO•"'
4PGOrt"t ICtl ll"'•<: vet(l ~ dr I••'~
'" fe•t pe' wcan6
14Q-
KK LL MM
, .. o~--=-:----'--'"1 -- ==t"'••o r------:::.. ::..:~ '.:.!.~~~ ' ·" v, ~00~.;;;;;;;;===
1001 100
I B•dnH:I .. "2000 14000 " / m e.d,Dek v. 12000·14000 11/n< I 60 ~ .. ·-· ·· - -- --· ·.;-_ - ··--· . ----- -;, .,-2J;-- ----3;;;; ·-- -- . 4~-----;ro60
S· - 39+00 r 1 40~
I
00
1 I
GG 'j' !
1-tO-i
'
·~y · ',IH G. . ...
. .'lR' ~• '·' ~ - ' ""' ... ~ ·.
~------------1
·,
c-=-~ ::· ~- _:::.·_::;_ ~ .. !!::'~----~ 100 .....1
I ' I
·~Lo
IT
f(
.T :
~ ------,,-~~-, : 2SOO III'Irc T1J1 V, 2:!!f!. ·EiJf2_!!./.!!f. ________ --------
rl _ __,...--------------------- ---...IJ/1 V..:!200· JC'?i071.Ji , l
~--------100 1
! 8'drocl V. '2500 I I /S'c 8rdr«i l>, 12000 I I /UC Btdrock V, 12000 If / U r
60·~-----------,,----------,-,-r- - ·-- ----· - ---· - -- ·-- .. ---r--~-··· --·· ·-- - ·· - - ·--· • · (, (.
•· 0 o I 00 200 220 300 400 440
TT
140 · · 0: (.
'1j!L_V...!!,0!:3"!!!!_ ::::..rc - 100 -....._ __ 100 ~---- Till V, 2800-~000 ff./.lrc-:-::r-- - _ -----------&drock V. 12000 tt/Uc S#dNJ&i v. 12000 11./UC
so+---.------------,,-------·~·,-----------,,------ ·· ·--- , .• o 660 100 BOO 880 900 1000 1100
YY
140 ~--~------------------------~--------INTERPRETATIVE GEOLO GI C SECTIONS ALONG SEISMIC TRAvERSE 5
ROUTE N O I ··f- ..... ;;,,.~ · .. ~~-~-~-. · .... ~~'. ""~-~"'!t. ~-··~ ... ~;,
•'" ·100 . .. .• , ., . 100 NOT£'
TOPSFIELD ~--~~~~~~~~~~~~~~~-----
~ELOCATION RTE. I STAS 34-52 t-- !!!!2~ ~-...:__
~~~II-A~.
~~--------------~r~ 100 l o 0
. ~ -
Dotted portions of wctlons •ndleott '"~lulivt stilmic dola ~-------------~IIC~O~P~P~ER~M~I~N~E~R~O~A~O~~~RE~A~~~~---------- ·-
·v S· ;.. •• '1 "- ·: -+ 40 Ft Ef
·~ · , .. 0.. - ~ • f' 'll Sf'l.l 1'1 •: on~ ou:;;l ~) I• c~ .
·· •ufiM'~~cf
~,- OCT- NOV 1949 i -!j ••' ·' ?
'/ ~- · /-;
' •, t~o : :. . ... . V! ·....:. - •• .
'· f ' 1\C' y l•, '
.... -··· ' • ~ f - ••
-----+ ... __ ---~ •· •. ~ z:;oo f ' /s~~-- - ---- __ _._ -~ -- . ..____
- --------- -------- ! : ----......_ ---- LC'Osr /1 /l "• A/":>•o• P$0{; /f ,•srC -- ......_--:::------=== -=--~·=·= -~- ...::-.::. .. :::.---=. ~
~XI • · ;~0-?:J , ,. ~ sf'C
r '•
i
. I
t l 300 l2S 3l0
, .. 40
' 160 980
I 4 00 500
· 4 () ~ Sta41 <-! .)42 ',f.; .. ~
~-~ _ !2:;. ~~ii/0!~--- :__ ~- _::_·__;_ -----I
I 60-t --
0 •00
6~ ·ocA V, 14000 -PJ!JOO 11 / ut:
200
Sto 47 -' 30 Sto 47+35 -:- · ; -.. .
TI '-
---------..::::=:::==~~::==~=----_:s•~·L·~·~~~==~~~~~s~••J,~·~'- Sta 4 8 Sto 49 •ntersfG' · ·~ ~~~~'!!.-S!ff!9.!!..!!'!__=:-n-------~-l------ 1 )l')' .n
------;.ODsr/111 V. e50o -JOoOf,;m~----' ,_·_~.::._ ___ -. ~-------' i
~---------~-x------ -·-500-- ----- ----JO...,.... ___ - · -.;Jt 61tfro: t .t, IIC. JO- 20000 II /S« & drod V, 7000 2 500·? 11 /U,.
' -- - - ---- - - - -·· - ·- t ... 700 8:D ':tOO
INTERPRETATIV: GEOLOGIC SECTIONS ALONG SE •:O"' : ~=>.:.,;:;. ;;:;
fLAN.OF,TRAil,ERSES
StALE' \ INCW• F[t 1
--TOPSFIELD T - __ j__ ROUTE r-.C 1
1------::R::E:-:L-:O=-c=A-::T:-:1:::0:-::N::-:R=-T:=-;E I STAS 34 --5-2 _ _ _ (COPPER MINE ROAD AREAl
!CAL E . I NC._. • 40 FEET G£ :::L ' G'f 8" JAVE'S E -.n- .:.;
~~----------------+----------------·--_-.1.-. ' Apo o• t '"•' ,. ,.,,u, " ' ''"'' ' (•n l
,n , . ... IMt' secono.
DD· ' 1"-
1
' '!
T ,.\ " '1 • I
I .. . :-
L _____ --~
~- · :::~ ~-- .. 30
.-
~-------------,-..:·c..3"!!' ~01' 2200-CSOO lt / SfC
t"'- ----.!...,_--------- .::::-:::::--- . --- A
>00~ ---~~--=-=-~-~=:::_----==-=-~::._:·~-~=-::~ ---- ~ I ---1
60+---- - - - -----· --. - ---- -- - - - · .... ·· ---, ------
200
PlAN OF TRAVERSES
Sr;\l[ I I N :. t-~
-~
I
' -- : + ~25 3~
- -- - y - - . .. "} 5 )ry
INTERPRETATIVE GEOLOGIC SECT •O NS At ONG SEISM IC TRAVfR SES
TOPSFIE-~0 -l- RJU7E NO I
1-------- REioc"Ar 1oN" tirE: ,- s·-rAs--34-=-52 -- ---(COPPER MI ~:E RO:,:A~D-:__::A_:_:R::.E:::.AlL.. ______ ~
4C , t.l'
'-~D l 't " ' ,.,.,,_., ·. ,,. ,.t'.l)f''"f' -
' • I ~,;
, · ~ ' rp JAMES E Mlilt.IARO
~ '" ~ t.f "' '"- G ~ • 'II "' S • t: 4iJ L •. ' ._, f ••
~- · Oct - NOV •••• [ :;HH - 4 ' ' 4
top related