SOUTHEASTERN    NEW    YORK.  625 
In  the  study  of  the  metamorphic  rocks  of  the  Highlands  and  Sara- 
toga County,  as  in  the  other  districts,  most  attention  is  given  to  the 
limestones.  At  Warwick  the  white  limestone  is  rarely  stratified  or 
shows  any  distinct  traces  of  stratification,  but  in  some  places  it  exhib- 
its a  regular  gradation  into  the  gray  and  blue  limestone,  which  is  f os- 
siferous in  some  places  and  oolitic  in  others,  and  stratified  in  nearly 
horizontal  strata.  The  limestones  of  the  Highlands  of  Orange,  Rock- 
land, and  Putnam  counties  are  in  long,  narrow  belts  associated  with 
the  granite,  syenite,  hornblende,  and  augite  rocks  and  some  anoma- 
lous aggregates.  The  limestones  of  Washington  County  are  coarse, 
white,  and  crystalline.  They  contain  various  embedded  crystalline 
and  amorphous  minerals,  the  most  common  of  which  are  plum- 
bago, augite,  and  hornblende.  Hornblende,  coccolite,  and  plum- 
bago are  the  most  constant  associates.  Sea  polite  is  not  uncommon. 
In  some  places  the  limestone  is  so  much  intermixed  with  other  ma- 
terials found  in  the  gneissoid  and  granitic  rocks  that  without  close 
examination  one  would  not  suspect  it  of  being  a  limestone.  Quartz 
is  frequently  found  in  it,  transparent  or  translucent,  witli  irregular, 
rounded  forms,  as  if  it  had  been  partially  melted.  Many  localities 
visited  show  that  it  has  been  softened,  if  not  melted.  The  similarity 
of  the  crystalline  limestones  of  the  northern  counties  to  the  crystalline 
phases  of  those  at  Warwick  which  grade  unmistakably  into  fossilifer- 
ous  forms  leads  to  the  conclusion  that  they  are  all  really  the  same 
rock.  The  limonitic  and  hematitic  ores  are  confined  to  the  valleys 
of  the  Taconic  and  metamorphic  rocks  and  are  usually  associated 
with  talcky  slate  on  one  side  and  limestone  on  the  other. 
Under  Primary  rocks  are  included  those  usually  called  by  that 
name  and  those  not  yet  described  as  Taconic  or  metamorphic,  though 
some  of  them  are  probably  of  the  same  age  as  the  metamorphic  rocks. 
This  is  particularly  the  case  with  the  plutonic  rocks,  as  granites, 
syenites,  hornblende  rocks,  some  of  the  trappean  rocks,  and  the  metal- 
liferous beds  and  veins  which  have  intruded  themselves  among  and 
altered  the  adjacent  rocks.  The  hornblendic  gneiss,  micaceous  gneiss, 
and  mica  slate  may  perhaps  be  referred  to  the  same  period.  The 
Primary  rocks  in  the  different  districts  are  very  similar.  They  in- 
clude granite,  syenite,  gneiss,  mica  slate  augite  rock,  greenstone, 
hornblende  rocks,  quartz  rock,  talcose  slate,  limestone,  serpentine,  and 
steatite,  although  the  last  five  have  been  already  included  among  the 
metamorphic  rocks.  In  Rockland  and  Orange  counties  the  strata 
dip  to  the  southeast  at  angles  of  50°  to  90°,  but  there  are  localities 
where  the  strike  and  dip  are  transverse  to  the  general  directions. 
Granite  veins  are  very  numerous  in  the  granitic  gneiss;  the  green- 
stones include  basaltic  greenstone1  or  trap,  granular  green-tone,  and 
Primitive  greenstone.  Associated  with  the  Primary  rocks  is  mag- 
55721— Rail.  360—09 40 
