Rocks With Spots!

Natural Bridges State Beach, located at the western edge of Santa Cruz, California, is a great place to play in the sand, explore tide pools, and marvel at the single remaining "natural bridge".  Early photographs show that there were originally three dramatic arches here.  However, by the mid-1970's, two arches had collapsed, leaving just the one (for more information on this, see Santa Cruz Coast: Then and Now, Arcadia Press, 2006, pages 27 - 28)

As you climb up over the rocks to get a closer look at the tide pools, you stumble upon something else that grabs your attention: unmistakable markings on the rocks underfoot that look like spots of varying sizes, forming spiraling patterns and lines.

These warm brown, slightly faded spots and lines dance around the sun-kissed surfaces in counterpoint to the inherent jointing in the rock.  They create bold, yet harmonious compositions everywhere.

Coastal geologist and oceanographer, Gary Griggs, says that this rock is Santa Cruz mudstone, and the markings were most likely created by the process of iron oxide precipitation.  Apparently, a rock's exposure to a variety of biological processes, in addition to salt water spray, runoff and seeping ground water, can markedly alter the way rocks look.  In his book, Introduction to California's Beaches and Coast, he writes:

"The fractures or joint patterns are usually due to the stress the rocks have been exposed to in the eons since they were formed, and these fractures tend to occur in geometric patterns.  As the water seeps into the cracks, the iron contained in the water will gradually precipitate out, leaving rusty iron oxide marks behind as the water slowly dries out or evaporates.  The stains will form in different geometric patterns based on the rock structure and weaknesses that water has been able to penetrate. The leopard spotting results from the same iron oxide precipitation process but may be a result of microbial activity within the rocks that was spaced out somewhat uniformly within the cracks in the rocks and served as points where the iron could be precipitated more easily."

Photo courtesy of Gary Griggs

Photo courtesy of Gary Griggs

How fascinating that a natural process can create distinct markings, as if guided by a sentient hand. Just looking at these images makes me want to head out to Natural Bridges State Beach very soon to see what other mesmerizing compositions I can capture...so stay tuned...

All of the images posted here are available for purchase as 8x10 and 5x7 fine art prints and A2 size greeting cards (all printed on archival water color paper) at http://DigitalYak.etsy.com/.  Be sure to send me a message if there is something you'd like that you don't see listed, or if you'd like a custom size or item, as I truly enjoy creating one of a kind items that hold special meaning. Thanks!!

Tafoni: Architecture by Nature

To be surrounded by tafoni is to be transported to another world...a cavernous labyrinthine world where one loses all sense of scale and space and time.

This series of tafoni photographs was taken just north of Santa Cruz, California on the San Mateo Coast. The geomorphology of the area is so strikingly similar to Point Lobos (which is sixty miles to the south), that geologists actually believe that this stretch of coast sheared off from Point Lobos several million years ago, and that it has been transported northward along the San Gregorio fault to its current location (and that it is moving still!).

In his book, Introduction to California's Beaches and Coast, Gary Griggs writes:

"Tafoni seem to start as shallow pits, although why and when they start is not well understood. In some cases, the pits may form due to differences in the distribution of mineral grains or structural weaknesses within the rock that allow salt water, or the salt that crystallizes from the water, to etch, dissolve,or begin to break down small circular sections of rock. This process continues slowly over time as the pits deepen, expand and eventually coalesce. Tafoni continues to be a curiosity whenever we find it and stimulates even non-scientists to ponder on its origin."

While the science of tafoni formation may be complex, there is no doubt that it makes for a most fascinating tactile landscape that totally captures your imagination and begs to be experienced and explored.

All of the images posted here are available for purchase as 8x10 and 5x7 fine art prints and A2 size greeting cards (all printed on archival water color paper) at http://DigitalYak.etsy.com/.  Be sure to send me a message if there is something you'd like that you don't see listed, or if you'd like a custom size or item, as I truly enjoy creating one of a kind items that hold special meaning. Thanks!!