The "Marble Arch" while being a magnificent feature, it is also a indication that the landmass that is now Mayor Isalnd, was once bigger and this is an eroded remnant of the Main Cone lavas. This archway lies off Waikawa Point at the Northern end of Omapu Bay.
View down Omapu Bay from the north.
The outcrops along this beach are one of the many puzzles that Mayor Island has. However, the sequence here was a key to determing the largest of eruption of the volcano in its history. The caldera forming explosion. Dated actuately because of my find!
At the northern end of Omapu Bay the Main Cone lava flows outcrop and here you can see the black obsidian selvedges on the base and top of the flow units. The redhead with the hammer is "moi" at a much younger age.
