diff --git a/src/regolith/regolith_streamtube_head.f90 b/src/regolith/regolith_streamtube_head.f90
index 38735c85..9cef521b 100644
--- a/src/regolith/regolith_streamtube_head.f90
+++ b/src/regolith/regolith_streamtube_head.f90
@@ -18,7 +18,7 @@
 !  Notes       :  The stream tube's head is always attached to the surface. 
 !
 !**********************************************************************************************************************************
-subroutine regolith_streamtube_head(user,surfi,deltar,totmare,tots)
+subroutine regolith_streamtube_head(user,surfi,deltar,newlayer,eradi,rm)
 !subroutine regolith_streamtube_head(user,surfi,deltar,totmare,tots,turnover)
    use module_globals 
    use module_regolith, EXCEPT_THIS_ONE => regolith_streamtube_head
@@ -27,7 +27,8 @@ subroutine regolith_streamtube_head(user,surfi,deltar,totmare,tots)
    type(usertype),intent(in) :: user
    type(surftype),intent(in) :: surfi
    real(DP),intent(in) :: deltar
-   real(DP),intent(inout) :: totmare,tots
+   type(regodatatype),intent(inout) :: newlayer
+   real(DP),intent(in) :: eradi,rm
 
    ! internal variables
    type(regolisttype),pointer :: current
@@ -36,52 +37,49 @@ subroutine regolith_streamtube_head(user,surfi,deltar,totmare,tots)
                                                       ! from the analytical function that we use here to approximate the stream tube's 
                                                       ! head intersected with underlying layers, about 30% of volume difference. 
    real(DP) :: z,zstart,zend,zmin,zmax
-   real(DP) :: tothead,totmarehead,marehead,vhead,vsgly
-
-   ! * Mixing
-   real(DP) :: zmix
+   real(DP) :: headtot,headcomp,headmelt,vhead,vsgly
 
    current => surfi%regolayer
    z = current%regodata%thickness
-   zmix = z
    vsgly = vratio * PI * deltar**3
-   tothead = 0._DP
-   totmarehead = 0._DP
-   vhead = 0._DP
-   marehead = 0.0_DP
    zstart = 0._DP
    zend = z
    zmin = zstart 
    zmax = 2.0 * deltar
 
    if (zend >= zmax) then ! Stream tube's head is inside the 1st layer.
-      tots = tots + vsgly
-      totmare = totmare + vsgly * current%regodata%comp
-      !write(*,*) '0',zstart,zend,zmin,zmax,current%comp,totmare/2500.0,tots/2500.0
+
+      newlayer%thickness = newlayer%thickness + vsgly
+      newlayer%comp      = newlayer%comp + vsgly * current%regodata%comp
+
    else ! head is not intersected with layers. 
 
+   headtot = 0._DP
+   headcomp = 0._DP
+   headmelt = 0._DP
+   vhead = 0._DP
+
    do
       if (.not. associated(current%next)) exit
       
       if (zend < zmax) then 
          vhead = regolith_circle_sector_func(deltar,zstart,zend)
-         tothead = tothead + vhead * vratio 
-         totmarehead = totmarehead + vhead * vratio * current%regodata%comp
-         !write(*,*) '1',zstart,zend,current%comp,vhead*vratio/2500.0,totmarehead/2500.0,tothead/2500.0
+         headtot = headtot + vhead * vratio 
+         headcomp = headcomp + vhead * vratio * current%regodata%comp
          current => current%next
          z = z + current%regodata%thickness
          zstart = zend
          zend = z
       else 
-         totmarehead = totmarehead + (vsgly-tothead) * current%regodata%comp
-         tothead = vsgly
+         headcomp = headcomp + (vsgly-headtot) * current%regodata%comp
+         headtot = vsgly
          !write(*,*) '2',zstart,zend,current%comp,(vsgly-tothead)/2500.0,totmarehead/2500.0,tothead/2500.0
          exit
       end if
    end do
 
-   tots = tots + tothead
-   totmare = totmare + totmarehead
+   newlayer%thickness = newlayer%thickness + headtot
+   newlayer%comp      = newlayer%comp      + headcomp
 
    end if