Within creation science, there are numerous subjects where creationists may hold diverse, often very different, opinions. The biblical narrative is more specific on certain points than it is on others. Our understanding of the natural world is like a puzzle: the Biblical Creation account and Flood narrative offer us edges and corners as a framing reference, and we figure out the rest of the pieces using science and logic. Much of creation science comes from collaborative work, as different researchers investigate problems in astronomy, physics, geology, atmospheric science, biology, and more. They publish, debate, and discuss. Sometimes there are less-collaborative researchers who are more interested in pushing their own agendas. Overall, though, creation science tends to move forward.
One of the few true schisms in creation science is the debate over the Flood/post-Flood boundary. We know that there are sedimentary layers and a fossil record that exists because of a global flood. Almost every creationist agrees that fossils below the K-T boundary are Flood fossils (with perhaps the ‘earliest’ representing pre-Flood fossilization). Most creationists who have studied the paleontological record have suggested that fossils above the K-T boundary (Cenozoic fossils) are mostly the result of post-Flood events that involved localized flooding, volcanic ash fall events, lake sedimentation burials, or other fossilizing phenomena.
Recently, a few creationists have argued that almost the entire fossil record is Flood deposit, and that the upper boundary of the Flood record is in the Upper Cenozoic (for example, between Pliocene and Pleistocene layers). This position makes a significant departure in how we discern the differences between the pre- and post-Flood worlds, in how we understand the biological changes possible within biblical kinds, and in how we grasp the theological underpinning of the Flood narrative. More concerning is that these creationists don’t actually seem to understand the issues and use hand-waving tactics to dismiss and minimize the problem.
Unlike certain areas where a researcher may speculate and theorize broadly, we actually have guidance here from Scripture regarding the position of the Flood/post-Flood boundary. It doesn’t come from the day-by-day narrative of the Flood action, though. Instead, it comes from the number of animals that God brought onto the Ark. Specifically, the Bible tells us that only one pair of each unclean, terrestrial animal kind was saved on the Ark.