WHAT'S HERE?
See salt marsh and mangroves growing on basalt.
LEARN ABOUT IT
Until relatively recently it had been thought that this lava flow had come from Three Kings Volcano or Mt Eden or even from Mt Albert, as all three have lava flows that flow into the headwaters of this valley. In 2008 University graduate student Jeremy Eade used geochemical analyses that showed it had come from Mt St John and none of the other three.
The lava flow would have been confined within a low valley as it flowed from Meola Rd area out to the Waitemata River. Since then and especially since sea level has risen the sides of this valley have eroded away as they are made of softer rock than the basalt lava flow and now the erosion-resistant reef sticks out above the harbour flats.
After the flow came down the valley the original stream was displaced to both sides and now we have Meola Creek and Motions Creek on the west and east side respectively, where previously there would have been just one stream down the middle.
From Meola Rd to the sea is Meola Reef Reserve which is a grassed-over rubbish tip, which was built up on top of the surface of the lava flow.
HAVE A LOOK!
What has happened to most of the original ropey or rubbly surface of the lava flow at high tide level do you think?
Can you see Meola and Motions Creeks flowing out across the intertidal flats to the sea? Why is there one on each side of the lava flow?
In the 1940s-1950s the top of the lava flow at mid-tide level was covered in tube worms (Spirobranchus) - today it is covered in Pacific oysters - why do you think this is and where did the oysters come from?
Can you see Mt St John from Meola Reef? Why not?
Try and trace the Mt St John lava flow back to its source - what is in the way?
Carpark for Meola Reef Reserve is off Meola Rd opposite the MoTAT aircraft hangar.
Beware of razor sharp rock oysters on top of the flow in the upper half of its tidal range.
Beware of soft deep mud along the edge of the flow through the mangroves and down towards low tide.
Watch out for the incoming tide if you venture out towards the northern tip.
Best to visit on a low spring tide in the early afternoon if you intend to head for the tip.
Take metal walking track from carpark to north (harbour) end of Reserve and then step from grass onto the surface of the basalt flow among salt marsh (avoid the mangroves that accumulate mud). Walk seaward on the flow. Beyond the mangroves the lava has dense oysters on top that are razor sharp - avoid if possible by visiting at lower tides and skirting along the side. To get further out towards the end of the flow it is easiest to stop at the end of Garnet Rd and walk out across the sand flats to where the flow meets the low tide mark (may have to wade an intertidal stream) and pick a place to get onto the reef where there is less soft mud right along its edge. It is then possible on spring low tides to walk out towards Birkenhead on the reef.