Special Edition: Baja #4 - Dinosaur Eggs

Aside from boasting some of the most diverse, accessible, and undeveloped reefs for snorkeling and diving in the hemisphere*, Cabo Pulmo hosts a very strange conglomeration of smooth granite boulders the size of, well, dinosaur eggs. 

Dinosaur eggs, Cabo Pulmo, 2012.

I have done some online research on the geology of the area and found nothing. So I'm forced to speculate on the matter. Looking at the surrounding geology, one can observe layers of sandstone and granite. Also in some of the sandstone is a formation found in other parts of the Pacific coast known as tafoni (see below), which I recognized from Salt Point in northern CA and even in the Presidio.

"The exact process of formation of tafoni is not entirely understood. The waves and salt spray leaves salt crystals on the sandstones. Salt and water interacting with the cement between the sand grains, and in minute fractures in the rock alternately hardens portions and loosens others, creating the lacy, box-like pattern." Dr. Sue Ellen Hirschfeld.

Tafoni/Dino Eggs, Cabo Pulmo, 2012.

I suspect the same process, expressed in a different way on this far-harder material, is occurring to give these boulders their shape. 

Shown below is a series of cairns that inspired visitors have created.

Dino egg cairns, Cabo Pulmo, 2012.

* By the way, this in itself is a great story, since the reef was closed to commercial fishing in 1995 and has since seen tremendous rebounds in marine life. Read more here... or translated here.