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| Moolack Beach, north of Newport. |
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| Guy DiTorrice |
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Petrified? Relax.
Let it rain. When you’re hunting
for fossils, a good time is set in stone
[Published April 4, 2008]
[View our full photo gallery of the Moolack Beach fossil hunt!]
By Niki Price
Oregon Coast Today
Between the driving rain and the Moolack Creek crossing, my jeans were soaked. Not just damp, or wet in places. They were drenched, heavy, as if I had jumped into the deep end of a swimming pool and walked out again, then decided to go out hunting for beach fossils. My gloves, shirt sleeves, hat, socks — all were wet and growing colder every minute.
My rock safari guide was only slightly better off, having had the sense to wear a rain slicker and knee-high muckboots, but neither one of us was comfortable, despite our brave demeanors. We had the drawstrings of our jacket hoods pulled tight around our faces so that only our lips, eyes and noses were visible. Questions and answers were yelled across the rock bed. Noses, running with the ghosts of colds yet to come, were left to drip as we talked about sedimentary layers, mudstone, clam deaths and bone marrow.
It was the greatest fossil-hunting day in geologic history.
It was the best bonebug field trip since the Miocene era, when my porpoise skull was first buried by sand and the worms bored through what became my specimen of Teredo wood. It was the most exciting outing since my Patinopecten sucked its last valve full of water next to a broken log that became my taupe-and-black chunk of petrified wood.
For this success, we had the rain to thank. Winter storms make the seawalls of Moolack Beach, north of Newport, rupture small slides laden with 20-million-year-old rocks that tumble onto the beach below. They make creeks and rivers overflow, uncovering new layers of rock with every season. The rain even makes the fossils easier to spot, because like agates they are shiny when wet.
We might have wished for a little less force, perhaps. But I gained a visceral education by standing in the downpour, with the pounding surf on one side and the crumbling bluff on the other, with basalt headlands in the distance and sands shifting south in the wind. I thought about plate tectonics and tilted rock layers, igneous and sedimentary rocks, marine mollusks and tertiary animals preserved forever in the fossil record.
After a while, though, I was thinking mostly about a bowl of hot chili. We loaded up our treasures, turned into the wind, and pushed out way back up the muddy slopes to the Moolack Beach parking lot.
This day, rocks!
Rainy-day rockhounding has its merits, but in truth there are few places in this world that are not improved by the addition of sunshine and young people. So it was one week later, when I returned for another foray into the rock beds near Moolack Creek. I met up again with Guy DiTorrice, a branch manager for a regional credit union, who spends his free time fossil hunting, giving talks and leading field trips like this one.
This sunny day, he welcomed a group of repeat customers: Virginia Leonnig, her son Grant Siwinski, her grandsons Duncan, Dillin and Trevor, and their friend David. They’re a family who meets on the beach for vacation — Leonnig splits her time between Waldport and Portland, while the Siwinskis live in Spokane, Wash. They went hunting with the “Oregon Fossil Guy” three years ago, and they’ve been talking about it ever since, Leonnig said. They assembled near the open hatch of DiTorrice’s Jeep Wagoneer, which is filled with the tools of his trade: extra gloves, plastic bags, pre-printed labels and plastic bins filled with specimens that show his students what they’re looking for. They pass these rocks around and learn a few frequently used terms.
Rock attached to fossils, for example, is called matrix. Fossils encased in rock are concretions. Specimens that are already broken free from their rock surroundings, and ready to be cleaned or polished the moment you pick them up, are often called “free and clears.”
Fossils can be found year-round, but some months are much better than others. Winter storms scour the beaches, removing yards of sand and leaving the rocks behind; summer does the opposite, bringing in sand that covers the rock layer once more. The difference can be remarkable. In March, it may be a cobbled street, filled with fossil finds; in August, the same bend in the shore will be sandcastle city.
On the central coast, creatures and plants from the past are found in two formations. The Astoria Formation, made up of sandstone layers mixed with compressed volcanic ash, is 15 to 20 million years old; today, it appears as rock that is light and sandy in color. The Nye Formation, made up of compacted sand, volcanic ash and river-borne silt, is up to 20 million years old. In the modern day, Nye Formation rocks appear dark gray.
These Astoria and Nye rocks hold a variety of fossils, including bivalves (with shells much like the clams and scallops of today), gastropods (with a twisted shell, like snails), petrified wood and bone fossils.
Trouble is, these rocks emerge from the sediment and settle amidst a great crowd of other, non-fossil bearing stuff: eroding basalt (lava rock, “baby rock” compared to Nye and Astoria formations), modern day mudstone and siltstone, and sand. How will you know what you’re looking for?
‘That’s good poop’
To hedge your bets, look for stretches of shore that are rocky, rather than smooth layers of gravel or fine sand. Stick close to the bluffs, near fresh disturbances or creek beds. Keep in mind that it’s against the law to remove anything, by hand or with tools, from the seawall; but all the rocks at the base of a fall are fair game.
Start by looking for rocks decorated with white lines, which indicate agate-ized shells are trapped within.
“Nike swooshes, smiles, hearts, eyeballs — let’s be picking them up. Bring them to me, and I’ll play with them. We’ll see what’s inside,” DiTorrice told his group.
When he’s out with a group, DiTorrice carries a bucket with extra bags, a spray bottle and laminated fossil identification cards, and keeps his rock hammer holstered above his left pocket. He’s a quick draw with that hammer, made of tempered steel that is harder than most anything his students are liable to pick up. He takes concretions, which can be round, egg-shaped or flat (also known as a “clamburger”), and stands them on their sides. With an expertly aimed “flack!” he’ll crack it open to find what ancient thingy lies within.
DiTorrice calls them “Crackerjack boxes,” because you never know what you’ll find inside. Sometimes concretions are empty. Others contain a field of very small objects, or bits of fossilized wood or shell. He keeps trying, opening up every concretion that the boys from Spokane bring his way, until one reveals a large brown circle.
“This one has poop inside. We can take this poop down to the docks today, and compare it. It’s from a seal or a sea lion. They’ve been eating the same thing for 15 million years,” DiTorrice said. “Kids love to find the poop.”
“That’s good poop,” agreed Grant Siwinski.
Both DiTorrice and Siwinski, however, are big fans of fossilized mammal bone. To find it, they look for gray rocks that have a spongy or porous pattern, or bits of a spongy pattern within a smoother, lighter field. That’s marrow, the substance in between the harder bones of a fish or mammal. With practice, you can begin to see the form of the bone within the rock: vertebrae or rib, skull or fragments.
Dillon Siwinski walked up with a round rock, marked with a long stripe in a spongy pattern, and inspired DiTorrice to cheer.
“We got the prize of the day! That’s bone, in series. In the rock. This kid really gets it – that’s a beautiful display piece,” he said. “Look at that! Yes!”
The Oregon Fossil Guy’s field trips have had great luck on Moolack Beach in the past month. We saw large specimens, covered in clams and other bivalves, as well as Teredo wood (marked by its long stone worm casts), leaf fossils, petrified wood, bone, and free-and-clear Andara devincta, Oregon’s most common marine fossil.
“When they get done with one of my field trips, people always say, ‘I’ll never look at the beach the same way again,’” DiTorrice said.
This was true for me. What’s more, I might not see a howling rainstorm in the same way either. Instead of snuggling in with a cup of cocoa, I may shake out my rubber boots and find my long underwear, thinking: “Time for a fossil hunt.”
Resources
Guy DiTorrice is the author of a two-page primer on this subject, “Fossils You Can Find on Oregon’s Beaches.” You can download the pdf from Oregon SeaGrant at http://seagrant.oregonstate.edu/sgpubs/onlinepubs.html.
His web site, with information about field trips and group presentations, is oregonfossilguy.com; or call 541-961-1762.
We also recommend “Fossil Shells From Western Oregon: A Guide to Identification,” by Ellen J. Moore (2000, Chintimini Press).
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