As requested, here are some examples:
1. In this school, there were talks of [bullying].
2. There were talks of [demolishing the public square].
3. For the past year, there have been talks of [merging two schools].
4. We were pleasantly surprised to know that several inmates were talking of [going to law school].
I hope you are convinced that gerunds or gerund phrases (shown above in square brackets [ ]) are common as objects of prepositions when using "talk of".
"Talk of" is used to focus more on some possibility in speech or writing, which makes sense as we "talk of" something (gerunds/gerund phrases).
Just as a side remark, "talk of" may be different from "talk about". Take a look at the example below:
5. Today, we are going to talk about travelling. (makes sense, as we will be expressing our thoughts and sharing our vacation experiences and advice)
6. Today, we are going to talk of travelling. (sounds off, as we are not linking this sentence with something previously mentioned; neither are we bringing this topic up as a possibility.)
You mentioned that talk about + gerund are very common.
In fact, "about" itself is a preposition, so yes, talk about + gerund phrase (as an object of a preposition) is common.
7. Today, we are going to talk about [travelling] (gerund which is an object of a preposition).
8. Today, we are going to talk about [travelling in Africa] (gerund phrase which is an object of a preposition).
Last side discussion (and I know it is not part of a gerund but it just came to my mind): we can also use "talk of the town" to refer to something or someone who is a sensation, and generates interest in many people. (e.g. The double homicide in such a small rural town has quickly become the talk of the town.)
I hope this helps.