[R] thickness of tick marks

[David J. Netherway]

Hi,

I am unable to get the tick marks to appear thicker in plot. I have 
tried things like
par(lw=2) but this only seems to affect other line thicknesses.

The use of axes directly fixes the problem because lw = 2 applies to 
both the axis and the ticks.

Is there is  way of feeding a single parameter to plot or setting a par 
parameter to do this?

I am using R 1.9.0 on a windows 2000 platform.

Thanks, David