<p>I have observed some occasional delamination in horizontal layers of my resin prints — see two examples:</p>
<p><a href="https://i.stack.imgur.com/DxGPD.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DxGPD.png" alt="downward" /></a>
<a href="https://i.stack.imgur.com/BZEoF.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/BZEoF.png" alt="upward" /></a></p>
<p>What is the cause, and how can this be minimized?</p>

With the information provided my thought is that your layers are underexposed for their thickness. Each layer is just barely bonding to the layer above it. After being pulled on by layers below eventually one of the layers fails. This is especially likely to happen on a thin part of the print any may need more support if it is followed by wider layers. But I would suggest trying to increase your exposure time first.
option two: it could be your FEP if that has seen too much use it may be time to replace it.
calibrating a resin 3D printer