When you unzip your gk_quark.zip package you should have three directories. Please select the Quark directory, click the right button of your mouse and create a new archive (zip) package from the Quark directory.
Now you can use this package Quark.zip as a default theme, so navigate to your Appearance -> Themes, Click "Add New" button and "Upload Theme", now you can drag & drop your Quark.zip package and start the installation.