HALENDID: ICELANDIC HIGHLANDS

Glaciers, mountains, active volcanoes — Iceland has it all. 

Sitting at the junction of the North Atlantic and Arctic Oceans is the ruggedly beautiful island of Iceland. It is Europe's second-largest island after Great Britain. 

Geologically, Iceland is part of the Mid-Atlantic Ridge — a wee bit of the oceanic crust sitting just above a mantle plume, hence all the showy volcanic eruptions and lava flows.

The interior of Iceland is usually referred to as the central highlands or as the locals call it — Halendid — which roughly translates to Highlands in Icelandic. It is considered one of the last great wilderness areas in all of Europe, covering nearly 40,000 square kilometres. Truly one of the last untamed regions on earth. Halendid contains high concentrations of waterfalls, volcanoes, glaciers, and rivers. Large expanses of black sand, lava fields, and fragile vegetation are found throughout the region.

Still, one of the features that make this region so unique are the rivers. These rivers carry glacial runoff and sediment from the interior of the island to the ocean. Along the way, this mix of minerals and water produces dramatic colours, complex systems, and vibrant patterns.

AMMONITE TIME PIECE: INDEX FOSSILS

Ammonites were prolific breeders that evolved rapidly. If you could cast a fishing line into our ancient seas, it is likely that you would hook an ammonite, not a fish.

They were prolific back in the day, living — and sometimes dying — in schools in oceans around the globe.  We find ammonite fossils, and plenty of them, in sedimentary rock from all over the world. In some cases, we find rock beds where we can see evidence of a new species that evolved, lived and died out in such a short time span that we can walk through time, following the course of evolution using ammonites as a window into the past.

For this reason, they make excellent index fossils. An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. Generally, deeper is older, so we use the sedimentary layers of rock to match up to specific geologic time periods, rather like the way we use tree rings to date trees.

GORGONS: APEX PREDATORS OF THE PERMIAN

Step back into the deep Paleozoic—an era that began some 540 million years ago with oceans bustling with trilobites, early fish, and soft-bodied wonders, while the continents themselves hosted little more than humble mats of mosses and fungi. Life’s great drama was still mostly underwater.

Fast-forward 240 million years, and the evolutionary landscape had transformed dramatically. 

Vertebrates had conquered the land, ecosystems had diversified, and Earth’s surface teemed with reptilian innovators, amphibians the size of crocodiles, and the early ancestors of mammals. Among these emerging terrestrial titans strode the Gorgonopsians, or “Gorgons”—ferocious sabre-toothed therapsids that dominated the Middle to Late Permian, from about 265 to 252 million years ago.

These were no sluggish proto-reptiles. Gorgons were highly specialized predators, boasting elongated canine teeth worthy of any future saber-toothed cat, powerful jaws, and sleek, muscular bodies built for pursuit. Their anatomy blended the primitive and the prophetic: reptile-like postures paired with early mammalian traits such as differentiated teeth and strong jaw musculature. 

Their clawed limbs, keen forward-facing eyes, and cutting-edge predatory adaptations placed them firmly at the top of the Permian food chain. In a world long before dinosaurs, they were the undisputed apex hunters.

My own fascination with these remarkable creatures was ignited by Gorgons, Peter Ward’s wonderfully wry and insightful dive into the ancient landscapes of South Africa. Ward’s vivid tales of fieldwork in the blistering, bone-dry vastness of the Karoo Basin—ancestral home of the Gorgons—captured both the hardships and the sheer exhilaration of unearthing deep time. 

His descriptions of sunburn and scientific revelations in that arid world made me laugh more than once. It is a highly enjoyable read.

The Great Karoo itself is a geological and paleontological marvel. This enormous, semi-arid expanse formed within a vast inland basin roughly 320 million years ago, at a time when the part of Gondwana destined to become Africa lay draped across the South Pole. 

Layer upon layer of sedimentary rock accumulated as glaciers advanced and retreated, rivers meandered, lakes dried, and ecosystems rose and fell. Today, those layers read like a grand evolutionary chronicle, preserving a world populated by beaked herbivores, hulking amphibians, and the charismatic, toothy Gorgonopsians.

This was a pivotal chapter in Earth’s history—just before the catastrophic Permian-Triassic extinction swept away nearly 90% of life. Yet in the twilight of the Permian, before that great dying, the Karoo thrived with innovation and ecological complexity. It was a world where the early steps toward warm-bloodedness were being taken, where synapsids (our own deep ancestors) were experimenting with new forms, and where the Gorgons reigned supreme.

LIPAROCERAS IN SEPTARIAN NODULE

Robin Hoods Bay is a small fishing village and a bay located in the North York Moors National Park, 5 miles (8 km) south of Whitby and 15 miles (24 km) north of Scarborough on the coast of North Yorkshire, England. 

Bay Town, its local name, is in the ancient chapelry of Fylingdales in the wapentake of Whitby Strand.

Here, 552 kilometres (343 miles) to the north of the Kimmeridge Clay exposures, near the picturesque town of Robin Hoods Bay on the Yorkshire Coast we find beautiful septarian nodules — and when we are very lucky, ammonites and other fossilized material along with them.

These photos show a delightful example of a lovely Liparoceras sp. from Robin Hoods Bay with some interesting septarian veins radiating away from the ammonite. The awesome Harry Tabiner gets full credit — and my unending respect — for the find, preparation and photo of this lovely Lower Jurassic, Lower Lias specimen.

Around Robin Hood’s Bay, well-developed platforms cut across outcrops of Liassic shales. The cliffs are primarily till resting on the Lias. Cliff falls at this location are common. The cliffs are about 50 m in height in the northern part of the bay where they are cut by two steep-sided valleys, Mill Beck and Stoupe Beck. Here the Lower Lias forms most of the slope, with near-vertical lower cliffs comprised entirely of Lower Lias rocks.

The rocks in the lower cliffs are dark grey marine shales from the Redcar Mudstone Formation. The Lias Group at Robin Hood’s Bay is represented, in ascending order, by the Redcar Mudstone Formation, Staithes Sandstone Formation, Cleveland Ironstone Formation and Whitby Mudstone Formation and contains stratotypes for several zones and horizons.

Most fossils are found either from the foreshore exposures during scouring conditions or in rocks, boulders and nodules. They can also be found after cliff falls. To search for septarian nodules, head north for several miles along the coast from Robin Hoods Bay.

Be mindful of the tides as this location should only be attempted on a retreating tide. Minerals can be found in both the large Septarian nodules and partially replacing the many fossilized tree limbs and roots found in the sandstone blocks from higher up in the cliffs. This site can be dangerous and is not appropriate for children.

To look for fossils, search through the rocks and concretions along the foreshore. Ammonites can often be found this way, but you will need the right tools and good eye protection.

Fossils loose on the foreshore are rare. You generally need to work for finds at this location. A few good storms help with collecting here. Robin Hood’s Bay yields little during the summer months. The best time to collect is after the winter storms.

The north side of the bay is rich in ammonite remains and these can mostly be found after cliff falls. The ammonites (Platypleuroceras, Tropidoceras, Acanthopleuroceras and Androgynoceras) can be found, along with the large bivalve, Pinna. Within the calcareous shales, exposed in the low tide reefs at the centre of the bay, you can find the ammonites, Arnioceras and Caenisites.

Robin Hoods Bay Directions from the good folk at UK Fossils Network:

At Robin Hood’s Bay village, you can park in either the small car park at the top of the hill or the second larger one just a short walk away.

• From here, the best end to visit is the north side. You will find a footpath at the top of the hill, to the left of the main street leading to the beach. This winds around and passes a picnic area.
• You can also visit the south and middle part of the bay. To do this, go down into the main street at the bottom of the hill and follow round to the right. You will see some steps, which follow the sea defence and lead to the shore.
• Paleo-coordinates: 54.43442°N, 0.53079°W

Photos: The deeply awesome Harry Tabiner gets full credit (and my unending respect) for the find, preparation and photo of this lovely Liparoceras sp. in a septarian nodule, Lower Jurassic, Lower Lias specimen.

Reference: Humberside Geologist No. 14, Humberside Geologist Online, The geology of East Yorkshire coast.http://www.hullgeolsoc.co.uk/hg146t.htm

Reference: UK Fossils Network: https://ukfossils.co.uk/2007/03/18/robin-hoods-bay/ This website provides a wealth of information and is very well done. Highly recommend checking them out!
Reference: https://www.mindat.org/loc-267536.html

ROCKY MOUNTAIN TRENCH

Trapper Cabin on Isaac Lake / Bowron Provincial Park

The Bowron Canoe Circuit is a 149,207 hectare geologic wonderland, where a fortuitous combination of plate tectonics and glacial erosion have carved an unusual 116 kilometre near-continuous rectangular circuit of lakes, streams and rivers bound on all sides by snow capped mountains.

From all descriptions, something like heaven.

The east and south sides of the route are bound by the imposing white peaks of the Cariboo Mountains, the northern boundary of the Interior wet belt, rising up across the Rocky Mountain Trench, and the Isaac Formation, the oldest of seven formations that make up the Cariboo Group (Struik, 1988).

Some 270 million years ago, had one wanted to buy waterfront property in what is now British Columbia, you’d be looking somewhere between Prince George and the Alberta border. The rest of the province had yet to arrive but would be made up of over twenty major terranes from around the Pacific. The rock that would eventually become the Cariboo Mountains and form the lakes and valleys of Bowron was far out in the Pacific Ocean, down near the equator.

With tectonic shifting, these rocks drifted north-eastward, riding the continental plate until they collided with and joined the Cordillera in what is now British Columbia. Continued pressure and volcanic activity helped create the tremendous slopes of the Cariboo Range we see today with repeated bouts of glaciation during the Pleistocene carving their final shape.

PLIENSBACHIAN APODEROCERAS OF DORSET

The lovely large specimen (macroconch) of Apoderoceras pictured here is likely a female. Her larger body perfected for egg production.

Apoderoceras is a wonderful example of sexual dimorphism within ammonites as the macroconch (female) shells grew to diameters in excess of 40 cm – many times larger than the diameters of the smaller microconch (male) shells.

Apoderoceras has been found in the Lower Jurassic of Argentina, Hungary, Italy, Portugal, and most of North-West and central Europe, including as this one is, the United Kingdom. This specimen was found on the beaches of Charmouth in West Dorset and prepped by the wonderfully talented Lizzie Hingley.

Neither Apoderoceras nor Bifericeras donovani are strictly index fossils for the Taylori subzone, the index being Phricodoceras taylori. Note that Bifericeras is typical of the earlier Oxynotum Zone, and ‘Bifericeras’ donovani is doubtfully attributable to the genus. The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum of genus Apoderoceras and of Bifericeras donovani the defining biological marker for the start of the Pliensbachian Stage of the Jurassic, 190.8 ± 1.0 million years ago.

Apoderoceras, Family Coeloceratidae, appears out of nowhere in the basal Pliensbachian and dominates the ammonite faunas of NW Europe. It is superficially similar to the earlier Eteoderoceras, Family Eoderoceratidae, of the Raricostatum Zone, but on close inspection can be seen to be quite different. It is, therefore, an ‘invader’ and its ancestry is cryptic.

The Pacific ammonite Andicoeloceras, known from Chile, appears quite closely related and may be ancestral, but the time correlation of Pacific and NW European ammonite faunas is challenging. Even if Andicoeloceras is ancestral to Apoderoceras, no other preceding ammonites attributable to Coeloceratidae are known. We may yet find clues in the Lias of Canada. Apoderoceras remains present in NW Europe throughout the Taylori Subzone, showing endemic evolution. It becomes progressively more inflated during this interval of time, the adult ribs more distant, and there is evidence that the diameter of the macroconch evolved to become larger. At the end of the Taylori Subzone, Apoderoceras disappeared as suddenly as it appeared in the region, and ammonite faunas of the remaining Jamesoni Zone are dominated by the Platypleuroceras–Uptonia lineage, generally assigned (though erroneously) to the Family Polymorphitidae.

In the NW European Taylori Subzone, Apoderoceras is accompanied (as well as by the Eoderoceratid, B. donovani, which is only documented from the Yorkshire coast, although there are known examples from Northern Ireland) by the oxycones Radstockiceras (quite common) and Oxynoticeras (very rare), the late Schlotheimid, Phricoderoceras (uncommon) Note: P. taylori is a microconch, and P. lamellosum, the macroconch), and the Eoderoceratid, Tetraspidoceras (very rare).

DACTYLIOCERAS OF THE HOLDERNESS

Dactylioceras ammonite, Photo: Harry Tabiner

A lovely Dactylioceras ammonite from the Lower Jurassic Upper Lias Holderness of the Yorkshire Coast. This beauty measures over 8cm with especially attractive colouring.

Holderness is an area of the East Riding of Yorkshire, on the east coast of England. An area of rich agricultural land, Holderness was marshland until it was drained in the Middle Ages. Topographically, Holderness has more in common with the Netherlands than with other parts of Yorkshire. To the north and west are the Yorkshire Wolds.

Geologically, Holderness is underlain by Cretaceous chalk but in most places, it is so deeply buried beneath glacial deposits that it has no influence on the landscape.

The landscape is dominated by deposits of till, boulder clays and glacial lake clays. These were deposited during the Devensian glaciation. The glacial deposits form a more or less continuous lowland plain which has some peat filled depressions (known locally as meres) which mark the presence of former lake beds. There are other glacial landscape features such as drumlin mounds, ridges and kettle holes scattered throughout the area.

Dactylioceras ammonite, Photo: Harry Tabiner

The well-drained glacial deposits provide fertile soils that can support intensive arable cultivation. Fields are generally large and bounded by drainage ditches. There is very little woodland in the area and this leads to a landscape that is essentially rural but very flat and exposed. The coast is subject to rapid marine erosion.

The Geology of Yorkshire in northern England shows a very close relationship between the major topographical areas and the geological period in which their rocks were formed. The rocks of the Pennine chain of hills in the west are of Carboniferous origin whilst those of the central vale are Permo-Triassic.

The North York Moors in the north-east of the county are Jurassic in age while the Yorkshire Wolds to the southeast are Cretaceous chalk uplands. The plain of Holderness and the Humberhead levels both owe their present form to the Quaternary ice ages.

The strata become gradually younger from west to east. Much of Yorkshire presents heavily glaciated scenery as few places escaped the direct or indirect impact of the great ice sheets as they first advanced and then retreated during the last ice age. This beauty is in the collection of the deeply awesome Harry Tabiner.

CRETACEOUS AFRICA SUPER CROC

Sarcosuchus imperator

An impressive Super Croc tooth and scute from Sarcosuchus imperator, an extinct genus of giant crocodile-like reptiles that lived in the rivers of an ancient tropical plain in the Sahara of Africa during the Lower Cretaceous.

Sarcosuchus were ambush hunters, eating anything that entered their watery homes from wee fish to large dinosaurs. These big beasties were the precursors to our modern crocodiles -- and they were big. Really big. 

Almost twice as large as their modern saltwater cousins, weighing in at 8-10 tons. They lived 50-60 years. Modern Saltwater & Nile crocodiles live 70-100 years on average. This scute and tooth are from the Elrhaz Formation, Gadoufaoua, Ténéré Desert, Niger. Photo care of the deeply awesome Andy Chua.

SARCOSUCHUS IMPERATOR

This mighty beast is Sarcosuchus. He is an extinct genus of crocodyliform, so not quite a crocodile as we know them but the distant relative of crocodylians that lived ~129-112 million years ago. 

We have learned about them through fossil remains that date from the Lower Cretaceous of what is now Africa and South America.

Strictly speaking, Sarcosuchus was not a crocodile as we know them today, but a kind of pre-crocodile. These early croc-types were Crocodylomorphs.

This crocodylian lineage (clade Pseudosuchia, formerly Crurotarsi) was a very diverse and adaptive group of reptiles. We used to lump all known living and extinct crocodiles indiscriminately into the order Crocodilia. Sometime in the late 1980s, we finally moved all living species into the order Crocodilia, segregating closely related extinct relatives such as Mekosuchus. Our true "modern" crocodiles, now all safely ensconced in the order Crocodilia without their ancient ancestors, arrived millions of years after the first crocodylomorphs, with the first members of the modern species arriving on the scene in the Upper Cretaceous.

The Crocodylomorpha were a very ancient group of animals, at least as old as the dinosaurs, who evolved into a very diverse spectrum of weird and wonderful forms you might not recognize as croc-like. During the Jurassic and the Cretaceous, marine Crocodylomorphs in the family Metriorhynchidae, such as Metriorhynchus, evolved forelimbs that were paddle-like and had a tail similar to modern fish. Dakosaurus andiniensis, a species closely related to Metriorhynchus, had a skull that was adapted to feast upon large marine reptiles. We see several (unexpected) herbivorous terrestrial species during the Cretaceous, such as the tiny and adorable Simosuchus clarki and Chimaerasuchus paradoxus, both roughly the size of a dog. During the Cenozoic, a number of lineages left their ancient river homes and became wholly terrestrial predators.

Sarcosuchus was one of the largest early crocodile-like reptiles, reaching up to 9.5 m in body length and weighing up to 8 to 10 tons. He was almost twice as long as our modern saltwater crocodiles, so one big croc! These big beasts lived and hunted in ancient rivers, grabbing and crushing prey that came too close to the water.

The first remains were discovered during field expeditions in the Sahara led by French paleontologist, Albert-Félix de Lapparent, from 1946 to 1959. Remains were found of skull fragments, vertebrae, teeth, and scutes.

In 1964, an almost complete skull was found in Niger by the French CEA, but it was not until 1997 and 2000 that most of its anatomy became known to science when an expedition led by the American paleontologist Paul Sereno discovered six new specimens, including one with about half the skeleton intact and most of the spine.

A common method to estimate the size of crocodiles and crocodile-like reptiles is the use of the length of the skull measured in the midline from the tip of the snout to the back of the skull table since in living crocodilians there is a strong correlation between skull length and total body length in subadult and adult individuals irrespective of their sex, this method was used by Sereno et al. (2001) for Sarcosuchus due to the absence of a complete enough skeleton. Two regression equations were used to estimate the size of S. imperator, they were created based on measurements gathered from 17 captive gharial individuals from northern India and from 28 wild saltwater crocodile individuals from northern Australia, both datasets supplemented by available measurements of individuals over 1.5 m (4.92 ft) in length found in the literature.

The largest known skull of Sarcosuchus imperator (the type specimen) is 1.6 m (5.25 ft) long (1.5 m (4.92 ft) in the midline), and it was estimated that the individual it belonged to had a total body length of 11.65 m (38.2 ft), its snout-vent length of 5.7 m (18.7 ft) was estimated using linear equations for the saltwater crocodile and in turn, this measurement was used to estimate its body weight at 8 tonnes (8.8 short tons). These new measurements meant Sarcosuchus was able to reach a maximum body size not only greater than previously estimated but also greater than that of the Miocene "Beak crocodile" Rhamphosuchus, the Late Cretaceous Deinosuchus crocodilian related to our modern alligators, and the Miocene Purussaurus.

However, extrapolation from the femur of a subadult individual as well as measurements of the skull width further showed that the largest S. imperator was significantly smaller than was estimated by Sereno et al. (2001) based on modern crocodilians. O’Brien et al. (2019) estimated the length of the largest S. imperator specimen at 9.5 meters and body weight at 4.7 tons based on longirostrine crocodylians skull width to total length ratio. This estimate is very close to the femur based estimate is 9.1 m (29.9 ft).

Sereno, Paul C.; Larson, Hans C. E.; Sidor, Christian A.; Gado, Boubé (2001). "The Giant Crocodyliform Sarcosuchus from the Cretaceous of Africa". Science. 294 (5546): 1516–9. Bibcode:2001Sci...294.1516S. doi:10.1126/science.1066521. PMID 11679634.

OUR EARLY ATMOSPHERE

Our early Earth was a molten world

When the Earth formed 4.5 billion years ago, it was an inhospitable place. 

Even with a Sun some 25 per cent weaker than it is today, ours was a molten world that needed to undergo a long period of cooling before the conditions for life would arise.

And arise they did. On the planet's surface, volcanoes spewed lava and volatile gasses into what would become our earliest atmosphere. 

Again, in composition, it looked very different from the one we know today. Nitrogen, carbon dioxide, ammonia, methane and small amounts of water vapour made up the gassy soup surrounding our world.

But that first water would change everything. As the water vapour condensed, it came back to the surface bit by bit. Over a very long period of time, those waters pooled and gathered and became our first oceans. It was in this early ocean some 2.7 billion years ago that cyanobacteria, or blue-green algae, wonderous photosynthetic microbes, would take up that weakened sunlight and water vapour to process the carbon dioxide from the atmosphere, producing other chemical compounds and oxygen as a by-product.  

RED LIPPED BATFISH

Red Lipped Batfish, Ogcocephalus darwini

This sexy monkey with her luscious red pucker is a Red Lipped Batfish, Ogcocephalus darwini.

Our world's oceans have some of the most amazing, beautiful, ugly and interesting creatures on the planet. Red Lipped Batfish are no exception. They can be found along the sandy ocean floor and reefs around the Galapagos Islands and off the shores of Peru.

Their most distinguishing feature is revealed in their name and one look at this photo gives it away — they have very distinctive bright red lips. They also have a rather fetching illicium, the dangling projection you see here. It's a lure to attract prey to those luscious lips so she can enjoy a tasty snack. Above the illicium is an esca, an unusual feature that emits a bright light. Between the light and the lure, small fish and curious invertebrates — shrimp, molluscs, crab — deep in the Southeast Pacific investigate the light and get swallowed up by those lips.

Most of their flattened flounder-like bodies are light brown and a greyish in colour with white colouring on the underside. They are roughly the size of a dinner plate. On the top side of the batfish, there is usually a dark brown stripe starting at the head and going down the back to the tail.

Their face has a definite red sheen. Comically, with the red face and bored expressions, it looks like they're perpetually unimpressed and slightly embarrassed.

Once you get past those lips, the next thing that stands out with these interesting beauties is how they move. They're not terribly good swimmers but do walk rather well on their highly adapted fins. They march or waddle across the seafloor in search of more interesting sights to practise the art of deep-sea fishing.

Batfish are descendants of lophiiform fishes. In 2011, a new genus and species of batfish, Tarkus squirei, was described from Eocene (Ypresian) limestone deposits in the celebrated locality of Monte Bolca, Italy. Tarkus squirei was a tropical batfish that inhabited the inner-shelf palaeobiotopes of the central-western Tethys Sea.  Tarkus gen. nov. shows a certain degree of phenetic affinity with the extant shallow-water batfish genera Halieutaea and —more particularly — Halieutichthys. The specimens of this taxon are the first articulated skeletal remains of the Ogcocephalidae ever recorded as fossils, also representing the oldest members of the family known to date.

Reference: CARNEVALE, G., & PIETSCH, T. (2011). Batfishes from the Eocene of Monte Bolca. Geological Magazine, 148(3), 461-472. doi:10.1017/S0016756810000907

FROM RUSSIA WITH LOVE: AULACOSTEPHANUS

A beautiful example of Aulacostephanus undorae (Pavlow, 1886), a Late Jurassic, Upper Kimmeridgian, upper zone Eudoxus ammonite from an old quarry near the river Serena, near the village Lipitsy, Kaluga Region, Russia. 

Kaluga is known for its most famous resident, Konstantin Tsiolkovsky, a rocket scientist who pioneered astronautic theory.

The Tsiolkovsky State Museum of the History of Cosmonautics in Kaluga is dedicated to his work and its practical applications for space research. The city's coat of arms and motto gives a respectful nod to work — the Cradle of Space Exploration.

Kaluga, founded in the mid-14th century as a border fortress on the southwestern borders of the Grand Duchy of Moscow. The city's name has changed over time. If you poke through historical records and chronicles from the 14th century, you'll see it written as Koluga — derived from the Old Russian word for bog or quagmire. 

Historically, Kolunga has sat on the sidelines of history. It is the sort of place you might have a country home away from the hubbub of the bustling city. Indeed, the area has served as such for many of Russia's Royals. In the Middle Ages Kaluga was a smallish settlement owned by the Princes Vorotynsky whose relationship with the townsfolk looked more akin to how you and I might picture slaver versus a liege lord. 

Over time, the village grew more prosperous and opened its first drama theatre in 1777. As in many parts of the world, the first geologic exploration and mapping were done to locate natural resources that would be used to fund monarchies, wars and infrastructure.  

Kaluga is connected to Moscow by a railway line and by the ancient roadway, the Kaluga Road (now partly within Moscow — as Starokaluzhskoye Shosse - the Old Kaluga Highway — partly the A101 road. This road offered Napoleon his favoured escape route from the Moscow trap in the fall of 1812. 

General Kutuzov repelled Napoleon's advances in this direction and forced the retreating French army onto the old Smolensk road, previously devastated by the French during their invasion of Russia — an event that may be attributed to poor planning and tin buttons, but that is for another post.

On several occasions during the Russian Empire Kaluga was the residence of political exiles and prisoners such as the last Crimean khan Şahin Giray (1786), the Kyrgyz sultan Arigazi-Abdul-Aziz (1828), the Georgian princess Thecla (1834–1835), and the Avar leader Imam Shamil (1859–1868).

The German army briefly occupied Kaluga during the climactic Battle of Moscow, as part of Operation Barbarossa. The city was under full or partial German occupation from October 12th to December 30, 1941. In 1944, the Soviet Government used its local military buildings to intern hundreds of Polish prisoners of war — soldiers of the Polish underground Home Army — whom the advancing Soviet front had arrested in the area around Vilnius. This specimen is in the collection of the deeply awesome Emil Black. Maximum diameter of 58mm. 

FOOL'S GOLD: A PERSONAL GOLD RUSH

When I was little, maybe 5 or 6 years old, I struck gold! Well, it wasn't real gold, but I was most convinced. 

Someone had dumped a tailings pile near the woods where I lived and in the sun, those crushed pieces of rock sparkled. I had already been bitten by the love of minerals and fossils and so naturally I filled my pockets and brought as much home as a youngster can carry.

Where I was told that it was Fool's Gold. 

But, still... it was so compelling and just so gold-like. So, secretly I continued my forays and dragged as many of those lovely sparkly bits home as I could. The pile soon amassed to what could not be concealed in a youngsters room — those socks have to live somewhere. So we struck a bargain. My folks would let me keep my gold if I kept it under the house. I suspect it is still there to this day. 

I did eventually find gold up in Atlin, British Columbia — and loads of it — but none that I could keep. I met a fellow who pans for it and had built out a sluicing system to great success. He showed me an ice cream bucket full of gold nuggets that I still ponder to this day.

So, what exactly is Fool's Gold? Is it gold mixed with another mineral or something else altogether? Turns out it is pyrite which has a brass-yellow colour and metallic lustre similar to gold, but pyrite is brittle and will break rather than bend as gold does. 

A good field test is to give it a streak test. Gold leaves a yellow streak, while pyrite’s streak is brownish-black. 

Pyrite is named from the Greek word for fire, "pyr" because pyrite can create sparks for starting a fire when struck against metal or stone — also fun to try in the field. Pyrite was once a source of sulfur and sulfuric acid, but today most sulfur is obtained as a byproduct of natural gas and crude oil processing.

We sometimes see pyrite sold as a novelty item or made into costume jewellery. But pyrite does have its uses beyond amusing youngsters dreaming of their own gold rush. 

Pyrite can sometimes help you find real gold because the two form together under similar conditions. Gold can even occur as inclusions inside pyrite, sometimes in mineable quantities depending on how effectively the gold can be recovered.

Fool’s Gold is truly pyrite or iron sulfide (FeS2) and is one of the most common sulfide minerals. Sulfide minerals are a group of inorganic compounds containing sulfur and one or more elements. 

I still have a fondness for it and share a wry smile when I find it out in the field. It is remarkably common. And, I do still want it to be real gold even though my grown-up brain knows it is not. 

When I am very lucky, however, I find pyritized fossils — even better than gold!