,acid ,ra9 &                            
,our ,nation's ,capital               ,a
 ,guide to ,effects on ,build+s &       
,monum5ts                             by
 ,ela9e ,mc,gee              ,= sale by 
! ,u4,s4 ,gov]nm5t ,pr9t+ ,(fice        
,sup]9t5d5t ( ,docum5ts1 ,mail ,/op3    
,,ssop1 ,wa%+ton1 ,,dc #bjdjb-icbh      
,,isbn #j-af-jdhjfh-,x                  
,illu/ration3 ,m>ble surfaces expos$ to 
ra9 develop a r\gh     8sug>y0 texture  
because ! calcite gra9s are loos5$ z !  
edges dissolve 9 ! ra9 wat]4 ,column    
capital volute1 ,jeff]son     ,memorial1
 ,wa%+ton1 ,d4,c4      ,illu/ration3 ,a 
summ] ra9 /orm 9 ,wa%+ton1 ,d4 ,c4      
7,memorial     ,cont95tal ,hall7  ,:5   
pollut$ air mixes ) ra91 sn[1 & fog1    
acid precipitation =ms4 ,?is acidity has
 caus$ p to worry ab\t ! environm5t2 "s 
reports %[ t acid ra9 has affect$ lakes1
 trees1 & fi% populations 9 ! ,nor!a/]n 
,unit$ ,/ates & ,canada4 ,ano!r conc]n  
is its effect on hi/oric build+s &      
monum5ts4  ,! booklet focuses on acid   

ra9 & its impact on our ,nation's       
capital4 ,ra9 9 ,wa%+ton1 ,d4 ,c41 has  
an av]age acidity ( #d4b1 ab\t z acid z 
a c>bonat$ dr9k & m ?an t5 times z acid 
z clean1 unpollut$ ra94 ,?is booklet w  
def9e acid ra91 expla9 :at effects x has
 on m>ble & lime/one build+s1 & %[1 on a
 walk+ t\r1 "s ( ! places 9 our         
,nation's capital :]e y c see ! impact (
 acid precipitation4      ,illu/ration3 
,! p,h scale3 p,h  #g is neutral1 nei!r 
acid or     alkal9e2 small] p,h values  
are acid1 l>g] p,h values are alkal9e4  
,a liquid ) a p,h ( #c is t5 times z    
acid z "o ) a p,h ( #d4    #a ,batt]y   
,acid   #b4h ,v9eg>   #d ,adult fi% die 
#e4e ,,acid ,,ra9   #e4b-f4e ,normal    
range ( precipitation   #f-h ,normal    
range ( /ream p,h   #g ,acid   #g       
,neutral   #g ,alkal9e   #h4f ,bak+ soda
 & sea wat]   #ac ,lye                  
,:at is acid ra98   ,! t]m 8acid ra90 is
 commonly us$ to mean ! deposition (    
acidic compon5ts 9 ra91 sn[1 fog1 dew1  
or dry p>ticles4 ,! m accurate t]m is   

8acid precipitation40 ,di/ill$ wat]1 :i*
 conta9s no c>bon dioxide1 has a neutral
 p,h ( #g4 ,liquids ) a p,h less ?an #g 
are acid1 & ^? ) a p,h great] ?an #g are
 alkal9e 7or basic74 8,clean0 or        
unpollut$ ra9 has a slightly acidic p,h 
( #e4f1 because c>bon dioxide & wat] 9 !
 air react toge!r to =m c>bonic acid1 a 
weak acid4 ,ar\nd ,wa%+ton1 ,d4,c41     
h[ev]1 ! av]age ra9 p,h is betwe5 #d4b &
 #d4d4  ,! extra acidity 9 ra9 comes f !
 reaction ( air pollutants1 prim>ily    
sulfur oxides & nitrog5 oxides1 ) wat] 9
 ! air to =m /rong acids 7l sulfuric &  
nitric acid74 ,! ma9 s\rces ( ^!        
pollutants are vehicles & indu/rial &   
p[]-g5]at+ plants4 ,9 ,wa%+ton1 ! ma9   
local s\rces are c>s1 trucks1 & buses4  
,acidity 9 ra9 is measur$ by collect+   
samples ( ra9 & measur+ its p,h4 ,to f9d
 ! di/ribution ( ra9 acidity1 wea!r     
conditions are monitor$ & ra9 samples   
are collect$ at sites all ov] ! c\ntry4 
,! areas ( greate/ acidity 7l[e/ p,h    
values7 are locat$ 9 ! ,nor!a/]n ,unit$ 

,/ates4 ,?is patt]n ( high acidity is   
caus$ by ! l>ge numb] ( cities1 ! d5se  
population1 & ! conc5tration ( p[] &    
indu/rial plants 9 ! ,nor!a/4 ,9        
addition1 ! prevail+ w9d direction br+s 
/orms & pollution to ! ,nor!a/ f !      
,midwe/1 & du/ f ! soil & rocks 9 !     
,nor!a/]n ,unit$ ,/ates is less likely  
to neutralize acidity 9 ! ra94          
,illu/ration3 ,wet & dry bucket         
collector1 us$ to collect samples     = 
measur+ ra9fall acidity4                
,illu/ration3 #aiib annual              
precipitation-weight$ mean hydrog5 ion  
conc5trations z p,h      ,a p,h         
di/ribution map %[s areas 9 ! cont95tal 
,unit$ ,/ates     ( greate/ acidity 9 ! 
ra94  ,:5 y he> or read 9 ! m$ia ab\t ! 
effects ( acid ra91 y are usually told  
ab\t ! lakes1 fi%1 & trees 9 ,new ,engl&
 & ,canada4 ,h[ev]1 we are becom+ aw>e (
 an additional conc]n3 _m ( our hi/oric 
build+s & monum5ts are locat$ 9 ! areas 
( highe/ acidity4 ,9 ,europe1 :]e       
build+s are mu* old] & pollution levels 

h be5 t5 times great] ?an 9 ! ,unit$    
,/ates1 !re is a gr[+ aw>5ess t         
pollution & acid ra9 are accel]at+ !    
det]ioration ( build+s & monum5ts4      
,/one wea!rs 7det]iorates7 z "p ( !     
normal geologic cycle ?r\gh natural     
*emical1 physical1 & biological         
processes :5 x is expos$ to !           
environm5t4 ,?is wea!r+ process1 ov]    
hundr$s ( millions ( ye>s1 turn$ !      
,appala*ian ,m\nta9s f t[]+ peaks z high
 z ! ,rockies to ! r\nd$ knobs we see   
today4 ,our conc]n is t air pollution1  
p>ticul>ly 9 urban areas1 may be        
accel]at+ ! normal1 natural rate ( /one 
det]ioration1 s t we may prematurely    
lose build+s & sculptures ( hi/oric or  
cultural value4                         
,:at ab\t build+s8   ,_m build+s &      
monum5ts are made ( /one1 & _m build+s  
use /one = decorative trim4 ,granite is 
n[ ! mo/ widely us$ /one = build+s1     
monum5ts1 & bridges4 ,lime/one is !     
second mo/ us$ build+ /one4 ,x 0 widely 
us$ be=e ,portl& cem5t became available 

9 ! e>ly #ai? c5tury because ( its uni=m
 color & texture & because x c\ld be    
easily c>v$4 ,s&/one f local s\rces 0   
commonly us$ 9 ! ,nor!a/]n ,unit$       
,/ates1 especially be=e #aijj4          
,nationwide1 m>ble is us$ mu* less (t5  
?an ! o!r /one types1 b x has be5 us$ = 
_m build+s & monum5ts ( hi/orical       
significance4 ,because ( _! composition1
 "s /ones are m likely to be damag$ by  
acidic deposition ?an o!rs4 ,granite is 
prim>ily compos$ ( silicate m9]als1 l   
feldsp> & qu>tz1 :i* are resi/ant to    
acid attack4 ,s&/one is also prim>ily   
compos$ ( silica & is ?us resi/ant4 ,a  
few s&/ones are less resi/ant because !y
 conta9 a c>bonate cem5t t dissolves    
readily 9 weak acid4 ,lime/one & m>ble  
are prim>ily compos$ ( ! m9]al calcite  
7calcium c>bonate71 :i* dissolves       
readily 9 weak acid2 9 fact1 ?is        
*>act]i/ic is (t5 us$ to id5tify ! m9]al
 calcite4 ,because build+s & monum5ts   
made ( lime/one & m>ble are m likely to 
be damag$ by acid precipitation1 !y are 

! ma9 focus ( ?is booklet4              
,illu/ration3 ,memorial ,bridge 9       
,wa%+ton1 ,d4,c41 is made (     granite1
 ! mo/ widely us$ /one type4            
,illu/ration3 ,m>ble us$ z a trim on !  
,fir/ ,bank 9     ,philadelphia1        
,p5nsylvania4                    ,h[ d y
 recognize lime/one & m>ble8   ,! ma9   
diff]5ce betwe5 lime/one & m>ble is t   
lime/one is a s$im5t>y rock1 typically  
compos$ ( calcium c>bonate fossils1 &   
m>ble is a metamorphic rock4 ,lime/one  
=ms :5 %ells1 s&1 & mud are deposit$ at 
! bottom ( oceans & lakes & ov] "t      
solidify into rock4 ,m>ble =ms :5       
s$im5t>y lime/one is heat$ & squeez$ by 
natural rock-=m+ processes s t ! gra9s  
recry/allize4 ,if y look closely at a   
lime/one1 y c usually see fossil        
fragm5ts 7= example1 bits ( %ell7 held  
toge!r by a calcite matrix4 ,lime/one is
 m por\s ?an m>ble1 because !re are     
small op5+s betwe5 ! fossil fragm5ts4   
,m>ble is usually light color$ & is     
compos$ ( cry/als ( calcite lock$ toge!r

 l pieces ( a jigsaw puzzle4 ,m>ble may 
conta9 color$ /reaks t are inclusions ( 
non-calcite m9]als4      ,illu/ration3  
,lime/one is made ( fossil fragm5ts1    
held toge!r     ) calcite2 ! %ell ne> ! 
c5t] is ab\t #a cm across4     ,botanic 
,g>d5s build+1 ,wa%+ton1 ,d4,c4         
,illu/ration3 ,m>ble is made ( calcite  
cry/als 7:ite7 & "s     color$ gra9s (  
mica inclusions2 ! gra9s 9 a m>ble are  
lock$     toge!r l jigsaw puzzle pieces4
        ,h[ does acid precipitation     
affect m>ble & lime/one build+s8   ,acid
 precipitation affects /one prim>ily 9  
two ways3 dissolution & alt]ation4 ,:5  
sulfur\s1 sulfuric1 & nitric acids 9    
pollut$ air react ) ! calcite 9 m>ble & 
lime/one1 ! calcite dissolves4 ,9 expos$
 areas ( build+s & /atues1 we see r\gh5$
 surfaces1 removal ( mat]ial1 & loss (  
c>v$ details4 ,/one surface mat]ial may 
be lo/ all ov] or only 9 spots t are m  
reactive4  ,y might expect t %elt]$     
areas ( /one build+s & monum5ts w\ld n  
be affect$ by acid precipitation4       

,h[ev]1 %elt]$ areas on lime/one & m>ble
 build+s & monum5ts %[ black5$ cru/s t h
 spall$ 7peel$7 (f 9 "s places1 reveal+ 
crumbl+ /one b5ea?4 ,?is black cru/ is  
prim>ily compos$ ( gypsum1 a m9]al t =ms
 f ! reaction betwe5 calcite1 wat]1 &   
sulfuric acid4 ,gypsum is soluble 9     
wat]2 al?\gh x c =m any:]e on c>bonate  
/one surfaces t are expos$ to sulfur    
dioxide gas 7,,s71 x is usually wa%$    
away4 ,x rema9s only on protect$        
surfaces t are n directly wa%$ by ! ra94
 ,gypsum is :ite1 b ! cry/als =m        
networks t trap p>ticles ( dirt &       
pollutants1 s ! cru/ looks black4       
,ev5tually ! black cru/s bli/] & spall  
(f1 reveal+ crumbl+ /one4               
,illu/ration3 ,:5 m>ble is expos$ to    
acidic ra91 %>p edges     & c>v+ details
 gradually become r\nd$4 ,antefixes1 ro(
 ( !     ,philadelphia ,m]*ants'        
,ex*ange 7built 9 #ahcb74               
,illu/ration3 ,black5$ cru/s on %elt]$  
portions ( !     lime/one ,*icago       
,tribune ,build+1 ,*icago1 ,ill9ois4    

,illu/ration3 ,=m$ z a result ( air     
pollution1 gypsum     alt]ation cru/s h 
black5$1 bli/]$1 & spall$ f a     m>ble 
balu/] at ! ,organization ( ,am]ican    
,/ates build+1     ,wa%+ton1 ,d4,c4     
,illu/ration3 ,scann+ electron          
microscope photograph ( gypsum          
cry/als ) dirt & pollution p>ticles     
trapp$ by ! network (     cry/als4 ,!   
scale b> is #aj micromet]s long4        
,illu/ration3 ,a m>ble column at !      
,m]*ants' ,ex*ange 9     ,philadelphia  
%[s loss ( mat]ial :]e ! /one is expos$ 
to     ra9 & black5+ ( ! /one surface   
:]e ! /one is     %elt]$ f ra94         
,:]e c we see ! effects ( acid          
precipitation8   ,wa%+ton's build+s &   
monum5ts use _m diff]5t /one types4     
,m>ble & lime/one build+s are ! mo/     
likely to %[ damage1 because !y are m   
affect$ by acidic precipitation & urban 
pollution4 ,z y foll[ ! t\r describ$ 9  
?is book1 see h[ granite & s&/one       
build+s comp>e ) ! m>ble & lime/one 9 ! 
same environm5t4  ,?is guide w help y   

recognize "s geologic features (        
build+s1 9 addition to _! hi/orical &   
ar*itectural aspects1 :]ev] y travel4   
,h[ev]1 rememb] "o important po9t :5    
exam9+ build+s & monum5ts =             
det]ioration3 /one det]ioration has _m  
causes4 ,al?\gh acid precipitation &    
urban pollution c accel]ate /one        
det]ioration1 p1 pigeons1 & o!r         
organisms may also h>m our /one         
/ructures4 ,9 addition1 ! process (     
wea!r+ has be5 go+ on s9ce ! ,e>? fir/  
_h an atmosph]e4 ,al?\gh we c obs]ve    
det]ioration ( ! /one1 x is h>d to      
det]m9e h[ mu* ( ! det]ioration is f    
acid precipitation & h[ mu* is f o!r    
causes4      ,illu/ration3 ,pigeons     
sitt+ on ! /atue heads h creat$         
di/9ctive det]ioration on ?is build+4   
,illu/ration3 ,fl[]s & grasses h gr[n 9 
! cracks betwe5     /ones on ?is *ur*4  
,illu/ration3 ,?is lime/one column 9 !  
,l9coln ,memorial is     d>k5$ & dirty f
 p's h&s t\*+ ! /one4      ,illu/ration3
 ,microorganisms h caus$ ?is /a9 to     

appe> on a     m>ble column at !        
,jeff]son ,memorial4                    
,:at are we do+ ab\t acid ra98          
,sci5ti/s f _m discipl9es are /udy+ acid
 precipitation & its impact4 ,!         
,national ,acid ,precipitation          
,assessm5t ,program 7,,napap71 a ,f$]al 
program involv+ repres5tatives f m ?an a
 doz5 ,f$]al ag5cies1 has sponsor$      
/udies on h[ acid ra9 =ms & h[ x affects
 lakes1 crops1 =e/s1 & mat]ials4        
,because build+s & monum5ts _c adapt to 
*anges 9 ! environm5t1 z plants &       
animals c1 hi/oric /ructures may be     
p>ticul>ly affect$ by acid              
precipitation4 ,sci5ti/s are /udy+      
effective control te*nologies to limit !
 emissions f p[] plants & automobiles t 
cause acid ra94 ,! impact & usefulness (
 regulations t w\ld require limits on   
air pollution are also be+ /udi$4       
,f9ally1 sci5ti/s are exam9+ ! processes
 ( det]ioration to f9d effective ways to
 protect & repair our hi/oric build+s & 
monum5ts4 ,ag5cies l ! ,national ,p>k   

,s]vice1 :i* are *>g$ ) protect+ &      
pres]v+ our national h]itage1 are       
p>ticul>ly conc]n$ n only ab\t ! impact 
( acid ra9 b also ab\t mak+ ! be/ *oices
 = ma9ta9+ & pres]v+ our hi/oric build+s
 & monum5ts4      ,illu/ration3 ,beg9n+ 
9 #aihd1 ! ,national ,acid              
,precipitation     ,assessm5t ,program  
sponsor$ exposure site /udies ( lime/one
 &     m>ble1 to exam9e ! contribution  
to /one det]ioration t     comes f acid 
precipitation4                ,a field  
guide to build+s 9 our ,nation's capital
   ,wa%+ton1 ,d4,c41 has _m build+s (   
hi/oric & cultural significance1 & _m ( 
!m are made ( m>ble & lime/one4 ,?is    
self-guid$ t\r w po9t out damage to     
build+s & monum5ts 9 our ,nation's      
capital t may h be5 caus$ by acid       
precipitation4 ,simil> effects may be   
f\nd 9 o!r cities z well4  ,places to   
visit h be5 divid$ into sev]al areas1 s 
! trip c be done ei!r 9 segm5ts or all 9
 "o day4 ,a sugge/$ t\r r\te is describ$
 )9 ea* area4 ,a c> provides ! mo/      

effici5t transport betwe5 areas1 b p>k+ 
may be h>d to f9d4 ,! ,metro subway     
sy/em c easily be us$ to visit all areas
 except ! ,jeff]son & ,l9coln           
,memorials4 ,! close/ ,metro /ations 9  
ea* area are %[n on ! map4 ,y w ne$     
com=table walk+ %oes1 & y may want to   
br+ along a cam]a1 a h& l5s 7ab\t #aj   
magnification7 = obs]v+ details ( m9]als
 & wea!r+1 & a pair ( b9ocul>s = clos]  
exam9ation ( inaccessible areas4   ,!   
area ar\nd ! ,national ,capitol    ,?is 
area includes ! ,capitol build+1 !      
,peace ,monum5t1 ! ,grant   ,memorial1 &
 ! ,botanic ,g>d5s4 ,we beg9 ! t\r at ! 
s\!a/   corn] ( ! ,capitol1 & g         
clockwise ar\nd ! ,capitol 7along !     
s\?1 we/1 & !n nor? sides74 ,we !n foll[
 a walkway head+   we/1 f ! nor!a/ corn]
 ( ! ,capitol1 to see ! ,peace          
,monum5t at ! int]section ( ,fir/ ,/reet
 & ,p5nsylvania ,av5ue1   ,,nw4 ,we     
cont9ue s\? along ,fir/ ,/reet to !     
,grant ,memorial &   !n s\? aga9 to !   
,botanic ,g>d5s4 ,total di/ance is ab\t 

"o   kilomet]1 or ab\t ?ree-qu>t]s ( a  
mile4                         ,!        
,capitol ,build+--,site #a  ,! ,capitol 
0 built 9 /ages2 ! corn]/one ( ! ma9    
build+ 0 laid 9 #agic1 ! nor? w+ 0      
complet$ 9 #ahjj1 & ! s\? w+ 0 complet$ 
9 #ahjg4 ,bo? w+s 7 burn$ by ! ,briti% 9
 #ahad4 ,! capitol 0 !n rebuilt1 & x has
 be5 modifi$ sev]al times ?r\gh\t !     
ye>s4 ,a major program ( clean+1        
replacem5t1 & repair 0 begun 9 ! late   
#aihj's4 ,! c5t] build+ ( ! ,capitol is 
pa9t$ s&/one1 b ! nor? & s\? w+s1 h\s+ !
 ,s5ate & ! ,h\se *amb]s1 are m>ble4    
,ar\nd ! ,capitol we w obs]ve v>i\s     
examples ( dissolution & black5$        
alt]ation1 especially on ! m>ble        
balu/rade t surr\nds ! s\?1 we/1 & nor? 
sides ( ! build+4  ,beg9n+ at ! s\!a/   
corn] ( ! build+1 by us+ b9ocul>s we c  
see "s areas ( black5$ alt]ation 9 !    
,cor9?ian column capitals4 ,a m         
accessible example is f\nd "u ! ov]hang 
( ! l>ge squ>e ends ( ! m>ble balu/rade 
at ! s\!a/ corn] ( ! build+4 ,! black   

cru/ is made ( gypsum plus dirt t       
accumulates 9 %elt]$ areas4 ,no black   
cru/ is pres5t along ! cracks betwe5 !  
/ones2 ra9 wat] probably fl[s 9 ^!      
areas1 dissolv+ ! gypsum & prev5t+      
accumulation ( a cru/4 ,n all black     
areas on ?is balu/] are gypsum2 9 "s    
places ne> ! bu%es1 y c see gre5i%-black
 moss gr[+ on ! /one4 ,! top surfaces ( 
! m>ble balu/rade are co>se & r\gh1     
because ( dissolution betwe5 gra9s1     
comp>$ to areas t are protect$ f runn+  
or wa%+ wat] :]e ! black alt]ation cru/ 
=ms4      ,illu/ration3 ,! ,unit$ ,/ates
 ,capitol build+4      ,illu/ration3    
,black5$ alt]ation has accumulat$ "u !  
ov]hang+ edge ( ?is m>ble balu/rade     
corn]4 ,s\!a/ corn]1     ,u4,s4 ,capitol
 ,build+4      ,illu/ration3 ,pock m>ks 
9 m>ble columns1 s\? side ( ,u4,s4      
,capitol build+4 ,silicate m9]al        
inclusions 9 ! m>ble loos5     & fall   
out :5 ! calcite ar\nd !m is dissolv$ by
 acid     ra94  ,ano!r dissolution      
feature ( m>ble is ! pock-m>k effect on 

! squ>e bases ( ! build+ columns4       
,silicate m9]al inclusions 9 ! m>ble 7  
loos5$ by ! dissolution ( ! surr\nd+    
calcite1 caus+ ! inclusions to fall out 
( ! /one4 ,a p>ticul>ly good example (  
?is is f\nd on ! f\r? column we/ f !    
s\!a/ corn] ( ! ,capitol build+4 ,!     
pock-m>k dissolution is also f\nd at    
sev]al o!r places on ! build+4          
,illu/ration3 ,! m>ble balu/rade on !   
we/ side ( ! ,capitol     build+ %[s bo?
 dissolution & alt]ation4               
,illu/ration3 ,a rec5tly replac$ m>ble  
balu/] at ! ,capitol     has edges t are
 only beg9n+ to r\nd4      ,illu/ration3
 ,black alt]ation cru/s "u ! we/        
balu/rade (     ! ,capitol h begun to   
spall 7peel7 (f1 reveal+ crumbl+        
:ite m>ble und]nea?4  ,we w foll[ !     
m>ble balu/rade ar\nd ! build+1 not+    
diff]5ces 9 det]ioration4 ,"s p>ts ( !  
balu/rade h obvi\sly be5 replac$1 ?us   
enabl+ u to obs]ve v>i\s /ages 9 ! /one 
det]ioration4 ,! edges ( ! balu/]s are  
%>p :5 new & become r\nd$ z !y age4     

,black5$ alt]ation cru/s h accumulat$ on
 ! %elt]$ sides ( ! balu/]s & "u !      
ov]hang+ top ( ! balu/rade4 ,9 "s spots 
"u ! rail ! black5$ cru/ has spall$ (f1 
expos+ fre% surfaces & m vuln]able /one4
 ,"s c>v+s on ! balu/rade corn]s are    
worn1 :]eas o!rs h black5$ alt]ation2   
?is diff]5ce 9 wea!r+ may be due to     
local effects ( w9d & ra94 ,along ! /eps
 lead+ to ! t]race on ! we/ side ( !    
,capitol1 gypsum has accumulat$ on l>ge 
areas ( ! wall4 ,gypsum c accumulate on 
any surface t is n wa%$ by wat]4  ,z y  
walk nor? along ! we/ side ( ! ,capitol1
 look at ! c5tral "p ( ! build+4 ,!     
walls "h are pa9t$ s&/one4 ,despite     
rec5t re/oration ( ! build+1 y c see    
evid5ce ( pa/ /one det]ioration1 includ+
 ! acc5tuat$ l9es f b$d+ 9 ! /one & !   
pock m>ks :]e r\nd$ inclusions h        
disappe>$4 ,we w see an example ( ?is   
same s&/one t is n pa9t$ 9 ! build+s ne>
 #ag? ,/reet4  ,at ! nor!a/ corn] ( !   
,capitol build+1 ! m>ble balu/rade ends 
9 squ>e blocks l ! ones we fir/ exam9$4 

,"h y c see an example ( pref]5tial     
dissolution :]e ! silicate m9]al        
inclusions rema9 & ! calcite ar\nd !m   
has be5 dissolv$ away4 ,also1 on ! nor? 
side ( ?is block1 exam9e ! black5$ gra9s
 on ! top surface ) a h& l5s4 ,n all ( !
 black mat]ial y see on /one is gypsum2 
"s is ( biological orig91 probably algae
 or a fungus4      ,illu/ration3 ,a     
m>ble block t =ms ! nor!a/ corn] ( !    
,capitol balu/rade %[s pref]5tial       
erosion ( ! calcite ar\nd     a silicate
 m9]al inclusion4    ,to cont9ue ! t\r1 
foll[ ! pa?way t heads we/ along !      
nor? side ( ! ,capitol1 t[>ds ,fir/     
,/reet4 ,z y approa* ,fir/   ,/reet y w 
see a s&/one1 diabase 7a d>k igne\s     
rock71 &   granite f5ce ) v>i\s c>v+s4  
,because ^! /one types are   resi/ant to
 acid attack1 ! c>v+s %[ little damage4 
,! ,peace ,monum5t--,site #b            
,illu/ration3 ,! ,peace ,monum5t1       
d$icat$ 9 #ahgh1 is made (     ,italian 
m>ble4  ,?is monum5t1 d$icat$ 9 #ahgh1  
is made ( m>ble f ,c>r>a1 ,italy4 ,!    

/atue does n %[ mu* damage1 b if y look 
closely1 y c see alt]ation cru/s 7"s are
 light orange7 9 protect$ places &      
gra99ess & r\ghness 9 places t are      
expos$ to ra94 ,c>v$ /atues pres5t v>i$ 
surfaces t direct ra9 wa%+ & run(f4     
,illu/ration3 ,,map ,,( ,,wa%+ton       
,sites on ! t\r3   #a4 ,,! ,,capitol    
,,build+   #b4 ,,! ,,peace ,,monum5t    
#c4 ,,! ,,grant ,,memorial   #d4        
,,botanic ,,g>d5s ,,build+   #e4        
,,jeff]son ,,memorial   #f4 ,,l9coln    
,,memorial   #g4 ,,capitol ,,gateh\se   
#h4 ,,organization ,,( ,,am]ican ,,/ates
 ,,build+   #i4 ,,d>--,,con/itution     
,,hall   #aj4 ,,d>--,,memorial          
,,cont95tal ,,hall   #aa4 ,,corcoran    
,,build+   #ab4 ,,r5wick ,,gall]y   #ac4
 ,,f$]al ,,triangle ,,build+s   #ad4    
,,wa%+ton ,,monum5t    ,cont9ue s\?     
along ,fir/ ,/reet to ! ,grant ,memorial
 on y\r "r4                          ,! 
,grant ,memorial--,site #c              
,illu/ration3 ,! ,grant ,memorial       
consi/s ( bronze /atues on     m>ble    

bases2 al?\gh ! /atues 7 clean$1 ! /a9+ 
on !     m>ble rema9s4  ,?is memorial1  
d$icat$ 9 #aibb1 consi/s ( a gr\p (     
bronze sculptures m\nt$ on m>ble bases4 
,bronze wea!rs outdoors if x is n clean$
 & wax$ regul>ly4 ,l /one1 bronze       
dissolves :]e x is expos$ to ra9fall1   
develop+ a gre5 color & a pitt$ surface1
 & x also alt]s 9 %elt]$ areas1 )       
accumulation ( a black5$ lay]4 ,! mo/   
notable /one det]ioration visible "h is 
! gre5 /a9 on ! m>ble bases1 caus$ by   
run(f f ! wea!r$ bronze4 ,! gre5 /a9    
does n damage ! m>ble1 b x is           
unattractive1 & !re are no me?ods       
curr5tly available to remove ! /a9 )\t  
damag+ ! m>ble4      ,illu/ration3 ,!   
light-gre5 color on ! bronze /atues at !
     ,grant ,memorial is typical ( ! way
 bronze wea!rs :5 x is     expos$ to    
acidic ra92 ! ra9 dissolves "s ( ! metal
 &     causes /a9+ ( ! :ite m>ble bases4
    ,cont9ue s\?1 cross+ ,m>yl& ,av5ue1 
to ! ,botanic ,g>d5s4                   
,botanic ,g>d5s ,build+--,site #d       

,illu/ration3 ,! ,botanic ,g>d5s build+ 
is made ( lime/one4  ,?is lime/one      
build+ 0 built 9 #aica4 ,l _m ( !       
lime/one build+s 9 ,wa%+ton1 ?is build+ 
has be5 clean$1 s x does n h an         
accumulation ( surface dirt4 ,h[ev]1 !  
clean+ & regul> wa%+ by ra9fall h       
acc5tuat$ ! fossils 9 ! /one1 :i*       
dissolve less readily ?an ! calcite     
matrix4 ,"s ( ! sculpt$ heads above !   
ar*es ( ! build+ %[ small black cru/s4  
,on ! ea/ side ( ! build+1              
microorganisms naturally pres5t 9 ! /one
 contribute to ! det]ioration 7black5+7 
( ! /one1 :]e wat] drips f a jo9t 9 !   
ro(4      ,illu/ration3 ,fossil details 
/& out on ! lime/one at !     ,botanic  
,g>d5s build+2 ! fossils are m resi/ant 
to     dissolution ?an ! calcite matrix 
t holds ! fragm5ts     toge!r4    ,!    
,botanic ,g>d5s ,build+ is ! la/ /op 9 !
 ,capitol area (   ! t\r2 y may wi%1    
h[ev]1 to see "s bronze alt]ation on !  
,g>field ,memorial 7,fir/ ,/4 & ,m>yl&  
,ave47 & ! acc5tuat$   fossils )        

surr\nd+ algae or fungi on ! lime/one   
po/s ne>   ! ,capitol ,reflect+ ,pool4  
,! next /op1 ! ,jeff]son ,memorial1 is  
ab\t #c4e kilomet]s 7#b4b miles7 f !    
,capitol4                               
,jeff]son ,memorial--,site #e           
,illu/ration3 ,! ,jeff]son ,memorial is 
made ( m>ble & 0     d$icat$ 9 #aidc4   
,! ,jeff]son ,memorial is a m>ble       
build+1 d$icat$ 9 #aidc4 ,"o ( ! mo/    
/rik+ det]ioration features to obs]ve "h
 is ! loss ( silicate m9]al inclusions 9
 ! m>ble columns because ( dissolution (
 ! calcite matrix4 ,close exam9ation ( !
 grooves %[s flakes ( mica & sometimes  
gra9s ( pyrite4 ,black5$ cru/s are      
visible on ! column capitals t are      
%elt]$ f ra9 & f regul> wa%+ ( !        
monum5t4      ,illu/ration3 ,sev]al ( ! 
column %afts at ! ,jeff]son             
,memorial h grooves t foll[ ! inclusion 
traces 9 !     m>ble1 :]e ! m9]al       
inclusions h wea!r$ out & be5     lo/4  
,illu/ration3 ,a close look at "s ( !   
wea!r$ grooves 9 !     columns %[s t    

small bits ( mica & pyrite rema94  ,!   
,national ,p>k ,s]vice began a survey ( 
! condition ( ?is memorial & ! ,l9coln  
,memorial 9 #aiib4 ,! results w be us$  
to help make decisions on treatm5t1     
clean+1 & pres]vation4 ,! in=mation     
ga!r$ f ! survey w s]ve z a kn[n basel9e
 = ! condition ( ! /one1 s t future     
*anges 9 ! condition ( ! build+s c be   
assess$4 ,9 ,may #aiij1 a "p ( "o ( !   
column capitals 7call$ a volute7 broke  
(f & fell onto ! nor?we/ portico4 ,?is  
failure rais$ conc]n ab\t all ! volutes 
at ! ,memorial1 s sev]al o!r crack$     
volutes 7 remov$1 & /udies are be+      
conduct$ to det]m9e :y !y crack$4       
,because ( :]e & h[ ! volute broke1 x is
 unlikely t acid ra9 or air pollution   
contribut$ to ! failure4 ,! brok5 pieces
 w probably be replac$1 b only :5 !     
reason = _! failure is und]/ood1 s t an 
appropriate replacem5t te*nique c be    
*os54      ,illu/ration3 ,"p ( "o ( !   
column capitals at ! ,jeff]son          
,memorial broke (f & fell onto ! portico

 9 #aiij4    ,! next /op is ! ,l9coln   
,memorial1 #a4h kilomet]s 7a little m   
?an a mile7 nor!a/ ( ! ,jeff]son        
,memorial4                              
,l9coln ,memorial--,site #f  ,! ,l9coln 
,memorial1 d$icat$ 9 #aibb1 is made (   
m>ble f ,colorado4 ,?is build+ has few  
alt]ation cru/s1 9 "p because x receives
 regul> clean+ & 9 "p because ( ! design
 ( ! build+4 ,except = ! features ar\nd 
! entablature 7! edge ( ! ro(71 !re are 
few %elt]$ areas :]e alt]ation cru/s c  
accumulate4 ,) ! aid ( b9ocul>s1 y c see
 "s alt]ation cru/s along ! und]side ( !
 ro( ov]hang2 9 ^! places ! m>ble is v  
badly crumbl$ "u ! alt]ation cru/s4 ,"s 
columns %[ pref]5tial wea!r+ or loss (  
inclusions1 b "s ( ?is damage might be f
 graffiti removal4 ,! mo/ visible       
dissolution feature is sug>+1 :]e ! /one
 has lo/ its poli% & ! surface n[ feels 
r\gh4 ,visitors h affect$ ?is popul>    
memorial too2 sev]al ( ! columns1       
especially ! lime/one columns inside !  
*amb]1 %[ d>k5+ & r\nd+ ( edges :]e     

visitors h t\*$ !m ov] ! ye>s4  ,"o     
int]e/+ feature at ! ,l9coln ,memorial  
is diff]5ces 9 /one condition t mu/ come
 f v>iations 9 ! /one4 ,at sev]al places
 ar\nd ! outside ( ! memorial1 adjac5t  
blocks ( m>ble %[ v diff]5t surface     
r\ghness4 ,s9ce ! blocks ( /one h ! same
 ori5tation ) respect to w9d1 ra91 &    
pollution1 ! diff]5ce 9 condition _c be 
due to exposure & mu/ be relat$ to basic
 *>act]i/ics 9 ! /one t 0 us$4          
,illu/ration3 ,! ,l9coln ,memorial is   
made ( m>ble & 0     d$icat$ 9 #aibb4   
,illu/ration3 ,"u ! ro( ov]hang is "o ( 
! few places at     ! ,l9coln ,memorial 
:]e alt]ation cru/s h develop$ on !     
m>ble4      ,illu/ration3 ,"s columns at
 ! ,l9coln ,memorial h flatt5$     *alky
 areas :]e inclusions h wea!r$ diff]5tly
 f !     surr\nd+ calcite4              
,illu/ration3 ,! m>ble guttae on ! ro(  
ov]hang are crumbl+     & fall+ ap>t    
und]nea? black5$ alt]ation cru/s4       
,build+s along #ag? ,/reet1 ,,nw    ,"s 
notable examples ( /one det]ioration are

 includ$ 9 ?is "p   ( our t\r4 ,we w    
beg9 ?is segm5t at ! nor!a/ corn] (     
#ag? ,/reet & ,con/itution ,av5ue1 ) !  
,capitol ,gateh\se4 ,we   w !n cross    
#ag? ,/reet & exam9e sev]al build+s     
along #ag?   ,/reet z we walk nor? t[>ds
 ,p5nsylvania ,av5ue4 ,! total   di/ance
 is ab\t ?ree-f\r?s ( a kilomet] 7half a
 mile74                                 
,capital ,gateh\se--,site #g            
,illu/ration3 ,! ,capitol ,gateh\se1 n[ 
locat$ at #ag? ,/reet &     ,con/itution
 ,av5ue1 is made ( ! same s&/one us$ 9 !
 ,:ite     ,h\se & ! c5t] "p ( !        
,capitol1 b x 0 left unpa9t$4           
,det]ioration ( ?is /one is due to !    
clay x conta9s1 n to     ! effects (    
acid ra94  ,?is small s&/one build+ 0   
built ar\nd #ahbh at ! we/ entrance to !
 ,capitol4 ,9 #ahhj x 0 mov$ 7along ) a 
tw9 & f\r gatepo/s7 to its pres5t site4 
,?is build+ is made ( ! same s&/one t 0 
us$ 9 ! c5tral "p ( ! ,capitol & 9 !    
,:ite ,h\se4 ,?ree types ( det]ioration 
are readily visible at ! gateh\se3      

spall+1 pock m>ks1 & pref]5tial wea!r+ (
 clay lay]s 9 ! /one4 ,?is /one may be m
 degrad$ ?an /one 9 ! ,capitol or !     
,:ite ,h\se1 because ( v>iations 9 /one 
quality & ma9t5ance to ! build+s &      
because x has nev] be5 pa9t$4           
,illu/ration3 ,?is k9d ( s&/one 0 soon  
f\nd to be a poor     build+ /one       
because ( its t5d5cy to spall4 7detail  
on ,capitol     ,gateh\se7    ,to       
cont9ue1 we w cross #ag? ,/reet & exam9e
 p>ts ( sev]al   build+s z we walk nor?4
               ,organization ( ,am]ican 
,/ates ,build+--,site #h                
,illu/ration3 ,! ,organization (        
,am]ican ,/ates ,build+ is made     (   
m>ble & 0 d$icat$ 9 #aiaj4  ,?is m>ble  
build+ 0 d$icat$ 9 #aiaj4 ,two          
sculptures 9 ! front ( ! build+ %[ "s   
alt]ation cru/s 9 %elt]$ areas &        
dissolution 9 expos$ areas4 ,9 back ( ! 
build+ ! m>ble balu/]s on ! patio are   
cov]$ ) black5$ cru/s1 especially on !  
sides fac+ ! g>d54 ,9 _m places ! cru/s 
h bli/]$ or spall$ (f1 expos+ new       

surfaces to alt]ation4 ,9 g5]al1 ! patio
 sides ( ! balu/]s are 9 mu* bett]      
condition ?an ! sides t face ! g>d51    
p]haps because wa%+ ( ! patio has wa%$  
(f ! gypsum cru/s on t side ( ! balu/]s4
      ,illu/ration3 ,black5$ gypsum     
cru/s may bli/] & spall (f1     expos+ a
 crumbl+ /one surface to fur!r          
pollution4    ,cont9ue nor? ?r\gh ! g>d5
 & p>k+ lot & cross ,c ,/reet   to !    
,daught]s ( ! ,am]ican ,revolution      
7,,d>7 ,build+s4                        
,,d>--,con/itution ,hall--,site #i      
,illu/ration3 ,,d>--,con/itution ,hall  
is made ( lime/one & 0     built 9 !    
#aicj's4  ,! ma9 damage on ?is lime/one 
build+1 built 9 ! #aicj's1 is ! black5+ 
( ! side balu/rade f algae or fungi4 ,! 
/one is por\s & !re=e reta9s moi/ure1   
?us enc\rag+ gr[? ( organisms4 ,!       
lime/one 9 ?is build+ is q uni=m & %[s  
little pref]5tial dissolution1 except 9 
a few places4 ,on ! top ( ! balu/rade   
along ,c ,/reet1 = example1 "s ( !      
calcite matrix has dissolv$ f ar\nd !   

fossil fragm5ts1 & "s holes are fill$ ) 
calcite cry/als4      ,illu/ration3 ,"s 
( ! black5+ on lime/one surfaces may be 
f algae or fungi t readily gr[ 9 ! r\gh 
surface 9     ,wa%+ton's w>m1 humid     
climate4    ,cont9ue ea/ along ,c ,/reet
 to ,memorial ,cont95tal ,hall4         
,,d>--,memorial ,cont95tal ,hall--,site 
#aj      ,illu/ration3 ,memorial        
,cont95tal ,hall1 built 9 #aiji1 is "p (
     ! ,daught]s ( ! ,am]ican           
,revolution build+ complex4             
,illu/ration3 ,c>v+s at ! base ( !      
columns on ! s\? side     ( ,memorial   
,cont95tal ,hall %[ t c>v$ details & %>p
     edges rema9 on %elt]$ areas4  ,!   
por* area on ! s\? side ( ?is m>ble     
build+ built 9 #aiji is a good place to 
look at "s contra/s 9 m>ble             
det]ioration4 ,p>ts ( ! balu/rade h be5 
replac$1 z %[n by diff]5ces 9 color &   
surface r\ghness ( ! /one4 ,! expos$    
/one surface along ! top ( ! balu/rade  
is r\gh] ?an ! surfaces 9 m %elt]$      
areas4 ,! columns on ?is por* are c>v$  

ar\nd ! base1 s y c exam9e ! effects (  
exposure to ra9 on ! c>v+ details4 ,! m 
expos$ c>v+s h lo/ _! %>p edges &       
def9ition comp>$ to ! %elt]$ c>v+s4 ,!  
bases ( ! columns conta9 small am\nts ( 
pyrite1 :i* is m resi/ant to wea!r+ ?an 
is ! calcite 9 ! m>ble surr\nd+ !       
pyrite4 ,! %elt]$ "p ( ! w9d[-sill      
support on ! we/ side ( ! por* %[s an   
alt]ation cru/1 a dull gray accumulation
 on ! /one surface4      ,illu/ration3  
,on an expos$ portion ( ! c>v+ on !     
columns     at ,memorial ,cont95tal     
,hall1 ! edges ( ! m>ble h r\nd$     & !
 surface has r\gh5$4      ,illu/ration3 
,pyrite gra9s /& 9 relief :]e calcite & 
micas     h wea!r$ out ( ! m>ble at     
,memorial ,cont95tal ,hall4             
,illu/ration3 ,a dull gray surface on ! 
m>ble on ! w9d[-sill     support %[s :]e
 an alt]ation cru/ is j beg9n+ to       
develop4    ,at ! corn] ( #ag? & ,c     
,/reets1 turn left & walk nor? along    
#ag? ,/reet4 ,on our way to ! ,corcoran 
,gall]y1 we w pass ! ,r$   ,cross build+

 7m>ble1 #aiag74 ,"s ( ! same types (   
m>ble   det]ioration obs]v$ at o!r      
locations are also pres5t "h4           
,corcoran ,gall]y--,site #aa            
,illu/ration3 ,! ,corcoran ,gall]y is   
built mo/ly ( m>ble4  ,! ,corcoran      
,gall]y is m>ble ) a granite base4 ,x 0 
built 9 #ahgi & enl>g$ 9 #aibg4 ,ornate 
c>v+s ar\nd ! ro(1 doors1 & w9d[s h     
black5$ cru/s ( gypsum1 z d p>ts ( !    
m>ble p$e/als support+ ! bronze lions at
 ! front door4 ,! m>ble bases also h    
inclusions t /& out above ! surr\nd+    
calcite1 :i* has be5 dissolv$ away4     
,illu/ration3 ,m>ble bases = bronze     
lions outside ! entrance to     !       
,corcoran ,gall]y h feldsp> inclusions t
 /& 9 relief     comp>$ to ! r\gh5$     
surr\nd+ calcite4    ,cont9u+ nor? along
 #ag? ,/reet t[>ds ,p5nsylvania ,av5ue1 
y   w see sev]al mod]n granite (fice    
build+s & ! ,executive   ,(fice build+  
7=m]ly ! ,/ate-,w> & ,navy build+71 :i* 
0   built f granite & complet$ 9 #ahhh4 
,^! granite build+s %[   little         

det]ioration4 ,turn "r onto ,p5nsylvania
 ,av5ue & proce$   to ! ,r5wick ,galley 
on ! nor!a/ corn] ( ! int]section (     
#ag? ,/reets & ,p5nsylvania ,av5ue4     
,r5wick ,gall]y--,site #ab              
,illu/ration3 ,! ,r5wick ,gall]y1 made (
 brick & s&/one1 0     complet$ 9 #ahei4
  ,?is build+ ( brick & s&/one1 complet$
 9 #ahei1 is int]e/+ f a /one           
pres]vation po9t ( view4 ,! decorative  
s&/one panels 7 badly det]iorat$1 s 9   
#aifh ! panels 7 saturat$ ) epoxy to    
/r5g!n !m4 ,?is treatm5t actually       
accel]at$ ! det]ioration because :5 wat]
 p5etrat$ beh9d ! epoxy-fill$ area1 l>ge
 portions ( ! treat$ panels spall$ (f4  
,a second r5ovation attempt 0 !re=e     
necess>y two ye>s aft] ! fir/1 & !      
pres5t panels are ca/ s&/one4 ,a po/ ( !
 orig9al s&/one /&s at ! s\!a/ corn] ( !
 build+4      ,illu/ration3 ,ca/s (     
gr\nd s&/one & epoxy replac$ !          
orig9al c>v$ s&/one decorative trim at !
 ,r5wick ,gall]y     :5 a fir/ attempt  
to pres]ve ! c>v$ /one fail$4    ,! next

 "p ( ! t\r beg9s at #ae? ,/reet &      
,p5nsylvania   ,av5ue ,s4 ,to get !re1  
walk ea/ along ,p5nsylvania ,av5ue1 pa/ 
,blair ,h\se & betwe5 ,lafayette ,p>k & 
! ,:ite ,h\se4 ,lafayette   ,p>k has a  
numb] ( bronze /atues t h be5 clean$    
fairly   rec5tly4 ,! ,:ite ,h\se is     
built ( s&/one t 0 pa9t$   :ite2 ! pa9t 
0 us$ 9 "p to improve ! durability ( !  
/one4 ,aft] y pass ! ,:ite ,h\se1 y w   
come to ! ,treasury   ,build+4 ,turn "r 
onto #ae? ,/reet & walk s\?1 t[>ds !    
,wa%+ton ,monum5t & ! ,mall4 ,! total   
di/ance f ! ,r5wick   to ! corn] ( #ae? 
& ,p5nsylvania is ab\t ?ree-f\r?s ( a   
kilomet] 7half a mile74                 
,f$]al ,triangle ,build+s--,site #ac    
,on ! ea/ side ( #ae? ,/reet1 beg9n+ at 
,e ,/reet1 is ! ,comm]ce ,dep>tm5t      
build+1 :i* 0 con/ruct$ ( lime/one 9 !  
#aicj's4 ,?is build+ is "p ( ! ,f$]al   
,triangle1 a clu/] ( ,f$]al (fice       
build+s 9 ! area b\nd$ by ,p5nsylvania  
,av5ue1 ,con/itution ,av5ue1 & #ae?     
,/reet1 built prim>ily dur+ ! ,new ,deal

 adm9i/ration ( ,presid5t ,frankl9 ,d4  
,roosevelt4 ,"s sculptures on ! build+s 
7 done by p>ticipants 9 ! ,,wpa program4
 ,^! build+s 7 clean$ 9 ! #aifj's1      
probably by s&bla/+4 ,look = fossils 9  
relief & alt]ation cru/s 9 "s %elt]$    
places on ! c>v$ "w4 ,"s ( ! black5+ on 
?is build+ is f dirt & organic mat]ial  
trapp$ or gr[+ 9 ! r\gh surface ( !     
/one4      ,illu/ration3 ,all ( ! ,f$]al
 build+s t =m ! ,f$]al     ,triangle    
7betwe5 ,p5nsylvania ,av5ue1            
,con/itution ,av5ue1 & #ae?     ,/reet7 
are made ( lime/one4    ,cont9ue s\? on 
#ae? ,/reet to ,con/itution ,av5ue4 ,f !
 corn]   ( #ae? ,/reet & ,con/itution1  
foll[ "s ( ! foot pa?s half a   kilomet]
 7?ree t5?s ( a mile7 to ! ,wa%+ton     
,monum5t4                               
,wa%+ton ,monum5t--,site #ad  ,?is      
monum5t 0 begun 9 #ahdh1 b x 0 n f9i%$  
until #ahhe2 ! *ange 9 color ab\t #aej  
feet up m>ks a *ange 9 ! type ( m>ble   
us$ to face ! monum5t4 ,al?\gh x is made
 ( m>ble1 its smoo?1 /raight %ape & !   

massive blocks us$ 9 ?is monum5t h      
m9imiz$ ! effect ( acid precipitation4  
,dissolution does occur 9 a few areas1 b
 ! am\nt ( /one mat]ial lo/ f           
dissolution is insignificant comp>$ to !
 mass ( ! /one4      ,illu/ration3 ,!   
/raight %ape & massive /ones 9 !        
,wa%+ton ,monum5t m9imize ! impact (    
acid precipitation to     ?is important 
l&m>k4    ,our t\r ends "h1 b !re are _m
 m /one build+s &   monum5ts 9 ,wa%+ton 
& 9 o!r cities t may also %[ !   effects
 ( urban pollution & acid precipitation4
 ,h[ev]1 z se5 on   ?is t\r1 n all ( !  
det]ioration ( /one build+s is caus$    
by acid ra94 ,to protect our hi/oric    
/one build+s & monum5ts1   we ne$ to    
limit air pollution t contributes to    
acid ra9   det]ioration1 & we ne$ to    
develop effective ma9t5ance &           
pres]vation proc$ures t w n fur!r h>m ! 
/one4                   ,gloss>y (      
,geologic & ,ar*itectural ,t]ms         
,antefix--an ornam5t along ! edge ( a   
ro(1 (t5 %ap$ l a %ell or %ield         

,balu/]--a po/ or support = a h&rail    
,balu/rade--a rail & r[ ( support+ po/s1
 especially along a /air or por*        
,bronze--a metal alloy ( copp] & t92    
al?\gh br[n :5 fre%1 x wea!rs to a m    
commonly se5 gre5 color  ,calcite--a    
m9]al compos$ ( calcium c>bonate3       
,ca,c,o  ,column ,capital--,! top       
portion ( a column4 ,!re are ?ree ma9   
types2 f lea/ ornate to mo/ ornate1 !y  
are ,doric1 ,ionic1 & ,cor9?ian         
,diabase--a d>k-gray to black1          
f9e-textur$ igne\s rock1 compos$ ( !    
m9]als feldsp> & pyrox5e  ,feldsp>--a   
common m9]al compos$ ( silica 7,si71    
alum9um 7,al71 & calcium 7,ca71         
potassium 7,k71 or sodium 7,na73        
,ca,al,si,o1 ,k,al,si,o1 ,na,al,si,o    
,fossil--rema9s or trace ( a plant or   
animal pres]v$ 9 a rock f "s pa/1       
prehi/oric "t  ,granite--a light or     
speckl$1 co>se-gra9$ igne\s rock compos$
 ( qu>tz1 feldsp>1 & mica               
,guttae--small1 drop-l r\nd$ ornam5ts "u
 a ro( ov]hang  ,gypsum--a m9]al compos$

 ( hydrat$ calcium sulfate3             
,ca,s,o#b;,h,o  ,igne\s--=m$ f melt$ or 
p>tially molt5 rock  ,inclusion--a m9]al
 phase t is di/9ct 79 composition or    
appe>ance7 f ! ma9 m9]al compon5ts ( a  
rock  ,lime/one--a s$im5t>y rock1 *iefly
 compos$ ( calcium c>bonate2 =m$ f !    
%ells ( m>9e animals  ,m>ble--a         
metamorphic rock1 *iefly compos$ (      
calcium c>bonate  ,metamorphic--*ang$2  
usually by heat or pressure to a diff]5t
 =m b ! same composition  ,mica--a      
silicate m9]al t =ms %eets or lay]s &   
conta9s alum9um1 hydroxyl1 & alkali     
ions3 ,k,al,si,al,o7,,oh1,f71           
,k7,mg1,fe7,si,al,o7,,oh1,f7  ,m9]al--a 
naturally occurr+ inorganic sub/ance )  
an ord]$ /ructure2 rocks are made ( "o  
or m m9]als  ,portico--a por*1 ) a ro(  
support$ by columns  ,pyrite--a m9]al   
78fool's gold07 compos$ ( iron sulfide3 
,fe,s  ,pyrox5e--a silicate m9]al       
conta9+ two metal oxides3 ,ca,mg,si,o1  
,ca,fe,si,o1 7,mg1,fe7,si,o  ,qu>tz--a  
m9]al compos$ ( silicon dioxide1 or     

silica3 ,si,o  ,s&/one--a s$im5t>y rock 
compos$ *iefly ( qu>tz gra9s            
,s$im5t>y--=m$ f p>ticles t 7 transport$
 by wat] or w9d & deposit$ 9 lay]s      
,volute--a scroll-l ornam5t on an ,ionic
 column capital                         
,fur!r ,read+   ,acid ra93 ,! facts1    
#aihh3 available f ,inquiry ,c5tre1     
,environm5t ,canada1 ,ottawa1 ,ont>io1  
,canada ,k#a;,a #j;,h#c4  ,amoroso1     
,g4,g41 & ,fass9a1 ,v41 #aihc1 ,/one    
decay & cons]vation3 ,new ,york1        
,elsevi]1 #dec p4  ,hannibal1 ,j4,t41 & 
,p>k1 ,l4,e41 #aiib1 ,a guide to select$
 s\rces ( in=mation on /one us$ =       
build+s1 monum5ts1 & works ( art3       
,j\rnal ( ,geological ,education1 v4    
#dj1 p4 #ab-bd4  ,pick]+1 ,r4,j41 #aihg1
 ,acid ra93 ,u4,s4 ,geological ,survey  
,op5-,file ,report #hg-cii4  ,u4,s4     
,geological ,survey1 ,build+ /ones ( our
 ,nation's ,capital3 ,re/on1 ,va41      
,u4,s4 ,geological ,survey g5]al-int]e/ 
publication4  ,w9kl]1 ,e4,m41 #aigc1    
,/one3 ,prop]ties1 durability 9 man's   

environm5t3 ,new ,york1 ,spr+]-,v]lag1  
#bcj p4      ,illu/ration3 ,lime/one    
,illu/ration3 ,m>ble      ,illu/ration3 
,s&/one      ,illu/ration3 ,granite     
,photographs by ! au?or  ,edit$ by      
,ka?le5 ,gohn  ,publication design by   
,elizabe? ,junek    ,u4,s4 ,gov]nm5t    
,pr9t+ ,(fice3 #aiie-cid-ijd            
,:at ,type ( ,rock is ,x8       ,look at
 ! ov]all appe>ance ( ! /one 9 ! build+4
 ,obs]ve     ! color1 texture1 &        
/ructure ( ! /one4    ,does ! /one look 
ev5ly color$1 ) an ev5 texture8         
,,yes  ,look at ! gra9s up close4 ,d y  
see fossil fragm5ts 7bits           (   
%ells or skeletons78       ,,yes        
,,lime/one       ,,no  ,are ! gra9s     
r\nd$1 l s& on ! bea*8         ,,yes    
,,s&/one         ,,no  same z next l9e  
,,no  ,d y see /reaks or cl\ds ( color 9
 a mo/ly :ite /one8       ,,yes  ,,m>ble
       ,,no  ,look at ! gra9s up close4 
,d y see a mixture ( colors             
7black1 :ite1 gray1 maybe p9k or r$78   
,,yes  ,,granite         ,,no  ,,m>ble  

,"s ( ^! /ones may h lay]s t 7 ! orig9al
 b$s     t =m$ ! /ones4                 
,illu/ration3 ,,lime/one                
,illu/ration3 ,,s&/one      ,! gra9s 9  
^! rocks may look l cry/als t fit toge!r
     l jigsaw puzzle pieces4            
,illu/ration3 ,,m>ble      ,illu/ration3
 ,,granite      ,illu/ration3 ,dep>tm5t 
( ! ,int]ior  ,m>* #c1 #ahdi  ,z !      
,nation's pr9cipal cons]vation ag5cy1 ! 
,dep>tm5t ( ! ,int]ior has              
responsibility = mo/ ( our nationally   
own$ public l&s & natural & cultural    
res\rces4 ,?is includes fo/]+ s\nd use (
 our l& & wat] res\rces2 protect+ our   
fi%1 wildlife1 & biological div]sity2   
pres]v+ ! environm5tal & cultural values
 ( our national p>ks & hi/orical places2
 & provid+ = ! enjoym5t ( life ?r\gh    
outdoor recreation4 ,! ,dep>tm5t        
assesses our en]gy & m9]al res\rces &   
works to ensure t _! developm5t is 9 !  
be/ int]e/s ( all our p by enc\rag+     
/ew>d%ip & citiz5 p>ticipation 9 _! c>e4
 ,! ,dep>tm5t also has a major          

responsibility = ,am]ican ,indian       
res]vation communities & = p :o live 9  
isl& t]ritories "u ,u4,s4 adm9i/ration4 
,?is publication is "o ( a s]ies ( g5]al
 int]e/ publications prep>$ by ! ,u4,s4 
,geological ,survey to provide in=mation
 ab\t ! e>? sci5ces1 natural res\rces1 &
 ! environm5t4 ,to obta9 a catalog (    
additional titles 9 ! s]ies 8,g5]al     
,int]e/ ,publications ( ! ,u4,s4        
,geological ,survey10 write3    ,u4,s4  
,geological ,survey   ,in=mation        
,s]vices   ,p4,o4 ,box #bebhf   ,d5v]1  
,,co #hjbbe                             
,transcrib]'s ,notes   --,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