bash: cannot execute binary file exec format error fortran - bash

Question

When I run the code given below, it always gives me the following error:
bash: cannot execute binary file exec format error fortran
Also, the file "file" is not being created at the location mentioned in the code. I've a 64-bit processor and 64-bit version of Ubuntu 16.04, so that does not appear to be the issue. Can someone please point out where I'm wrong?
program sandpile_model
implicit none
integer, parameter :: len = 20
integer, dimension(len,len) :: square
!real, dimension(len,len) :: blah
!open(unit=1,file="\\home\\sandpile\\fortran\\file")
!dummy variables
integer :: i,j,d
do i=1,len
do j=1,len
square(i,j)=2
end do
end do
do d=1,10000
square((len/2)-1,(len/2)-1)=square((len/2)-1,(len/2)-1)+1
if(square((len/2)-1,(len/2)-1)>3) then
call toppling((len/2)-1,(len/2)-1)
end if
end do
!open(unit=1,file="\\home\\sandpile\\fortran\\file")
do i=1,len
do j=1,len
write(1,*), i,'\t',j,'\t',square(i,j)
end do
print*, '\n'
end do
end program sandpile_model
!This subroutine specifies the evolution rules of the model
recursive subroutine toppling(x,y)
!implicit none
integer, parameter :: len = 20
integer, dimension(len,len) :: square
!real, dimension(len,len) :: blah
integer, intent(in) :: x,y
square(x,y)=square(x,y)-4
square(x+1,y)=square(x+1,y)+1
if(square(x+1,y)>3) then
call toppling(x+1,y)
end if
square(x-1,y)=square(x-1,y)+1
if(square(x-1,y)>3) then
call toppling(x-1,y)
end if
square(x,y+1)=square(x,y+1)+1
if(square(x,y+1)>3) then
call toppling(x,y+1)
end if
square(x,y-1)=square(x,y-1)+1
if(square(x,y-1)>3) then
call toppling(x,y-1)
end if
end subroutine toppling

Answer 1

The problem appears here that an attempt is made to run an object file and not an executable.
Very small / limited instructions:
To create an object file: gfortran -c <fortran file>
To create an executable: gfortran <fortran file>
When using multiple source files:
Create objects from the individual files and link the together by means of gfortran <object files>
Create executable directly from source files gfortran <fortran files>
Note:
order of the files might be important
It might be necessary to link libraries as well into the executable (`-l option)
Name of the output file can be specified by means of the -ooption
Further initial reading:
compiler documentation
man gfortran
man make for automation in more complex situations.