,,indu/rial ,,m9]als ,,& ,,metals ,,(   
,,ill9ois                               
,j4 ,e4 ,lam>                           
,ill9ois ,/ate ,geological ,survey      
,educational ,s]ies #h      ,,/ate (    
,,ill9ois        ,illu/ration3          
,,dep>tm5t ( ,,regi/ration & ,,education
    #aife      ,,ill9ois ,,/ate         
,,geological ,,survey    ,john ,c4      
,frye1 ,*ief    ,,urbana1 ,,ill9ois     
,pr9t$ by ,au?ority ( ,/ate ( ,ill9ois1 
,*4 #abg1 ,,irs1 ,p>4 #eh4be4           
7#ae,m-#d_/fe-higf7 #aj                 
,,indu/rial ,,m9]als ,,& ,,metals ,,(   
,,ill9ois                               
,j4 ,e4 ,lam>      ,! m9]al res\rces (  
,ill9ois include _m rocks & m9]als (    
v>i$ "* & uses4 ,f !m are made an array 
( ev]yday  products ^: s\rces may n ev5 
be recogniz$ by ! consum]4 ,!  us] ( a  
glass bottle1 = in/ance1 r>ely kn[s t x 
may h be5  made f ,ill9ois silica s&1   
nor is ! driv] ( an automobile  g5]ally 
aw>e t ! ,ill9ois concrete highway on   
:i* he is  driv+ probably 0 con/ruct$ f 

a mixture ( cem5t1 s& &  gravel1 or     
cru%$ /one t may h come f ,ill9ois pits 
or  qu>ries4    ,! significance ( ^!    
rocks & m9]als to ! economy ( ,ill9ois  
is great1 al?\gh (t5 unappreciat$4 ,( ! 
m ?an #fjj million  doll> value ( all   
,ill9ois m9]al production 9 #aifc1 almo/
 #bjj  million 0 f indu/rial m9]als4 ,! 
div]sity & widespread  di/ribution ( ^! 
m9]al res\rces l5d v>iety & balance to !
  m9]al indu/ry ( ! /ate1 & _!          
production1 process+1 &  utilization    
af=d direct & indirect employm5t to _m  
p4    ,! t]m indu/rial m9]als is us$ z a
 conv5i5t gr\p t]m =  nonmetallic m9]als
 t are n fuels4 ,9 ,ill9ois !y include  
lime/one1 dolomite1 clay1 %ale1 silica  
s& & o!r s&s1  fluorsp>1 tripoli        
7amorph\s silica71 gani/]1 novaculite1  
s&/one1  feldsp>-be>+ s&s1 b>ite1       
gypsum1 anhydrite1 br9es1 gre5s&1  oil  
%ale1 m>l1 peat1 humus1 & tufa4 ,!      
metallic m9]als (  ,ill9ois are gal5a   
7lead ore71 sphal]ite 7z9c ore71 pyrite1
 &  m>casite4    ,?is booklet briefly & 

nonte*nically discusses ! =ego+         
mat]ials & "s ( ! "w ! ,ill9ois ,/ate   
,geological ,survey does  9 ga!r+       
in=mation ab\t _! occurr5ce1 & "* & 9   
develop+ new uses4    ,! assi/ance ( _m 
,survey /aff memb]s & ( _m p 9 !        
,ill9ois m9]al indu/ry 9 ! prep>ation ( 
?is booklet is  ackn[l$g$4              
,,lime/one      ,lime/one is a mo/      
v]satile rock4 ,)\t x !re w\ld be no    
portl& cem5t = mak+ concrete roads &    
build+s1 no lime =  pla/]+ & *emical    
use1 no agricultural lime/one = f>ms1 & 
no  cru%$ lime/one = driveways4 ,a wide 
v>iety ( indu/ries1 f  /eel mak+ to     
glass manufactur+1 use lime/one 9 "o way
 or  ano!r4    ,! e>ly settl]s (        
,ill9ois recogniz$ ! value ( lime/one & 
qu>ri$ /one blocks & slabs = mak+       
f\ndations1 *imneys1 &  ev5 h\ses4 ,=   
mort> !y us$ a mixture ( s& & lime to   
hold !  blocks toge!r4 ,! lime 0 made by
 heat+ lime/one r$ hot 9  simple        
furnaces or kilns1 ! ru9s ( a few ( :i* 
may /ill be se54                        

,k9ds ( ,lime/one    ,ill9ois has two   
pr9cipal v>ieties ( lime/one1 ref]r$ to 
te*nically z lime/one & dolomite4       
8,lime/one0 may be us$ z a  g5]al "n =  
bo? v>ieties4    ,lime/one consi/s      
pr9cipally ( cry/all9e p>ticles ( !     
m9]al  calcite 7fig4 #a74 ,?is m9]al is 
glassy 9 appe>ance & is compos$  (      
calcium1 c>bon1 & oxyg5 comb9$ to =m    
calcium c>bonate--,ca,c,o4  ,dolomite is
 l>gely made ( cry/all9e p>ticles ( !   
m9]al  dolomite1 :i* also has a glassy  
appe>ance & consi/s ( calcium1          
magnesium1 c>bon1 & oxyg5--,ca,mg7,,co74
 ,! cry/all9e p>ticles (  lime/one &    
dolomite v>y 9 size4 ,"s are co>se en\gh
 to be se5  easily1 o!rs are s small t  
!y c be di/+ui%$ only ) a  microscope4  
,=mation ( ,lime/one & ,dolomite        
,almo/ all ,ill9ois lime/ones 7 =m$ 9   
seas t cov]$ ,ill9ois  millions ( ye>s  
ago4 ,! _m diff]5t lime/one =mations 9  
,ill9ois sugge/ t oceans cov]$ all or "p
 ( ! area sev]al  times4 ,num]\s k9ds ( 
%ell fi%1 corals1 & o!r m>9e animals    

liv$ 9 ^! oceans & _h %ells & o!r h>d   
p>ts made (  calcium c>bonate4 ,?r\gh   
c\ntless g5]ations1 ^! animal rema9s    
accumulat$ on ! ocean floor & gradually 
7 compact$ & cem5t$  into lime/one 7fig4
 #b74    ,o!r ,ill9ois lime/ones1 h[ev]1
 7 =m$ by ! h>d5+ ( muds  compos$ ma9ly 
( calcium c>bonate t accumulat$ on !    
floors (  ! anci5t seas4 ,/ill o!r      
lime/ones 7 =m$ ( a comb9ation (  animal
 rema9s & lime mud4        ,illu/ration3
 ,figure #a--;,calcite cry/als4         
,lime/one is made up      ma9ly (       
calcite cry/als1 b !y are less p]fectly 
=m$ &      are cr[d$ toge!r4    ,! coral
 reefs ( ! ,s\? ,pacific ,ocean h _!    
c\nt]p>ts 9  ,ill9ois4 ,! anci5t        
,ill9ois oceans conta9$ ext5sive reefs t
  7 built up j z ! mod]n reefs h be54 ,9
 nor!rn ,ill9ois1  ar\nd ,*icago =      
in/ance1 a numb] ( ! anci5t reefs are n[
 !  site ( /one qu>ries4 ,9 s\?we/]n    
,ill9ois su* reefs are a s\rce  (       
petroleum4    ,! dolomites ( ,ill9ois   
probably 7 orig9ally lime/ones1 b1  ei!r

 :ile ! lime/ones 7 /ill b5ea? ! sea or 
aft] ! sea  _h )drawn1 magnesium 0      
ex*ang$ = "s ( ! calcium 9 !  lime/ones4
 ,if ! ex*ange took place "u ! sea1 !   
sea wat] 0  ! s\rce ( ! magnesium4 ,if x
 happ5$ :5 ! lime/ones 7 a  "p ( ! l&1 !
 magnesium 0 br\ght 9 by wat] circulat+ 
?r\gh ! rock4 ,_m ( ! m>9e animal       
fossils became difficult to  recognize  
aft] ! *ange1 & ! texture & g5]al       
appe>ance (  ! rock also 7 alt]$4 ,"s ( 
x became noticeably por\s4              
,illu/ration3 ,figure #b--,lime/one     
conta9+ fossils4 ,an ,ar*im$es          
screw appe>s at l[] left1 lace-l bryozoa
 9 ! c5t]1 &      flut$ bra*iopod %ells 
at top & c5t]4                          
,uses ( ,lime/one & ,dolomite    ,"s ( !
 major uses = ,ill9ois lime/one &       
dolomite are m5tion$  bel[4 ,n e        
lime/one or dolomite c be us$ = all     
purposes  because = ea* use ! /one mu/  
fulfill special requirem5ts ( a  *emical
 or physical nature4 ,= example1 x mu/ h
 high purity =  lime1 resi/ance to we> &

 wea!r = roads & build+s1 & a  pleas+   
appe>ance = decorative /one & m>ble4    
,lime4--,:5 lime/one or dolomite is     
heat$ to a high temp]ature1 x  und]goes 
a *ange & c>bon dioxide is lib]at$4 ,!  
weight ( !  gas set free is equal to    
some:at less ?an half ! weight ( ! rock 
if ! rock is pure4 ,! solid product     
rema9+ aft] ! gas has be5  driv5 (f is  
kn[n z lime4 ,! heat+ process is call$  
burn+4    ,besides be+ us$ 9 mak+ mort> 
& pla/]1 lime is valuable 9  _m o!r     
ways1 especially 9 v>i\s *emical        
processes ( mod]n  indu/ry4 ,plants at  
,*icago & ,qu9cy make lime f ,ill9ois   
lime/one  & dolomite4                   
,illu/ration3 ,figure #c--;,an ,ill9ois 
dolomite qu>ry4    ,cem5t4--,portl&     
cem5t1 sometimes call$ simply cem5t1 is 
made at  ,la,salle1 ,oglesby1 & ,dixon 9
 nor!rn ,ill9ois f lime/one & a  small]1
 c>efully measur$ am\nt ( clay or %ale4 
,cem5t also is made  at ,joppa 9 s\!rn  
,ill9ois4 ,! bl5d ( mat]ials is ?or\ghly
  gr\nd & mix$1 !n heat$ at a high      

temp]ature 9 huge rotat+  horizontal    
furnaces1 call$ kilns1 until x =ms a    
cl9k]4 ,aft] x  cools1 ! cl9k] is gr\nd 
to a fl\rlike p[d]4 ,?is is basically  !
 cem5t t b9ds toge!r ! mixture ( s& &   
lime/one 7or  dolomite71 or ( s& &      
gravel1 to make ! concrete f :i* roads1 
bridges1 build+s1 & o!r /ructures are   
made4    ,aggregate4--,! cru%$ /one us$ 
9 mak+ concrete is kn[n z  concrete     
aggregate4 ,?is is a major use =        
,ill9ois lime/ones &  dolomites4 ,l>ge  
am\nts ( /one aggregate also are us$ 9  
bitum9\s  roads1 popul>ly call$         
8blacktop0 roads4    ,agricultural      
,uses4--,agricultural lime/one 7ag/one7 
is appli$ to f>m  l& to neutralize soil 
acids & o!rwise b5efit ! soil4 ,bo?     
lime/one & dolomite are s us$4 ,*ick5s  
are f$ small lime/one  *ips to provide  
calcium = ! =mation ( egg %ells4 ,pigs &
 c[s  get calcium f m9]al supplem5ts    
conta9+ p[d]$ pure lime/one4            
,illu/ration3 ,figure #d--;,an und]gr\nd
 lime/one m9e4    ,o!r ,uses4--,ill9ois 

lime/one or dolomite is us$ 9 /eel mak+1
 z  build+ /one & m>ble1 z road /one1 z 
balla/ = ! road b$s  ( railroad tracks1 
= mak+ refractory dolomite us$ 9 ! /eel 
indu/ry1 & = a v>iety ( less common     
uses4                                   
,qu>ries    ,!re are ab\t #bjj /one     
qu>ries 9 ,ill9ois4 ,mo/ ( ! l>g]       
qu>ries 7fig4 #c7 are 9 ! ,*icago1      
,joliet1 ,kankakee1 & ,ea/ ,/4  ,l\is   
areas1 b "o or m lime/one or dolomite   
qu>ry occurs 9 _m  c\nties4    ,if all !
 /one tak5 f ,ill9ois qu>ries 9 #aifc 7 
remov$ f  a hole #ajj feet squ>e1 ! hole
 w\ld p5etrate into ! e>? ab\t #h       
miles4 ,x w\ld take m ?an #cej1jjj      
railroad c>s hold+ #ajj tons  ea* to    
haul away ! /one4 ,lime/one1 dolomite1 &
 _! products  add$ ov] #hj million      
doll>s to ! economy ( ! /ate 9 #aifc1   
approximately #h doll>s = ea* p]son 9   
,ill9ois4    ,mo/ ,ill9ois lime/one &   
dolomite is qu>ri$ f op5 pits1 b 9  "s  
places1 z 9 ! rocky bluffs along !      
,mississippi ,riv]1 !  /one is tak5 f   

und]gr\nd m9es 7fig4 #d74 ,!re is also a
 dolomite  m9e 9 ,*icago4 ,at ! qu>ries 
! fir/ /ep is ! removal ( !  e>? ov]ly+ 
! /one4 ,next1 9 bo? pit & m9e1 ! /one  
is  bla/$ to free x f ! p>5t deposit &  
break x into pieces4  ,me*anical %ovels 
7fig4 #c7 load ! /one into trucks t take
 x to  ! cru%+ plant :]e p[]ful cru%]s  
fur!r break ! /one into  pieces4 ,!     
pieces are sort$ into v>i\s sizes by    
l>ge scre5s4 ,at  "s ( ! plants1 ! /one 
is gr\nd into p[d]4                     
,location ( ,lime/one ,deposits    ,!   
geologic map ( ,ill9ois prep>$ by !     
,ill9ois ,/ate ,geological  survey %[s1 
) reasonable exactness1 :at b$rock      
=mations w\ld  crop out at ! surface if 
! ov]ly+ clay1 s&1 gravel1 & e>?  7     
remov$4 ,?ick dolomite =mations w\ld be 
expos$ 9 mu* ( !  nor!rn fif? ( ! /ate1 
b w\ld be r>e else:]e4 ,?ick  lime/one  
=mations w\ld occur 9 an almo/ cont9u\s 
zone1 v>y+  9 wid? f #c to #be miles1   
along ! ,mississippi ,riv] f ,rock      
,isl& to s\!rn ,ill9ois & !n ea/w>d     

across ! extreme  s\!rn tip ( ! /ate4   
,lime/one also w\ld be se5 along !      
,ill9ois ,riv] f ,havana s\?w>d4    ,9 !
 c5tral area ( ! /ate1 lime/ones are    
pres5t1 b !y are  r>ely ov] #be & (t5   
less ?an #ae feet ?ick4 ,consequ5tly1   
mo/ (  ! l>g] qu>ries are 9 ! nor!rn1   
we/]n1 & s\!rn p>ts (  ,ill9ois4 ,! ?9n]
 lime/ones1 none!less1 are ( mu*        
importance  & are qu>ri$ at _m places1  
*iefly to provide agricultural          
lime/one1 road /one1 & lime/one = mak+  
cem5t4    ,! ,geological ,survey locates
 & maps lime/one & dolomite deposits  & 
analyzes & te/s samples to det]m9e ! be/
 possible uses =  ! /one4 ,_m reports h 
be5 publi%$ ab\t ! "* &  g5]al use ( !  
deposits 9 v>i\s p>ts ( ! /ate4 ,o!r    
reports  deal ) ! use ( lime/one &      
dolomite = specific purposes su*  z     
cem5t mak+1 build+ & decorative /one1   
rock wool1 t]razzo  *ips1 & lime4       
,,metallic ,,ores ,,& ,,fluorsp>        
,lead & ,z9c    ,lead m9+ 0 "o ( !      
e>lie/ indu/ries ( ,ill9ois4 ,! e>ly    

settl]s' ne$ = bullets = procur+ food & 
= def5se ( _!  lives & prop]ty made lead
 an important commodity1 & ! deposits ( 
lead ore 9 ! nor?we/]n corn] ( ,ill9ois 
7 quickly exploit$4  ,! ore 0 ! m9]al   
gal5a 7fig4 #e71 = :i* ! city ( ,gal5a 9
  ,jo ,daviess ,c\nty is believ$ to h   
be5 nam$4        ,illu/ration3 ,figure  
#e--;,gal5a ) cubic cleavage blocks 9   
=egr\nd4    ,gal5a is a d>k1 %9y m9]al t
 breaks readily into cubes or           
comb9ations ( cubes4 ,x is compos$ (    
lead & sulfur 7,pb,s74 ,gal5a  itself is
 n suitable = use z a metal2 ! lead mu/ 
fir/ be  sep>at$ f ! sulfur4    ,!      
e>lie/ me?od ( recov]+ lead f gal5a 0   
crude4 ,a pile (  logs1 small] pieces ( 
wood1 & ore 0 built on slop+ gr\nd4 ,j  
bel[ x a pit 0 dug4 ,:5 ! wood 0 set on 
fire1 ! heat caus$  ! lead & sulfur to  
sep>ate1 & ! molt5 lead trickl$ d[n into
  ! pit4 ,! smelt+ process 0 lat]       
improv$1 & /one 8furnaces0  7 built to  
h\se ! op]ations4    ,crevice ,deposits 
& ,residual ,deposits4--,mo/ ( ! lead   

ore m9$ 9  ! e>ly days ( ! nor?we/]n    
,ill9ois m9+ di/rict came f  crevice    
deposits 9 ! dolomite b$rock & f        
residual deposits at  or ne> ! surface (
 ! gr\nd4 ,! crevices 7 v]tical n>r[    
jo9ts or fissures4 ,ore 0 n cont9u\sly  
pres5t along !m b  occurr$ f place to   
place 9 8pods0 7fig4 #f & fig4 #g74     
,dim5sions  ( ! pods v>i$1 b typical    
ones 7 ab\t #c feet wide1 #e feet  high1
 & a few to a few hundr$ feet long4 ,!  
gal5a1 = ! mo/  "p1 occurr$ 9 a mixture 
( clay & wea!r$ dolomite t fill$1  or   
p>tly fill$1 ! crevices4    ,! residual 
deposits 7 f\nd :]e ! action ( ! wea!r =
  _m ?\s&s ( ye>s _h dissolv$ ! dolomite
 f ! outcropp+  p>ts ( a crevice deposit
 & left beh9d a residue ( br[n or r$    
clay conta9+ gal5a4    ,"s ( ! crevice &
 residual deposits work$ by ! e>ly m9]s 
cropp$ out at ! surface1 b mo/ ( !m 7   
cov]$ by e>?4  ,o!r crevices 7 expos$ 9 
! bluffs ( ! ,mississippi ,riv] &       
ext5d$ back into !m = #a1jjj feet or m4 
,illu/ration3 ,figure #f--;,diagrammatic

 cross section ( two crevice            
deposits4 ,a rea*es gr\nd surface & is  
fill$ ) clay2 ,b is      only p>tly clay
 fill$4 ,gal5a coats p>ts ( ! walls &   
occurs      z pieces scatt]$ ?r\gh !    
clay4 ,typical crevices are ab\t #c     
feet wide & #e feet high4      ,,soil   
,a      ,,gal5a      ,,clay ,,& ,,rott$ 
,,dolomite    ,b      ,,gal5a           
,,clay ,,& ,,rott$ ,,dolomite           
,,dolomite    ,:5 ! ri*] deposits ( ore 
9 ! crevices 7 work$ out1 "s  m9es 7    
deep5$ into ! dolomite b$rock1 b usually
 less r  ?an m gal5a 0 f\nd4    ,z !    
am\nt ( gal5a decreas$1 h[ev]1 ano!r    
m9]al1 :i* _h  be5 pres5t be=e 9 only   
small am\nts1 0 f\nd 9 increas+         
quantities4 ,?is 0 sphal]ite--a yell[1  
br[n1 or black m9]al (  res9\s appe>ance
 t is compos$ ( z9c & sulfur 7,zn,s74 ,x
 does  n look l a metallic ore4    ,at  
fir/ ! sphal]ite 0 n us$ because !re 7  
no smelt]s 9  ! area t c\ld sep>ate !   
z9c f ! sulfur ) :i* x 0  comb9$ 9 !    
ore4 ,betwe5 #ahej & #ahgj1 h[ev]1      

smelt]s 7 built  9 nor?we/]n ,ill9ois & 
s\!rn ,wiscons9 & ! ore 0 %ipp$  !re4   
,sphal]ite is n[ ! pr9cipal ore m9]al   
produc$ 9  nor?we/]n ,ill9ois4    ,!    
sphal]ite & gal5a ( s\!rn ,ill9ois1     
describ$ lat]1 are  simil> to t f\nd 9  
nor?we/]n ,ill9ois4        ,illu/ration3
 ,figure #g--;,crevice lead m9e4 ,m9]   
pries ore loose &      pu%es x into c>  
at bottom ( crevice4 ,%9y gal5a lay]    
occurs      above 8 head & ano!r at     
level ( 8 wai/4    ,m9+ & ,mill+4--,"o  
l>ge m9e is produc+ z9c & lead ne>      
,gal5a at pres5t4 ,small] m9es op]ate   
irregul>ly4 ,! ore may occur  z pockets1
 irregul>ly %ap$ r flat masses1 v]tical 
or incl9$  ve9s 7fig4 #h71 or small     
p>ticles scatt]$ ?r\gh ! dolomite4 ,!   
pr9cipal ore bodies t h be5 work$ 9     
rec5t ye>s h be5 (  irregul> %ape1 bo?  
horizontally & v]tically1 & usually h   
be5  betwe5 #ej & #bjj feet wide & f a  
few to z mu* z #ajj feet high4  ,!y lie 
at a dep? ( r\ghly #cjj feet4    ,bla/+ 
is requir$ to loos5 & break ! ore4 ,at !

 l>ge m9e !  ore is br\ght to ! surface 
by a hoi/4 ,9 "s relatively %all[  m9es 
an incl9$ tunnel has be5 driv5 to ! ore 
body & ! ore  br\ght to ! surface 9     
trucks4        ,illu/ration3 ,figure    
#h--;,diagrammatic cross section ( a z9c
 ore      deposit %[+ flats & pit*es4 ,!
 deposit occurs 9 lime/one      &       
dolomite4 ,mu* ( ! ore is a mixture (   
dolomite1 lime/one1      calcite1 &     
sphal]ite4 ,typical dim5sions ( su* a   
deposit are      ab\t #cj feet high &   
#ajj to #bjj feet wide4      ,,ore      
,,pit*es    ,,flats    ,because ! ore   
consi/s ( gal5a & sphal]ite atta*$ to & 
scatt]$ ?r\gh dolomite1 x mu/ be mill$  
to free & sep>ate !  metals f ! rock4   
,cru%+1 gr9d+1 & o!r op]ations are      
involv$4 ,! dolomite is disc>d$ & !     
gal5a & sphal]ite  conc5trates are %ipp$
 away to be smelt$4 ,no smelt]s h op]at$
  9 ! ,gal5a area = "s "t4    ,aids to  
,prospect+4--,f9d+ deposits ( ore #cjj  
feet und]gr\nd is  n easy4 ,inspection (
 ! surface usually tells little4 ,to f9d

 &  outl9e a comm]cial ore deposit _m   
holes (t5 mu/ be drill$ to  explore !   
unexpos$ rock /rata4 ,because ?is is a  
co/ly process1  e possible means is     
employ$ to drill ! holes :]e ore is mo/ 
likely to be f\nd4 ,?is is :]e geologi/s
 are useful--geologi/s (  ! m9+         
companies & ( ! ,ill9ois ,geological    
,survey4 ,?ree  examples ( h[ _!        
inve/igations help to f9d ore are giv5  
"h4    ,x 0 not$ e>ly 9 ! developm5t ( !
 nor?we/]n ,ill9ois  m9+ di/rict t z9c  
ore deposits 7 mo/ common along small   
d[nfolds 9 ! b$rock1 call$ syncl9es1 t 7
 a few hundr$ feet  wide & a mile or s  
long4 ,! syncl9es 7 associat$ ) mu*     
l>g] syncl9es t ext5d$ = sev]al miles4  
,a map prep>$ by !  ,ill9ois ,geological
 ,survey %[s ! possible location & ext5t
 (  _m ( ^! d[nfolds & has _h mu*       
practical use 9 ! selection  ( ! mo/    
promis+ areas = te/ drill+ to f9d ore4  
,! ,survey also collects ! records (    
bor+s made by companies &  individuals 9
 _! se>* = ore4 ,! records are on       

p]man5t file  at ! ,survey (fices & are 
valuable 9 sev]al ways4 ,"s indicate    
:]e no ore 0 f\nd & :]e x is1 !re=e1    
useless to drill  fur!r2 o!rs %[ only   
traces ( ore b sugge/ t m drill+  9 !   
vic9ity might discov] a deposit l>ge    
en\gh to be m9$  pr(itably4 ,/ill o!r   
records are ( bor+s t enc\nt]$ ri* ore  
9 :i* m9es h be5 develop$4    ,! ?ird   
aid to prospect+ is ! /udy ( ore bodies 
& _!  m9]als to det]m9e h[ ! deposits 7 
=m$4 ,! ore bodies h  be5 & are be+     
/udi$ 9 ! m9es4 ,ore specim5s are       
c>efully  exam9$ 9 ! ,survey            
laboratories4 ,if geologi/s c le>n h[ ! 
kn[n deposits 7 =m$1 x may be possible  
to direct exploration  into promis+ new 
areas4                                  
,fluorsp>    ,9 ! s\!a/]n tip ( ,ill9ois
 lie deposits ( a m9]al t  conta9s !    
*emical elem5t fluor9e4 ,?is elem5t is  
us$ 9 mak+  ! propellant t activates    
a]osol sprays1 a pla/ic t resi/s        
*emicals & oil & is /rong en\gh to be   
us$ = be>+s1  comp\nds t are said to    

help to prev5t too? decay1 & _m o!r     
useful *emicals4    ,! m9]al is fluorite
 7fig4 #i71 commonly call$ fluorsp>4 ,x 
is  compos$ ( calcium fluoride 7,ca,f71 
a comp\nd ( calcium & fluor9e1  & is a  
glassy m9]al t is g5]ally :ite or gray b
 may be  purple1 rose1 yell[1 blue1 or  
gre54 ,9 r>e in/ances x is colorless4   
,fluorsp> m9+ 9 ,h>d9 & ,pope ,c\nties  
began ) lead m9+4  ,gal5a 0 fir/        
discov]$ !re 9 #ahci 9 a well be+ dug at
 !  t[n ( ,rosicl>e4 ,m9+ ( gal5a began 
9 ! e>ly #ahdj's1 &  some:at lat] ore 0 
be+ smelt$ by ?ree furnaces1 all ( :i*  
h long s9ce disappe>$4    ,! ve9s t 7   
work$ = gal5a also conta9$ fluorsp>1 b z
  !re 0 little or no use = fluorsp> 9 ! 
#ahdj's x 0 consid]$  wa/e4 ,9 "t1 uses 
develop$1 h[ev]1 & ab\t #ahgj x 0 m9$ & 
%ipp$ 9 comm]cial quantities4 ,s9ce !n !
 tonnage & value (  ! fluorsp> produc$ f
 ! ,rosicl>e area h increas$ until      
fluorsp> is ! major product4            
,illu/ration3 ,figure #i--;,gr\p ( cubic
 fluorite cry/als4    ,! fluorsp> m9+   

di/rict nor? ( ! t[n ( ,cave 9 ,rock 9  
ea/]n ,h>d9 ,c\nty also 0 an e>ly       
produc] ( gal5a4 ,9 t area  !           
fluorsp>-gal5a deposits are elongate &  
approximately flat4 ,!  fir/ m9]s foll[$
 ! ore bodies f outcrops by tunnel+ into
 !  hillsides4 ,9 ! late #aicj's & e>ly 
#aidj's1 _m holes 7 drill$  into !      
b$rock 9 se>* ( new deposits4 ,ore 0    
f\nd t conta9$  n only gal5a & fluorsp> 
b also important am\nts ( sphal]ite4    
,ve9 ,deposits4--,9 ! ,rosicl>e di/rict1
 ! fluorsp> & its  accompany+ m9]als    
occur z /eeply incl9$ ve9s a few in*es  
to #be  feet or m wide 7fig4 #aj71      
usually 9 lime/one /rata4 ,! ve9s are  n
 uni=mly ?ick b wid5 or n>r[ f place to 
place bo?  v]tically & horizontally4 ,!y
 occur along faults--planes along :i*  !
 rocks ( ! e>?'s cru/ h brok5 & slipp$4 
,a fault may be a  s+le plane ( slippage
 b m (t5 is a zone ( brok5 &  displac$  
rocks4 ,9 mo/ ( ! faults t conta9       
fluorsp>1 !  slippage is v]tical1 or    
ne>ly s4 ,along "o ( ! faults 9 !       

,rosicl>e di/rict1 ! rocks on "o side ( 
! fault h mov$  d[nw>d z mu* z #fej feet
 9 relation to ! rocks on ! o!r side4   
,"s faults are m ?an #aj miles long1 & !
 dep? to :i* !y  ext5d into ! e>? is    
unkn[n4 ,fluorsp> has be5 m9$ f "o (  !m
 at dep?s ( #hjj feet4 ,n all faults1   
nor all p>ts ( any "o  fault1 conta9    
fluorsp>4        ,illu/ration3 ,figure  
#aj--;,diagrammatic cross section (     
fluorsp>      ve9 along a fault4 ,!     
/rata on ! left side ( ! fault h        
mov$ d[nw>d ) ref]5ce to ^? on ! "r     
side4      ,,soil    ,,fault            
,,fluorsp> ,,ve9 ,,along ,,fault        
d[n        ,,s&/one ,a        ,,lime/one
 ,b        ,,%ale ,c        ,,s&/one ,d 
,,lime/one ,e      up        ,,lime/one 
,b        ,,%ale ,c        ,,s&/one ,d  
,,lime/one ,e    ,b$d+ ,deposits4--,9   
contra/ to ! ve9 deposits ( ! ,rosicl>e 
di/rict1 ! b$d+ deposits ( ! ,cave 9    
,rock area are flat1 or  ne>ly flat1    
commonly #e to #ae feet ?ick1 & f a few 
to #bjj feet  wide 7fig4 #aa74 ,!y may  

be z mu* z #bjjj feet long1 wid5+ or    
n>r[+ & ?ick5+ or ?9n+ ?r\gh\t _! ext5t4
 ,!y are  call$ b$d+ deposits because !y
 lie along ! b$s or lay]s ( !  lime/one 
9 :i* !y occur4 ,mo/ ( ! ore bodies are 
associat$  ) a fracture or a small      
fault4        ,illu/ration3 ,figure     
#aa--;,diagrammatic cross section ( b$d+
      deposit ( fluorsp>1 lead1 & z9c   
ore4      ,,soil    ,,s&/one ,,& ,,%ale 
,,ore    ,,lime/one    ,,fracture ,,or  
,,small ,,fault    ,grades & ,uses (    
,fluorsp>4--,!re are ?ree pr9cipal      
grades (  fluorsp>--metallurgical1 acid1
 & c]amic4 ,! metallurgical sp> is  us$ 
z a flux 9 mak+ /eel & 9 metal f\ndries4
 ,acid sp> is us$  to make hydr(luoric  
acid1 :i* plays a "p 9 ! prep>ation (   
uranium isotopes & 9 ! production ( a   
syn!tic m9]al ess5tial  9 ref9+ alum9um4
 ,! acid is also us$ 9 ! production (   
high-octane gasol9e & is ! basis = a    
v>iety ( important  *emical comp\nds1   
among !m refrig]ants & insecticides4    
,c]amic  grade fluorsp> is us$ 9 mak+   

enamels1 glazes1 & c]ta9 k9ds (  glass4 
,m9+ & ,mill+4--,fluorsp> & its         
associat$ ores are m9$ 9  diff]5t ways 9
 ! ,rosicl>e & ,cave 9 ,rock di/ricts   
because !  types ( deposits diff]4      
,h[ev]1 9 bo? areas mo/ ( ! l>g]  m9es  
are ent]$ by v]tical %afts4 ,9 ! m9es1  
explosives are  plac$ 9 holes drill$ by 
ma*9es & are !n detonat$ to %oot d[n  ! 
ore 7fig4 #ab74 ,m9e c>s1 trucks1 or    
conveyor belts c>ry ! ore to  ! bottom (
 ! m9e %aft :]e hoi/s raise x to ! mills
 at !  surface4 ,9 ! mills a v>iety (   
ore-classify+ ma*9es sep>ate !  gal5a1  
sphal]ite1 & fluorsp> f ! wa/e m9]al    
mat]ials  7*iefly lime/one & calcite7 ) 
:i* !y occur4 ,"s fluorsp>  aft] !      
sep>ation process is almo/ fl\r-f9e4 ,to
 increase its use1  mu* ( ?is sp> is    
mix$ ) a b9d] & made into pellets or    
briquets "o-half to "o in* 9 size4      
,illu/ration3 ,figure #ab--,ma*9e load+ 
fluorsp> ore 9 m9e ne>      ,cave 9     
,rock4    ,geological & ,*emical        
,/udies4--,because mu* ( ! fluorsp>     

produc$ 9 s\!rn ,ill9ois has come f ve9s
 along faults1  geologi/s h mapp$ !     
faults ( ! area by inve/igat+ !         
di/ribution & nature ( ! v>i\s b$rock   
outcrops4 ,! "w 0  complicat$ by !      
mantle ( e>? & vegetation t cov]s !     
b$rock at _m places4 ,h[ev]1 a geologic 
map 0 made t %[s  :]e ! v>i\s rock      
=mations--s&/one1 lime/one1 & %ale--lie 
b5ea? ! surface & :]e ! num]\s faults   
crisscross !  di/rict4    ,! fir/       
geologic map ( ! fluorsp> di/rict 0 made
 9 #aibj by !  ,ill9ois & ,u4 ,s4       
,geological ,surveys4 ,new maps on a mu*
 l>g] scale  h be5 made rec5tly by !    
,ill9ois ,survey to meet ! ne$s ( !     
mod]n fluorsp> indu/ry4    ,! ,ill9ois  
,survey also has /udi$ ! ores & ore     
deposits (  s\!rn ,ill9ois to det]m9e h[
 !y 7 =m$4 ,! records ( _m  bor+s & pits
 sunk to f9d ore h be5 collect$ & fil$  
at !  ,survey to guide future prospect+4
    ,survey *emi/s are f9d+ new uses =  
,ill9ois fluorsp>4 ,_!  rese>* has      
produc$ new organic fluor9e comp\nds t  

are be+  te/$ = use 9 agriculture1      
m$ic9e1 & indu/ry4 ,!y also h  work$ out
 easi] & *eap] me?ods ( mak+ c]ta9      
fluor9e  comp\nds4 ,survey *emical      
eng9e]s h help$ to obta9 ne$$  in=mation
 ab\t ! physical prop]ties ( ! pellets  
made f  fluorsp> p[d]4                  
,orig9 ( ,ill9ois ,ore ,deposits    ,!  
ore deposits ( nor?we/]n & s\!rn        
,ill9ois 7 =m$ s  _m millions ( ye>s ago
 t x is possible to propose only !ories 
( _! orig94 ,mo/ geologi/s ?9k t !      
m9]als1 dissolv$ 9  w>m or hot wat]1    
came f deep 9 ! e>?4 ,p]haps !          
m9]al-be>+ wat] came f1 or 0 associat$  
)1 rocks t 7  or _h be5 molt5 7igne\s   
rocks71 b x may h _h "s o!r  s\rce4 ,:y 
! ores occur :]e we n[ f9d !m is n fully
 kn[n4  ,! cool+ ( ! solutions & !      
less5+ ( pressure z !  solutions rose   
t[>d ! surface may h _h a "p 9 ore      
deposition4  ,faults & ! nature ( !     
rocks enc\nt]$ by ! deposit+  solutions 
also appe> to h _h an influ5ce4         
,ill9ois z a ,m9+ ,/ate    ,al?\gh      

,ill9ois is n usually ?\ght ( z a m9+   
/ate1  nor?we/]n & s\!rn ,ill9ois toge!r
 produc$ 9 #aifc ne>ly  #e1jjj1jjj wor? 
( z9c1 ab\t #fjj1jjj wor? ( lead1 &     
#f1ejj1jjj  wor? ( fluorsp>4 ,! annual  
total value is ab\t #ab1jjj1jjj4    ,!  
s\!rn ,ill9ois fluorsp> di/rict has     
ano!r di/9ction--=  _m ye>s its m9es h  
be5 ! major dome/ic s\rce ( ! nation's  
fluorsp>4                               
,,silica ,,s&      ,ab\t #dej1jjj1jjj   
ye>s ago1 a %all[ ocean cov]$ ,ill9ois4 
,its waves  & curr5ts c>ri$ clean :ite  
s& & deposit$ x z curv+  bea*es1 s& b>s1
 & dunes4 ,?is s& diff]$ f _m s&s 9  t x
 0 compos$ almo/ exclusively ( gra9s ( !
 m9]al qu>tz  in/ead ( be+ a mixture (  
qu>tz & o!r m9]als4    ,qu>tz is compos$
 ( silica 7,si,o71 & s&s su* z ! anci5t 
,ill9ois s& t are compos$ ( qu>tz are   
kn[n z silica s&s4  ,qu>tz is v h>d & w 
scrat* glass & "s /eel4 ,p]fect  qu>tz  
cry/als1 :i* are r>e1 are long] ?an !y  
are ?ick & end  9 pyramids4 ,probably n 
_m gra9s ( ! anci5t s& came f  p]fect   

cry/als2 !y m likely result$ f ! decay+ 
&  break+ d[n ( rocks su* z granite1 :i*
 are mixtures ( qu>tz  gra9s & o!r m9]al
 p>ticles4    ,! qu>tz gra9s probably   
did n come directly f _! s\rce to       
,ill9ois4 ,in/ead1 x is likely !y fir/ 7
 deposit$ else:]e &  =m$ into s&/one4 ,t
 s&/one 0 subsequ5tly brok5 d[n by      
wea!r+ ag5ts & ! gra9s transport$ to !  
anci5t ,ill9ois sea  by /reams4    ,z a 
result ( ! erosive action ( ! ag5ts t   
transport$ !m1  _m ( ! orig9ally angul> 
gra9s1 p>ticul>ly ! co>s] ones1  7 r\nd$
 & _! surfaces dull$ l t ( fro/$ glass  
7fig4  #ac74 ,consequ5tly1 !y appe>     
:ite1 al?\gh !y actually are  colorless4
    ,s9ce ! anci5t sea deposit$ its     
silica s&1 o!r seas h cov]$  ,ill9ois at
 v>i\s times & ea* has left deposits (  
s&1 mud1 or  limy mat]ials4 ,! silica s&
 ?us 0 buri$ by hundr$s ( feet (  o!r   
s$im5ts & became s&/one4 ,?is s&/one is 
call$ ! ,/4  ,pet] ,s&/one4 ,x is nam$ f
 ! ,/4 ,pet] ,riv]1 n[ ! ,m9nesota      
,riv]1 9 ,m9nesota :]e ! s&/one 0 fir/  

describ$ & nam$ by  geologi/s4 ,! ov]ly+
 deposits also 7 consolidat$ into rock4 
,/4 ,pet] ,s&/one is expos$ at ! surface
 at _m places 9 nor!rn  ,ill9ois & 9 "o 
small area 9 ! we/]n "p ( ! /ate4 ,!    
s&/one expos$ 9 nor!rn ,ill9ois g5]ally 
v>ies f #abe to #cjj  feet ?ick4 ,! fact
 t x crops out at ! surface indicates t 
!  mat]ials t =m]ly cov]$ x h be5       
remov$4    ,! uncov]+ 0 n a s+le1 simple
 ev5t b r a s]ies (  ev5ts t took place 
at v>i\s times dur+ ! _m ye>s s9ce !    
,/4 ,pet] s& 0 deposit$4 ,among ^! 0 !  
up-b[+ ( ! rocks  ( c5tral nor!rn       
,ill9ois into a broad ar*4 ,/reams !n   
began to  cut across ! ar*$ rock1 sl[ly 
b p]si/5tly /ripp+ away !  top lay]s    
until ! core ( ! ar* 0 laid b>e4 ,among 
! rocks  ?us expos$ 0 ! ,/4 ,pet]       
,s&/one1 :i* may be se5 9 nor!rn        
,ill9ois 9 ! valleys & tribut>ies ( !   
,rock ,riv] ne> ,dixon &  ,oregon &     
along ! ,ill9ois & ,fox ,riv]s & "s ( _!
  tribut>ies ne> ,ottawa1 ,w$ron1       
,mill+ton1 & ,troy ,grove4 ,! ,/4  ,pet]

 ,s&/one at ,/>v$ ,rock & ,mat?iess5    
/ate p>ks ne> ,la,salle  & along !      
highway betwe5 ,dixon & ,oregon is erod$
 into sc5ic  bluffs & canyons4          
,illu/ration3 ,figure #ac--;,enl>g$     
photograph ( ,/4 ,pet] s&      %[+ !    
r\nd$ & fro/$ "* ( ! gra9s4             
,silica ,s& ,indu/ry    ,! ,ill9ois     
silica s& indu/ry is bas$ on ! ,/4 ,pet]
 ,s&/one4  ,x c5t]s ar\nd ,ottawa1      
,w$ron1 ,troy ,grove1 & ,utica 9        
,la,salle  ,c\nty & 9 ,oregon 9 ,ogle   
,c\nty4 ,two pr9cipal grades ( silica s&
  are produc$--wa%$ & crude4 ,! value ( 
! silica s& produc$ 9  ,ill9ois 9 #aifc 
0 ab\t #i1jjj1jjj4    ,wa%$             
,s&4--,al?\gh ! ,/4 ,pet] ,s&/one is    
compos$ almo/  entirely ( qu>tz gra9s1 a
 small am\nt ( clay is pres5t4 ,= "s    
uses x is n necess>y to remove ! clay1 =
 o!rs its elim9ation  is important & is 
a*iev$ by wa%+ ! s&4    ,9 ! m9+ (      
silica s& t is to be wa%$1 ! s&/one is  
fir/ bla/$ loose f ! p>5t deposit to    
break x into s& or  pieces ( v>i\s      

sizes4 ,"s ( ! l>g] pieces may require a
 second  bla/+ to dis9tegrate !m4    ,at
 "s pits ! mat]ial is load$ me*anically 
& transport$ to !  wa%+ plant4 ,at o!rs 
a p[]ful /ream ( wat] is direct$ aga9/  
! brok5 s&/one 7fig4 #ad7 & ! result+   
mixture ( s& &  wat] fl[s to a collect+ 
bas9 f :i* x is pump$ ?r\gh l>ge  pipes 
to ! process+ mill4    ,9 bo? types (   
op]ation ! s& is ?or\ghly wa%$ at !     
plants4  ,aft] x is wa%$1 ! s& is fur!r 
process$ to suit ! ne$s (  its us]s4    
,mu* ( x is scre5$ into diff]5t size    
grades4    ,uses ( ,wa%$ ,silica        
,s&4--,! wa%$ silica s& produc$ 9       
,ill9ois has _m uses1 "s ( :i* are      
briefly m5tion$ bel[4 ,!  suitability ( 
! s& = "s purposes dep5ds 9 "p on its   
hav+  be5 scre5$ to specifi$ sizes4     
,! high purity ( ,ill9ois wa%$ silica s&
 makes x suitable =  mak+ glass1 :i* is 
m ?an half silica s&4 ,ea* ye> ov] a    
million tons is us$ = ?is purpose4 ,!   
purity ( ! s& also is (  importance =   
*emical & metallurgical uses su* z !    

manufacture  ( sodium silicate & silicon
 c>bide & 9 alloy+4    ,! h>dness ( ! s&
 makes x useful = gr9d+ l>ge %eets (    
plate glass to prep>e !m = poli%+ & also
 makes x an effective  abrasive ag5t =  
s&bla/+4 ,metal ca/+s 9 f\ndries & !    
ext]iors ( build+s are clean$ by ?is    
process4 ,ill9ois produces  ?\s&s ( tons
 ( s& ye>ly = su* abrasive purposes4    
,because ! co>s] gra9s ( ! wa%$ silica  
s& are r\nd$1  /rong1 & available 9     
uni=m sizes1 oil op]ators use ?\s&s (   
tons ( x annually 9 ! hydraulic fractur+
 ( oil-be>+ /rata4  ,! s& is mix$ ) oil1
 o!r petroleum products1 or wat] & is   
=c$ by p[]ful pumps into s&/one or      
lime/one =mations t  conta9 oil4 ,!     
great =ce ?us ex]t$ op5s fractures 9 !  
rock  /rata & pu%es ! liquid & s& into  
!m4 ,:5 ! pressure is  reliev$1 ! s&    
gra9s s]ve z props to hold ! fractures  
op54 ,!  oil c !n fl[ m easily into !   
wells & oil production is ?us  increas$4
    ,! wa%$ s&1 because x is clean &    
does n dissolve 9 wat]1 is  us$ to filt]

 impurities f dr9k+ wat]4 ,its :it5ess  
makes x a  desirable con/itu5t 9 pla/]1 
mort>1 & preca/ build+ panels4          
,illu/ration3 ,figure #ad--;,hydraulic  
m9+ ( silica s& ne>      ,ottawa4       
,because x is r\nd gra9$ & )/&s high    
temp]atures )\t  melt+1 l>ge tonnages ( 
! wa%$ silica s& are us$ to make molds  
into :i* molt5 metal is p\r$ to make    
v>i\s k9ds ( ca/+s4    ,a special type (
 co>se silica s& f ,ill9ois t is        
c>efully  prep>$ s t x is always ( !    
same gra9 size is us$ ?r\gh\t  ! _w z a 
/&>d 9 laboratories t te/ cem5t & o!r   
comm]cial products4        ,illu/ration3
 ,figure #ae--,load+ crude silica s&4   
,"s silica s& is gr\nd to a f9e1 :ite   
p[d]4 ,! p[d]1 call$  gr\nd qu>tz1 gr\nd
 silica1 silica fl\r1 or pott]'s fl9t1  
has _m  uses4 ,x is an +r$i5t 9 pa9ts1  
pott]s use x 9 mak+ pott]y  & *9a1 x    
goes into sc\r+ p[d]s1 into molds us$ = 
precision  types ( metal ca/+s1 & into  
enamels4    ,crude ,silica ,s&4--,!     
crude silica s& produc$ f ! ,/4 ,pet]   

,s&/one g5]ally is yell[ or yell[i% :ite
 & is n wa%$  be=e x is us$4 ,x probably
 orig9ally 0 :ite1 b iron oxide1  simil>
 to ! ru/ t =ms on iron1 n[ coats _m ( !
 s&  gra9s & colors ! small am\nt ( clay
 9 ! s&4 ,?\s&s (  tons ( crude silica  
s& are m9$ annually 7fig4 #ae74 ,because
 x is  highly heat resi/ant1 f\ndries   
buy mu* ( x to make ! molds us$  =      
ca/+s1 especially /eel ca/+s1 & =       
automobile eng9e  blocks1 tra9 :eels1 & 
a v>iety ( o!r metal products4 ,crude   
silica s& also is us$ ar\nd indu/rial   
furnaces to seal cracks &  op5+s to     
prev5t ! loss ( heat1 9 c]ta9 c]amic    
products1 &  = adju/+ ! silica cont5t ( 
! raw mat]ials us$ = mak+  portl& cem5t4
                         ,/udies ( ! ,/4
 ,pet] ,s&/one    ,! ,ill9ois           
,geological ,survey has made field      
/udies & prep>$ maps  %[+ :]e ! ,/4     
,pet] ,s&/one is expos$ 9 nor!rn & we/]n
  ,ill9ois4 ,_m samples h be5 scre5$ &  
exam9$ "u a  microscope to det]m9e h[ ! 
s& ( diff]5t deposits1 or diff]5t  p>ts 

( ! same deposit1 v>ies 9 gra9 size &   
m9]al composition4  ,! possibility ( us+
 ,ill9ois silica s& = mak+ silica brick 
also has be5 inve/igat$4                
,,gravel ,,& ,,s&      ,"s #bbe1jjj ye>s
 ago1 mo/ ( :at is n[ ,ill9ois 0 buri$  
"u  ! ice ( ! ,ill9oian glaci]4 ,two    
e>li] glaci]s _h cov]$ l>ge  p>ts (     
,ill9ois1 & ano!r1 kn[n z ! ,wiscons9an 
glaci]1 came  into ! /ate lat]1 ab\t    
#ej1jjj to #gj1jjj ye>s ago 7fig4 #af74 
,! relatively small glaci]s 9 ! ,unit$  
,/ates today1 su* z ^?  9 ! nor!rn      
,rocky ,m\nta9s1 are conc5trat$ 9       
valleys & are  call$ valley glaci]s4 ,! 
glaci]s t cov]$ ,ill9ois 7 p>ts (  huge 
ice %eets t ext5d$ ov] mu* ( ! ,nor?    
,am]ican cont95t  & are call$ cont95tal 
glaci]s4 ,!y spread ov] mo/ ( ,canada1  
!n pu%$ s\?w>d to bury ,new ,engl& & a  
great area 9 !  nor?-c5tral "p ( !      
,unit$ ,/ates nor? ( ! ,ohio & ,miss\ri 
,riv]s4                       ,=mation (
 ,gravel & ,s& ,deposits    ,z ! glacial
 ice edg$ sl[ly s\?w>d f ,canada1 x     

froze fa/ to  & pick$ up soil & loose   
pieces ( rock1 ) enorm\s =ce tore  away 
huge *unks ( b$rock1 & mix$ & gr\nd ^!  
mat]ials  toge!r 7fig4 #ag74    ,into   
,ill9ois ! glaci] c>ri$ rock mat]ials f 
,canada1 ,wiscons91  ,m9nesota1 &       
,mi*igan2 o!r rock fragm5ts 7 pick$ up 9
 ,ill9ois  z ! ice front advanc$4 ,:5 ! 
glaci] melt$1 x left beh9d its  load (  
rock fl\r & rock fragm5ts1 mu* ( x z a  
gray clay  conta9+ pebbles1 cobbles1 &  
b\ld]s4 ,geologi/s call su* deposits    
glacial till4        ,illu/ration3      
,figure #af--;,ext5t ( ! expos$ deposits
 ( !      ,wiscons9an1 ,ill9oian1 &     
,kansan glaci]s 9 ,ill9ois1 & !         
unglaciat$ areas ( ! /ate4              
,,unglaciat$    ,,wiscons9an ,,glaci]   
,freeport      ,fulton      ,peoria     
,decatur      ,*>le/on    ,,ill9oian    
,,glaci]      ,kewanee      ,wat]loo    
,c>bondale      ,h>risburg    ,,kansan  
,,glaci]    ,,unglaciat$      ,h>d9     
,! ice 9 ! cont95tal glaci]s usually    
crept =w>d1 sometimes  sl[ly1 sometimes 

m rapidly4 ,:e!r ! front ( a glaci] mov$
  =w>d or back dep5d$ on ! balance      
betwe5 ! rate ( =w>d  motion ( ! ice & !
 rate ( melt+4 ,:5 ! ice advanc$ fa/]   
?an x melt$1 ! front ( ! glaci] mov$    
=w>d4 ,:5 ! glacial  ice melt$ fa/] ?an 
x mov$ =w>d1 ! front ( ! glaci]  rec$$4 
,:5 ! rates ( melt+ & advance 7 ab\t    
equal1 !  front ( ! glaci] /ood /ill or 
mov$ back & =? 9 a n>r[  zone4          
,illu/ration3 ,figure #ag--,/riat$      
b\ld]4 ,scrat*es & flatt5$      surfaces
 7 caus$ by abrasion by o!r rocks :ile  
b\ld] 0      emb$d$ 9 glacial ice4      
,:5 su* a m or less /ation>y front      
exi/$1 an enorm\s am\nt (  clay1 silt1  
s&1 pebbles1 & b\ld]s 0 deposit$ 9 a    
belt only a  few miles wide along !     
front ( ! glaci]1 creat+ a l9e ( hills  
& ridges t ext5d$ = _m miles4 ,su*      
belts1 call$ end  mora9es1 c be se5     
today 9 _m p>ts ( ,ill9ois4    ,! build+
 ( end mora9es (t5 0 accompani$ by !    
release (  great quantities ( wat]      
7meltwat]7 f ! melt+ ice4 ,! wat]1  lad5

 ) rock debris1 fl[$ f ! front ( !      
glaci] 9 _m  /reams4    ,z ! meltwat]   
fl[$ away f ! glaci] x sort$ its load1  
al?\gh ! sort+ 0 r>ely p]fect4 ,! heavy 
b\ld]s & pebbles  usually 7 dropp$ fir/1
 !n ! s&1 next ! silt1 & f9ally  ! clay4
 ,9 g5]al1 ! f>!r ! deposits 7 f !      
glaci] !  f9] !y 74 ,! major /reams     
frequ5tly c>ri$ pebbles #ej to #ajj     
miles f ! glaci] & x 0 _m m miles be=e  
all ! s&  0 dropp$4 ,!y c>ri$ "s ( ! f9e
 silt & clay z f> z !  ,gulf ( ,mexico4 
,sometimes ! floods ( glacial wat] 7    
great] & fl[$ fa/]  ?an usual & s 7 able
 to c>ry co>se rock mat]ials f>!r4 ,z a 
result1 gravel 0 laid d[n on top ( e>li]
 s& deposits4 ,lat]  !re may h be5 fur!r
 s& deposition4    ,! debris-lad5       
meltwat] t fl[$ into valleys (t5        
deposit$ 9  !m a consid]able fill+ ( s& 
& gravel4 ,"s valleys 7 fill$  to a dep?
 ( z mu* z #ajj feet4 ,su* deposits are 
call$ valley fills  or valley tra9s4    
,mod]n /reams h cut _! c\rses into _m ( 
^! fills & ev5 worn away l>ge p>ts ( !m4

 ,remnants ( valley  tra9 deposits are  
n[ l>ge t]races or b5*es along /reams1  
_m (  !m well above ! pres5t /ream      
*annels4    ,:]e _m small /reams fl[$ f 
! glaci]1 !y deposit$ s&  & gravel z a  
l>ge apron 9 front ( ! glaci]4 ,su*     
deposits are  call$ outwa% pla9s & _m ( 
!m ext5d = miles4    ,two o!r types ( s&
 & gravel deposits made by glacial      
meltwat]s  also are significant4 ,"o 0  
=m$ :]e wat] issu$ f ! front  ( a glaci]
 or p\r$ into holes or crevasses 9 !    
ice4 ,! s& &  gravel 9 ! wat] =m$ a     
deposit t n[ appe>s z a r\nd$ hill      
associat$ ) a t]m9al mora9e & is call$ a
 kame4 ,! second type  ( deposit 0 laid 
d[n 9 b$s ( /reams fl[+ "u1 ?r\gh1 or   
on ! glaci]s & 0 left z a m or less     
cont9u\s ridge ( s&  & gravel :5 ! ice  
melt$4 ,su* a deposit is call$ an esk]4 
,"s  esk]s 9 ,ill9ois are ab\t a qu>t] (
 a mile wide & sev]al miles  long4      
,typical are ! ,kaneville ,esk] nor?we/ 
( ,aurora1 ! ,adel9e  ,esk] s\? (       
,freeport1 & ! ,exet] ,esk] we/ (       

,jacksonville4    ,! deposits ( bo? !   
,ill9oian & ,wiscons9an glaci]s are     
widely  di/ribut$ ?r\gh\t ! /ate4 ,melt+
 ( ! ,ill9oian glaci]  caus$            
comp>atively little flood+2 consequ5tly1
 ext5sive gravel  deposits 7 =m$ 9 only 
a few places4 ,! ice ( ! ,wiscons9an    
glaci]1 h[ev]1 melt$ rapidly & produc$  
great floods lad5 )  s& & gravel4 ,?us1 
mo/ major gravel deposits 9 ,ill9ois are
  relat$ to ! ,wiscons9an glaci]4       
,w9d sweep+ across ! s& & gravel        
deposits blew ! s& into  hills or s&    
dunes ne> su* places z ,havana1         
,prophet/[n1 ,kankakee1  & ,watseka4    
,ev5 today ! w9d %ifts s& ( long-=gott5 
glacial  floods4                        
,/udies ( ,glacial ,deposits    ,! =ego+
 discussion ( glaci]s & _! deposits is  
greatly  simplifi$4 ,= "s "t geologi/s (
 ! ,ill9ois ,geological ,survey  h be5  
mapp+ ! mora9es1 valley tra9s1 outwa%   
pla9s1 & o!r  glacial deposits ( ! /ate4
 ,because ! ,ill9oian & ,wiscons9an     
glaci]s advanc$ & retreat$ sev]al times1

 !y built _m mora9es4  ,! ,survey has   
made a map 7fig4 #ah7 t %[s ! complexity
 ( !  mora9es left by ! ,wiscons9an     
glaci]4 ,!y are r\ghly conc5tric1       
indicat+ t ! g5]al %ape ( ! glaci] front
 rema9$ ab\t  ! same4                   
,pr9cipal ,comm]cial ,s\rces ( ,s& &    
,gravel    ,! s& & gravel indu/ry is    
widely di/ribut$ ?r\gh\t ,ill9ois4  ,!  
pr9cipal comm]cial s\rces ( s& & gravel 
are valley tra9s  & outwa% pla9s4 ,!    
,fox1 ,rock1 ,ill9ois1 ,mississippi1 &  
,waba%  ,riv]s & _m small] /reams h     
t]races 9 _! valleys t are  p>ts (      
valley tra9s4 ,9 ^! deposits are "s ( ! 
l>ge/ s&-  & gravel-produc+ op]ations 9 
! /ate4                                 
,composition    ,an exam9ation ( glacial
 gravel deposits 9 ,ill9ois reveals     
pebbles  & l>g] pieces ( _m k9ds ( rock4
 ,"s are gray1 o!rs :ite1  p9k1 br[n1 or
 black4 ,!y commonly include lime/one1  
dolomite1  granite1 & _m rocks ) less   
common names su* z qu>tzite1  s*i/1 &   
basalt4 ,! lime/one & dolomite 7 pick$  

up by !  glaci]s f outcrops 9 nor!rn    
,ill9ois1 ,wiscons91 & ,mi*igan4  ,"s ( 
! granite pebbles resemble outcrops 9   
,wiscons92 o!rs look  l granite t crops 
out 9 ,canada4 ,! qu>tzite probably came
 f  ,wiscons91 & black %ale fragm5ts    
f\nd 9 "s gravel deposits came  f !     
floor ( ,lake ,mi*igan or f we/]n       
,mi*igan4 ,occasionally  pieces (       
metallic copp] are f\nd t probably _h _!
 s\rce 9  ! ,lake ,sup]ior copp]-be>+   
area4    ,9 addition to ! s& associat$ )
 gravel deposits1 ext5sive  deposits (  
s& alone are f\nd at _m places 9        
,ill9ois4 ,mo/ ( !  s& gra9s are pieces 
( m9]als t 7 con/itu5ts ( rocks until   
wea!r+1 ! gr9d+ action ( ! glaci]s1 &   
o!r erosive  ag5cies broke ! rocks into 
s&4 ,! pr9cipal m9]al 9 glacial  s& is  
qu>tz1 b _m o!rs occur 9 less] am\nts1  
includ+  calcite1 dolomite1 feldsp>1    
pyrox5e1 t\rmal9e1 g>net1 magnetite1  & 
hornbl5de4 ,mo/ ( ^! are =eign to       
,ill9ois1 al?\gh !  calcite & dolomite  
may be native4        ,illu/ration3     

,figure #ah--,mora9es left by           
,wiscons9an glaci]4      ,modifi$ f     
,george ,e4 ,ekblaw1 #aifj    ,,ill9ois 
,,/ate ,,geological ,,survey            
,illu/ration3 ,figure #ai--;,gravel     
dr$ge1 ) plant = process+      ! gravel 
9 backgr\nd4                            
,uses ( ,s& & ,gravel    ,9 #aifc m ?an 
#bg million tons ( s& & gravel1 directly
 or  indirectly ( glacial orig91 0 sold 
by ,ill9ois produc]s = almo/  #be       
million doll>s4 ,! s& alone w\ld h fill$
 a *ild's s& box1  ) an area ( #h squ>e 
miles1 to a dep? ( #a foot4 ,! gravel   
w\ld  h cov]$ an ev5 l>g] area4    ,!   
gravel 0 us$ 9 mak+ concrete = roads &  
build+s1 =  surfac+ roads1 = balla/ =   
railroad tracks1 & = o!r  purposes4 ,!  
s& f\nd its way into pla/]1 mort>1      
concrete1 & a  v>iety ( o!r products &  
uses4 ,"s ( x 0 produc$ = use z  mold+  
s&4                                     
,production ( ,s& & ,gravel    ,!       
production ( s& & gravel f its deposits 
may be a relatively  simple op]ation or 

"o ( consid]able complexity4 ,gravel =  
surfac+  a road may be dug f a          
conv5i5tly locat$ pit & load$           
me*anically into trucks t haul x to !   
road4 ,a l>ge s&- &  gravel-produc+     
op]ation1 h[ev]1 may include n only     
me*anical  equipm5t to load & transport 
! mat]ial b also a process+ plant  :]e x
 c be wa%$ if necess>y & scre5$ to v>i\s
 sizes4    ,9 a 8dry pit0 op]ation1     
me*anical cranes or %ovels pick up !    
gravel & s& & load x into trucks1       
railroad c>s1 or conveyor  belts to be  
transf]r$ to ! process+ plant4 ,!re clay
 & dirt may  be wa%$ out & ! s& & gravel
 is siz$ by scre5s4 ,conveyor  belts    
c>ry s& & gravel to ! v>i\s process+    
op]ations & to  /orage b9s or piles on !
 gr\nd4    ,a 8wet pit0 op]ation        
produces s& & gravel f an artificial    
pond  or lake4 ,9 "s op]ations ! s& &   
gravel is m9$ by a dr$ge  t floats on ! 
wat] 7fig4 #ai74 ,9 "s pits1 a /ream (  
wat] is  direct$ f ! dr$ge aga9/ ! bank 
( gravel to wa% ! gravel  into ! lake4  

,a l>ge metal pipe at ! front ( ! dr$ge 
slants d[n  into ! wat] & sucks up ! s& 
& gravel f ! und]wat] "p  ( ! deposit4  
,! gravel1 s&1 & wat] is !n pump$ ?r\gh 
a  pipe at ! re> ( ! dr$ge to ! process+
 plant on ! %ore4    ,9 "s types ( wet  
pit op]ations a l>ge scoop or bucket    
op]at$  f a crane on ! %ore1 or by      
cables fa/5$ to ! %ore1 is us$  to dig  
s& & gravel f b5ea? ! wat]4    ,dr$ges  
are us$ to pump up s& & gravel f ! b$s (
 ,ill9ois  riv]s1 especially !          
,mississippi1 ,ohio1 & ,waba%4    ,! s& 
& gravel res\rces ( _m p>ts ( ! /ate h  
be5  mapp$ & /udi$ by ! ,ill9ois        
,geological ,survey1 & "w ( ?is  k9d is 
cont9u+4              ,,silica          
7,,tripoli7 ,,& ,,o!r ,,m9]al ,,mat]ials
 ,,( ,,extreme ,,s\!rn                  
,,ill9ois      ,! hills ( extreme s\!rn 
,ill9ois conta9 sev]al m9]al mat]ials  t
 are entirely or l>gely re/rict$1 9     
important quantities1 to  t "p ( ! /ate4
 ,"s ( !m1 su* z silica & novaculite1   
come directly f b$rock deposits ( great 

age2 o!rs1 su* z "s  ( ! s&s & gravels1 
are ( m rec5t orig94                    
,silica 7,tripoli7    ,a m9]al mat]ial  
unique 9 ,ill9ois is ! amorph\s silica1 
or  tripoli1 m9$ 9 ! hills ( s\!rn      
,ill9ois ab\t #bj miles nor? (  ,cairo4 
,mo/ ( ! silica m9es are f\nd at ! heads
 ( valleys or 9  tree-cov]$ hill slopes 
along ! less travel$ roads4 ,an ar*$    
op5+ 7fig4 #bj7 ) a road lead+ into x   
may be all t is visible  ( ! m9e f !    
outside4 ,inside are _m rooms1 "s #cj   
feet high1  sep>at$ by r\nd$ pill>s ab\t
 #bj feet ?ick t h be5 left to  support 
! ar*$ m9e ro(4    ,mo/ ( ! silica 9 !  
m9es is :ite1 & ?is is ! "p t is  m9$4  
,a silica deposit is made up ( lay]s--"s
 ( :ite1 p[d]y rock  mat]ial1 o!rs t    
look *alky b are firm or h>d4           
,illu/ration3 ,figure #bj--;,entrance to
 a silica m9e4    ,9 ! m9es ! silica is 
bla/$ loose f ! natural deposit &  load$
 into trucks t take x to ! process+     
mills at ,elco &  ,tamms1 :]e x is cru%$
 & !n transf]r$ to huge gr9d+ mills  t  

pulv]ize x to a v f9e p[d]4 ,air curr5ts
 ( diff]5t  velocities sep>ate ! p[d]   
into v>i\s grades ( f95ess1 & !  f9i%$  
silica goes into l>ge pap] bags =       
%ipm5t4    ,orig9 ( ,silica4--,"s ( !   
hi/ory ( ! =mation ( silica  deposits is
 n fully kn[n1 b x seems probable t _!  
orig9al  "* 0 q diff]5t f :at x is      
today4 ,inve/igations by  ,survey       
geologi/s sugge/ t ! p>5t rock =mation 0
 lime/one  & *]t4 ,! lime/one 0 compos$ 
( ! m9]al calcite1 b  scatt]$ ?r\gh x 7 
myriads ( small p>ticles ( qu>tz4       
,int]lay]$ ) x 7 b&s & b$s ( *]t t      
conta9$ v>y+  am\nts ( calcite4    ,z ! 
rocks above !m 7 worn away by !         
ceaseless erosion (  /reams & riv]s1 ^! 
orig9al deposits 7 uncov]$4 ,ra9 &      
sn[-wat] !n work$ d[n into ! lime/one & 
*]t deposits  ?r\gh cracks & crevices & 
dissolv$ ! calcite 9 ! rock4 ,!  qu>tz  
rema9$ because x is mu* less soluble ?an
 ! calcite4 ,aft]  _m ?\s&s ( ye>s all !
 calcite _h be5 remov$1 leav+ beh9d  a  
8skeleton0 ( qu>tz--! silica deposits ( 

today4    ,uses ( ,silica4-,! silica m9$
 & mill$ 9 s\!rn ,ill9ois has  _m uses4 
,a sup]f9e grade1 kn[n z :ite r\ge1 is  
us$ to poli%  optical l5ses4 ,o!r grades
 are us$ 9 sc\r+ comp\nds1 metal        
poli%es1 pa9ts1 electrical resi/ors1    
high-temp]ature pipe cov]+s1  fib]glass 
manufacture1 pla/ics1 silicone rubb]1   
wood fill]1 caulk+  comp\nds1 c]amic    
products1 floor tile1 billi>d cue *alk1 
z f\ndry  p>t+ or fac+1 concrete        
admixture1 9 ! manufacture ( buff+      
comp\nds t are us$ to poli% metal       
objects1 & = o!r purposes4  ,indu/ry    
uses _m ?\s&s ( tons ( silica ea* ye>4  
,*]t & ,*]t ,gravel    ,deposits ( *]t1 
*]t gravel1 & gani/] also are among !   
v>iety  ( m9]al mat]ials f\nd 9 extreme 
s\!rn ,ill9ois4 ,*]t consi/s  pr9cipally
 ( m9utely cry/all9e p>ticles ( qu>tz4  
,"s *]t is  popul>ly call$ fl9t4 ,9     
s\!rn ,ill9ois *]t occurs 9 two         
pr9cipal k9ds ( deposits1 ^? compos$ (  
solid l$ges & ^?  consi/+ ( gravel4 ,!  
t]m novaculite is us$ 9 s\!rn ,ill9ois  

= ^? solid deposits t are :ite1         
comp>atively ?ick1 & free  ( o!r        
int]lay]$ mat]ials4 ,no novaculite is   
m9$ at pres5t1 b  x is said to h be5    
sold 9 pa/ ye>s = mak+ sodium silicate  
& silica brick4    ,! *]t gravels (     
s\!rn ,ill9ois are ( ?ree               
k9ds--novaculite  gravel1 ,elco gravel1 
& 8,lafayette0 ,gravel4 ,! novaculite & 
,elco  gravels consi/ ( fragm5ts ( *]t  
plus less] am\nts ( f9e silica  p>ticles
 & clay4 ,! *]t fragm5ts ( ! novaculite 
gravel are  angul>1 b ! ,elco gravel    
includes bo? angul> & r\nd$  fragm5ts4  
,^! gravels are :ite1 yell[1 br[n1 or   
r$di% br[n1 !  novaculite gravel usually
 be+ ! m highly color$4 ,deposits 9     
,union & ,alex&] ,c\nties h be5 us$ =   
road surfac+ & o!r  purposes4 ,deposits 
( *]t gravel also occur 9 ,h>d9 & ,sal9e
  ,c\nties1 & "s /ream valleys 9 s\!rn &
 we/]n ,ill9ois also  conta9 su* gravel4
    8,lafayette0 ,gravel consi/s        
pr9cipally ( br[n *]t pebbles4 ,mo/ (  !
 pebbles are r\nd$ & h a smoo?1         

semi-poli%$ surface4 ,!  s& & clay      
occurr+ ) ! gravel are br[n or d>k r$4  
,9 "s  places !re are deposits ( co>se1 
r$ qu>tz s&4 ,! gravel is mo/  abundant 
9 ! f\r s\!rnmo/ c\nties ( ! /ate1 &    
deposits  may be z mu* z #fe feet ?ick4 
,x is us$ pr9cipally z a  road-surfac+  
mat]ial4                                
,gani/]    ,gani/] occurs 9 ! hills (   
,alex&] & ,union ,c\nties & is a        
loosely consolidat$1 granul> mat]ial    
consi/+ ( irregul>  p>ticles up to ab\t 
an in* 9 diamet] or ( masses ( mat]ial  
readily dis9tegrat$ into su* p>ticles4  
,! p>ticles are compos$  ma9ly ( f9e    
cry/all9e qu>tz4 ,gani/] is :ite1 cream1
 light  yell[1 or r$ & occurs 9 deposits
 up to #be feet or m ?ick4  ,relatively 
small tonnages ( ! light color$ gani/]  
are n[ us$1  pr9cipally 9 mak+          
refractories1 b gani/] is said to h be5 
m widely us$ 9 t field 9 ! pa/4 ,x is   
produc$ f  und]gr\nd m9es4 ,"s r$       
gani/]1 or gani/] l mat]ial1 m9$  f op5 
pits has be5 us$ = road surfac+4        

,/udies ( ,s\!rn ,ill9ois ,mat]ials     
,survey geologi/s h mapp$ ! *]t- &      
silica-be>+ =mations  ( ,alex&] & ,union
 ,c\nties & also _m ( ! v>i\s k9ds (    
gravel deposits4 ,samples h be5 te/$ to 
det]m9e _! *emical  composition & ! size
 ( ! p>ticles compos+ !m4 ,laboratory   
/udies by c]ami/s indicate t novaculite 
& novaculite gravel1  :5 suitably       
process$1 c be us$ = mak+ silica brick1 
:i*  )/&s great heat4 ,cani/] & !       
gravels ( s\!rn ,ill9ois  (f] a v>iety (
 raw mat]ials await+ increas$ indu/rial 
use4                         ,s&s (     
,extreme ,s\!rn ,ill9ois    ,9 s\!rn    
,ill9ois deposits ( s& laid d[n 9 an arm
 ( ! ocean  t once ext5d$ nor?w>d into  
,ill9ois f ! ,gulf ( ,mexico are  f\nd 9
 ,alex&]1 ,union1 ,pulaski1 ,pope1 &    
,massac ,c\nties4 ,!  deposits are      
commonly a light color--:ite1 cream1    
yell[1 or gray4    ,! gra9s ( ! s& are  
almo/ all qu>tz & g5]ally are angul>4   
,"s ( ! s&s are ( almo/ p[d]-l f95ess1  
o!rs are f9e or  m$ium gra9$4 ,_m ( !   

s&s conta9 flakes ( :ite mica1 a        
gli/5+1 silv]y-look+ m9]al (t5 mi/ak5 = 
silv] or  plat9um4 ,unlike ^! metals1   
h[ev]1 mica is comp>atively light 9     
weight & is n metallic4 ,also pres5t 9  
"s s&s are small flakes  ( ! m9]al      
graphite4    ,! s\!rn ,ill9ois s&s h n  
be5 widely us$1 b "s ( !m  h be5 employ$
 9 mak+ concrete4 ,!y also may h        
possibilities  = mold+ & core s&4    ,z 
a result ( "w by ,survey geologi/s1 !   
location & prop]ties (  _m ( ! s\!rn    
,ill9ois s& deposits are kn[n4          
,,clay ,,& ,,%ale      ,man has us$ clay
 9 v>i\s ways = _m hundr$s ( ye>s4 ,f x 
he  made1 & /ill makes1 bricks to build 
8 dwell+s1 pott]y ut5sils  ( _m k9ds1 & 
o!r useful products4    ,ev]yone kn[s   
:at clay is1 yet x is a sub/ance        
difficult to def9e4  ,all clays are e>? 
mat]ials1 mo/ ( !m pla/ic or /icky :5   
wet  b firm :5 dry4 ,if heat$           
suffici5tly 7fir$7 !y become h>d4       
,clays are compos$ ( v>i\s m9]als4 ,(   
^!1 ! s-call$ clay  m9]als--complex     

sub/ances compos$ mo/ly ( alum9a1       
silica1 &  wat]--g5]ally are ! mo/      
important4 ,!y imp>t ! prop]ty (        
pla/icity & also cause clays to become  
h>d :5 fir$4    ,mo/ clays are :at      
geologi/s call un9durat$ 7unh>d5$7      
rocks4 ,clay  t has be5 indurat$ &      
occurs 9 lay]$ deposits is commonly     
call$ %ale4 ,! lay]s may be f a fraction
 ( an in* to sev]al  in*es ?ick4 ,mo/   
,ill9ois %ales are n pla/ic :5 dug f    
fre%ly  expos$ deposits1 b !y become    
pla/ic :5 cru%$ & knead$ )  wat]4 ,!    
clays & %ales ( ,ill9ois are ! basis ( a
 huge &  important indu/ry4             
,e>ly ,uses 9 ,ill9ois    ,clays & %ales
 are useful because !y c be made pla/ic 
by add+  wat]1 =m$ into desir$ %apes1 & 
fir$ to a rock l h>dness4 ,z  a result1 
v>i\s k9ds ( bricks1 dra9 tile1 pott]y1 
& o!r useful  products are made f !m4 ,9
 its e>ly ye>s1 ,ill9ois _h _m  widely  
di/ribut$ pott]ies t us$ clay f ne>by   
deposits to make  a v>iety ( jugs1      
crocks1 & b[ls t s]v$ 9 place ( _m      

pres5t-day glass or metal articles4     
,dra9 tile has be5 ( major importance 9 
! developm5t ( ! /ate4  ,e>ly settl]s   
f\nd _m l[ ly+1 swampy areas & tracts ( 
l&  t dra9$ poorly aft] heavy ra9s4     
,dit*es 7 dug to c>ry away  ! wat] f "s 
areas1 b o!rs 7 dra9$ by means ( dra9   
tile--pieces ( fir$ clay pipe sev]al    
in*es 9 diamet] & ab\t a  foot long t 7 
laid end to end 9 tr5*es bel[ pl\gh dep?
 &  !n cov]$ ) e>?4 ,wat] seep$ into !  
tile1 :i* dis*>g$ x  into dit*es4 ,tile 
factories1 built ?r\gh\t ,ill9ois ne>   
clay or  %ale deposits1 did an active   
bus9ess4 ,gradually1 h[ev]1 z m &  m f>m
 l& 0 dra9$ ! dem& slack5$ & _m tile    
factories  w5t out ( bus9ess4 ,al?\gh   
!re are few] factories1 mu* dra9  tile  
is /ill manufactur$ 9 ,ill9ois4    ,_m (
 ! e>ly tile plants also made bricks to 
be us$ = mak+  f\ndations1 build+s1     
sidewalks1 & o!r /ructures4 ,! bricks 7 
made by h&-op]at$ equipm5t4 ,"s ( ! old 
h&-mold$ bricks may  /ill be se5 9 old] 
build+s4 ,n[ ! brick-mak+ process is    

highly  me*aniz$ & ev5 ?\gh !re are few]
 plants !y produce m  bricks4           
,clay & ,%ale ,deposits    ,ill9ois     
%ales are a "p ( ! b$rock--t is1 !y are 
associat$  ) indurat$ rocks su* z s&/one
 & lime/one4 ,mo/ clays are  surficial  
rocks occurr+ 9 deposits ne> ! surface1 
:]e !y lie  above ! b$rock4 ,exceptions 
are c]ta9 clays f\nd 9 extreme  s\!rn   
,ill9ois & ! und]clays1 also call$      
fireclays1 t occur  b5ea? coal seams &  
are "p ( ! b$rock4    ,! surficial clays
 are ( two pr9cipal k9ds--till & loess4 
,till is a  deposit left by glaci]s4 ,x 
is a gray1 blue-gray1 or br[n clay      
conta9+ v>y+ am\nts ( s&1 pebbles1      
cobbles1 & ev5 b\ld]s4  ,till is f\nd at
 _m places 9 ! /ate & is us$ = brick    
mak+1  especially 9 ! ,*icago area4     
,loess is a w9d-deposit$ silty clay or  
clayey silt & is f\nd 9 _m  p>ts (      
,ill9ois4 ,x is ?icke/ on or ne> !      
bluffs ( !  ,mississippi1 ,ill9ois1 &   
,ohio ,riv]s4 ,x g5]ally is br[n & /&s  
9 /eep faces 9 roadcuts & o!r           

excavations4 ,x once 0 widely  us$ =    
mak+ brick & tile4    ,( major          
importance 9 mak+ clay products 9       
,ill9ois are ! b$rock  %ales & ! clays  
associat$ ) ! coal-be>+ rocks t  und]lie
 mu* ( ! /ate4 ,! %ales1 & ! clays to a 
less]  ext5t1 are dug at _m places =    
mak+ /ructural clay products su*  z     
bricks1 /ructural tile1 & dra9 tile4 ,!y
 also are us$ to make  lightweight      
aggregate = concrete4 ,! und]clays ( "s 
( ! old]  coal seams are us$ to make    
buff-color$ brick1 /onew>e1 & a highly  
heat-resi/ant brick 7firebrick7 t is us$
 9 indu/rial furnaces or  9 o!r         
op]ations involv+ high temp]atures4 ,"s 
fireclay1 gr\nd  z f9e z fl\r1 is add$  
to mold+ s& to make x coh]5t en\gh to   
=m into molds = metal ca/+4 ,sew] pipe &
 flue l9+ also are  made f und]clays4   
,clays unlike ^? f\nd else:]e 9 ! /ate  
occur 9 extreme  s\!rn ,ill9ois4 ,"o (  
^! has ! prop]ty ( remov+ color f  oils 
& 0 s us$ at "o "t by petroleum         
ref9]ies4 ,ano!r1  kaol91 0 ext5sively  

us$ dur+ ,_w ,w> ,i = mak+ crucibles4   
,clay ,m9]als    ,! uses ( clay & %ale  
are det]m9$ to a l>ge degree by !       
prop]ties ( _! clay m9]als & to a less] 
degree by !  impurities pres5t4 ,a clay 
or %ale conta9+ ! clay m9]al illite1  & 
o!r simil> b less important clay m9]als1
 commonly becomes r$  :5 fir$ & gets h>d
 at a relatively l[ temp]ature4 ,x !re=e
  is us$ to make r$ bricks1 dra9 tile1  
build+ tile1 & o!r  /ructural clay      
products4    ,ano!r clay m9]al1         
kaol9ite1 g5]ally burns to a light color
 & is  difficult to fuse4 ,!re=e1 clays 
compos$ :olly or ma9ly (  kaol9ite c be 
us$ = mak+ buff or light-color$ bricks &
 =  ! manufacture ( highly heat-resi/ant
 7refractory7 bricks4    ,! clay m9]al 9
 ! s\!rn ,ill9ois clay t 0 us$ to       
decolorize oil is montmorillonite4 ,?is 
clay is n[ us$ 9 sweep+  comp\nds1 z an 
oil absorb5t1 z animal litt]1 & = o!r   
purposes4                               
,/udies ( ,clay & ,%ale    ,9 view ( !  
significant relation%ip betwe5 ! clay   

m9]als &  ! utilization ( ! clays &     
%ales 9 :i* !y occur1 !  ,ill9ois       
,geological ,survey has inve/igat$      
ext5sively ! clay  m9]als 9 ! clay &    
%ale deposits ( ,ill9ois4 ,_m samples 7 
/udi$ by means ( p[]ful microscopes1    
,x-ray1 & *emical analysis4  ,mo/ ( !   
surface clays & %ales prov$ to be       
compos$ pr9cipally  ( illite or relat$  
m9]als4 ,! kaol9 clay ( extreme s\!rn   
,ill9ois conta9s ! m9]al kaol9ite4 ,!   
old] und]clays also  conta9 kaol9ite1 b 
_m ( !m also conta9 small] am\nts (     
illite4    ,! ,survey also has te/$ _m  
clays to det]m9e _! burn+  prop]ties &  
color :5 fir$1 & h5ce _! pot5tial uses4 
,!  bond+ capabilities ( o!r clays h be5
 measur$ to f9d out  :e!r !y c be us$ z 
a bond+ mat]ial = mold+ s&4 ,!  bloat+  
prop]ties ( ,ill9ois clays & %ales f _m 
deposits h  be5 /udi$ to det]m9e :i* are
 suitable = mak+ lightweight  aggregate 
= ! manufacture ( concrete4    ,! object
 ( ^! /udies has be5 to discov] !       
location1  "*1 & possible uses ( !      

/ate's clay & %ale res\rces4  ,special  
/udies are cont9u+ 9 sev]al p>ts ( !    
/ate4 ,ill9ois  is well end[$ ) clays & 
%ales t c be us$ = a v>iety (  purposes 
& has res\rces to fill future z well z  
pres5t ne$s4                            
,h[ ,bricks ,are ,made    ,conv]sion (  
,ill9ois clays & %ales into useful      
products is an  int]e/+ process & is    
exemplifi$ by ! mak+ ( build+ bricks4   
,me*anical %ovels dig ! clay or %ale &  
load x into trucks or  small railroad   
c>s t take x to ! brick plant4 ,!re1    
ma*9es  gr9d ! raw mat]ial & mix wat] ) 
x until x has !  consi/5cy ( /iff mud4  
,next1 a ma*9e1 :i* op]ates some:at l a 
meat gr9d]1 extrudes a  brick-siz$      
column ( clay4 ,z ! column moves =w>d1 x
 is  automatically cut into bricks by   
wires4 ,! bricks are !n dri$ 9  l>ge    
heat$ rooms4        ,illu/ration3       
,figure #ba--;,beehive brick kiln4    ,f
 ! dri]s1 ! bricks g to huge ov5s       
7kilns7 & are heat$  until !y are h>d & 
h atta9$ ! desir$ color4 ,?is is kn[n  z

 fir+ or burn+ ! bricks4 ,temp]atures   
employ$ are r>ely l[]  ?an #ahjj ,f4    
,?ree k9ds ( kilns are us$ 9 ,ill9ois = 
burn+ bricks--beehive1  tunnel1 & scove4
 ,a beehive kiln 7fig4 #ba7 has a r\nd  
base & a  dome-%ap$ top & some:at       
resembles an ov]siz$ beehive4 ,unfir$   
bricks are /ack$ 9 ! kiln & ! doors are 
seal$ ) burn$  bricks & clay4 ,fires are
 />t$ 9 he>?s or fire boxes 9 ! wall  ( 
! kiln & ! heat is circulat$ into &     
?r\gh ! kiln4 ,x  usually takes sev]al  
days to fire ! bricks adequately & let !
  kiln cool s t ! bricks c be remov$4   
,tunnel kilns1 made f heat-resi/ant     
bricks1 are actually tunnels big  en\gh 
= a man to /& 94 ,! unburn$ bricks are  
load$ on flat  /eel c>s on top ( a lay] 
( refractory blocks t protect ! /eel  f 
! heat4 ,! c>s ent] ! kiln & heat+      
beg9s4 ,z !y move  ?r\gh ! kiln1 !y c>ry
 ! bricks ?r\gh a fir+ area1 !n  ?r\gh a
 cool+ zone1 & f9ally out into ! air4   
,9 "s bricky>ds 9 ! ,*icago area1 dri$  
unburn$ bricks are  c>efully /ack$ by   

ma*9es into piles ab\t #ag feet high1   
#ce feet  wide1 & #aae feet long1 :i*   
are kn[n z scoves or scove kilns4 ,a    
lay] ( burn$ bricks t is pla/]$ ) clay  
cov]s ! sides (  ! scove4 ,a jet ( flame
 is direct$ ?r\gh small tunnels at !    
base  ( ! scove1 & ! heat fires !       
bricks4    ,dur+ #aifc1 m ?an           
#cbe1jjj1jjj bricks 7 produc$ by        
,ill9ois  brick plants4 ,9 ! same ye>1 !
 value ( all ! clay & clay  products    
produc$ 9 ,ill9ois 0 ne>ly #ed1jjj1jjj4 
,besides brick &  dra9 tile1 ! products 
( ! clay & %ale indu/ry ( ,ill9ois      
include refractory brick1 build+ block &
 tile1 fire-pro(+1 sew]  pipe1 flue     
l9]s1 /onew>e1 lightweight bloat$ burn$ 
clay aggregate  = concrete1 & a v>iety (
 unburn$ clays = special purposes1      
includ+ bond+ clay1 refractory          
fireclays1 absorb5t = use on  g>age     
floors1 & litt] = animal cages4         
,,peat      ,aft] ! retreat ( ! la/ ( ! 
great ice %eets f ,ill9ois1  num]\s     
ponds & lakes 7 left 9 nor!rn ,ill9ois1 

especially 9  ! ea/]n section4 ,"s ( !m 
7 soon dra9$ by natural  processes1 b   
o!rs rema9$4 ,9 ! %all[ wat] along _!   
%ores  grew v>i\s plants1 *iefly re$s & 
s$ges &1 locally1 a v>iety (  moss4 ,z !
 plants di$1 _! p>tially decompos$      
rema9s 7  pres]v$ b5ea? ! wat]4         
,ultimately1 ! ponds & lakes 7  ov]gr[n 
& m or less completely fill$ by ! plants
 & _!  rema9s1 giv+ rise to peat 7fig4  
#bb7 bogs4    ,"s peat bogs h be5 dra9$ 
& are n[ us$ z f>m l&4 ,o!rs  rema9 & a 
few ( !m are ! s\rce ( peat or humus =  
horticultural purposes4 ,produc+        
op]ations are locat$ 9 nor!a/]n         
,ill9ois & 9 ,:iteside ,c\nty 9         
nor?we/]n ,ill9ois4                     
,,o!r ,,m9]al ,,res\rces      ,9 !      
future1 new uses w be made ( ! ,ill9ois 
indu/rial m9]als  already discuss$4 ,9  
addition1 o!r m9]al res\rces ( ! /ate  t
 are n n[ be+ us$ may be ! bases ( new  
m9]al indu/ries4  ,"s ( ^! m9]als are at
 pres5t too co/ly to m9e because !      
deposits are deeply buri$ or are n      

suffici5tly ri* to be work$ at  a pr(it4
 ,o!rs are n conv5i5t to m>kets1 & /ill 
o!rs h no  pres5t comm]cial use4 ,9 ye>s
 to come1 h[ev]1 *anges may occur  t w  
make x practical to m9e1 process1 & use 
"s ( ^!  res\rces4 ,fur!rmore1 "s o!r   
m9]al deposits t are n[ be+  utiliz$ 9 a
 limit$ way may h great] future use4 ,! 
,ill9ois  ,geological ,survey cont9ues  
to /udy ! location1 "*1 &  composition (
 _m su* m9]al mat]ials & is al]t = !    
developm5t ( new uses4 ,"s ( ! mat]ials 
are discuss$ briefly  bel[4             
,illu/ration3 ,figure #bb--,peat f ,kane
 ,c\nty %[+ its fibr\s      nature &    
rema9s ( plants4                        
,gypsum & ,anhydrite    ,gypsum is a    
m9]al t consi/s ( calcium sulfate plus  
two molecules  ( wat] 7,ca,s,o#b;,h,o74 
,by suitably heat+ x1 ! am\nt ( wat] c  
be r$uc$1 & a product call$ calc9$      
gypsum 7pla/] ( p>is7  results4 ,?is    
mat]ial *anges back to gypsum if mix$ ) 
an  appropriate quantity ( wat]4 ,!     
ability ( calc9$ gypsum to 8set0  :5    

wat] is add$ makes x important 9 !      
manufacture ( a v>iety  ( pla/]s &      
relat$ products1 especially build+      
mat]ials4 ,gypsum  also is us$ 9 cem5t  
mak+ & 9 agriculture4    ,anhydrite     
7,ca,s,o7 is l gypsum except t x conta9s
 no wat] &  h5ce _c be made into pla/] (
 p>is4 ,its uses are limit$ 9 !  ,unit$ 
,/ates4    ,wells t 7 drill$ = oil1     
wat]1 or coal h enc\nt]$ gypsum  &_/or  
anhydrite 9 "s p>ts ( s\?-c5tral        
,ill9ois1 b ! gypsum  & anhydrite are n 
kn[n to crop out at ! surface4 ,a /udy (
  diamond drill cores & well cutt+s on  
file at ! ,survey %[$ t  ! %all[e/      
gypsum & anhydrite report$ occurr$ at a 
dep? ( #dgj  feet 9 ,madison ,c\nty4 ,! 
greate/ cont9u\s ?ickness ( gypsum  f\nd
 0 #b feet2 b 9 "o well1 ov] #f feet (  
/rata 0 p5etrat$  t av]ag$ almo/ #ge    
p]c5t gypsum4 ,x is possible t ?ick]    
deposits ( gypsum might be f\nd if      
drill+ 7 done especially 9  se>* ( x4   
,feldsp>-,be>+ ,s&s    ,feldsp> is ! "n 
appli$ to a gr\p ( m9]als t are ma9ly   

silicates ( potassium1 sodium1 &        
calcium4 ,v>i\s k9ds ( feldsp>  are us$ 
indu/rially 9 mak+ glass1 enamels1      
pott]y1 & o!r  products4 ,all ! feldsp> 
n[ us$ 9 ,ill9ois is %ipp$ into !  /ate4
 ,! discov]y by ! ,ill9ois ,survey t "s 
,ill9ois s&s  conta9 consid]able feldsp>
 l$ ,survey geologi/s & *emi/s to f9d   
:]e deposits highe/ 9 feldsp> occur1 :at
 k9ds ( feldsp> !y  conta91 & :e!r x    
c\ld be sep>at$ f ! s& 9 :i* x  occurs4 
,bea* s&s1 riv] s&s1 dune s&s1 & s&s f  
o!r k9ds  ( deposits 7 /udi$4    ,x 0   
f\nd t _m s&s conta9 m ?an #ae p]c5t    
feldsp> &  "s z mu* z #be p]c5t4 ,means 
( sep>at+ ! feldsp> f !  s& are believ$ 
to exi/1 b problems relat+ to ! purity (
 !  sep>at$ sp> rema9 to be solv$4      
,br9es    ,no salt is n[ produc$ 9      
,ill9ois1 b at "o "t ! /ate 0 a  major  
salt produc]4 ,salt works 7 9 op]ation  
ne> ,equality1 ,c5tral  ,city1          
,murphysboro1 ,/4 ,john1 ,danville1 &   
possibly o!r places4 ,!  salt 0 obta9$  
by evaporat+ salt wat] 7br9e7 t came f  

natural spr+s or f wells4 ,! ,equality  
area 0 a p>ticul>ly  important produc] (
 salt 9 ! #ahjj's4 ,discov]y else:]e 9 !
  ,middle ,we/ ( deposits ( rock salt & 
br9es t conta9$ m salt  ?an ^? (        
,ill9ois is said to h be5 responsible = 
!  discont9uance ( salt mak+ 9 ! /ate4  
,no salt b$s crop out 9 ,ill9ois1 nor   
are any kn[n to h be5  enc\nt]$ 9 ! _m  
wells t h be5 drill$ = coal1 oil1 or    
wat]4 ,h[ev]1 mo/ oil well drill+       
enc\nt]s br9es conta9+  v>i\s am\nts &  
k9ds ( salts1 includ+ ! common table    
salt1  sodium *loride4    ,= reasons    
relat+ to ! production ( oil1 ,survey   
geologi/s &  *emi/s h collect$ & analyz$
 _m samples ( ,ill9ois oil field  br9es1
 & data are !re=e available on _! salt  
cont5t4 ,no  comm]cial use is be+ made (
 ! br9es z s\rces ( salt4               
,oil ,%ale    ,ill9ois has a l>ge       
oil-produc+ indu/ry t obta9s oil f      
wells4  ,! /ate also conta9s b$s ( %ale 
t yield oil :5 ! %ale is  heat$4    ,9  
ord] to e/imate ! pres5t & future       

importance ( ! oil %ale  res\rces1 !    
,survey collect$ & te/$ m ?an #ajj %ale 
samples  f #da ,ill9ois c\nties4 ,a few 
samples conta9$ m ?an #be gallons  ( oil
 p] ton ( %ale1 b mo/ conta9$ less ?an  
#ae gallons p]  ton4 ,a /udy ( ! crude  
oil di/ill$ f select$ %ale samples  %[$ 
x to be some:at diff]5t f ! oil t comes 
f wells4  ,x c\ld1 nev]!less1 be made to
 yield gasol9e1 fuel oil1 & o!r         
products if suitably process$4    ,!    
%ale /rata g5]ally ! ri*e/ 9 oil are    
f\nd above coal  seams1 are black1 & are
 sometimes call$ slate by coal m9]s4 ,!y
  are r>ely m ?an #c feet ?ick1 b !y    
ext5d ov] l>ge areas4                   
,s&/one    ,s&/one has a long hi/ory (  
use 9 ,ill9ois4 ,pione]s built          
f\ndations = _! h\ses & b>ns & curbs    
ar\nd _! wells f  x4 ,slabs ( s&/one 7  
once a popul> mat]ial = sidewalks1 "s  (
 :i* are /ill 9 use4 ,*ur*es & o!r      
sizable build+s h  be5 con/ruct$ f x1 & 
at "o "t an ,ill9ois s&/one 0 us$  to   
make gr9d/ones4 ,except = ! ,/4 ,pet]   

,s&/one1 :i* 0  discuss$ "u 8,silica    
,s&10 ! use ( s&/one has decreas$1      
al?\gh comp>atively small quantities are
 /ill us$ z build+  /one4    ,mo/       
,ill9ois s&/ones may be ?\ght ( z a mass
 ( s& ^:  gra9s are m or less firmly    
cem5t$ toge!r by clay1 iron oxide1  &   
qu>tz1 ei!r s+ly or 9 comb9ation1 or1   
less commonly1 by  calcite4 ,! gra9s are
 p>ticles ( v>i\s m9]als1 b mo/ ( !m    
are qu>tz4    ,s&/ones are especially   
common 9 ! hill c\ntry ( extreme s\!rn  
,ill9ois4 ,! ,survey's inve/igations 9  
?is area reveal$ t if !y  are suitably  
process$ "s ( ! s&/ones may h           
possibilities =  comm]cial use4 ,s&/ones
 9 o!r p>ts ( ! /ate also h be5  /udi$1 
) simil> conclusions4                   
,b>ite    ,b>ite 7b>ium sulfate1        
,ba,s,o7 is a deceptive m9]al--x is mu* 
heavi]  ?an x looks4 ,b>ite f\nd 9      
,ill9ois is g5]ally :ite or light       
color$1 &1 al?\gh "s ( x looks r l :ite 
lime/one1 x  is m ?an half aga9 z heavy 
z lime/one4 ,b>ite's unusual weight  is 

responsible = "o ( its major uses--z a  
con/itu5t ( drill+  muds = ! oil        
indu/ry4 ,^! muds are a mixture ( clay1 
wat]1 &  a weight+ mat]ial su* z b>ite4 
,!y are us$ 9 v>i\s ways 9  ! drill+ (  
oil wells by rot>y drills4 ,b>ite also  
is an important  raw mat]ial = !        
manufacture ( *emicals4    ,b>ite is    
f\nd 9 ,h>d9 & ,pope ,c\nties1 ! site ( 
! fluorsp>  indu/ry4 ,accord+ to /udies 
made by ,survey geologi/s1 ! b>ite      
occurs bo? z ve9s & b$s associat$ )     
fluorsp>1 b its  di/ribution is irregul>
 & ! deposits are ( limit$ size4 ,a     
b>ite  m9e is said to h be5 work$ ye>s  
ago1 & m rec5tly  comp>atively small    
tonnages h be5 tak5 f op5 pits4 ,future 
exploration 9 s\!rn ,ill9ois may reveal 
deposits ( b>ite t w  be pr(itable to   
m9e4                                    
,gre5s&    ,9 "s p>ts ( ,ill9ois occur  
s&s or s&/one t conta9 num]\s  gra9s ( !
 gre5 m9]al glauconite4 ,if ! s&s are n 
discolor$  by iron comp\nds or o!r      
sub/ances1 !y too h a gre5i% color  &1  

!re=e1 are call$ gre5s&s4 ,glauconite   
v>ies 9 composition  b conta9s          
potassium1 magnesium1 iron1 alum9um1    
silicon1 & wat]4  ,gre5s& is said to be 
us$ 9 relatively small am\nts z a soil  
condition] & z a wat]-s(t5+ ag5t4       
,gre5s& is kn[n to occur 9 ! g5]al      
vic9ity ( ,olm/$ 9  s\!rn ,ill9ois4 ,ne>
 ,oregon 9 nor!rn ,ill9ois an old qu>ry 
expos$ #aj feet ( gre5i% br[n s&/one t  
conta9s glauconite4  ,samples f s\!rn   
,ill9ois & f ! s&/one at ,oregon        
conta9$ m ?an #f p]c5t potassium oxide4 
,m>l    ,9 "s ( ! lakes & ponds left by 
! glaci]s liv$ num]\s small  mollusks ) 
calcium c>bonate %ells4 ,z ! animals    
di$1 _!  %ells =m$ a deposit on ! bottom
 ( ! lakes & ponds4 ,c]ta9  plants1     
especially algae1 may h add$ a mudlike  
precipitate (  calcium c>bonate to !    
deposits1 & v>y+ am\nts ( clay wa%$  f !
 %ores mix$ ) bo? ^! mat]ials4 ,!       
resultant deposit  is call$ m>l4 ,"s m>l
 deposits h peat mix$ ) !m1 & peat  also
 ov]lies "s m>l deposits4    ,only      

comp>atively small am\nts ( m>l are kn[n
 to h be5 dug 9  ,ill9ois4 ,"o deposit  
conta9+ _m %ells & %ell fragm5ts1 "s  ( 
x associat$ ) peat1 0 work$ 9 s\!a/]n   
,liv+/on ,c\nty  z a s\rce (            
agricultural lim+ mat]ial4 ,o!r deposits
 h be5  report$ at o!r places 9 nor!a/]n
 ,ill9ois4 ,! available  in=mation      
indicates t ! m>l deposits are likely to
 be  pr9cipally ( local importance4     
,tufa & ,trav]t9e    ,! tufa 7fig4 #bc7 
& trav]t9e occurr+ z surficial deposits 
9  ,ill9ois 7 =m$ by spr+s4 ,! deposits 
usually occur at or ne>  ! outcrop ( a  
lay] ( por\s wat]-be>+ e>? mat]ial1 su* 
z  gravel1 s&/one1 or fissur$ lime/one1 
t is und]la9 by a  nonpor\s clay or %ale
 =mation4 ,wat] mov+ d[n ?r\gh ! por\s  
lay] _c s9k ?r\gh ! clay or %ale & s is 
=c$ to move  lat]ally4 ,:]e valleys h   
cut into ! lay]s ( gravel or rock1 !    
wat] em]ges z spr+s4    ,if ! mat]ial   
?r\gh :i* ! wat] has pass$ is lime/one1 
or  gravel conta9+ lime/one z mo/       
,ill9ois gravels d1 "s ( !  lime/one is 

likely to h dissolv$ 9 ! wat]4 ,:5 !    
wat]  issues z a spr+1 conditions may be
 su* z to cause precipitation (  !      
dissolv$ lime/one z tufa or1 m r>ely1   
trav]t9e4    ,tufa is g5]ally highly    
por\s & m or less impure1 :]eas         
trav]t9e is h>d] & less por\s4    ,!    
middle or l[] slopes ( bluffs are common
 sites =  spr+-deposit$ tufa or         
trav]t9e4 ,deposits h be5 se5 9 v>i\s   
p>ts ( ,ill9ois1 b are n kn[n to h be5  
work$1 except 9  ,calh\n ,c\nty :]e     
small quantities ( tufa 7 produc$ = use 
z  agricultural lime/one4 ,x is ?\ght t 
! tufa & trav]t9e  deposits ( ,ill9ois  
are relatively small1 b !y may be (     
local  importance4        ,illu/ration3 
,figure #bc--;,calc>e\s tufa f ,pike    
,c\nty4 ,9      addition to ! l>ge      
visible pores !re are num]\s t9y ones4  
,pyrite & ,m>casite    ,! m9]al pyrite  
consi/s ( iron & sulfur z ! comp\nd iron
  sulfide 7,fe,s7 &1 because ( its %9y1 
brassy yell[ color1 is  sometimes call$ 
fool's gold4 ,m>casite has ! same       

composition z  pyrite1 b its cry/als h a
 diff]5t %ape & x is (t5 light]  color$4
 ,bo? m9]als occur 9 v>i\s p>ts ( !     
/ate2 !y are  p>ticul>ly preval5t 9 "s  
coal seams1 & :5 s occurr+ are 9  "s    
cases call$ coal brasses or 8sulfur40   
,pyrite & m>casite are us$ comm]cially z
 raw mat]ials = mak+  sulfuric acid1    
al?\gh sulfur itself is m ext5sively us$
 = t  purpose4 ,at "o "t coal brasses   
recov]$ dur+ coal-clean+  op]ations at a
 nor?we/]n ,ill9ois coal m9e 7 sold =   
acid  mak+4 ,a l>ge quantity ( coal     
brasses probably c\ld be recov]$  f su* 
op]ations at ,ill9ois coal m9es4        
,uranium    ,uranium has be5 s\ght 9    
,ill9ois by _m p 9 rec5t ye>s4 ,!       
,geological ,survey also c>ri$ out a    
wide se>* = uranium &  p>ticul> att5tion
 0 paid to c]ta9 clays & o!r rocks 9    
,h>d9  ,c\nty & c]ta9 black %ales 9 o!r 
p>ts ( ! /ate4    ,ab\t #bjj samples f  
,h>d9 ,c\nty & #age samples ( ! %ales 7 
te/$ by ! ,survey4 ,no deposits 7 f\nd t
 are kn[n to be ( !  requir$ ri*ness &  

quantity4                               
,iron ,ore    ,ab\t ! middle ( ! #ai?   
c5tury two furnaces 9 ,h>d9 ,c\nty 9    
extreme s\!rn ,ill9ois = a "t produc$   
iron f local limonite  ores4 ,! ore is  
said to h occurr$ z pellets1 *unks1 &   
masses  scatt]$ ?r\gh soil & clay &     
app>5tly 0 ( irregul>  di/ribution4     
,little c be se5 ( ! deposits today4 ,_!
 ext5t is  n kn[n1 b !y are believ$ to  
be ( limit$ size4      ,! ,ill9ois ,/ate
 ,geological ,survey c>ries on a        
cont9u\s program (  rese>* on !         
indu/rial m9]als & metals ( ,ill9ois &  
_!  uses4    ,9 addition to !           
inve/igations m5tion$ 9 ?is booklet1 _m 
o!rs  h be5 made or are 9 progress4 ,su*
 /udies are necess>ily a  cont9u+       
activity if ! full pot5tialities (      
,ill9ois m9]al  res\rces are to be      
realiz$1 = indu/ry cont9ually dem&s new 
raw  mat]ials & *anges its requirem5ts =
 ^? n[ us$4    ,! ,survey has issu$     
num]\s reports t deal ) ! res\rces      
discuss$ "h & mimeograph$ li/s ( ^! are 

available ^u  reque/4      ,if          
reproduction is made ( ! mat]ial h]e91  
ackn[l$gm5t ( !  ,ill9ois ,/ate         
,geological ,survey is reque/$4         
,transcrib]'s ,notes      --,sil5tly    
correct$ a few typos4    --,reta9$      
publication in=mation f ! pr9t$ edition3
 ?is e,book    is public-doma9 9 !      
c\ntry ( publication4    --,9 ! text    
v]sions only1 text 9 italics is delimit$
 by    und]scores4