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Oregon’s Green rock Ophiolites

Oregon’s Green rock Ophilites

Oregon Subduction Zones bake precious gemstones
photo by author

Oregon’s geology would be boring without multiple odd green mineralized Ophilites. Without Ophilites, all of Oregon is basically prehistoric lava flows deposits or erosional volcanic sediments (i.e. sandstone) heading into the Pacific Ocean.

Ophilites are the colorful twist of nature that brought in gold and other valuable minerals to Oregonians. The cover photo shows some colorful gemstones found in Oregon Ophilites.

If you have seen green “Snakeskin” serpentine rock layers in your travels around Oregon, you have seen a prehistoric “Subduction Zone”.

Moreover, Oregon’s Jade comes from Subduction Zones and the last article in December explores China passion for Ancient Jade; as the world’s known supplies are rapidly being exhausted outside Oregon.

“Geologists have a saying - rocks remember.”

Neil Armstrong

Though today the TV news reports may seem more urgent as a warning on a future massive earthquake along our current Oregon’s floating “Ophilites” or “Subduction Zone” off our coast line about 40 miles west of Newport Oregon.

Here are some excellent websites to study Oregon’s next mega quake:

Oregon Earthquake Commission Predicts Potential Catastrophe

“It is impossible to predict exactly when an earthquake will strike, but the Pacific Northwest is due for a 9.0 magnitude quake along the Cascadia subduction zone — as early as the next 50 years. According to a recent resiliency report by the Oregon Seismic Safety Policy Advisory Commission (OSSPAC), also known as the Earthquake Commission, such an earthquake would devastate much of western Oregon. Buildings would crumble; bridges would fall; and thousands of people would die. Oregon would be looking at $32 billion in economic losses.

The Earthquake Commission’s Resiliency Plan contains a series of recommendations for the legislature’s consideration, including statewide renovations to schools, highways and emergency response facilities in preparation for the quake and subsequent tsunami. (You can see a pdf draft summary here.)

Are you prepared for a major earthquake where you live or work?

Here is another source:

Oregon's Next Huge Earthquake: Not If, But When

“Following the deadly magnitude-9.0 Tohoku earthquake and tsunami that struck Japan in March 2011, Oregon legislators commissioned a study of the impact a similar quake could have on the state, according to the Associated Press….The report, "Oregon Resilience Plan: Reducing Risk and Improving Recovery for the Next Cascadia Earthquake and Tsunami," was presented to legislators Thursday (March 14, 2013).

The seismically active region has felt temblors before, most notably a massive earthquake and tsunami in January 1700 that wiped out entire forests in what is now Oregon and Washington and caused a deadly tsunami in Japan, thousands of miles across the Pacific Ocean. [Waves of Destruction: History's Biggest Tsunamis]

"This earthquake will hit us again," Kent Yu, chair of the commission that developed the report, told Oregon legislators, according to the Daily Mail. "It's just a matter of how soon."

Mega Tsunami to Hit Northwest? Experts Report Mega-Quake Is Overdue; How Do We Prepare?

By Philip Ross on March 15, 2013

The attached NOAA YouTube video below shows what all Pacific Northwest residents should learn today; as the local Cascadia Subduction Zone earthquakes t are coming. It is not a question of “if”; it is a question of when.

The author hopefully wants to prepare and protect all the readers and friends and their families out there!

This article will not delve further into this well publicized future PNW quake potential threat; as it been well covered. But the Up side to earthquake’s high pressures and heat and mixing and time is Jade and other commercial gem stone very popular in China today!

Thankful for our Oregon Jade & China’s passion for it!

Frankly, this natural, huge, factory like retort is how Nature makes Jade and other gems is made out of very rare surface deposits of deep forest green serpentine with earthquakes!

In a chemistry laboratory, a retort is a glassware device used for distillation or dry distillation of substances. It consists of a spherical vessel with a long downward-pointing neck. The liquid to be distilled is placed in the vessel and heated. The neck acts as a condenser, allowing the vapors to condense and flow along the neck to a collection vessel placed underneath.[1]

In the chemical industry, a retort is an airtight vessel in which substances are heated for a chemical reaction producing gaseous products to be collected in a collection vessel or for further processing. Such industrial-scale retorts are used in shale oil extraction and the production of charcoal. A process of heating oil shale to produce shale oil, shale gas, and spent shale is commonly called retorting.

In the food industry, pressure cookers are often referred to as retorts, meaning "canning retorts".

Oregon’s unique and rare very serious earthquakes, do literally cook these gems. Maybe more importantly, after the several hundred year cycle-quakes, this fact will explain why Oregon has Jade to sell to China.

Readers, there is a world-wide shortage of commercial jade sources now and high quality gems have always been very precious.

What Is an Ophilites?

“The earliest geologists were puzzled by a peculiar set of rock types in the European Alps like nothing else found on land: bodies of dark and heavy peridotite associated with deep… bodies of serpentinite, with a thin cap of deep-sea sedimentary rocks.

In 1821 Alexandre Brongniart named this assemblage ophilites ("snake stone" in scientific Greek) after its distinctive exposures of serpentinite ("snake stone" in scientific Latin). Fractured, altered and faulted, with almost no fossil evidence to date them, ophilites was a stubborn mystery until plate tectonics revealed their important role.

Readers we rarely see what is going on below our Pacific sea floor surface in Oregon, but rare ophilites bring the abyss chemistry up to the surface for all to see.

Seafloor Origin of Ophiolites

A hundred and fifty years after Brongniart, the advent of plate tectonics gave ophilites a place in the big cycle: they appear to be small pieces of oceanic crust that have been attached to the continents.

Until the mid-20th century program we didn't know just how the seafloor is constructed, but once we did the resemblance with Ophiolites was persuasive. The seafloor is covered with a layer of deep-sea clay and siliceous ooze, which grows thinner as we approach the mid-ocean ridges. There the surface is revealed as a thick layer of pillow basalt, black lava erupted in round loaves that form in the deep cold seawater….

“Beneath the pillow basalt are the vertical dikes that feed the basalt magma to the ocean bottom surface. These dikes are so abundant that in many places the crust is nothing but dikes, lying together like slices in a bread loaf. They clearly form at a spreading center like the mid-ocean ridge, where the two sides are constantly spreading apart allowing magma to rise between them. (See more at "Divergent Zones in a Nutshell.")

Beneath these "sheeted dike complexes" are bodies of gabbro, or coarse-grained basaltic rock, and beneath them are the huge bodies of peridotite that make up the upper mantle. (Have a look at all these rocks in the ophiolitic rocks picture gallery.) The partial melting of peridotite is what gives rise to the overlying gabbro and basalt (see "About the Earth's Crust"). And when hot peridotite reacts with seawater, the product is the soft and slippery serpentinite that is so common in Ophiolites. (See more about serpentinization.)

This detailed resemblance led geologists in the 1960s to a working hypothesis: Ophiolites are tectonic fossils of ancient deep seafloor.

Above is what Pacific Ocean drilling of the sea floor has found; but what happens in rare ophilites/earthquake phenomena?

“Ophiolites Disruption

Ophiolites differ from intact seafloor crust in some important ways, most notably in that they aren't intact. Ophiolites are almost always broken apart, so the peridotite, gabbro, sheeted dikes and lava layers don't stack up nicely for the geologist. Instead they are usually strewn along mountain ranges in isolated bodies. As a result, very few Ophiolites have all the parts of the typical oceanic crust. Sheeted dikes are usually what are missing.

The pieces must be painstakingly correlated with each other using radiometric dates and rare exposures of the contacts between rock types. Movement along faults can be estimated in some cases to show that separated pieces were once connected….”

“The more we study Ophiolites, the less we can assume about them. If no sheeted dikes can be found, for instance, we cannot infer them just because Ophiolites are supposed to have them.

The chemistry of many Ophiolites rocks does not quite match the chemistry of mid-ocean ridge rocks….”

As Portland’s OREGON NATURE EXAMINER, the author strives to inform Readers about Oregon’s hidden treasures for all Oregonian to explore and enjoy for free for an outdoor outing!

Enjoy your home.

Our benevolent Oregon Sun melts the fog and makes up for our incessant rains; so does other largely hidden blessings.

Other Points to Ponder:

We learn geology the morning after the earthquake.”

- Ralph Waldo Emerson

“A cultivated man, wise to know and bold to perform, is the end to which nature works, and the education of the willing is the flowering and result of all this geology and astronomy.”

- Ralph Waldo Emerson (May 25, 1803 – April 27, 1882

“Rocks are records of events that took place at the time they formed. They are books. They have a different vocabulary, a different alphabet, but you learn how to read them.”

-John McPhee

“Civilization exists by geological consent, subject to change without notice.”

-Will Durant “

If you enjoyed this well-researched insight into our Earth’s unique nature and outdoors, please subscribe at top for free to receive every new Earth Insight or Oregon’s must see outdoor adventure site.

Dave has already written almost 250 “Must See Oregon Wonders”-articles on file here, as Portland’s Oregon Nature Examiner. Many use this Oregon based digest for planning their future special outdoor recreation adventures in the upcoming year. He also writes non-fiction books for sell as Amazon and EBooks and hardcovers on nature & human history. Just do a search for the author.


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