A pedra do orgulho polar - chamada “a descoberta do milênio” por especialistas em comércio - foi descoberta no Canadá. A pedra de 18 toneladas foi dividida ao meio para talhar. Cortesia do Jade West Group.
Jade
é um termo comercial que engloba material verde, branco, preto ou
marrom-amarelo que consiste em piroxeno rico em Na (jadeita) ou
anfibólios prismáticos a aciculares da série tremolita-actinolita que
formam feixes orientados aleatoriamente e intertravados (nefrita) .
A nefrita é mais resistente (mais difícil de quebrar) do que o material de jadeíta. Sua resistência à fratura é de cerca de 200 MN / m2, enquanto a de jadeíta é de cerca de 100 MN / m2. Por outro lado, o material de jadeíta é mais duro (7 comparado a 6,5 na escala de Mohs ).
Jade Na Colúmbia Britânica
O jade foi identificado pela primeira vez no Canadá por colonos chineses em 1886 na Colúmbia Britânica. Naquele momento, o jade era considerado inútil, pois eles procuravam ouro. Jade não foi comercializado no Canadá até a década de 1970.
O negócio de mineração Loex James Ltd., iniciado por dois
californianos, iniciou a mineração comercial de jade canadense em 1972.
Existem mais de cinquenta ocorrências conhecidas de nefrite na Colúmbia Britânica. Eles estão localizados nas áreas de Cassiar, Cry and Dease Lake e Mount Ogden, bem como no sul da Colúmbia Britânica. Essas ocorrências consistem em blocos individuais, campos de rochas, blocos de talus e ocorrências in situ. A maioria das ocorrências in situ é do tipo lente ou charuto.
Ocorrem nos contatos de rochas ultramáficas / máficas
(principalmente serpentinitas) ou próximas a elas, e outras rochas
félsicas metassedimentares ou ígneas de terranos oceânicos, como os
terranos Cache Creek (Mississippian a Jurassic) e Slide Mountain
(Devonian a Permian).
Esses contatos são comumente interpretados como relacionados a cisalhamento / falha.
Em geral, acredita-se que a nefrita da Colúmbia Britânica seja formada
por trocas metassomáticas entre rochas ultramáficas e siliciosas.
As impurezas na nefrita são minerais do grupo espinélio (cromita,
magnetita, picolita), diopsídeo, uvarovita, titanita, clorita e talco.
Até a década de 1960, quase toda a nefrita produzida na Colúmbia Britânica vinha de depósitos secundários.
Com a rápida expansão da atividade lapidária amadora após a Segunda
Guerra Mundial, a produção nos campos de jade da Colúmbia Britânica
aumentou e eles se tornaram os fornecedores mais importantes. Na mesma época, os mercados foram abertos na Alemanha e no Oriente.
A atividade de mineração esgotou gradualmente os depósitos secundários, mas os valores crescentes levaram a novas explorações.
Esses esforços descobriram depósitos primários adjacentes à área do rio
Fraser, no sul da Colúmbia Britânica, à área do Monte Ogden, no centro
da Colúmbia Britânica, e aos campos de jade Cassiar, no extremo norte. Hoje, a Colúmbia Britânica é o principal fornecedor para o mercado da China.
Nefrite na Colúmbia Britânica. Crédito da foto: e-NetworkAssociates. com
O Jade West Group, fundado em 1981, é o maior participante em mineração e comércio de nefrita verde na Colúmbia Britânica. Kirk Makepeace, fundador da empresa, é um ávido promotor da pedra. Ele começou com um emprego de verão como perfurador de jade.
A mineração de nefrita na Colúmbia Britânica é muito desafiadora.
Os invernos são longos e rigorosamente frios, e os depósitos são
remotos; portanto, a mineração só pode acontecer durante a curta
temporada de verão, cerca de 60 dias por ano. Quase todos os depósitos secundários estão esgotados; portanto, a mineração atual é quase toda de depósitos primários. Transportar o equipamento pesado para os locais de mineração é um trabalho árduo.
Nefrita extraída na Colúmbia Britânica no Canadá
A Jade West usa serras circulares e arame revestidas de diamante e
modernos separadores hidráulicos de alta pressão para remover a nefrita
da montanha e a viu em pedaços de tamanho gerenciável. A excelente tenacidade de Nephrite torna extremamente difícil romper a rocha. Embora a explosão tenha sido usada no passado, Jade West não usa mais explosivos.
Depósitos de nefrite variam de 12 polegadas a 12 pés de largura. Os depósitos mais amplos são muito difíceis de extrair.
Os pedregulhos de nefrita na superfície às vezes atingem pesos de 200
toneladas e raramente atingem menos de 100 libras, mas a Jade West tenta
limitar o peso de seus pedregulhos a cinco toneladas, que é um tamanho
razoável para mineração, manuseio e transporte em caminhões. a cidade
mais próxima, a cerca de 160 quilômetros de distância. O peso médio é de duas toneladas, tamanho que satisfaz a maioria das fábricas de escultura na China.
Preserved worm burrows in
Canadian rock were invisible to the naked eye. In this image, a large,
lined, horizontal burrow is almost 0.8 inches (20 mm) wide.
Credit: University of Saskatchewan
About a half billion years ago, an ancient sea covered what is now the
northernmost stretches of Canada. Its seafloor was long thought to be a
dead zone, devoid of the oxygen needed to support life.
But as it turns out, minuscule worms lived quite happily in these ocean
sediments — they even created their own "superhighway" of tunnels by
burrowing through the soil.
Traces of these fossilized tunnels were found in rocks collected
decades ago from Canada's Mackenzie Mountains in the Northwest
Territories. But scientists more recently found the tiny tunnels only
after reanalyzing them, they reported in a new study.
Their discovery sheds light on the region's ocean ecosystems during the Cambrian era
(543 million to 490 million years ago), suggesting that these
environments may have harbored more oxygen — and more life — than
expected, according to the study. [Cambrian Creatures Gallery: Photos of Primitive Sea Life]
The tunnels that the worms left behind in the weathered rock weren't
visible to the naked eye, and were detected purely by chance, lead study
author Brian Pratt, a professor of geological sciences with the College
of Arts and Sciences at the University of Saskatchewan in Canada, told
Live Science in an email.
Pratt and his co-author Julien Kimmig, a collections manager of
invertebrate paleontology with the Biodiversity Institute and Natural
History Museum at the University of Kansas, found the tunnels while
collaborating on another study published in 2018. (They described a "poop picnic" enjoyed by Cambrian worms at the same site where the worm tunnels were found, Pratt said.)
Pratt and Kimmig were preparing samples for the 2018 study — sawing and
grinding the rocks — when they discovered something that they hadn't
seen before.
"I noticed some slight variation in shading," Pratt said. He dampened
the smooth surface of a rock sample with alcohol, scanned it on a
flatbed scanner and enhanced the image brightness and contrast.
Suddenly, "a riot of burrows appeared," he said. Some areas were
crisscrossed by just a few tunnels, but other portions of rock were
"completely churned" by the worms' activities, he said.
The preserved tunnel shapes were exceptionally well-defined and had not
collapsed, hinting that the sediment around them was firm and not
"soupy," the study authors wrote.
Researcher Brian Pratt found
evidence of worm activity from 500 million years ago preserved in a
fossil-rich site in British Columbia, Canada.
Credit: University of Saskatchewan
In width, the tunnels measured from 0.02 to 0.6 inches (0.5 to 15
millimeters), made by worms ranging from about a millimeter in length to
finger-size, according to the study. Most of the burrows were tiny, dug
out by worms that scoured the ocean sediment looking for organic matter
to eat. The rare, larger tunnels likely housed predatory filter-feeders
— "animals that projected a feeding apparatus up into the water column
to catch organic particles and tiny animals," Pratt said.
Also contained in the rock were the preserved bodies of worms — not the
worms that dug the tunnels — and "large poops" containing shreds of
body tissues that likely belonged to other worms that were eaten,
according to Pratt.
Together, this evidence presents a fascinating snapshot of an ancient
seafloor habitat, in an ocean ecosystem that was far richer — in oxygen
and species — than expected, the scientists reported.
The findings were published online in the March issue of the journal Geology.
KOOTENAY NATIONAL PARK IN CANADA—The drumming
of the jackhammer deepens. Then, a block of shale butterflies open,
exposing to crisp mountain air a surface that hasn't seen sunlight in
half a billion years. "Woo!" says paleontologist Cédric Aria of the
Nanjing Institute of Geology and Palaeontology in China, bracing the top
slab of rock upright.
Its underside bears charcoal-colored smudges that look vaguely like horseshoe crabs or the Millennium Falcon from Star Wars.
"It's a spaceship landing area here," says expedition leader
Jean-Bernard Caron, curator of invertebrate paleontology at the Royal
Ontario Museum (ROM) in Toronto, Canada.
Those "spaceships" are carapaces, molted onto a long-vanished ocean
floor by a species new to science. This field season they've been
spilling out of the rocks here, where Caron's team has spent the past
few years unearthing groundbreaking animal fossils from the Cambrian
period, the coming-out party for animal life on Earth. During the
Cambrian, which began about 540 million years ago, nearly all modern
animal groups—as diverse as mollusks and chordates—leapt into the fossil
record. Those early marine animals exhibited a dazzling array of body
plans, as though evolution needed to indulge a creative streak before
buckling down. For more than a century, scientists have struggled to
make heads or tails—sometimes literally—of those specimens, figure out
how they relate to life today, and understand what fueled the
evolutionary explosion.
Com cuidado, Aria e Caron colocam a parte de cima da laje de lado. O espaço é difícil de encontrar na pedreira, empoleirado em uma saliência do tamanho de um pequeno quarto a uma altitude de 2500 metros, muito acima de Tokumm Creek. Durante anos, um local igualmente ameaçador, a cerca de 40 quilômetros a noroeste desse vale, oferecia a janela mais clara do Cambriano. Lá, em 1909, o paleontologista norte-americano Charles Doolittle Walcott descobriu o Burgess Shale, uma formação fóssil que preserva não apenas conchas duras, mas também características suaves como as pernas, os olhos e as entranhas dos creepy crawlies.
But in recent years, Caron has shown that the richest fossil-bearing
rock extends many kilometers beyond Walcott's site. This summer's
excavation marks his latest visit to this long Cambrian tapestry. Each
new stop has offered striking views of unfamiliar animals, many already
described in high-profile papers: the little fish relative Metaspriggina, a vertebrate ancestor that Caron now speculates clustered in schools; the pincered Tokummia;
and the ice cream cone–shaped fossils called hyoliths, which Caron's
Ph.D. student Joseph Moysiuk last year linked to shelled animals called
brachiopods, some of which persist today.
Other sites around the world are also opening new vistas of the
Cambrian. Scientists can now explore the animal explosion with a
highlight reel of specimens, along with results from new imaging
technologies and genetic and developmental studies of living organisms.
"There have been a host of new discoveries," says paleontologist Doug
Erwin of the Smithsonian Institution's National Museum of Natural
History in Washington, D.C. Researchers may be closer than ever to
fitting these strange creatures into their proper places in the tree of
life—and understanding the "explosion" that birthed them.
Jean-Bernard Caron shows off the "mothership," an enigmatic
Cambrian life form his team found in the Canadian Rockies this summer.
(PHOTO) JOHN LEHMANN; (FOSSIL) ROYAL ONTARIO MUSEUM
Each new find brings the simple joy of unearthing and imagining
a seemingly alien creature. On a break, Caron cautiously shows off this
year's crown jewel, found about a week earlier. It's an intact,
hand-size carapace with a center spine, like a Prussian spiked helmet
frozen in ancient rock. Another undescribed species, it seems to be
related to the spaceships. Caron's team calls it the mothership.
He's nervous just holding it. Burgess Shale fossils are so valuable
that Parks Canada keeps the exact locations of Caron's sites secret,
monitors them with cameras, and prosecutes fossil poachers. ROM once
insured a Burgess Shale specimen for half a million Canadian dollars
when it went on loan, he says—and that was an animal known through
multiple fossils. This is one of a kind.
"It's going to be iconic," Caron says. "It's the most extraordinary fossil I've ever found."
For years, Caron suspected Walcott's site might be rivaled elsewhere
in the Rocky Mountains. The breakthrough came in 2012, near an area
called Marble Canyon, where a 2003 wildfire had burned off the trees.
While crossing an avalanche chute filled with broken tiles of rock, his
reconnaissance party found itself surrounded by impressions of
soft-bodied creatures, many with unfamiliar shapes. "It was clear that
nobody had ever been walking over this pile of rocks before with this
purpose in mind," says Bob Gaines, a geochemist from Pomona College in
Claremont, California, who has joined Caron's expeditions since the
beginning.
They returned to excavate in 2014. At least one in five of the
animals they found at Marble Canyon belongs to species new to science,
the team concluded. Now, they've moved on to other sites along the
valley.
How Cambrian species are related to today's animals has been debated
since the fossils first came to light. Walcott classified his oddities
within known groups, noting that some Burgess Shale fossils, such as the
brachiopods, persisted after the Cambrian or even into the present. So,
for example, he concluded almost all the creatures resembling today's
arthropods were crustaceans.
But later paleontologists had other ideas. Harvard University's
Stephen Jay Gould perhaps best captured the charisma of Cambrian life in
his 1989 book Wonderful Life: The Burgess Shale and the Nature of History,
in which he lavished attention on the "weird wonders" excavated from
Walcott's city block–size quarry. Gould argued that oddballs such as the
aptly named Hallucigenia, a worm with legs and hard spines,
seem unrelated to later animals. He slotted the unusual forms into their
own phyla and argued that they were evolution's forgotten experiments,
later cast aside by contingencies of fate.
Contemporary paleontologists have settled on yet another way to
understand them. Consider the arthropods, arguably Earth's most
successful animals. In a family tree, the spray of recent branches that
end in living arthropods—spiders, insects, crustaceans—constitutes a
"crown" group. But some animals in the Burgess Shale probably come from
earlier "stems" that branched off before the crown arthropods. These
branches of the tree don't have surviving descendants, like a childless
great-uncle grinning out from a family photo. In that view, many of
Gould's weird wonders are stem group organisms, related to the ancestors
of current creatures although not ancestors themselves. Newer fossils
from the Canadian Rockies help support that view. Caron argued in 2015,
for example, that his specimens of Hallucigenia have features
suggesting the animal belongs on a stem group of the velvet worms,
creatures that still crawl around in tropical forests spitting slime.
All in the family
A partial schematic of a proposed
family tree of arthropods shows the complex relations among living and
extinct groups. Some extinct Cambrian creatures (red) may belong to
"stem" groups that branched off the arthropod tree before the common
ancestor of living groups like arachnids and insects.
(GRAPHIC) N. DESAI/SCIENCE; (DATA) JO WOLFE, MIT
Similar analysis awaits the spaceships. At first glance,
Caron's team thinks they are a new species or group of radiodontans,
stem arthropods that also include Anomalocaris, the Cambrian's
charismatic apex predator—a clawed, fearsome-jawed swimmer half a meter
long. Filling out the branches of that stem group gives a "step-by-step
view of how an arthropod built its body" through evolutionary time, says
paleontologist Allison Daley at the University of Lausanne in
Switzerland.
Throughout much of Cambrian paleontology, that's the game—a
high-stakes, sometimes contentious race to find diagnostic body parts on
known or new fossils, make arguments about what taxonomic groups they
belong to, and maybe revise evolutionary history in the process.
In the past few years, paleontologists have approached the problem
with an array of new techniques. Those include scanning electron
microscopes, which can discern a specimen's chemical makeup as well as
image it, and computerized tomography (CT) scans, which can penetrate
fossils without scraping away material. Those tools have also
illuminated a startling series of internal features: fossilized Cambrian
brains. Beginning in 2011, paleontologist Xiaoya Ma, now at the
University of Exeter in the United Kingdom, published a string of papers
tracing nervous tissue in exceptionally preserved Chinese fossils.
Those nervous system architectures offer a parallel way to sort animals
into evolutionary groups, beyond the usual anatomical structures, and
other teams have presented their own compelling specimens.
In fossils of the shrimplike Chengjiangocaris kunmingensis
from southwest China, for example, "we have this structure that looks
almost like a pearl necklace," running almost head to tail, says Javier
Ortega-Hernández, an incoming professor at Harvard. His team, led by Jie
Yang at Yunnan University in Kunming, China, argued in 2016 that the
necklace is a nerve cord studded with smaller clusters of neurons,
themselves sprouting tiny nerve fibers. Living arthropods no longer have
those fibers. But today's velvet worms and priapulid worms do, implying
kinship between long-vanished stem arthropods and those groups.
Critics argue that paleontologists such as Ma and Ortega-Hernández
overinterpret some fossils, spotting nervous tissues that aren't there.
Many of those structures, the critics say, might just be "halos,"
biofilms formed when microbes broke down internal parts like muscles or
guts after death. But other researchers are convinced. "If you look at
the best-preserved nervous systems, there's no doubt" that the features
are real, says Graham Budd, a paleontologist at Uppsala University in
Sweden and an architect of the current stem-and-crown concept.
Bold claims that use anatomy to revise family trees engender similar controversy throughout the field. One argument that Hallucigenia
fits with the velvet worms, for example, depends on the exact shape of
its claws. But other teams counter that the claws aren't diagnostic of
ancestry.
The uncertainties leave paleontologists ever hungry for newer, better
specimens. "When there is a debate, you bring a new fossil and say,
‘Look, this is the feature we see,’" Caron says, warming up in a tent
perched high above Tokumm Creek. "Without fossils, it's speculation."
Banff
Lake Louise
Bow River
Columbia River
Tokumm Creek
Walcott Quarry
Yoho National Park
Yoko National Park
Banff National Park
Kootenay National Park
0
25
Km
FRANCE
FRANCE
Alberta
British Columbia
Bilbao
Madrid
Marble Canyon
N. DESAI/SCIENCE
The fossils make up for the discomfort: 6 weeks in tents above
the tree line warding off grizzlies with an electrified fence,
contending with hot days and snow days and wildfire smoke, obeying the
smelly requirement to carry everything—everything—out of the national
park at the expedition's end.
It's a chilly August morning, 1 day before a helicopter comes to take
all human traces away. Today is the last chance to stumble on a fossil
that could crack a mystery—say, to find the body that belongs in the
mothership carapace.
The nine-member team hikes from camp to their quarry, up steep,
rock-littered slopes. Ridged trilobite fossils poke out from exposed
layers, but on this expedition, they don't even warrant a second glance.
At the quarry, most people split rock while Caron's grad students help
ROM curator Maryam Akrami pack away the most recent finds in
swimming-pool noodles. "It's the last day," Caron says. "No injuries!"
Each successive excavation in this valley has targeted the same band
of rock, which records a single slice of geologic time. But each dig has
yielded a different array of new species. That's because conditions
varied across the ancient sea floor, favoring different animals. Such
variation is "not a shock to anybody that has ever strapped on a snorkel
and swum around," Gaines says. But this vast, wide-open valley captures
that kind of diversity at a single moment, allowing glimpses of how the
earliest animal ecosystems were structured.
As Caron's quarries bring this moment into ever-sharper focus, other
sites have opened portals on other stages of the Cambrian. Nearly
everywhere, the fossils preserve levels of squishy detail that are
absent in specimens from later in Earth's fossil record. In 2012, Gaines
and colleagues proposed a reason: Perhaps unique chemical conditions
suffused Cambrian seas. After dead animals settled into mud on the sea
floor, low levels of sulfates could have slowed decay by sulfur-loving
bacteria while alkaline chemistry encased the dead animals in coats of
carbonate, sealing soft tissues inside.
In summer 1984, for example, paleontologist Hou Xian-guang of Yunnan
University uncovered an arthropod glistening in Cambrian mudstone, its
legs seemingly alive. He had discovered the Chengjiang biota, a trove of
immaculate fossils that sprawls over a region in southwest China.
Perched in their quarry 2500 meters up, paleontologists hammer open slabs of shale to expose the rare fossils inside.
JOHN LEHMANN
Slightly older than the Burgess Shale—about 518 million years
old compared with the Burgess's roughly 507 million years—those deposits
showcase related animals in a different style of preservation. Unlike
Caron's sites, where geologic processes have squashed the fossils almost
flat, the Chengjiang animals still retain some depth. Since 2015,
Chinese researchers, including Hou, have capitalized on that by using CT
scans to make 3D images of the specimens without destroying them.
Today, three rival Chinese teams, each with international collaborators,
compete to pull out new discoveries from the site. "There is an
absolute landslide of material," Ortega-Hernández says.
Add to that sites such as Emu Bay in Australia, where paleontologists
announced in 2011 that they had unearthed radiodontan fossils revealing
their complex, multifaceted eyes; and Morocco's Fezouata Formation,
which paleontologist Peter Van Roy at Ghent University in Belgium
reported in 2010. Each site offers distinct insights. "Every fossil
assemblage is horrifically biased," says paleontologist Nick Butterfield
of the University of Cambridge in the United Kingdom, "but they're
horrifically biased in different ways."
The Moroccan samples, for example, date to a little after the
Cambrian, and they show a blend between the Cambrian's signature
oddities and the more familiar fauna that dominated later periods. "We
are still at the point of unpacking fossils," says Daley, a collaborator
on that research. "This is a chance to study why some taxa go extinct
and why others are able to replace them."
Although show-stopping animals keep falling out of the strata, the
full significance of the Cambrian explosion remains a mystery.
Arthropods, the most diverse and common creatures known from the time,
littered Cambrian ecosystems. Judging by the fossils, Daley argued in a
paper in May, the Cambrian witnessed both the birth and step-by-step
diversification of many modern groups. Another approach yields a
different answer, however. Geneticists use a tool called molecular
clocks to trace back down the tree of life. By starting with genetic
differences between living animals, which have accrued as a result of
random mutations over the eons, molecular clocks can rewind time to the
point where branches diverged.
According to recent studies using that method, modern animals began
to march off into their separate phyla some 100 million years before the
Cambrian. The finding implies that those groups then hung out,
inconspicuous or unnoticed in the fossil record, before suddenly
stepping on stage.
Paleontologists have a cryptic set of clues about life before the
explosion. Long before the odd beasts of the Cambrian evolved, an even
more alien set of ocean organisms left impressions on sedimentary rocks
now seen in Namibia and Australia. The Ediacarans, as those fossils are
called, taunt paleontologists with the same kind of interpretive
challenge as the Cambrian's weird wonders. But they're even weirder.
Their imprints suggest some grew in fractal patterns; others had
three-part symmetry. Unhelpfully, they don't have obvious mouths, guts,
or appendages. "That's where the freak flags are going now," says Jo
Wolfe, a paleontologist at the Massachusetts Institute of Technology in
Cambridge.
A lace crab—a long-extinct "stem" arthropod called Marrella splendens—turns up in a slab.
(PHOTO) JOHN LEHMANN; (FOSSIL) ROYAL ONTARIO MUSEUM
Most Ediacarans vanished before Cambrian deposits, perhaps
perishing in the world's first mass extinction. But many researchers
suspect some belong on the tree of animal life, perhaps as early stems.
One Ediacaran, Kimberella, looks like an animal: a snail or slug that grazed along the sea floor. In August, Stromatoveris,
a frondlike Cambrian creature already thought to be an animal, was
pegged as an Ediacaran survivor on the basis of its fractal branches.
That would make its Ediacaran relatives animals, too. And in September,
researchers announced that an iconic Ediacaran fossil called Dickinsonia, which looks like a halved Christmas ham, contained lipid molecules that resemble those of living animals.
"We're seeing the beginning of the advent of animals in the
Ediacaran," says paleobiologist Mary Droser of the University of
California, Riverside. "It's more fun and exciting than just the
Cambrian explosion."
And yet even as the Ediacarans shove Cambrian creatures off their
perch as the first animals, Cambrian science itself continues to
explode. Caron and others keep hunting for fossil features that could
reveal the relationships among Ediacaran, Cambrian, and present-day
groups. Other researchers struggle to explain what caused the explosion
of animal forms. Atmospheric oxygen may have spiked, enabling animals to
grow bigger, stronger, and more active. Or erosion could have dumped
toxic calcium into the oceans, prompting organisms to shunt it into
building hard skeletons.
Or biology itself could have led the way. Inventions such as
predation, free swimming, and burrowing into the sea floor—all first
seen in or shortly before the Cambrian—could have transformed a placid
global ecology into a high-stakes contest, spurring waves of
call-and-response innovation between groups. The explosion might also
mark the moment when, after millions of years of quiet progress, animals
had finally accrued the developmental recipes to build body parts and
improvise on basic themes. That genetic toolkit, Butterfield argues, is
"absolutely, astronomically, inconceivably complex. It just took a while
to figure that out." Or, of course, multiple causes could have piled up
together.
After a lunch break, the paleontologists chisel into a few more
slabs. Gaines takes rock samples from each layer of their quarries,
hoping to reconstruct each environment's chemistry. Then Caron delivers
the announcement: "It's over, guys. No more digging."
The next day, its last, the ROM team breaks camp. Over several hours,
a helicopter ferries nets sagging with fossils toward a staging area by
the highway, making the roughly 10-minute trip again and again. Some
specimens, like the spaceships, will be rushed to publication in coming
months, now that visiting journalists have seen them. Other finds will
sit in drawers, awaiting new techniques or the graduate student who asks
the right question.
As the team huddles, waiting for its helicopter ride, tiny,
rabbitlike mammals called pikas cry out from the hills. Each helicopter
trip erases the signs of human presence one by one, until only
carved-out quarries remain. More fossils still rest inside, pressed
between folio sheets of rock, waiting for the next season.
