Over/under extrusion?

[jackal24]

ABS at 260/110. I also tried it at 240 and it looks about exactly the same, and 225 (which had too little layer adhesion).
Printing at 60mm/s with Outline Underspeed of 40%, Solid Underfill Underspeed of 80%.

[iDig3Dprinting]

Unfortunately all the images of the top of the print are out of focus. From the image of the base I would say that your nozzle is probably too far away from the print bed, the lines of plastic should be joined up as well so there could be an under extrusion issue but don't look to this until you check your nozzle height.

As to the top, the images are a bit out of focus to tell properly but it could be that it's collapsing in on itself as the filament does not have time to cool before the next layer is added. What are your fan settings? Although you have to be careful with using a fan for ABS as it enhances warping. See if you can change the fan settings and make it trigger when the layer print time is very small so that it only turns on at the top layer. This is one possible explanation.