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2015 Trip Chronicles:    Contents

Summer 2015 Trip Chronicles:  Page 14

Andrew Molera State Park 11/7

On Saturday November 7, I drove the 95 miles south to Andrew Molera State Park in order to work a Pacific shore with fascinating geology. Areas between the Big Sur region and Monterey have some small beach areas that contain colorful purple hued manganese garnet sands. In the past I've photographed the sands at Carmel River State Park while the Molera Beach shores contain some larger areas of the sand. The following is a crop from the geological map for that area.

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Mountainous areas to the east along the Big Sur River contain considerable granite and piles of those rocks that have come down the river, that is at the top of the map at left, are common along beach areas. As most such granite rocks tend to be mostly hard quartz, they spend a long lifetime rolling about in surf areas ending up rather rounded. As one walks along the beach there is quite a variation of rock types both as bedrock exposed on the eroded bluff cliffs and as boulders, cobbles, and stones rolling about in the wave zone.

Most trail junctions are not signed thus a trail map is recommended. From the main parking lot that requires a $10 parking fee, the Beach Trail along the Big Sur River leads to the beach about one mile downstream. One must first wade across the river with the very popular trail rather level. Trail map:

www.redwoodhikes.com/BigSur/Molera.html

There is a nice area of purple sands right at the end of the Beach Trail at the upper high tide beach limits however it is likely to be trampled by footprints. As a photographer interested in natural subjects, my plan was to explore more remote areas early before others made footprints. Photographing subjects at ocean sandy beach areas are a day to day gamble because sand is continually covering then uncovering then recovering areas. Thus one may visit and find interesting bedrock or stone beds on one trip and return only to find those rocks deeply buried under sand. And so it is with the purple sand areas along these shores. From the river outlet to Cooper Point is about 2.7 miles. One can travel along the beach at average low tide for about a mile. Although the Bluffs Trail travels along the beach for a couple miles, the bluff itself is a cliff face with dense chaparral everywhere including considerable poison oak and a single beach access point to the south at the Spring Trail. Beyond that access, a rocky point requires a minus tide or wading. Further along the beach north are another 2 similar rocky points. Average high tides wash right against the foot of the bluff cliffs along most of the shores. The high tide on this day November 7 was 4.9 feet at 7:37am PST then down to 1.3 feet at 2:07pm.

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Skies were a sunny blue, temperature low 60s, with light breezes, thus pleasant. After leaving the parking lot at 8:35am, I reached my target section of beach about 10am that required climbing up over a steep chaparral covered rib that I could have waded around a rocky point to reach. What a fine environment to excite the human spirit. The smells of the sea, the soothing sound of waves rolling in on the shore, seagulls and other shore birds calling in the morning quiet. I wasn't the first to walk the beach.

A raccoon had been about at dawn as its tracks went across damp wave washed purple sands. And also one deer with large hoof prints had visited too maybe to sample grass growing out of seeps still dripping from bluff cliffs. During this day I would doubtless crush hundreds of sand fleas aka beach hoppers, platorchestia platensis, that are actually crustaceans that feed on decaying kelp washed ashore, as dozens hopped about the sand with each step. The fate of many tiny creatures in a world giants tread. The clean granite sand of most of the beach is a mix of white, darker, and black grains generally whiter than average coast sands. Thus the sea off the shore has a more aesthetic aqua blue green hue than most shores.

I came upon an area of uniquely light green hued sandstone bedrock. And like much sandstone along our Pacific Coast, there were areas of tafoni formations that are small cupped holes in the sandstone. On the above geological map, that is a Kss shaded rock type. The below image was not tafoni but rather bedrock with small raised bumps with manganese garnet sand between the bumps. Unless noted, all my close up images are taken with the Sigma 60mm F2.8 DN lens. Our human visuals system will have trouble with such an image so one may see instead concavities where the green sandstone is. If you see this optical illusion so, isolate a single hump by making a hole with your fingers to see through.

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This next image below, a 1x2 stitch blend taken with my Sigma 30mm F2.8 DN lens, shows a section of beach with the light green sandstone with tafoni holes.

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Below image of surf smoothed granite stones and a giant kelp small air bladder against manganese garnet sands.

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And below a 1x2 vertical stitch blend of more stones and sand. In most areas of the purple sands there are mixtures with normal white sands thus the saturation of the purple varies. To appreciate the fine detail on this and other images due to focus stack blending sets, select the enlarged vertical slice view links below most images. Use a browser Back button to return.

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Higher up the beach above the last night's high tide level were areas of dry wind blown sand. The image at page top, OT01808-18.jpg, was some of those wind wavy sands around a surf battered redwood log. The small white spots with holes in the middle are where sand hoppers that bury themselves to avoid predators crawled out. That also shows how the purple sands are shallow in this spot with the lighter white sand just below. Below image is a close up of a section of sand where beach wash seawater made patterns where the two sand colors mixed.

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A close up below of shallow tafoni holes on light green sandstone partially filled with purple sand. Unlike the tafoni image below this image, there are enough adjacent sandstone features that one's brain is less likely to see an optical illusion.

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Another close up below with an extension tube on my 60mm lens of shallow tafoni holes on light green sandstone partially filled with manganese garnet sand. An optical illusion, the inverse of the one above with green bumps is likely to appear that makes the purple sand areas appears as bumps instead of being what they are, shallow concave holes. Like the above, isolate your vision with fingers around single holes and elements will switch.

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Finally a close up again with an extension tube of green sandstone with quartz veins and manganese garnet sands. Note in the enlarged vertical slice view individual sand grains are translucent.

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By 1:30pm an increasing afternoon breeze grew to a stiff northwesterly wind with white caps on the seas. Instead of returning on the bluff route I'd come in on, since it was near low tide at 1.3 feet, I was interested in gauging the difficulty of passing 3 wade points. The first spot I could have waded knee deep but climbed the bluff as I did coming in. At 0 feet it would be passable. The second point required waiting a bit for a lull before passing through a tunnel hole in the bedrock point that cheated deeper water at the actual point. To actually go around the point like the next third spot would require a minus tide. Instead I removed boots, socks, and Levis, stuffed them in my daypack and waded around the point then through a larger cave tunnel. Water in the tunnel was however thigh deep. On the other side numbers of other beach walkers had piled up with most turning around then walking the mile back to the river outlet and trail. By time I reached the outlet it was 3pm. Lots of people were about as well as on the connecting Beach Trail with many groups just now making their way to the shore. I reflected on how the early morning with calm or light breezes was so much more pleasant while many people out for a group outdoor trip often don't even leave their homes before late morning.

2015 Trip Chronicles:    Contents

   David Senesac
   email: info@davidsenesac.com

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