Drawing is very valuable as it forces you to be careful and attentive to details.
The observations lead to the next question. What can these rocks tell us about the processes that put them in place?
In some places you can find very large boulders that have been deposited and left in scoured out hollows that have then been infilled with finer material.
So a fair interpretion of the Opunake sequences is that of volcanic material that has been eroded off Mount Taranaki and deposited in a fluvial (river) environment, possibly as reworked lahars or debris flows that have been mobilised by floods.
Here is the geological Qmap for Taranaki. The red rocks are volcanic lavas and related rocks centred on Taranaki / Egmont Volcano, whilst the pink rocks are pyroclastic and debris flow deposits.
Opunaki is on the coast half way up the map on the left.
You can see the profound effect of the volcano on the landscape, as it is at the centre of a radial arrangement of volcaniclastic deposits. The volcanic rocks have been spread across the landscape for large distances by the power of gravity and water.