Wednesday, March 13, 2019

What does a poisonous Southwestern plant, its insect pollinator, some famous paintings, Native American pottery and an eye exam have in common?

After visiting a number of museums in Italy during the summer, a curious coincidence occurred while hiking in Utah's Zion Canyon in the fall. But, it didn't stop there and continued the following week in Santa Fe and back home in Boston. The explanation requires a little geology, botany, neuroanatomy, lepidopterology, anthecology, phylogenetics, pharmacotoxicology, organic chemistry, ophthalmology and a basic knowledge of Italian Renaissance and American abstract art (though not in that order).

Angels Landing of Zion National Park
Constructed primarily of Navajo Sandstone, the infamous, ominous and vertiginous rocky sentinel towers 1,488 feet over the floor of Zion Canyon. 

As secularism took hold in Europe during the Renaissance, although far from abandonment, there was a shift away from the emphasis of Christianity, faith and salvation that existed during the Middle Ages. In addition to rediscovering the classical ancient past, there was an interest in the everyday "new world" that had emerged. Literature and art became more temporal and demonstrated that life was worth living for its own sake.

Renaissance subject matter paid more attention to scenery, nature, perspective and humanism than ever before. No longer sponsored solely by or for the church in the Medieval period, Italian portraiture, largely in the 15th century, became commissioned by the nobility and the wealthy. In particular, the female body and face was depicted by artists in a new manner, light and perspective.

One aspect involved the manipulation of the eyes. A familiar and famous example is the Mona Lisa by Leonardo da Vinci, painted in softly shaded, sfumato style.

The Most Famous Gaze of All Time
A four-year project starting around 1503, the Renaissance masterpiece possesses a gentle smile rivaled only by her mysterious eyes, wide open with large excited or interested pupils. Are they smiling along with the lips? Do they really follow you across the room? Both have been exhaustively analyzed and endlessly discussed. 

Lisa Gherardini's enigmatic gaze and alluring smile have been interpreted and debated about by every art historian, critic and member of the viewing public since the masterpiece's creation. Even geologists have studied the undulating valleys and rivers of the landscape behind the sitter and how the horizon focuses attention to her eyes. And yet, there's more than meets the eye. Not only is there a tiny letter "L" for Leonardo in the right pupil, but, easily overlooked, both pupils appear slightly enlarged. 

Another Renaissance example is "Woman with a Mirror" completed around 1515 by Venetian artist Tiziano Vecellio, better known as Titian. Also painted in typical sfumato fashion, the female subject possesses an idealized form of beauty: attractive, virtuous, poised and well-dressed with a well-proportioned face, high forehead, ruby lips, realistic flesh tones with fair but not pale skin with rosy cheeks, graceful hands and lively dark eyes with large seductive pupils.

Again, it's the latter attribute where our interest lies.

"Woman with a Mirror", 1515
While admiring her lovely coiffure in the mirror, might the woman in the portrait also have applied belladonna to dilate her eyes? If so, what's in the little jar? Renaissance artist Titian of the 16th Century Venetian school.

Fashionable Italian Renaissance women and ladies of the court, in order to achieve their definition of beauty (undoubtedly with the intent of attracting a male suitor), placed a drop of an extract from the berries of the Atropa belladonna plant in each eye or likely even rubbed a slice of the fruit itself over the eyelids. Meaning "beautiful lady" in Italian, the concentrate greatly enlarged the pupils to purposefully afford the user with a dreamy gaze and the artist with a seductive subject to paint.

Unbeknownst to the user, the desired look was accomplished with neurochemicals, naturally occurring and plant-based substances. As a result, a small Atropa belladonna extract will chemically stimulate two tiny smooth muscles, one in each eye, and cause the pupils to dilate or widen.

The Extremely Toxic Foliage and Enticingly Edible Purplish Berries of Deadly Nightshade
Carl Linnaeus, the Swedish physician and founder of modern taxonomy, captured the essentials of the plant by not only naming it "belladonna" but "Atropas." The latter refers to the oldest of the three Greek Moiras or Fates that was the cutter of the thread of life.

Dilation (enlarging) and constriction (shrinking) changes pupil size and thereby regulates the amount of light that reaches the retina at the back of the eye. That enhances night vision in low-light conditions in order to increase the depth of field and the reverse in bright light. The pupil also dilates in response to increased cognitive activity, such as when aroused, although I'm getting ahead of myself. 

As we all know, light reaching the eye passes through the dome-shaped, protective lens of the cornea and the transparent opening of the pupil. Surrounding the lens within the iris are two tiny sets of antagonistic muscles (encircled below). Their action is similar to that of the diaphragm and aperture of a camera (not digital ones).

The dilator pupillae muscle encircles the pupil in a spoke-like arrangement and pulls the iris open to dilate the pupil (Remember: the pupil is a black-appearing hole or opening in the center of the iris). It's action is antagonistic to the sphincter pupillae that is arranged radially around the pupil. Its contraction constricts the pupil making it smaller.

As we shall see, the contraction of these tiny muscles is NOT under our cognitive, conscious control but under the influence of our 'automatic', unconscious nervous system AND various externally administered chemical agents! 

Anatomy of the Human Eye in Cross-Section
Light that passes through the lens is focused on the retina, the photoreceptor-endowed sensory membrane that lines the back of the eye. It sends signals through the optic nerve to the brain's visual cortex that coverts them to the images that we see. Voila! Sight.


It turns out that the Italian Renaissance ladies were correct. Numerous psychological studies have confirmed that the curious pupillary-Atropa belladonna practice did in fact make them appear more seductive by mimicking the physiologic response of sexual arousal. It's because the berries contain various neuro-substances notably atropine (more on that later). 

Not only does atropine cause transient photophobia (light sensitivity), overuse can cause permanent blindness, and higher doses can dangerously increase heart rate and even kill. And yet, when used appropriately, neurochemicals are highly beneficial as analgesics, stimulants, antidotes in certain chemical poisonings and in the treatment of diseases and conditions such as malaria, asthma, cancer, nausea, fungal infections and more.

Pupillary Science and Product Sales
Body language experts assert that dilated pupils are a sign of attraction. It's neurologically akin to sweating and blushing, all bodily responses beyond our conscious control that can't be faked or prevented. Commercial proof occurred in a direct mailing campaign by Revlon when pupils were artificially enlarged by photoediting and catalog product sales increased by 45%.

After returning from Italy, my son and I headed to southern Utah and Zion Canyon, intent on climbing the National Park's legendary and vertiginous Angels Landing. Sculpted by erosion, the canyon was carved by the North Fork of the Virgin River over the course of two million years.

The geology includes nine Mesozoic-age sedimentary formations that span over 150 million years. Between the basalmost stratum of the Moenkopi and overlying Chinle Formations and extending upward through the uppermost Carmel Formation, the cross-bedded Middle Jurassic eolian Navajo Sandstone forms steep cliffs up to 2,200 feet. It's the signature rock formation that is responsible for Zion's majesty, popularity and incredible beauty. 

Zion Canyon, the Virgin River and Angels Landing
Mostly buff-colored, Navajo Sandstone takes on reds and browns from the varying amounts of oxidized iron and other minerals and white regions from chemical-bleaching via ground water that flowed through the porous rock. Awaiting our ascent, Angels Landing looms in the distance some 457 meters (1,500 feet) above the canyon floor. 

Zion is located on the lofty Colorado Plateau and borders two geological and ecological provinces: the Great Basin and Mohave Desert. With elevations from 3,600 to 8,700 feet, the landscape contains a mix of canyon, desert, high plateau, sandstone slickrock, hanging garden and riparian environments, each with their distinctive biomes. As a result, Zion is home to a remarkable diversity of flora and fauna, where an astounding 982 taxa of plants can be found.

One plant in particular became part of the coincidence. 

Southeast View of Zion Canyon
From the switchbacks of Walter's Wiggles, a narrow section of Zion Canyon is seen through the sun-deprived Refrigerator Canyon that developed in a series of closely-spaced joints. A portion of Scout Lookout and the eroded fin of Angels Landing is high up to the left. On the far side of the canyon, Red Arch Mountain displays exfoliation joints in pinkish Navajo Sandstone.

The Zion shuttle bus dropped us off at the Grotto Trailhead deep in the canyon along the Virgin River. With leaves of summer succumbing to the colors of fall in the crisp morning sun and the river running cold and clear, we couldn't resist a stroll along its banks. A familiar plant caught my eye sprawling weed-like on a sandy terrace. Pointing skyward, its trumpet-shaped, five-lobed white flowers with lavender tips were unmistakable.

Datura wrighti or Sacred Datura, its common name, is in the same angiosperm (flowering plant) family as the plant Atropa belladonna. What's more, both contain the same or similar neurochemicals and are therefore capable of pupillary dilation and far more with an incredible history of use and abuse. Standing along the river, my son and I mused about the bodily actions of the two plants. He was astonished by the use of atropine by proper ladies and portrait painters of the Italian Renaissance and Sacred Datura's highly poisonous nature.

Sacred Datura on the Banks of the Virgin River
The flowers of of genus Datura resemble closely-related and familiar Petunia of the same family. Some botanists contend that the genus of plants evolved an alkaloid poison to deter unwanted insects from feasting on their sumptuous flowers. Not seen on our hike and also indigenous and common to the park is a close relative of Datura wrighti, the prickled-stem, star-shaped Solanum elaeagnifolium or the Silverleaf Nettle.

Like its close relative, Sacred Datura is extremely poisonous. Within minutes, if any part of it from root to seedpod is ingested, inhaled or applied topically, one's mouth becomes severely dry followed by nausea, vomiting and difficulty swallowing. Respiration and heart rate begin to dramatically increase as speech becomes slurred and pupils begin to dilate.

 "Eat a little, and go to sleep.
Eat some more, and have a dream.
Eat some more, and don't wake up."
An old Navajo saying

With high doses, confusion ensues with changes in emotion followed by severe and uncontrollable psychotropic symptoms of incoherence and delirium with bizarre auditory and visual hallucinations. The "bad trip" can last for days, since gastric emptying is suppressed. Often the subject must be restrained to prevent personal injury. Higher doses may lead to sleep, coma, seizures and even death. 

 "Blind as a bat (loss of vision).
 Hot as a hare (feverish).
Dry as a bone (no secretions of tears, saliva and sweat).
Red as a beet (flushing).
Mad as a hatter (delirious).
Full as a flask (urine retention)."
Old Medical school mnemonic 

Sacred Datura blooms later in summer and early fall from dusk through mid-morning but curiously at night. I had an inkling why but didn't know the specifics. A little research confirmed that its curious blooming schedule is the result of nocturnal pollination by a night-flying moth that is attracted to the flowers' sweet-scent.

The Hawk Moth (aka Hawkmoth) pollinator was predicted by Darwin even before its existence was confirmed. To the mutual benefit of both plant and pollinator, he correctly theorized that the insect would require an elongated proboscis (hollow straw-like tongue) that evolved in order to reach Datura's deeply-buried nectarous bounty.

Datura's nocturnal mode of pollination occurs in contrast to flowers that bloom diurnally and those that rely on fragrance and color. Some night-blooming flowers such as black peppers and tomatoes possess an intense and unpleasant sulfurous smell and are pollinated by bats. These plants are also in the large Datura-Atropa plant family! 

A Characteristically Long-Tongued, Datura Hawkmoth Nocturnal Pollinator
From USDA Forest Service, Alfred University and Joseph Scheer

The powerful Hawk Moth is a member of insect family Sphingidae that includes 1,450 species. Although the moth is seldom seen, it's capable, as many others in the family, of hovering mid-air in hummingbird-fashion to obtain nectar as do bats, also nocturnal pollinators. It's an example of convergent evolution (independent evolution of similar features in species of different lineages). 

Unbeknownst to me at the time, the Hawk Moth would become part of the curious connection! 

I also discovered that Sacred Datura has a number of colorful monikers. It was 'sacred' to various Southwest Native American tribes that used it as an intoxicant in ritual ceremonies and rites of passage. It's called "Devil's Weed" due to its nefarious actions if ingested, "Devil's Trumpet" for the shape of the flower, "Sacred Thorn-Apple" after its spiny, round seedpods, "Indian Whiskey" by early California settlers for obvious reasons, and "Nightshade" and "Moonflower" since it blooms at night. In fact, the entire family of plants from which Sacred Datura belongs are referred to as the "Nightshades."

The Seed-Bearing Spiny Fruit of Sacred Datura
The word 'Datura' is derived from the Hindu vernacular, dhatura meaning "thorn-apple." It has been suggested that spiny fruits are adapted for long-distance dispersal by hitching a ride on an unsuspecting animal vector, while the naked ones are to maintain the local population. The spikes may also act to deter ingestion. 

Although somewhat of a misnomer, Sacred Datura is also known as "Jimson Weed", since it resembles its botanical cousin Datura stramonium, the 'true' Jimson. Its common name is a corruption of "Jamestown Weed" of colonial Virginia and involved a documented case of accidental ingestion. Here's an excerpt recorded in the "History and Present State of Virginia" in 1705.  

"British soldiers were sent to stop the Rebellion of Bacon (between Virginia settlers and the King's appointed governor). The Jamestown weed was boiled for inclusion in a salad, which the soldiers readily ate...In this frantic situation (that ensued), they were confined, lest they should, in their folly, destroy themselves."

Sacred Datura and many of its nightshade cousins have been used for over 6,000 years in sacred rituals as intoxicants, for medicinal practices and for assorted nefarious activities. Various ancient Egyptians, Greeks and Romans employed henbane and mandrake for political advantage. There are many references to both in the Old and New Testaments. The Datura flower Yangjinhua was used in China to treat asthma, convulsions, pain and rheumatism.  

 "a double dose causes downright insanity...any repeated ingestion moreover
...bringing instant death...(and) kills quicker than opium."
The Roman Pliny the Edler 

In the Americas, the Cherokee and Rappahannock smoked Datura for respiratory problems such as asthma and for ceremonial purposes. The Yaqui of Mexico made an ointment for its hallucinatory effects and to lessen the pain of childbirth. Charred seeds in various sites in the Southwest confirm its use. Polychrome pictographs on the walls of a cave in Southern California are thought to have been created by delirium-induced shaman priests of the Chumash tribe. Some shapes resemble the spiny, round seedpods of Datura. 

Petroglyph in Chumash Painted Cave Historic Park
The Chumash of coastal Southern California near Santa Barbara created cave wall pictographs with charcoal, red ochre and powdered shells. They practiced an initiation rite that likely documented the ritual use of Datura. The images are thought to depict animals, everyday objects and a variety of distorted geometric entities, possibly supernatural or celestial (such as eclipse that occurred in 1677). From Wikipedia 

Both Datura wrighti and Datura stramonium belong to genus Datura, while its relative Atropa belladonna belongs to genus Atropa. Along with safe-to-eat eggplants, potatoes, tomatoes, cherries, tobacco and a host of flowering plants, they're members of the large plant family Solanaceae. The name was derived from the encompassing order Solanum, which means from the "sun" or "soothing", possibly related to the calming affect of some of the plants on GI spasms.

The plants of Solanaceae are the "Nightshades", and because of Atropa belladonna's high concentration of atropine (and chemical relationship to scopolamine found in Sacred Datura), it's referred to as "Deadly Nightshade." A small handful of wild berries are fatal for the unsuspecting ingester. "Magical" mandrake within genus Mandragora is also a highly poisonous nightshade used in witchcraft and herbal medicine, as is henbane called "stinking nightshade" of genus Hyoscymus. 

The Nightshade Family Solanaceae and a few of its 90 Genera
Plant species Sacred Datura and Atropa belladonna are found in sister genera.

Many of the active ingredients in nightshade plants are nitrogen-containing substances. They're a diverse group of compounds found not only in plants, animals and even microorganisms but are manufactured synthetically for medicinal purposes.

They are a collection of over 200 potent organic compounds called tropane alkaloids, many of which are toxic. An incredible 64 different ones have been identified in species D. Stramonium. For everyone that took organic chemistry back in school, they contain a seven-carbon ring and a singular nitrogen atom.

Molecular Structure of a Typical Tropane Alkaloid
The seven-carbon tropane ring and singular nitrogen atom, derived from ammonia, make the compound an alkaloid. Found in all parts of the plant, they occur naturally and are the oldest plant medicines.


Nightshade alkaloids are classified as deliriants and anticholinergic agents. The latter means they oppose the action of nerve cells that use the chemical neurotransmitter acetylcholine. Its release in the central nervous system (CNS) activates certain muscles.

You see, our CNS (brain and spinal cord) connects to a peripheral system that runs throughout the body. It has two divisions: a somatic system under voluntary control that allows us to do things at will and an autonomic (or visceralsystem that operates involuntarily, sort of automatically. It regulates functions that don't require conscious thought, that is active brain-control, such as sweating, breathing, heart rate, digestion and (you guessed it) pupillary size. There's more.

The autonomic system also has two sub-divisions: a quick-response sympathetic (or adrenergic) system for "flight or fright" and an energy-conserving parasympathetic (or cholinergic) system for "resting and digesting." They're antagonistic systems but work together to maintain homeostasis (state of balance) by feeding-back on each other, similar in action to a thermostat that regulates room temperature. So, what's the point?

The Yin and Yang of the Autonomic Nervous System
The 'automatic' system is under involuntary control. It has two opposing subdivisions - parasympathetic and sympathetic - that work in conjunction to maintain homeostasis, that is, keep us balanced. Pupil dilation (encircled), a sympathetic activity, is induced by the anticholinergic Datura alkaloid that targets and blocks the parasympathetic system.

"Think: Parasympathetic-iris constrictor and sympathetic-iris dilator"

As mentioned, nightshade alkaloids are anticholinergic substances. That means they block the action of parasympathetic nerve impulses, which allows the sympathetic system to "take over." In order to fight or flee from harm, the heart beats faster, respiration increases, glucose is liberated for energy and the pupils dilate to let in more light in.

It also explains how Italian Renaissance ladies and their artists pharmochemically dilated their pupils with Atropa belladonna and how the plant Sacred Datura acts similarly.

The coincidence didn't end in Zion.

After hiking Zion Canyon, I joined my wife in Santa Fe, New Mexico. We strolled around town and savored the region's famous Southwestern cuisine, especially the red and green chili sauces, which, by the way, are made from safe-to-eat nightshade plants. We also visited a number of museums and galleries that displayed Native American artifacts and pottery and the wonderful Georgia O'Keeffe Museum, dedicated to the life, art and legacy of the twentieth century artist.

Ristras of Drying Red and Green Chile Peppers and Sun-bleached Cow Skulls
Both are iconic trademarks of New Mexico

O'Keeffe is a legendary name for those familiar with her vibrantly-colored, larger-than-life, iconic paintings of Southwestern desert flowers, floating sun-bleached cow skulls and bones bedecked with flowers, and favorite sweeping vistas and landscapes of northern New Mexico. She is referred to as the Mother of American Modernism, and her name is synonymous with the American abstract impressionist movement.

Born in rural Wisconsin in 1887 and after a marriage to Alfred Stieglitz, a pioneering 
New York City photographer, art promoter and gallery owner where O'Keeffe became well-established as a Modernist artist, she was inextricably drawn to New Mexico. First seasonally, it eventually became her home where her artistry reached a creative pinnacle and where she worked for over 40 years until her death in 1986 at the age of 98. 

Alfred Stieglitz Photographic Portrait of O'Keeffe in NYC, 1918

O'Keeffe's principal residence and studio was in the rural, tiny northern New Mexican village of Abiquiú, about 53 miles north of Santa Fe. The surrounding landscapes were a never-ending source of inspiration to the artist, which she repeatedly reproduced and reinterpreted on canvas throughout her life. 

O'Keeffe in 1960 with 'Pelvis Series Red With Yellow' 

Inspired to investigate the geology of northern New Mexico and O'Keeffe's favorite landscapes, we drove to her studio at the remote 21,000-acre Ghost Ranch some 60 miles northwest of Santa Fe. It was there that the artist could work, be alone and take time out from the real world. She was captivated by New Mexico's piercing sunlight, the clarity of the air, its expansive skies and the stark beauty and extreme solitude of the high-desert landscape.

"I wish you could see what I see out the window - 
the earth pink and yellow cliffs to the north - 
the full pale moon about to go down in an early morning lavender sky - 
pink and purple hills in front and the scrubby fine dull green cedars - 
and a feeling of much space. It is a very beautiful world."

Ghost Ranch has a fascinating history of ownership beginning in the early 1900s with the Archuleta family of cattle rustlers, who penned the name "ghost" to dispel unwanted visitation from curious neighbors. Following a deed acquisition during a lost poker game and a subsequent sale to Arthur Pack of Nature Magazine, he donated the property to the Presbyterian Church to which it remains. O'Keeffe acquired her adobe house and six acres from them and became her Ranchos de los Burros in 1940.

"I can think of no greater luxury than being at the ranch — 
even if the lights didn’t work and the sink wouldn’t drain.”

Sign at the Entrance to Ghost Ranch with O'Keeffe's Skull Logo

Today, the ranch is a National Landmark designated in 1975 and run by the church as an education, workshop, retreat and conference center. The ranch is famous both archaeologically and paleontologically, the former for 8,000 and 2,000 year-old rock-shelter sites and artifacts from several different indigenous tribes that lived and hunted in the region and the latter for its fossil quarries and museum.

Concentrated numbers of the significant and important Late Triassic early theropod dinosaur Coelophysis and a number of non-dinosaurian reptiles have been excavated are found in high concentration. The excavation site was designated a National Natural Landmark in 1976. Book your tour in advance!

The Geologic Landscape of Ghost Ranch
It's in the region of the shallow, downwarpped Chama Basin that formed during the Laramide compressional deformation event beginning about 75 million years ago. It's along the eastern margin of the lofty Colorado Plateau near the transition zone with the Rio Grande rift to the east.

A tremendous source of inspiration to the artist, O'Keeffe repeatedly reproduced and interpreted on canvas the stratigraphy at Ghost Ranch and the vistas she both observed and loved. Her ashes are scattered over the distant volcanics of "her mountain", the flat-topped, dark mesa of Cerro Pedernal in the Jémez Mountains.

The 700 feet-high sedimentary rocks at the ranch begin with multi-hued Late Triassic Chinle mudstones, siltstones and sandstones - the dino-rich stratum. Following a gap of some 44 million years, it's overlain by the highly recognizable, tri-banded, cliff-forming Jurassic eolian Entrada Sandstone and capped by Summerville Sandstones and Todilto Limestones.

The Jurassic strata were deposited in and around the Sundance Sea, which was a large incursion or embayment of the paleo-Pacific Ocean in an arid climate. It was the last marine invasion into the interior from the west.

"My Back Yard", 1943

“I only regret that I will not be able to see this beautiful country anymore,
unless the Indians are right and my spirit will walk here after I’m gone.”

"Red and Yellow Cliffs", 1949

Having seen O'Keeffe's landscape inspirations firsthand and after having achieved a greater understanding of the artist as a person, we returned to Santa Fe to tour the Georgia O'Keeffe Museum.

The moment we entered the first salon we were confronted with a large 70 x 83.5 inch, beautiful oil-on-canvas painting of Sacred Datura entitled "Bella Donna" completed in 1939. O'Keeffe is best known for her enlarged and close-up paintings of flowers especially Sacred Datura, which she often referred to as "Bella Donna." The flower comprised a significant percentage of her work, which was painted with numbered versions.

By this time the coincidences had became anticipated. 

"Bella Donna", 1939
The painting was created in New Mexico during a period of the artist's economic independence and popularity but also bitter turmoil and loneliness. It was a time when Stieglitz, her impresario, promoter and later husband, took on a new protégé and lover. The artist was torn between Stieglitz's useless sponsorship being successful and New Mexico, where she found a life of inspiration, innovation and creativity.

O'Keeffe also painted Sacred Datura, which she called "Jimson Weed." As early as the 1920s, O'Keeffe created a number of large close-ups. She was immensely fond of the heavily-scented, night blooming plant and painted it throughout her career. Ignoring its well-known toxicity if mistakenly (or intentionally) eaten, she allowed it to flourish around the patio of her Ghost Ranch studio.

"When I think of the delicate fragrance of the flowers,
I almost feel the coolness and sweetness of the evening."

Jimson Weed, 1936

"When you take a flower in your hand and really look at it,
 it's your world for the moment.
 I want to give that world to someone else." 

"Datura and Pedernal"

"Nobody sees a flower really — it is so small — we haven't time,
and to see takes time, like to have a friend takes time."

Jimson Weed/White Flower No. 1, 1932
This painting sold for $44,405,000 at Sotheby’s American Art sale in 2014. It was the highest price paid for a painting created by a female artist in the US.

The many galleries and museums in Santa Fe provide an exposure to the diversity and creativity of Native American rugs, baskets, jewelry, pottery and gourds. Fired from clay gathered from the banks of regional rivers and lakes, pottery was used for cooking, storage and ritual ceremonial and burial purposes. 

Many items are covered with a range of carved and painted decorative and symbolic designs. In addition to zig-zag geometrics, snake-like spirals, florals and solar images, many of the lifeforms include birds, rattlesnakes and insects such as grasshoppers, spiders, caterpillars, butterflies and moths.

Animals and insects are frequently mentioned in Native American mythology. They not only indicate a close association with nature, but call attention to the power attached to them. For instance, the power of flight is evoked with motifs of wings and feathers as well as depictions of the animals themselves. The butterfly symbolizes love, temptation and foolishness, especially to the Navajo, whereas moths are associated with maladies of spells, frenzy, trembling and seizures.

Sound familiar? Does this appear to be a Hawk Moth painted on the pottery and gourds?

Various Moths on Navajo Pottery and Gourds both Old and New

With thoughts and visions of my wonderful summer experiences in Italy and autumnal visit to Zion, Santa Fe and O'Keeffe country, we finally heading back to Boston. Among other things, it was time for my yearly eye exam. As we all know, one's eyes are typically dilated with an Atropa belladonna-like, synthetic neurochemical relative.

Mydryiasis - the pharmacological enlargement of the pupils - allows an unimpeded examination of the retina at the back of the eye. Synthetic medicines are now used that have shorter half-life of hours as opposed to days with no risk of central nervous system ill-effects. One type stimulates the contracting muscles that opens the pupil, while the other relaxes muscles that make it constrict, an example of pharmacological antagonism. Sometimes they're used together.  

A Medically Dilated Eye (not mine)

When will the coincidences end?

While composing this post and researching Italian Renaissance art on-line, I discovered an interesting panel painted by Sandro Botticelli in c.1485. Entitled "Venus and Mars", it depicts a lovely mythological Venus, the goddess of love, and a scantily clad Mars, the god of war, who is fast asleep on a forest floor surrounded by a bevy of playful, horned satyrs.

The painting is typical of the Renaissance period in that it contains symbolism and hidden meaning. Even period still life paintings that are literal in their subject matter surprisingly contain such abstruse innuendos and subtle metaphors. The classical interpretation of the panel is that it's a conjugal setting in which Venus is watching a sexually exhausted Mars, implied by the lance and conch that are futilely being used to awaken him by the woodland creatures. It gets more interesting.

"Mars and Venus" by Sandro Botticelli, c.1485 

Surfing the Web further, by coincidence (yet another) I stumbled on a reinterpretation of the painting by Piero di Cosimo entitled "Venus, Mars and Cupid." Completed in 1490, the subject matter was also infused with wit and fantasy and a few additional symbols. Cupid was nestled beside the breast of Venus, while a long-eared, white rabbit rests on her hip. The former, with breasts exposed, symbolizes love, attraction and devotion, whereas the cute bunny indicates sexual excess, in keeping with the earlier Botticeli creation.

But, notice a brightly colored moth resting on Venus's right leg. Why is it there, and what is its meaning? A few historians have suggested that it symbolizes the fragility of life or even the gaudy portent of death. If so, might this explain the condition of the limp-wristed Mars and not merely post-conjugal exhaustion? Might the moth be the nocturnal pollinator of a nightshade plant such as Sacred Datura? Has Mars succumbed to an anticholinergic, parasympathetically-blocked hypnotic sleep or worse?

"Venus, Mars and Cupid" by Piero di Cosimo, 1490

Pursuing the unlikely (my forte), I submitted the image to three well-known North American etymologists and one in the UK in an attempt to identify the moth. Everyone confirmed it was a Tiger Moth, in the same family as the Hawk Moth, although one expert conceded that "European Hawk Moths have some variability in color and pattern that may copy the former."

This would be an example of Müllerian mimicry in which two or more noxious species develop similar appearances as a shared protective device so that a predator will avoid both. If the insect is indeed a Hawk Moth, it would have lent an entirely different interpretation to the painting. 

A few weeks after our return to Boston, we headed out for a celebratory dinner to revel and reminisce on our year's travels and experiences. Picking up a menu, there it was, a final reminder of my countless "Nightshade Connections" - a cocktail called Belladonna.

Monday, December 31, 2018

2018 Geology Posts and Photos That "Never Made It"

Cyclonically Frozen in New England; Glorious Spring Has Finally Sprung; Born of Necessity; Volcanic Plumbing in Iceland; Seafloor of a Konservat-Lagerstätten; New England's Most Enigmatic Exposure; "Squantum" Tombolo at Low Tide; Testimony to an Arid Interior; Volcanic Dams of the Inner Gorge.

By the time the end of the year rolls around, there are always a number of posts that were never written. And so, with this final one of the year, in what has become a tradition on my blog for six years running, here’s my end-of-the-year post of those that "never made it" in 2018. Please visit the same for 2012 (here), 2013 (here), 2014 (here), 2015 (here), 2016 (here) and 2017 (here). 

Cyclonically Frozen in New England
Newton, Massachusetts

In January, New England was hammered by one nor'easter after another. According to the National Weather Service it's a "macro-scale, extra-tropical cyclone in the western North Atlantic Ocean." It gets its New England moniker since it tracks "down Maine" from the northeast along the eastern seaboard as hurricane-force winds whip the coast in a counter-clockwise direction from the sea.

The assault continued through March when four hit in ten days back-to-back. Like hurricanes, they had alphabetically friendly names. There was Riley, Quinn, Skylar and Toby. Unfortunately, Riley wasn't so amicable.

It underwent a process of bombogenesis when it dropped 24 millibars of atmospheric pressure over a 24-hour period and intensified to explosive levels with an enormous footprint. With plenty of Arctic air to work with, it blanketed the region with over two feet of snow overnight. Instead of being light and fluffy, it was wet, cardiac-heavy and downed trees and power lines everywhere while flooding the coast with enormous destruction of property. Riley did, however, leave the landscape strikingly pristine and sparklingly blue with the reflected colors of the sky. 

Glorious Spring Has Finally Sprung
Newton, Massachusetts

Sunrise on the Summit of Chestnut Hill

"Enough is enough!" "When will it end?"" Is this a spring thaw or the real thing?" In my nearly fifty years living in New England, I never heard so many complaints. It wasn't until May that winter loosened its icy grip. The elation brought about by warm sunshine, a verdant landscape and happy flowers was palpable. As we know, winter astronomically begins on the Winter Solstice and ends on the Vernal Equinox. It's marked on everyone's calendar, but in the Northeast, the dates are meaningless.

On the Solstice the sun appears to be "standing-still" (in Latin) at its southernmost turning-point before reversing direction with the Northern Hemisphere inclined away from the sun in winter. Galileo knew this but was forced to recant his revolutionary theory in 1633. Equinox, on the other hand, means "equal-night", hence equal-day and equal-illumination (or nearly so in reality). In the Northern Hemisphere it produces spring, and fall in the Southern. Historically, the dates were established by Julius Caesar but changed by Pope Gregory XIII to coincide with Easter and again by astronomers to precede Easter. 

At least on the Equinox in New England, although it still feels like winter, the sun's path on the ecliptic is higher and warmer, which melts the snow quicker, thaws the frozen earth and starts the Maple sap flowing. Winter's end-Spring's beginning is "slush season" and "mud month" up here. The unofficial first day of spring is when winter regalia and snow removal tools are noticeably absent, which is a far more accurate gauge than your calendar.

Born of Necessity
Chestnut Hill, Massachusetts

Sunrise on the Chestnut Hill Reservoir during My Morning Run
Named for the area around the surrounding towns of Boston, Brookline and Newton, the Chestnut Hill Reservoir is a quiet, recreational haven and easy escape from the clamor of the city. It's also known as the location of Boston College and the top of Heartbreak Hill on the Boston Marathon route.

Recognizing the need for a source of perennial fresh water, Puritan settlers in 1630 switched from Charlestown to the Shawmut Peninsula of 'Olde Boston' across the Charles River to take advantage of the Great Spring on Boston Common. As the population and demands of the settlement and growing town increased - 30% in the 1850s - one reservoir after another was added to the delivery system for domestic needs and in the event of a major fire.

In the early 1800s, gravity-fed Jamaica "kettle" Pond delivered water to Boston through wooden pipes. Wellesley's Lake Cochituate Reservoir to the west was added in 1863. By 1870, the Chestnut Hill Reservoir was completed some five miles west of Boston, excavated from marsh and meadowland acquired "by purchase or otherwise" from the Lawrence farm. Its basin covered 37.5 acres with a 180 million gallon capacity and conveyed water through cast-iron pipes. In the 1930s, the Wachusett and Quabbin Reservoirs were finally added 30 and 65 miles to the west with a capacity of 477 billion gallons. The latter was developed by forcing residents from their homes, relocating cemeteries of four 1700s-era towns and flooding 38.6 square miles of countryside.

At one time, Frederick Law Olmsted, the famous landscape designer of New York's Central Park, envisioned adding the Chestnut Hill Reservoir to the Emerald Necklace, his elegant system of Boston's interconnecting municipal parks and waterways.

These days, the reservoir is offline but on stand-by to maintain water pressure and as a back-up for water emergencies. It's surrounded by majestic old trees and rocky outcrops of Precambrian-age Roxbury Conglomerate. Replete with hilly woodland, stonewalls, walkways, hiking trails and a 1.56 mile-long loop for jogging, strolling and contemplation, it's a place to fish and observe water and birds of prey, turtles, muskrats, rabbits, squirrels and even fox at sunrise...all within city limits!

Volcanic Plumbing in Iceland
East Fjords

Julia Share on an Exhumed Dike in East Iceland

Following a vertical path of least resistance by cross-cutting strata, dikes are relatively shallow and narrow geologic bodies in contrast to sills that are deeper and broader horizontal sheets that dissect between strata. Both intrusions transport magma away from a central volcano, which is supplied by a large deep-seated reservoir.

Dikes may feed surface eruptions and are extremely common in Iceland. Most remain buried and solidified beneath the surface, only to be exhumed over time by erosion as demonstrated by my daughter Julia. 

Dikes, sills and batholiths (deeply-buried magma reservoirs) are testimony to the complexity of volcanic systems that participated in the formation of Iceland, the world's largest volcanic island and one of the youngest at 24 million years. The intrusions are either Tertiary (Miocene-Pliocene), Pleistocene or Holocene in age. This dike is one of many along the Ring Road that encircles Iceland near fjord Hamarsfjörður on the East Coast. It's part of a once-active swarm that fed the Tertiary Basalt Formation, the oldest in Iceland that spans the interval from 16 to 3.3 million years ago. 

Seafloor of a Konservat-Lagerstätten
The Walcott-Rust Quarry
Central New York State

Richly Fossiliferous and Diverse Turbidite from a Middle Ordovician Taconic Foredeep
The abundance of invertebrate remnants in this "hash", implies its preservation in a high energy system. Can you identify various fragments of disarticulated trilobites especially the cephalon? How about a bryozoan attached to a crinoid pluricolumnal? Beyond it's function as an attachment apparatus, might the bryozoan be a symbiont? An expanded post on the quarry is forthcoming in 2019.

On private land, concealed in the woods and surrounded by farm and pastureland of Upstate New York lies a most unique and paleontologically important site. The Walcott-Rust Quarry is a Konservat-Lagerstätten for its exceptional preservation and diversity of fossilized lifeforms. Under the auspices of Dan Cooper of Ohio, a premier fossil excavator and preparer, I was privileged to visit the quarry in the summer, walk in Walcott's footsteps and enjoy a laborious rockhammer workout and fascinating day of discovery.

The quarry was initially worked for about six years in the early 1870s by discoverer and farmer-owner William Rust and 20 year-old, unknown and self-educated paleontologist Charles Doolittle Walcott, who in 1909 discovered the half-a-billion year-old UNESCO Burgess Shale in the Canadian Rockies of British Columbia. Back then, the resistant strata was exposed along the bed and banks of lazy "Gray's Brook" but rediscovered after being "lost" for nearly 100 years.

The "Hole", excavated adjacent to the original streamside quarry, consists of multiple beds of the Rust Formation. It's a hard, fine-grained, shallowing-upwards, micritic (muddy) limestone sequence that entombs a diverse benthic fauna from 457 to 454 million years ago. It includes brachiopods, gastropods, pelycopods, crinoids, bryozoans, cystoids, cephalopods and graptolites. Various trilobites, the quarry's prized arthropods, uniquely have two rows of lateral appendages and antennae that were preserved by obrution (rapid and anoxic burial). How did the deposit form? 

The latest Proterozoic megacontinent of Laurentia (the cratonic core of North America) tectonically-morphed into supercontinent Pangaea throughout most of the Paleozoic. During the Taconic orogeny, the second of four-mountain-building collisions, a foreland basin downwarpped cratonward and filled with marine waters of the Iapetus Sea. Layer after layer of foreland shales, sandstones and limestones along with their resident ecosystems are beautifully displayed in roadcuts along the New York State Thruway. The quarry resides on an unstable slope of the foreland's foredeep and preserves a unique look at a tiny section of the Middle Ordovician seafloor.

New England's Most Enigmatic Exposure
Squantum Peninsula
South Shore of Boston, Massachusetts

Galli and Thompson's Outcrop A of the Western Headland
Located on Squantum Head peninsula that projects into Boston Harbor, the small outcrop is a "heterogeneous sequence of interbedded diamictite (lower stratum), mudstone and sandstone (base of the outcrop).

Geologists have been attempting to unravel the formative history of the Boston Basin for over 100 years, and the Squantum "tillite" is central to the enigma. It has arguably initiated more discussion than any other geological locality in New England. I've visited it a number of times, most recently on a field trip with Ken Galli, Ph.D, Department of Earth and Environmental Science of Boston College, who enthusiastically expounded upon its attributes, enigmatics and theorized geo-genetics. 

The Boston Basin is a large fault-bound, topographic depression surrounded by vastly eroded highlands of the Dedham-Lynn-Mattapan-Brighton volcanic complex. It extends a distance out to sea and includes Boston and surrounding towns, roughly everything within Route 128 for those familiar with the region. It's filled with rocks of the Boston Bay Group that was deposited as the basin rapidly subsided in a subduction/magmatic arc system. The group includes mudstones and sandstones of the >570 Ma Cambridge Argillite and the underlying <595 Ma Roxbury Conglomerate Formation. The latter is a thick, tripartite stacked-package of Squantum, Brookline and Dorchester Members of multi-sized clasts of metavolcanic and metasedimentary rocks embedded in a coarse sandstone matrix.

After rifting from the northern margin of Gondwana ~630 Ma, the basin was delivered to eastern Massachusetts onboard the elongate Avalonia island arc during the Devonian-age Acadian orogeny. According to Galli and Richard Bailey, Ph.d of Boston's Northeastern University, the environmental setting at the time of deposition of the Bay Group was a subsiding, intermontane basin surrounded by volcanic highlands that bordered the sea. 

For the longest time, the Squantum exposure was interpreted as a mixed sequence, matrix-supported sediment - a diamictite - and glacially-derived - a tillite - since major global glaciations existed during the Late Proterozoic era. But the authors' current thinking is that it's a mass debris flow - a debrite - delivered by streams and rivers and gravitation to the coast and into the sea, perhaps indirectly influenced by regional alpine glaciation within the highlands but not directly of glacial origin as was once thought.

A full post is forthcoming as Part II of "Part I: The Geology of Back Bay" seen here.

"Squantum-Thompson" Tombolo
Between Squantum Peninsula and Thompson Island
South Shore of Boston, Massachusetts 

"Thompson-Squantum" Tombolo al Low Tide
That's the skyline of Boston's Back Bay and Boston Harbor in the distance from the south.

Derived from the Latin word tumulus or "mound", the ephemeral landform connects an island to the mainland, in this case, glacial drumlin Thompson to Squantum Peninsula on which we stand. It's also a spit (transported coastline) or bar (submerged shoal) that formed by deposition on the lee side (sheltered downwind or downcurrent side) of the island as wave energy and longshore drift are reduced.

As waves sweep sediment from both sides of the island and re-deposit it, the tombolo conforms to the shape of the wave pattern and current. With finer sand on top, coarser below and cobbles at the base, it morphologically fluctuates contingent on sea level, dominant wave pattern, larger longshore sediment supply and of course, storms.

We're assumedly near the eastern extent of the Boston Basin, which is submerged on the continental shelf beneath Wisconsinan glaciomarine blue clays. It records over a half billion years of geological evolution from Late Proterozoic supercontinent Rodinia to Quaternary continental glaciers that bulldozed the region. The drumlin field of Boston's Harbor Islands, that resulted from at least two different age drifts, and their sediments form the ever-changing spits of tombolos. By the way, that's the Squantum Member in the foreground.  

Testimony to an Arid Interior
Zion National Park
Southwestern Utah

Spectacular Wall of Navajo Sandstone in Zion National Park of Utah
The Navajo assumes many forms: immense cliffs, ridge-shaped cuestas, rounded domes and broad bluffs. They're due to the rock's porosity, permeability, fracture susceptibility and resistance to erosion. Largely Middle Jurassic in age, the erg or sand-sea is famous for its dark streaks of desert varnish, massive conchoidal fractures, large-scale cross-bedded paleo-dunes, thin lenses of limestones, iron concretions and muted colors.

Every geologist has a favorite rock formation. For me, it's a toss up between the Late Triassic Chinle Formation and the Middle Jurassic Navajo Sandstone of the Southwest. Visually impressive and highly recognizable, the Navajo constitutes the White Cliffs of the Grand Staircase (here), the majestic domes of Capitol Reef (here) and the towering sheer walls of Zion National Park in Utah where it's nearly 700 meters thick. The sand sea or erg tells a dramatic story of the interior paleo-climate of supercontinent Pangaea. 

Originally thought to have been a marine deposit, it's considered to have been one of the largest eolian terrestrial formations in the geologic record, comparable to the Sahara Desert. Located on the highland of the Colorado Plateau in most of Utah and parts of Nevada, Arizona and Colorado, its muted colors are due to thin coatings of mineral oxides, iron in particular. Acquired after deposition by water flowing through the mass, they cemented the Navajo's sand grains and lithified its paleo-dunes.

As Pangaea tectonically aggregated global landmasses, it increasingly left the vast interior of the supercontinent exposed at hot equatorial latitudes. Proximity to the Tethys Ocean (my post here) acted as a source of moisture that maximized summer heating when the planet's axis was tilted toward the sun with the reverse occurring during summer. It is thought that the resulting mega-monsoonal circulation (seasonal wind reversal) hyper-dried and mega-heated the interior on the leeward side of the Central Pangaean Range that formed as the supercontinent assembled.

Sand grains from the weathering mountains may have been delivered to the west in four phases by a transcontinental river system long-gone, while the northwest winter monsoonal and dry easterly trade winds concentrated the erg within a flexural basin that formed at sea level. It eventually uplifted en masse with the Colorado Plateau to its present locale, while mass wasting, erosion and time did the rest.

A large taphone (singular of taphoni) in Zion's Navajo Sandstone makes a perfect window for my son Will.

Volcanic Dams of the Inner Gorge
Tuweep Overlook
North Rim of the Grand Canyon
Northern Arizona

"What a conflict of water and fire there must have been there! Just imagine a river of molten rock running down a river of melted snow. What a seething and boiling of waters, what clouds of steam rolled into the heavens!"
John Wesley Powell, August 25, 1869

View West from Toroweap Lookout on the North Rim
Remnants of ~518 ka Prospect Dam that spanned the Inner Gorge are preserved in patches of lava flows that cling to the north wall of the South Rim and the large flow that drapes down the North Rim's south wall (arrows). Vulcan's Throne lies just off to the north (right). The gently-undulating Esplanade Platform is well developed on both sides of the Inner Gorge that formed as the Hermit Formation eroded back from the canyon and exposed erosion-resistant Esplanade Sandstone. Prospect Canyon, directly across, is also a product of Toroweap fault but is being re-excavated by erosion.

With the exception of geologists, river-runners and backcountry enthusiasts, most everyone is surprised to discover that there's a ~72 ka volcano called Vulcan's Throne - albeit extinct - perched some 3,000 precipitous vertical-feet above the Colorado River on the North Rim of the Grand Canyon. What's more, lava has cascaded into the Inner Gorge and created a 700 meter-high Prospect Dam that impounded the river upstream past Moab, Utah. The reservoir that formed likely was greater than the combined volumes of Lakes Powell and Mead.  

Even more incredible is that over 13 Pleistocene-age lava dams have done the same or similar with many that catastrophically failed as waters of the Colorado re-excavated the canyon, re-established the former gradient and flowed downriver in a massive torrent. In fact, given the ~2 Ma age of volcanic activity of the ~600 sq mi Uinkaret Volcanic Field on the Uinkaret Plateau, it's likely that even older dams existed within the Grand Canyon.   

Our viewpoint is from Toroweap Overlook situated on the vertiginous edge of the broad Esplanade Platform. It's a flat, east-west, gently undulating expanse of erosion-resistant Esplanade Sandstone on both sides of the Colorado River in the western Grand Canyon that formed at the expense of soft shales of the overlying Hermit Formation. The still-active N-S Toroweap fault slices through the region and gave rise to downdropped Toroweap Valley that filled with over 150 individual lava flows of the Uinkaret Volcanic Field. Early flows went north, whereas, more recent ones spilled into the Inner Gorge and once funneled by the canyon, traveled far downstream.

The volcanic field is a consequence of ongoing extension along the fault and is a manifestation of the western margin of the Grand Canyon that is slowly foundering as the Basin and Range Province is encroaching upon it and pulling it apart. It has implications for future volcanics in the region and the Grand Canyon and Colorado Plateau on a large scale. Time will tell.

Vulcan's Throne and Escalante Sandstone Reflecting Pools from the East
Although the cinder cone is extinct, the region of the Uinkaret Volcanic Field is prime for another eruption probably not too far off on the geological time scale. In the photo, the south slope of the Throne (left) is literally perched on the rim of the Inner Gorge and lava flow drapes into the Inner Gorge's north wall. The north slope (right) extends outward in the direction of Toroweap Valley.

That's all for 2018. 
Thanks for following and contributing to my blog. 
As always, I'm humbled by your comments and most appreciative of your visits. 
Have a Happy and Healthy New Year! Can't wait to see what 2019 will bring.