SVG thumbnails black on live server
Craft requires Imagick to do any SVG transforms, so that fact that it is working on your MAMP install without it is the only weird thing I see here. :)

Craft will attempt to use Imagick if it is available on the server and fallback to GD otherwise or you can explicitly tell it which one to use via the imageDriver config setting.

As to why it's all black on production, make sure you're using a recent version of both the Imagick PHP extension as well as the underlying Imagick library.