The term "cone-less crater" isn't a standard geological term, but it likely refers to a crater without a central cone or peak. This is different from a volcanic crater, which typically has a cone-shaped structure built up from erupted material.

Here are some possible explanations for a "cone-less crater":

* Impact crater: These are formed by the impact of a meteorite or asteroid. While some impact craters have a central peak or uplift, many do not.

* Explosion crater: These can be formed by various types of explosions, like volcanic eruptions without significant cone formation, or even man-made detonations.

* Erosion: A crater, originally formed by a volcanic eruption or impact, could have lost its central cone due to erosion over time.

* Complex crater: Some impact craters are classified as "complex" and are characterized by a central uplift and a flat floor. However, not all complex craters have a central peak, and the uplift can be quite low.

To understand what kind of "cone-less crater" you're dealing with, you'd need more context. For example, where is this crater located? What is its size and shape? What are the surrounding geological features?

By considering these factors, you can start to narrow down the possibilities and determine the most likely cause for the lack of a central cone.