I love this thread going on the International Sand Collectors Society facebook page.
I am going to keep adding to this post. A is for Attu Island, Alaska. Attu Island is the westernmost island of the Aleutian Chain in the United States and the westernmost point of the state of Alaska. The island was the site of the only WWII land battle fought in the U.S. A Coast Guard LORAN station was on the island until it closed in 2010 making Attu an uninhabited island, the largest in the United States. (source: Wikipedia)
B is for Barren River in Kentucky. This sample from Barren River Lake, a Corp of Engineers impoundment, includes fossils: crinoid rods and rings plus bryozoan rods. These marine creatures lived about 450 million years ago when warm tropical seas covered what is now Kentucky and much of the north-central US. Many of the smaller grains are limestone, also remnants of that ancient ocean.
C is for Copper Harbor in Michigan. This town's name refers to the former use of the harbor for shipping copper mined from local mines in the mid-1800s. It is located near the tip of the Keweenaw Peninsula which juts out into Lake Superior. The pebbles in this sample are decomposed from the local bedrock, the Copper Harbor Conglomerate. Severe storms on the lake contribute to the rounding of the grains and often bring up rocks eroded from the lake bottom including agates, and other minerals.
D is for Douglas Lake, Tennessee. These reddish-brown nodules are ferruginous manganese oxide and eroded from local bedrock around Douglas Lake (aka Douglas Reservoir) in eastern Tennessee. The reservoir was created by the impoundment of the French Broad River when the Tennessee Valley Authority built the Douglas Dam in 1943 to generate hydroelectric power. The term "nodule" derives from the Latin "nodulus" meaning knot.
E is for Eleʻele on the island of Kauaʻi, Hawaiʻi. On Kauaʻi's south coast, the shoreline near Port Allen is littered with millions of pieces of glass: amber, green, red, blue, and clear, plus broken flasks and pottery. The glass dumped in a seaside landfill years ago has fallen into the ocean and been polished by the waves. Beachcombers have collected the larger fragments so today's glass is mostly sand-sized grains. The black and red rocks are volcanic in origin.
F is for Four Craters Lava Field, Oregon. The Four Craters Lava Field is a basaltic volcanic field located southeast of Newberry Caldera in Oregon. The Four Craters Lava Field originated from four pyroclastic cones and covers about 30 square kilometers. The cinders vary in color. If they fell while it was raining, the rain water reacted with the iron in the basalt and turned the cinders rusty red. Black cinders reflect a dry eruptive period. — with Kate Clover.
Like no place else on earth, the Dry Tortugas offer visitors an adventure they will never forget. If you’re visiting Key West, a trip to this oasis in the Gulf of Mexico is a must. From the pristine clear blue waters to the massive Civil War Fortress, there’s many reasons Dry Tortugas National Park is the #1 rated Key West attraction. Located just 70 miles west of Key West, in the middle of the Gulf of Mexico, the Dry Tortugas and Fort Jefferson National Park are surrounded by crystal blue waters. These warm shallow seas are just perfect for wading, snorkeling, kayaking, canoeing or just dipping your toes in. And if you’re one who likes to bask in the sun, the pristine white sandy beach delivers in a big way. Sink your toes in the sand, relax under a shady palm and let the worries of real life melt away.
H is for Haverstraw, New York on the Hudson River. This sample includes orange-red brick fragments; these are artifacts of Haverstraw's history as the brickmaking capital of the world. Starting in 1771, Dutch immigrants started making bricks using the blue and yellow clay found along the river banks. (The clay was deposited as the Ice Age glaciers melted.) Bricks were first made for use in fireplaces and chimneys; the industry quickly grew.
In 1883, there were 41 brickyards in and around Haverstraw. Annually, they shipped over a billion bricks 40 miles downriver to markets in metropolitan New York to build the tenements, schools, sewers, sidewalks, churches, houses and more. The brick industry continued to thrive until the Second World War when bricks lost their favor as a building material. Today, remnants of the brickmaking industry are scattered along Haverstraw's Hudson River shoreline. There is a brick museum too.
I is for the Ipswich, Massachusetts end of Plum Island. Plum Island is an 11-mile barrier island on the northeast coast of Massachusetts consisting of portions of four towns, from north to south: Newburyport, Newbury, Rowley and Ipswich. Two thirds of Plum Island is a mix of dunes and marshes protected as the Parker River National Wildlife Refuge and the Sandy Point State Reservation at the southern tip. The island was named for the wild beach plums found there, not the purple sand.
The sand is a mix of pink pyrope garnet, opaque black ilmenite and magnetite, rods of dark augite, plus quartz and feldspar. However, other heavy minerals are occasionally found in the sand including green epidote and (possibly) blue kyanite. The ratio of garnet to ilmenite and magnetite is such that the sand appears purple when on the beach and creates fascinating colored patterns in the sand.
Curiously, the two samples pictured here are from the same general area of the island, but they are different. The sample with the angular grains was found high up on the beach, well above the high water /high tide line and close to the dunes. This is part of the sand deposited when the glaciers melted and ocean currents transported tons of sediments and created the barrier island and the dunes.
The sample with the highly polished and rounded grains was found after a major storm above the normal high tide line. This is a wind and surf concentrated sample.The roundness of these grains indicates that the grains have spent a long time rolling in the surf and tides Note: An earlier post had a different identification for the blue grains. Based on local geology and suggestions from a geologist, we are now identifying the blue as kyanite. Further analysis will be done. We appreciate people making helpful comments on our posts.
WHY THE SAND IS PURPLE AND PINK ON CRANE BEACH, PLUM ISLAND, AND OTHER NORTH SHORE BEACHES
J is for Jordan Sandstone, Minnesota. The Jordan Sandstone is found in eastern and southeastern Minnesota, northeastern Iowa and across southern Wisconsin. Where it is exposed at the surface, it easily decomposes into quartz sand. This deposit represents an ancient shallow marine deposit of near pure quartz. Color ranges from clear to yellow, and grains range from fine to coarse. This sandstone is part of the Prairie du Chien-Jordan aquifer, a sequence of sedimentary bedrock units. The Jordan aquifer provides good drinking water to about a half-million Iowans, as well as water that is critical to industries that range from data centers to food processing and ethanol production
K is for Ke’anae Peninsula, Maui, Hawaii. The Ke’anae Peninsula juts out from the highway and is about the half-way marker on the famous, twisty Road to Hana. Historically, Ke’anae has been a taro producing Hawaiian village, and much of the land is in taro lo’i (taro fields) today. Taro grows in muddy soil, and legend says that dirt was brought there basket-by-basket to create the fields. Perhaps that's true since the area is lava rock, created quite recently (geologically speaking) in multiple massive lava flows from Haleakala. Taro was and is still a staple food in traditional Hawaiian life. They pound the root to make poi, a starchy food. The leaves are used to wrap packets of food which are then steamed. The peninsula offers spectacular ocean vistas with the blue ocean contrasting with foamy waves crashing against the black and gray rocks and lush green foliage on the land. With the wild surf and chaotic waves, swimming in not recommended, but there is a small beach where fishermen cast their lines and nets. The sand from this tiny beach includes black basalt, glassy-looking obsidian, and grains of yellow-green olivine, a ferro-magnesium mineral.
L is for La Sal, Utah. The sample comes from a mine near La Sal, Utah on the Utah-Colorado state line near Moab, Utah. These blue concretions are nicknamed "blueberries," and they get their color from the copper-bearing mineral, azurite. Likewise, the green nodules are colored with malachite, another copper-bearing mineral. Look closely between the green and blue in these concretions, those clear and white grains are quartz, the main constituent of these concretions.
Geologists believe these formed when copper-bearing solutions migrated into a fault and mineralized the adjacent Dakota Sandstone. The quartz sandstone is poorly cemented and when exposed at the surface, the azurite and malachite concretion weather out.
Mining has a long history in this area. The Anasazi Indians mined azurite here 700 - 1200 years ago. In more modern times, copper mining began around 1903 and millions of tons of copper were recovered. Mining boomed during the World Wars, then declined and pretty much ceased by the middle 1970s. In the 1980s, someone "discovered" beautiful mineral specimens in the area, and that started the next boom for mineral specimens. The hunt for mineral specimens continues.
Azurite has been used as dye and paint pigment for centuries. The ancient Egyptians used it as did artists during the Middle Ages and Renaissance (this was mined in France). Synthetic pigments, such as Prussian Blue, have now replaced the natural pigment. Note: Collecting sites around La Sal are closed to the public; however, collecting tours are sold through outfitters in Moab and Salt Lake City.
M is for Monument Valley. Monument Valley is located on the northern border of Arizona near the Four Corners area. As part of the Colorado Plateau, it is characterized by vast sandstone buttes. In 1942, uranium was discovered here, and the first mine opened in 1948; vanadium was also mined. When mining stopped in 1969, this area had produced more uranium oxide than any other district in Arizona. The Monument Valley area lies within the Navajo Nation Reservation; for environmental and health reasons the Navajo Nation declared a moratorium on mining in 2005.
The red and pink grains in the sample are iron-stained sandstone. The yellow grains are uranium or vanadium minerals. The blue grains likely contain copper. The fine-grained matrix includes remnants of the decaying Rocky Mountains and the local silica sandstone.
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N is for Neah Bay, Strait of Juan de Fuca, Washington. Neah Bay is home to the Makah Indian Tribe. Their reservation is located on the most northwesterly tip of Washington State, a rugged and scenic coastline. They have lived in the area for thousands of years and were skilled at using the natural resources from both land and sea. Traditionally the Makah were marine hunters, hunting seals, sea lions and whales from their dugout canoes made from red cedar. Today they are like the rest of us: they play video games, wear jeans and drive cars. Yet, the Makah still practice their ancient heritage, teach their language to their children, hold dance parties and participate in canoe journeys. Like many indigenous cultures today, the arts play an important role in their daily life, and many make a living as artists. Many are skilled woodcarvers. Others paint and depict marine creatures which were, and still are, important to their culture.
Considered a channel, the Strait of Juan de Fuca is a glacially carved fjord that formed about 14,000 years ago when a slow moving river of ice flowed through the valley. The strait connects Puget Sound (including Seattle) and the Pacific Ocean. The channel serves to exchange salty ocean water with freshwater running from rivers emptying into the sound. This mixing of waters creates strong and complicated tides and ocean currents and keeps the water constantly circulating. The strait is 97 miles long (154km) and between 11 - 25 miles wide (19 - 40 km). The international border between the United States and Canada runs down the center of the Strait. English fur trader, Captain Charles William Barkley named the strait in honor of a Greek mariner, Juan de Fuca who had explored the area as part of a Spanish expedition in 1592.
Geologically, the Washington coast has been subject to changing land and sea levels with tectonic uplift associated with movements on the subducting Juan de Fuca Plate. As a consequence, marine terraces (with fossils) are found at various levels in the region. The marine fossils found at the base of the cliffs and on the beach came from these deposits. Other rocks on the beach eroded from the bedrock cliffs or originated as glacial debris. Rivers also transported sediments to the shore. Biogenic grains in the sample include sea urchin spines, fragments of barnacle plates, polycheate worm tubes made from both sand grains and calcium carbonate. Many of the coiled and dics-shaped grains are likely the foram, Gyroidina soldanii (also known as Hansenisca soldanii) and between 42 and 26 million years old.
The indigenous tribes from Northern California to British Columbia, including the Makah in Washington, all have oral histories of the land shaking, the ocean flooding in, mountains sliding and covering villages and lots of deaths. These people had learned: when the shaking starts, get off the beach, head to higher ground, take long ropes and the canoes.
In the winter of 1969 - 70, a brutal Pacific storm uncovered old houses – parts of an ancestral coastal Makah village, called Ozette, located about 15 miles south of Cape Flattery. The hiker who found the site contacted the Makah who contacted archaeologists at the University of Washington. Working together between 1970 and 1981, they unearthed around 55,000 artifacts from the site. Miraculously, mud had sealed off all the organic material from air and preserved the site and the artifacts. All this evidence unearthed affirmed their oral histories of earthquakes, tsunamis and mudslides. In 1979, the tribe opened the Makah Cultural and Research Center in Neah Bay to house the collection. The best artifacts are on exhibit. The museum is worth a visit.
Geologists however hadn't put much credence into indigenous oral histories. In the mid-1980s, they began a study and linked evidence of the Cascadia Earthquake in 1700 (with an estimated magnitude between 8.7 - 9.2) with tsunamis around the Pacific, including Japan — and then to indigenous villages along the Pacific northwest coast of North America. They realized the Makah story correlated with Japanese tsunami records from 1700 (that's nearly a century before European contact in the Pacific Northwest). As ethnographers looked further into oral histories, they found that tribes all along the coast had been telling stories about this event and others like it from the deeper past. Their stories all said: the land does this at times.
O is for Ocracoke Island, North Carolina, The Island of Ocracoke is a part of the Outer Banks and one of the most remote islands in the long string of barrier islands that makes up Cape Hatteras National Seashore. There are no bridges to Ocracoke Island, but there is a car ferry at both ends of the island. The crossing from Hatteras takes ~60 minutes.
The oyster and clam shell fragments dominating this shell "hash" are not their original color. These are secondary colors. Shells acquire a stain when iron minerals in the sand – ilmenite and magnetite, degrade and gets into the interstices of the shell. This happens when shells are exposed to oxygen on or near the surface of the beach. The yellow-brown stain is iron oxide or limonite.
The black shells are stained with iron sulfide. This happens when shells are buried in mud or rotting seaweed in the absence of oxygen. Often beaches with replenished sands have black shells too; this sand could also have been dredged from depths in the ocean. The longer the burial in an anoxic environment, the blacker the stain. Intermixed with the shell fragments are grains of quartz and feldspar. The roundish orb with the “black spots” is a bryozoan as is the similar artifact on the left side of the photo. In both cases the pores are being filled with tiny sand grains.
This area of the Outer Banks has a rich cultural history. The area's nickname is Graveyard of the Atlantic. It's called that because of the treacherous water and hundreds of shipwrecks sunk due to war, piracy or weather. In addition to those causes, the shifting sand on the shallow ocean bottom causes the inlets to always be changing location and depth making navigation a challenge. A museum with the same "graveyard" name in Hatteras Village has thousands of artifacts and aims to interpret the area's rich maritime culture. (Note: It is temporarily closed but expects to reopen Spring 2023.)
The islands of the Outer Bank have been home to Native Americans, farmers, fishermen, enslaved people, pirates, and today, year-round residents. The island has seen hurricanes, civil war battles, the construction of lighthouses, hundreds of shipwrecks, the birth of the coast guard, and the death of Blackbeard (Edward Teach), the notorious pirate who frequently anchored offshore.
From a geological point of view, the islands that make up the Outer Banks are dynamic and continually change in position. There is nothing to prevent the waves, winds and tides from re-sculpting the shoreline. Nonetheless, on-going beach replenishment projects are part of the strategy to battle the shifting sands and rising sea levels.
For those who follow Dr. Beach's "America's Best Beaches" – Ocracoke Lifeguard Beach, North Carolina earned his #1spot in 2022.
P is for La Pocita de Pinones, Puerto Rico. This beach (also spelled La Posita) is located east of San Juan, on Puerto Rico's north coast on the Atlantic. Every grain in this sample is highly polished from rolling in the surf. It almost looks like a bowl of candy. Sea urchin spines are green and purple. Rods of coralline algae are creamy yellow. Coral fragments are irregularly shaped and mottled in color. Bright pink homotrema (an encrusting foram) is scattered around the sample. Other disk shaped forams are scattered in the sample as are ribbed caecum shells. This variety of marine life found in this sample reflects the vast diversity of organisms in the reefs around Puerto Rico. However, like reefs elsewhere in the world, those around Puerto Rico have declined due to a myriad of threats including overfishing, pollution and the impacts of climate change.
Q is for Qochyax Island, Charleston, Oregon. This is a busy sand and nearly all biological in origin. It reflects the rich marine environment off the rocky coast near Charleston, Oregon, near Coos Bay. That's about mid-way down Oregon's scenic coastline. If you attended SandFest in September 2022, you likely collected from this cove above Sunset Bay State Park. During low tides, Qochyax Island (pronounced Coke-yaw) is connected to the mainland via a land bridge; that's where this sample was collected. Sea urchin are represented by fragments of their spines and their tests (or bodies) – the rectangular fragments with the pores and the tubercules (bumps) where the spines attach. Some urchin spines are purple, others are green reflecting the two different urchin species that inhabit these waters. The segmented and branched item is a segment of red coralline algae (phylum rhodophyta). It is red when alive, but the color quickly fades. Marine worms are represented here too. Directly in the center is a coiled fragment of a spiral tubeworm. In the upper left quadrant is a worm tube fragment with grains of sand and shells cemented together constructed by another worm. In case you are keeping track, the quartz and feldspar grains in the worm tube are the non-biological component of this sample. The fragment with the red bumps is a segment of a sea star body. The other segment with pink is the tip of a sea star arm (closer to center of the photo). Barnacle plates are abundant too. Look for creamy yellow-colored fragments with tubes. If you've found one, look for others with that same color. What else? Gastropods and bivalves are scattered in the sample, including one blue mussel. The rod with the pores (lower right) is a bryozoan. The winged-shaped fragment with the blue-green iridescence on the tips (a little left of center) is a dorsal plate from a chiton. Keep looking. You'll probably find other interesting grains too. Ahh yes, memories of a great day collecting and exploring the Oregon coast!
Jutting
out from the Oregon shoreline above Sunset Bay is a hammer-shaped
extension of rocky outcrops connected by spits of accumulated sediment.
Qochyax (Coke-yaw) Island is the largest element and accessible only at
low tide. This tectonically active coast features several faults and
boasts diverse mineral deposits. But, the sand in this sample is
biological in origin.
Crustacean and echinoderm remains are dominant here. Fragments with wavy lines or parallel channels are from barnacles, sessile crustaceans encased in tent-like limestone plates. In addition to familiar sea urchin spines, this sample includes knobbly white and tan chunks—fragments of seastar or brittlestar skeletal ossicles. Also present are the distinctively loose spirals of vermetid snail shells, chunks of consolidated sand grains from polychaete worm tubes, a broken tip of a crab claw, and seed-shaped chambered tests of forams.
R is for Ritidian Point, Guam. Guam is a U.S. territory (like Puerto Rico), and the largest and southernmost island in the Mariana Archipelago, located about 13° north of the equator in the western Pacific Ocean. It is about 3,800 miles west of Honolulu and Tokyo is yet another 1,500 miles west, just a four-hour flight. Ritidian Point is the northernmost point of the island. It is owned by the U.S. Fish and Wildlife Service which administers the area as part of the Guam National Wildlife Refuge. The U.S. military has long had a military presence on Guam and still maintains both naval and air bases.
Guam has a composite geology: it is a volcanic island completely surrounded by a limestone plateau formed by reefs: fringing, patch, submerged, and barrier reefs along with offshore banks. The fringing reef at Ritidian Point is relatively flat, shallow and is teaming with marine life. Much of the island's shoreline has limestone cliffs. In contrast, evidence of the island's volcanic origins can be found at the mouth of the Ylig River. There you'll find a heavy mineral sand full of magnetite and olivine that gets washed down the river from the highlands.
Guam lies close to the center of high coral reef biodiversity in the western Pacific and has extensive and vibrant coral reef ecosystems in both shallow and deep waters. The biodiversity is considered the highest of any U.S. jurisdiction. Around Guam and the Northern Mariana Islands, there are approximately 377 species of hard corals, 200 species of soft corals, plus 1000 species of fish and lots more marine life. As on reefs around the world, Guam's reefs range from being in excellent to poor condition depending on factors such as adjacent land use, accessibility, river discharge, and recreation.
The reefs benefit the island. Not only do they provide an essential source of food, but the shallow-water reefs protect the coastlines. Guam is in the middle of the tropical Pacific typhoon belt and averages one substantial storm every year or so. The reefs protect the island's infrastructure by weakening the wave energy from the storms.
The sand here is entirely of reef origin. The puffy star and disc forams are particularly abundant. The puffy stars are from the genus Baculogypsina (sphaerulata?). The flat disc-shaped forams with pores are from the genus Marginopora (vertebralis?). The pink fragments are the encrusting foram Homotrema rubra. These three forams are common through the Indo-Pacific. Other grains include broken and whole molluscs, chalky white marine worms, small coral fragments, crab claws, sea urchin spines and body plates, and flat segment of Halimeda–a green alga that calcifies in warm, super-saturated, carbonate waters.
S is for Saint Lawrence Island, Alaska. St. Lawrence Island (SLI) is located west of mainland Alaska in the Bering Sea, ~100 miles (160 km) west of the Alaskan mainland. There are two main communities on the island, Savonnga on the northern coast and Gambell on the northwest cape. The island is part of Alaska but closer to Russia and Asia. SLI is the largest island in the Bering Sea, approximately 100 miles (160 km) long (from east to west), and it averages 20 miles (32 km) in width.
The island is jointly owned by the Yup’ik of Gambell and Savoonga. The Yup’ik who live there have TVs and modern implements and technology, but they still engage in fishing, reindeer herding, and hunting walrus and whale. It is a way of life for them. Reindeer, non-native to SLI, were introduced in the early 1900s to bolster the economy and as a source of subsistence meat. The Yup’ik people are known for the carving skills. For years, they have carved objects from walrus ivory and whale bone. And as the Yup’ik own the island, they may legally sell fossilized ivory and other artifacts found on the island. About 1400 people lived on SLI today; most are Yup’ik. Archaeological evidence suggests that the island has been Inhabited intermittently for ~2000 years.
Here's trivia and history. The island was visited by the Dutch/Russian explorer Vitus Bering on St. Lawrence's Day, August 10, 1728, and he named the island after the day of his visit. The Bering Strait, which links the Arctic and Pacific oceans, was also named after this explorer. The term "Beringia" was coined by a Swedish botanist in 1937 and refers to the submerged landmass that used to bridge the gap between North America and Siberia during the last ice age when sea levels were as much as 325 - 490 ft (100 - 150 meters) lower than now. Beringia was ice free – the air was too dry to snow, and the land connected North America and Siberia and allowed people to migrate. Today, the people on SLI share lineage and a common language (Siberian Yup’ik) with neighbors in Russia across the Bering Strait. St. Lawrence Island and a few other nearby islands are exposed remnants of Beringia.
The two sands pictured here are from two different beaches near Savoonga. The sample with the yellow-green olivine signifies a nearby volcano. And indeed, the central part of the island is dominated by a shield volcano that rises to an elevation of 2066 ft (630 meters). The black in that sample is basalt; the reddish grains are scoria, another volcanic rock. The island is largely of volcanic origin. The other photograph captures bits of marine organisms found in the near-shore region: a sea urchin spine, creamy colored barnacles plates, and blue mussel fragments. That sample also includes basalt and red scoria.
The island is home to far more seabirds than humans-–about 2.7 million seabirds during migratory season. The abundance of seabirds and marine mammals can be credited to the Anadyr Current. This brings nutrient-rich water from the depths of the Bering Sea to nourish marine life in the open water and the near shore marine life. Birding at Gambell is considered among the finest in Alaska.
Low mountains cover nearly half of the island. Steep cliffs border the mountainous regions and are the nesting places of sea birds. Much of the island is low and wet with tundra ponds. At higher elevations, the dry tundra is covered with moss and lichen. There are no trees on SLI except dwarf willow trees that are maybe a foot tall.
T is for Trinitite. On July 13, 1945 the world’s first nuclear device was exploded at the Trinity Site within the Jornada del Muerto Desert near Alamogordo, New Mexico. The atomic bomb was detonated atop a 100-foot steel tower producing a brilliant flash of light as temperatures rose about 9000°F and sand and debris were sucked into the atmosphere. A half mile wide crater remained where the tower had stood. The intense heat fused sand into a green glass-like sheet. That material is now known as trinitite.
Trinitite is mostly composed of quartz and feldspar as well as other materials. It is usually a light green in color. Small amounts of red and even rarer black trinitite are also found. The light green color is from iron in the sand. Red trinitite gets its color from copper electrical wiring consumed in the explosion. Black trinitite contains iron from the support tower. Air transport of molten trinitite resulted in teardrop, spheroid, and dumbbell shaped grains.
Trinitite was a popular souvenir for several years after WWII. In 1953, all trinitite on the site was buried by direction of the Atomic Energy Commission. It is now illegal to remove any remaining trinitite. Honey pot ants (Myrmecocystus mexicanus) still bring trinitite to the surface where they dump it on the mound at the entrance to the colony. This sample was excavated by ants.
U is for Utah's Spiral Jetty in the Great Salt Lake. Spiral Jetty is an odd name for a location, but that is the name of a monumental earthwork in the shape of a 15-foot-wide spiral created by artist Robert Smithson in 1970 and located in the north arm of Great Salt Lake. The spiral is made of basalt and earth and stretches ~1500 feet into the lake. The earthwork is affected by fluctuations in lake level and is currently completely exposed because of the protracted drought in the Great Basin Desert. The drought also threatens the survival of Great Salt Lake, the largest hypersaline lake in North America.
As the lake shrinks, it becomes saltier. This threatens the food chain in the lake, in particular the brine shrimp whose eggs are used worldwide as food for farmed fish. Algae feed the brine shrimp and nourish brine flies. Conservationists estimate 10 million migratory birds stop at Great Salt Lake to feast on the shrimp and flies. Without the food the lake provides, the birds can't survive their migration. The reality is — the lake is disappearing.
The shallow saline water of Great Salt Lake has a modern ooid sand, and the smooth grains consist of a nucleus coated by layers of aragonite. The ooid nuclei are composed of sub-angular quartz grains or brine shrimp fecal pellets. How do they form? The mechanism of ooid growth continues to be a contentious topic among sedimentologists, but they agree a hypersaline environment and some microbial activity likely play a role of their formation. Beyond that, it's still a mystery.
By Gary Shapiro, November 2019 Robert Smithson designed and directed the construction of his iconic work the Spiral Jetty in April 1970. The Jetty is a site-specific work, meant to interact with changing conditions of the surrounding water, land, and atmosphere. While located in a relatively barren, unpopulated place, Smithson chose the site not only because of the vast surrounding landscape, but with reference to nearby abandoned oil rigs and the Golden Spike monument marking the 1869 completion of the transcontinental railway. He understood these as industrial ruins, or entropic residues. The artist's essay "The Spiral Jetty" and the eponymous film he made with Nancy Holt, can be considered as coordinate "non-site" aspects of the artwork. In 2017 Utah designated the Spiral Jetty as the state's official work of art.
Photo: George Steinmetz
V is for Voznesenka, Kenai Peninsula, Alaska. From Homer, Alaska keep driving up Kachemak Bay on East End Road about 23 miles till you hit the dirt road. Then you've reached Voznesenka. To reach the beach, you need to hike or put your car into 4-wheel mode and snake down the switchbacks over the 1000 foot elevation drop to reach the head of the bay.
This sample is unlike most others we've seen. The beach is black, coal black, and the fragments are natural coal that erodes from the coal beds common on the Kenai Peninsula. This area is part of the Kenai coal field, and the coal ranges from lignite to sub-bituminous. Although mining has been attempted since about 1885, little coal has been commercially mined as it was hard to compete with coal from the lower 48 or coal from Canada. However for local residents, carrying a couple five-gallon buckets to the beach used to be an easy way to gather coal for cooking and heating. It is less commonly burned today, but lots of coal still litters the beaches. Clams, like the one seen in the photograph, are common along this shoreline too. They are edible.
Voznesenka is a small unincorporated community, one of several villages founded by Russian Old Believers in the Fox River area. The village was founded in 1985 by residents who decided to start a new settlement. About 40 families live in the village which has a public school and church; however, no grocery, gas or town buildings. The Old Believers speak a Russian dialect plus English; they can be seen around Homer wearing their traditional attire.
W is for Wells Creek, Steward County, Tennessee. Wells Creek is situated in the northern part of middle Tennessee, a region known as the Western Highland Rim. It is 70 miles (112 km) west of Nashville. Today, the land is overgrown, forested, and hilly with numerous creeks. In the early-mid 1800s, iron was mined and smelted here. Farmers reported good soil. It is a destination for geology geeks and fossil collectors.
There is a lot going on in this sample.
1) The blue slag. That is a bi-product from iron smelters in the early-to-middle 1800s. I think, If there is slag in the sample, there must be rocks with iron. Perhaps that explains the iron staining on some of the grains.
2) Then I ask, where is/was iron ore mined in Tennessee? Where was the coal mined that was used to fire the smelter? And the trees and wood to make the charcoal?
3) Then I see fossil crinoids. These are marine organisms and found in sedimentary rocks, such as limestone.
4) With further research, I read, people also collect "shatter cones" at Wells Creek Hmm, these are associated with meteorite impact craters.
There is always more of the story.
1) The blue slag: In iron smelters, the furnaces ran 24 hours a day. They chemically reduced large amounts of ore and limestone flux into molten metal and waste material. The process was accomplished by subjecting the charcoal fuel to a continuous blast of air that produced temperatures high enough to separate the iron from the impurities. These impurities floated to the top of the melt and were drawn off as slag. The slag ranges in color from clear Robin's Egg blue to greenish and purplish. It is glassy looking and brittle and often pitted with air bubbles created when the molten slag was cooling.
2) The iron ore: Tennessee has two regions with iron ore deposits. The "brown ore" occurs in the western Highland Rim of Middle Tennessee, and this ore was mined and smelted near Wells Creek. "Red ores" come from the eastern part of the state. Coal is pretty ubiquitous around Tennessee. Remnants of charcoal kilns are found around the region too. In 1847, there were a couple dozen blast furnaces, forges, and mills around Nashville, however, by the middle 1850, the industry was in decline with changes in technology and the economic Panic of 1857. The new "Age of Steel" doomed the charcoal iron industry. However, the stacks, buildings, cemeteries, and piles of slag remain across the county as evidence of this industry.
3) The crinoids: The rings in this sample are fossil crinoids. Some have a small opening in their centers, others are solid. These are marine organisms that lived in ancient seas that covered much of North America including the Tennessee/ Kentucky region about 320 million years ago. One of the photos includes a coral fragment.
4) The meteorite impact site: When work on the railroad started in 1854 around Wells Creek, engineers and surveyors noted the area's strange twisted rocks and tilted bedding planes which stood in contrast to the usual flat landscape of the area. They notified the state geologist, who roughly sketched the site; he inset a map into the 1869 Tennessee map, but he did not include suggestions about its origins. Farmers also noticed the soil was different. But the origin of the structure was controversial. In 1874, one geologist suggested the "evidence hints at a terrible subterranean convulsion at one time." In the 1930s, suggestions for its origin included a crypo-volcanic or cryptoexplosive (meteorite impact) origin. Fast forward to the 1960s and in preparation for the first lunar landing, detailed studies of the Wells Creek site were done as NASA scientists wanted to learn whether lunar craters were related to those on earth. After lots more research, scientists came to prefer the meteorite impact hypothesis to explain the origin of the Wells Creek site. Now, after 150 years of controversy and study, geologists finally agreed that the seven mile (13.7 km) diameter basin surrounded by ridges was an impact crater site. It is estimated the impact occurred between 100 and 300 million years ago.
Geology and rock enthusiasts are drawn to explore the center of the crater. It contains some of the best shatter cones; these conical rock fragments formed from the high pressure of the impact. They range from 1/4" to 2.5" ( .6 - 6.3 cm) across.
If you visit, check out the Wells Creek Impact Crater site and the Iron Furnace Trail to learn more about the crater and the historic iron industry in middle Tennessee.
X is for Crossed Out. Crossed off the list. Unsuitable for the collection. Location unknown. Another “mystery sand”. Collect sand for a little while and you will have several samples you have crossed off your collection list.
The crossed out sand might lack accurate or any collecting data. It could be pebbles, rocks or dirt and not sand at all. It could be a soggy, decayed mess you would never want in your home. Occasionally, the sample will have great data, be of suitable size, and still be an unknown and not suitable for your collection. I’ll provide examples of a few of my eXed out sands. (A few I still keep for amusement.)
Y is for Yellowstone River, Terry, Montana. Terry is located in southeastern Montana on the Yellowstone River and near the Powder River. The landscape includes rolling hills and badlands sculpted over thousands of years by water and wind.
Today it is a high and dry plain, but 60 million years ago, the area was a shallow and swampy basin. Rivers streaming from mountains in the west transported tons of sand, mud and silt over the low plain. Vegetation grew well in the swampy wet soils near the rivers. When rivers flooded during heavy rains, the sediments buried the vegetation. Afterwards, the plant life rebounded in the swamps; and then the next flood deposited more sediments and buried more plant material.
Again and again, over maybe eleven million years, the rivers flowed and flooded and transported sediments. The vegetation grew and died, and sediments piled up in alternating layers with the partially decaying organic matter. In this waterlogged environment, with little access to oxygen, the organic material didn't decompose, it formed peat. And in time, the weight and pressure of it all solidified – the silt into mudstone, the sand into sandstone, and the peat into lignite coal.
This sequence of coal beds and sedimentary rocks in north central Montana is called the Fort Union Formation. In some areas, the alternating layers include 32 lignite coal seams with a combined thickness of more than 300 ft. (91 meters). (Lignite is a low-grade coal.) Coal has been mined in Montana since territorial days, first as a heating fuel and later primarily for the railroads. Production peaked in the 1940s; however, as steam locomotives were phased out, production declined. Today (2023), there are still four coal mines in operation in the Powder River Basin in southeastern Montana. It is shipped to domestic and foreign consumers.
In 1806, Lewis and Clark explored the Yellowstone River and documented its colorful badland scenery with buttes, bridges and spires. They remarked on the landscape that appeared burnt in many places. They also noted the rocks: dark and light brown and lots of red rocks. They called the river the Red Stone River. They further noted that coal appears in layers between the burnt rock.
Lewis and Clark attributed the red rock to the heat from burning coal beds and called the area the "burnt hills." They were correct. When lightning ignited the coal, it baked the adjacent rocks. The coal turned to clinker, the sandstone baked to a brick like rock; the shale fused and looks like glazed ceramic pottery.
Clinker resembles pumice, and it may float; but it is not of volcanic origin and not seen in this sample. It is the term used to describe the burned coal and chunks of burnt coal fused with rock. The red and brown clinker is what Lewis and Clark saw on the caps of the buttes and plateaus. It is hard and resistant to erosion. Geologists use the term pyro-metamorphism to describe rocks and minerals altered by high temperatures caused after lightning strikes ignite coal seams and bake the adjacent rocks. Scientists estimate coal has been burning in eastern Montana for at least four million years. They do naturally extinguish. As the fire burns into the hill, the overlying rocks break and collapse; and eventually, too much rock collapses and restricts the air flow, and the fire goes out.
This sample was collected at an anthill. Visible here are examples of sandstone that baked into red brick like rocks, shale that fused into ceramic like products, plus other rocks that were subjected to the high heat. The clean to blue/gray grains are likely Montana agates. The ID of the yellow mineral grains remains a mystery. They are certainly well rounded which signifies significant transport from their point of origin. But did they experience the same pyro-metamorphism as the sandstone and shale seen in this sample or did they originate elsewhere?
Where does the name Yellowstone come from? The name has been attributed to Native Americans from as early as 1805 who were referring to yellow sandstones along the banks of the Yellowstone River in eastern Montana, several hundred miles downstream and northeast of the Yellowstone National Park.
Z is for Zephyr Cove, Lake Tahoe, Nevada. The community of Zephyr Cove is located on the southeastern shore of Lake Tahoe; it has a mile-long sandy beach. Established in 1862, the community was named after the Washoe Zephyr, that's a seasonal, daily wind that blows mostly in the summer and from mid-afternoon through late evening. It blows from the west and can be gusty; and with the arid terrain, the wind stirs up dust. Scientists think the wind is caused by intense heating over the Great Basin during summer afternoons.
Nestled between the Sierra Nevada Range on the west and Carson Range to the east, Lake Tahoe straddles the interstate boundary between California and Nevada. Elevations range from 6225 ft. (1897 meters) at lake level to 10,891 feet (3320 meters) at Freel Peak. The lake and region attract tourists who come for year-round recreation: to ski, hike, bike, scuba dive, sail and to gamble. The scenery is spectacular with snow-capped peaks, forested mountains and the lake with its deep blue water. The lake has had a few names over the years, and likely owes its current name to the Washoe Indian tribe's word Tah-hoe meaning "big water."
Lake Tahoe and the surrounding mountains are underlain by granitic rock, predominantly granodiorite. That is a medium to coarse-grained intrusive igneous rock. It contains quartz and is distinguished from granite by having more plagioclase feldspar than orthoclase feldspar; its other mineral constituents include hornblende, biotite, and augite. The sample here shows clean angular quartz and feldspar with distinctive near 90° angles. The dark grains likely include basalt. Many grains are iron stained.
Faulting was a key element in the formation of Lake Tahoe. The Tahoe Basin lies in a graben (a trench between two faults) that formed about 3.7 million years ago between the Sierra Nevada and Carson Range. Five east-dipping faults cut the basin, and three of them are covered by the lake. They are considered "active" and potentially capable of producing a magnitude 7 earthquake. If (or when) that occurs, it could also produce a tsunami in parts of the lake, plus landslides. The last time one of these faults ruptured was about 575 years ago. The probability of faults in the Tahoe Basin is similar to many parts of California and the Pacific Northwest.
If you visit and want to see the geology and beautiful vistas of the lake, drive the road that encircles the lake. It is a slow 72 miles (116 km) on narrow, twisty mountain roads.
Trivia: Deep lakes around the world. Lake Tahoe is the third deepest lake in North America at 1645 ft. (501 meters) and the ninth deepest in the world. Great Slave Lake in Canada is North America's deepest at 2015 ft. (614 meters). Lake Baikal in Russia is the world's deepest lake at 5315 ft. (1620 meters).
