Reimplementing data structures in the real world

Hope that helps Is it okay if the examples are a tad bit generic i.e. relate to graphs and not necessarily to trees? If it is, read on.

around this issue I would use boost::circular_buffer. You will get the cache benefits having a fixed memory area and no unexpected memory allocations.

may help you . A nice application of the deque is storing a web browser's history. Recently visited URLs are added to the front of the deque, and the URL at the back of the deque is removed after some specified number of insertions at the front. Another common application of the deque is storing a software application's list of undo operations. One example where a deque can be used is the A-Steal job scheduling algorithm.[5] This algorithm implements task scheduling for several processors. A separate deque with threads to be executed is maintained for each processor. To execute the next thread, the processor gets the first element from the deque (using the "remove first element" deque operation). If the current thread forks, it is put back to the front of the deque ("insert element at front") and a new thread is executed. When one of the processors finishes execution of its own threads (i.e. its deque is empty), it can "steal" a thread from another processor: it gets the last element from the deque of another processor ("remove last element") and executes it. - Courtesy Wikipedia

will help you As noted in my comment, I have no idea how MineCraft does this, but a common efficient way of representing this sort of data is an Octree; http://en.wikipedia.org/wiki/Octree. The general idea is that it's like a binary tree but in three-space. You recursively divide each block of space in each dimension to get eight smaller blocks, and each block contains the pointers to the smaller blocks and a pointer to its parent block.
This allows you to be efficient about storing large blocks of the same material (e.g., "empty space"), because you can terminate the recursion whenever you get to a block that is made up of all the same thing, even if you haven't recursed down to the level of individual "cube" units.

this one helps. You should consider FSharpx.Collections.Vector. Vector will give you Array-like features, including indexed O(log32(n)) look-up and update, which is within spitting distance of O(1), as well as adding new elements to the end of your sequence. There is another implementation of Vector which can be used from F# at Solid Vector. Very well documented and some functions perform up to 4X faster at large scale (element count > 10K). Both implementations perform very well up to and possibly beyond 1M elements.