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#15 Gentle FoldsAnticlines and Synclines

33°34.994' N 117°51.602' W

When the sand and tide are low enough,you will be able to see gently undulatinganticlines (upfolds) and synclines(downfolds) in the Monterey Formationexposed at beach level. Folds can becaused by compressional forces deepwithin Earth’s crust, where heat andpressure combine to alter the originallyhorizontal sedimentary layers. Commonly,folds are associated with faults, anotherindicator of stress.

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#16 Recumbent Folds 33°35.029' N 117°51.635' W

The severely folded Monterey bedsexposed in the cliff at the north end of thebeach at Crystal Cove are textbookexamples of recumbent folds. Theselayers are so tightly contorted that it ishard to imagine solid rock bending likethis – even under high heat and pressure.Despite the extreme folding, no visiblefaults are associated with this outcrop.Consequently, these rocks likely folded,not deep within Earth’s crust, but at thesurface before the sediments lithified(turned to stone). Picture yourself pushinga carpet up against a wall until it folds.Similarly, in the deep water environment,the water-saturated sediments probablyslid (triggered by an earthquake) downslope until they folded as you see here.

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#17 Cave and Oil 33°35.002' N 117°51.638' W

You may have already noticed black oilypatches on some of the rocks or thebeach sand. Be careful with youridentification. Some of the spots mayactually be “tar spot algae” or magnetite(POI #4). On the other hand, some mayindeed be petroleum.

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On a clear day you can see oil platformsoff shore Newport and HuntingtonBeaches. These platforms may hostseveral dozen wells radiating like spokesfrom the hub of a wheel and extendingdown to various reservoir rocks (porous,permeable rocks capable of yielding oiland gas). One thing these platforms andmany other land-based California oil wellshave in common is that the source of oil isthe Monterey Formation (although it hassince migrated to various reservoir rocks).

Nearly all oil originates from plankton inshallow marine environments – not fromland plants, which when preserved asfossil fuel produce coal. Despite old TVads to the contrary, neither dinosaurs norother land animals produce oil. Why? Theanswer, in part, is related to biomass.Even though individual plankton aresmall, total planktonic organic carbon (theraw material for oil and gas) dwarfs thatin whales, dinosaurs and all other animalscombined. It is primary producers (thephoto- and chemo-synthesizers) whichmanufacture food for all other creaturesand oil and gas.

In the Monterey the chief primaryproducers, which sometimes produce anooze exceeding 30% of the rock volume,are diatoms. Diatoms not only producethe raw material for petroleum but also forthe rock itself. These microscopic photo-synthetic plants manufacture porous“skeletons” of glass (SiO2, the chemicalcomposition of the mineral quartz and ofcommon window glass).

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Diatoms are not the only marine algae toproduce rock and oil. In the North Seaand throughout other regions of the worldand especially during the Mesozoic Era(the dinosaur ages), calcareousnannoplankton produced a great deal ofoil and the rock chalk (CaCO3). Yes, thesame stuff teachers used to write onblackboards (as opposed to the oily pensnow used to write on whiteboards). Atother times in the past various marineplankton produced oil and gas asevolution and extinction of various algalgroups progressed.

Their environment of origin is one thingall the oil-producing primary producershave in common. Most primary productionoccurs in shallow marine well-lightednear-shore water. The light is needed forphotosynthesis and near shore isconcentrated with the nutrients needed bythe plants. In upwelling zones nutrients(like nitrogen, potassium and vitamins)are brought up to the surface from theocean floor below. You may have amental image of the Middle East oil fieldsbeing in a sandy desert environment farremoved from marine upwelling zones.That certainly describes their presentcondition, but 100 million years ago whenmuch of that oil originated, theenvironment was shallow marine.

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#18 Newport Jetty Overlookand a Vexing Problem

33°35.027' N 117°51.642' W

From the beach climb the steps up to thebluff top and follow the path left to theNewport Jetty overlook. When lookingnorth toward Corona del Mar, you will seethe Monterey cropping out all along thebeach. Now observe the rocks exposedon the inland side of the trail. They appearvery similar to Monterey Formation rocksrising out of the beach sand and makingup the cliffs of the cave and surroundingareas. But we are standing on the120,000-year-old soils and elevatedterrace deposits which overlie theMonterey cliffs.

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What is the problem? How can MontereyFormation be both above and below theterrace deposits? Has a fault thrust oldrock up and over younger rocks producinga reversed age sequence of layers? Lookat the Monterey exposed above the trailvery carefully. You may have figured outthe solution. The rocks above the trail arefake, bogus, manmade! They cover aretaining wall meant to look like the rocksin the vicinity.

From this last point of interest, you mayretrace your steps along the beach orcontinue along the terrace trail weavingthrough California Coastal Sage ScrubCommunity ecosystem, several picnicareas, and overlooking view points. Otherhiking trails on the inland side of CoastHighway are available for your furtherexploration.

To explore further Orange Countygeology, visit:

Crystal Cove State Park Calendarwww.crystalcovestatepark.com

Merton Hill, PhD at Sadddleback Collegewww.saddleback.edu/faculty/mhill

Laguna Canyon Foundationwww.lagunacanyon.org/events.html

Irvine Ranch Natural Landmarkswww.irvineranchwildlands.org

Please remember

• Protect your park. Enjoy only trails designatedby park maps and signs.

• Camping reservations are required.• Be prepared. Pack plenty of water, snacks,

sun screen, and other backcountry essentials.

The following are prohibited:

• collection of rocks, fossils, plants, seeds,animals, or shells

• smoking or open fire pits in the backcountry• dogs

This guide was made possible by:

Merton Hill, PhD, Saddleback Collegeauthor and images

Annlia Hill, PhD, UC Irvineeditor and images

Crystal Cove Interpretive Associationproduction costs

Crystal Cove State Parks Personnel field assistance and images