Ignorance is not-knowing, greed, hatred, desire, and craving are emotional states. Okay so far?
Consciousness and emotions are formations. So how could formations be caused by craving or ignorance when they are formations themselves?
In Pali, there is the word 'sankhara'. This can be a thing, process or cause.
For example, in the Pali, there is the phrase: "Sabbe sankhara annica". Here sankhara means conditioned things or formations. All conditioned things are impermanent. Consciousness here is a conditioned thing or formation, just as the body or a block of cement is a conditioned thing.
However, sankhara can also mean a process, namely, the process of concocting or forming. Thus, one thing can concoct, condition or stir up another thing. For example, ignorance can stir up hatred, which can stir up bad karma such as killing which is the condition for imprisonment or mental derangement. Thus this process of formation, of things forming out of other things, is also sankhara.
Sankhara can also mean 'concocter', the thing that concocts or conditions. For example, in the second link of dependent origination, the word sankhara means 'concoctor' (although the scholars never say this). This meaning of concoctor is confirmed in the suttas, such as:
Having first directed one's thoughts and made an evaluation, one then breaks out into speech. That's why directed thought & evaluation are verbal fabricator.MN 44