I am sure that there are probably virtuemart options to enable you to do that properly - so I would ask the developers of virtuemart. Nevertheless, here is some CSS that will do it.
.com_virtuemart .category-view .vm3pr-1, .com_virtuemart .category-view .vm3pr-2, .com_virtuemart .category-view .vm-details-button {
display: none;
}
To create a custom CSS compatible with Gantry 5 please read this
http://docs.gantry.org/gantry5/tutorials/adding-a-custom-style-sheet
.
Remember to recompile CSS from base outline too.
Regards, Mark.