Friday, 31 January 2020

TRACKING THROUGH THE TRIASSIC

Grambergia sp. Early Anisian (Middle Triassic) Ammonoid of  BC, Canada
In the early 1980s, Tim Tozer, Geological Survey of Canada was looking at the spread of marine invertebrate fauna in the Triassic of North America. In the western terranes of the Cordillera, marine faunas from southern Alaska and Yukon to Mexico are known from the parts that are obviously allochthonous with regard to the North American plates.

Lower and upper Triadic faunas of these areas, as well as some that are today up to 63 ° North, have the characteristics of the lower paleo latitudes. As far as is known, Middle Triadic faunas in these zones do not provide any significant data.

In the western Cordillera, these faunas of the lower paleo latitudes can be found up to 3,000 km north of their counterparts on the American plate. This indicates a tectonic shift of significant magnitude. There are marine triads on the North American plate over 46 latitudes from California to Ellesmere Island. For some periods, two to three different faunal provinces can be distinguished. The differences in faunal species are linked, not surprisingly, to their paleolatitude. They are called LPL, MPL, HPL (lower, middle, higher paleolatitude).

Nevada provides the diagnostic features of the lower (LPL); northeastern British Columbia that of the middle (MPL) and Sverdrup Basin, the large igneous province on Axel Heiberg Island and Ellesmere Island, Nunavut, Canada near the rifted margin of the Arctic Ocean, that of the higher paleolatitude (HPL).

A distinction between the provinces of the middle and the higher paleo-situations can not be made for the lower Triassic and lower Middle Triassic (anise). However, all three provinces can be seen in the deposits of Ladin, Kam and Nor.

In the early 2000s, as part of a series of joint UBC, VIPS and VanPS fossil field trips (and then Chair of the VanPS), I explored much of the lower faunal outcrops of northeastern British Columbia. It was my first time seeing many of British Columbia's Triassic outcrops. Years later, and fueled by seeing paper after paper correlating the faunal assemblages of BC to those of Nevada, I had the very great pleasure of walking through the Nevada strata with John Fam (VanPS, Vice-Chair), Dan Bowen (VIPS, Chair) and Betty Franklin (VIPS, Goddess of Everything and BCPA, Treasurer) — and witnessing first-hand the correlation between the Nevada fauna and those from the Triassic of British Columbia, Canada.

Triassic ammonoids, West Humboldt Mountains, Nevada, USA
The Nevada faunal assemblages are a lovely match. The quality of preservation at localities like Fossil Hill in the Humboldt Mountains of Nevada, perhaps the most famous and important locality for the Middle Triassic (Anisian/Ladinian) of North America, is truly outstanding.

Aside from sheer beauty and spectacular preservation, the ammonoids and belemnites were tucked in cozily with very well preserved ichthyosaur remains.

Tozer's interest in our marine invert friends was their distribution. How and when did certain species migrate, cluster, evolve — and for those that were prolific, how could their occurrence — and therefore significance — aide in an assessment of plate and terrane movements that would help us to determine paleolatitudinal significance. I share a similar interest but not exclusive to our cephalopod fauna. The faunal collection of all of the invertebrates holds appeal.

Middle Triassic (Anisian/Ladinian) Fauna
This broader group held an interest for J.P. Smith who published on the marine fauna in the early 1900s based on his collecting in scree and outcrops of the West Humboldt Mountains, Nevada. He published his first monograph on North American Middle Triassic marine invertebrate fauna in 1914.

N. J. Siberling from the US Geological Survey published on these same Nevada outcrops in 1962. His work included nearly a dozen successive ammonite faunas, many of which were variants on previously described species. Both their works would inform what would become a lifelong piecing together of the Triassic puzzle for Tozer.

If one looks at the fauna and the type of sediment, the paleogeography of the Triassic can be interpreted as follows: a tectonically calm west coast of the North American plate that bordered on an open sea; in the area far from the coast, a series of volcanic archipelagos delivered sediment to the adjacent basins. Some were lined or temporarily covered with coral wadding and carbonate banks. Deeper pools were in between. The islands were probably within 30 degrees of the triadic equator. They moved away from the coast up to about 5000 km from the forerunner of the East Pacific Ridge. The geographical situation west of the back was probably similar.

Jurassic and later generations of the crust from near the back have brought some of the islands to the North American plate; some likely to South America; others have drifted west, to Asia. There are indications that New Guinea, New Caledonia and New Zealand were at a northern latitude of 30 ° or more during the Triassic period.

The terranes that now form the western Cordillera were probably welded together and reached the North American plate before the end of the Jurassic period.

Marine Triassic occurs on the North American Plate over a latitudinal spread of 46 degrees, from California to Ellesmere Island. At some intervals of time faunas on the Plate permit the discrimination of two or three provinces with distinctively different coeval faunas. The faunal differences are evidently related to paleolatitude and the provinces are designated LPL, MPL, HPL (low, mid, high paleolatitude). Nevada provides the diagnostic characters of the LPL province; northeastern British Columbia the MPL; the Sverdrup Basin the HPL. In the Lower Triassic and early Middle Triassic (Anisian), the distinction between the MPL and HPL provinces cannot be made. All three provinces are recognized in the Ladinian, Carnian and Norian deposits.

Juvavites sp. Geological Survey of Canada. Photo: John Fam
In the western tracts of the Cordillera, the part formed of suspect terranes, apparently allochthonous with respect to the North American Plate, marine faunas are known all the way from southern Alaska and Yukon to Mexico.

Lower and Upper Triassic faunas from these terranes, including some which today are at 63 degrees north, have the characters of the LPL province.

Middle Triassic faunas from the terranes, as presently known, do not contribute significant data. In the terranes of the Western Cordillera, LPL faunas were now up to 3,000 km north of their counterparts on the American Plate. Through the fossil fauna assemblages, we can see this level of tectonic displacement.

Taking into account the faunas and the nature of the rocks, the Triassic paleogeography is interpreted as a tectonically quiet west shore for the North American Plate, bordered by an open sea or ocean; then, well off-shore, a series of volcanic archipelagos shedding sediment into adjacent basins. Some were fringed or intermittently covered by coralline shoals and carbonate banks. Deeper basins were in between. The islands probably were within 30 degrees of the Triassic equator and extended offshore for about 5000 km, to the spreading ridge directly ancestral to the East Pacific Rise. The geography west of the spreading ridge was probably comparable.

Jurassic and later generation of crust at the ridge had driven some of the islands into the North American Plate; some probably to South America; others have gone west to Asia. Evidence is given that northern New Guinea, New Caledonia and New Zealand may have been at a north latitude of 30 degrees or more in the Triassic. The terranes now forming the Western Cordillera had probably amalgamated, and reached the North American Plate, before the end of the Jurassic.

At the end of the Rhaetian (part of the Triassic period), most of the ammonites had died out. The Hettangian, a rather poorly understood 3 million year time interval followed the Triassic-Jurassic mass extinction event.

During the Hettangian, the new or  Neoammonites developed quite quickly. Within a million years, a fairly large, diverse selection of genera and species had risen to fill the void. The gap created by the Triassic-Jurassic extinction event was re-filled and our ability to "read the rocks' to understand their continued movement through tectonic plate shifting recommenced.

Alsatites proaries, Hettangian Ammonite
It is during the Hettangian that the smooth shelled ammonite genus Psiloceras first appears. They span the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago). For my European friends, the Hettangian is the time span in which the marine limestone, shales and clay Lias of western Europe were deposited.

This Hettangian ammonite, Alsatites proaries, is a lovely example of the cephalopods cruising our ancient oceans at that time. Alsatites is an extinct genus of cephalopod belonging to the Ammonite subclass. They lived during the Early Jurassic, Hettangian till the Sinemurian and are generally extremely evolute, many whorled with a broad keel. Or, as described by one of my very young friends, he looks like a coiled snake you make in pottery class.

The Hettangian is an interesting little period of our history. It spans the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago). For my European friends, the Hettangian is the time in which the marine limestone, shales and clay Lias of western Europe were deposited. In British Columbia, Canada, we see the most diverse middle and late Hettangian (Early Jurassic) ammonite assemblages in the Queen Charlotte Islands (Haida Gwaii), an archipelago about 50 km off British Columbia's northern Pacific coast. In total, 53 ammonite taxa are described of which Paradasyceras carteri, Franziceras kennecottense, Pleuroacanthites charlottensis, Ectocentrites pacificus and Curviceras haidae are new.

In general, North American Early Jurassic ammonites are of Tethyan affinity or endemic to the eastern Pacific. For this reason, a separate zonation for the Hettangian and Sinemurian of the Western Cordillera of North America was established. Taylor et al. (2001), wrote up and published on much of this early research though, at the time, very little Canadian information was included.

Longridge, L. M., et al. “Three New Species of the Hettangian (Early Jurassic) Ammonite Sunrisites from British Columbia, Canada.” Journal of Paleontology, vol. 82, no. 1, 2008, pp. 128–139. JSTOR, www.jstor.org/stable/20144175. Accessed 27 Jan. 2020.

Tozer, ET (Tim): Marine Triassic faunas of North America: Their significance for assessing plate and terrane movements. Geol Rundsch 71, 1077-1104 (1982). https://doi.org/10.1007/BF01821119

Danner, W. (Ted): Limestone resources of southwestern British Columbia. Montana Bur. Mines & Geol., Special publ. 74: 171-185, 1976.

Davis, G., Monger, JWH & Burchfiel, BC: Mesozoic construction of the Cordilleran “collage”, central British Columbia to central California. Pacific Coast Paleography symposium 2, Soc. Economic Paleontologists and Mineralogists, Los Angeles: 1-32, 1978.

Gibson, DW: Triassic rocks of the Rocky Mountain foothills and front ranges of northeastern British Columbia and west-central Alberta. Geol. Surv. Canada Bull. 247, 1975.

Photo of the large belemnite (Atractites sp?) and ammonites (Sunrisites & Badouxia) from the Lower Jurassic (Late Hettangian), Last Creek Formation (Castle Pass member), Taseko Lakes area, British Columbia, Canada in the collection of the deeply awesome John Fam.

Photo: A drawer of Juvavites sp. in the collections of the Geological Survey of Canada. These rarely seen Upper Triassic (Carnian to Norian) ammonoids were collected over many decades by geologists of the Geological Survey of Canada from Northeastern British Columbia. Photo care of the deeply awesome John Fam.

Photo: Grambergia sp. from the Early Anisian (Middle Triassic) ammonoid biostratigraphy of northeastern British Columbia, Canada. Collection of Fossil Huntress.

Photo: Alsatites proaries, Coll. Reiter, Neoammoniten, 30 July 2011, 19:26:10

Thursday, 30 January 2020

CEPHALOPODS OF HALLSTATT

This beautiful slab of well-preserved Triassic, Carnian, upper Tuvalian ammonoids hails limestone outcrops near the salt-mining town of Hallstatt, Salzburgerland, Austria.

This area of the world boasts one of the richest deposits of Triassic ammonite units — more than five hundred magnificent ammonite species are found here along with a diversified selection of cephalopod fauna  — orthoceratids, nautiloids, ammonoids — we also see gastropods, bivalves (esp. halobiids), brachiopods, crinoids and a few corals. For microfauna, we see conodonts, foraminifera, sponge spicules, radiolaria, floating crinoids and holothurian sclerites —  polyp-like, soft-bodied "wormy" invertebrate echinozoans. On the left, you can see two specimens of Jovites bosniensis MOJS. The ammonoid in the middle of the plate is Juvavites sp. The right side of the block shows two Hypocladiscites subtornatus MOJS.

The larger specimen (15cm) is a phragmocone. Within its badly crushed body chamber (removed during prep) there are two washed in specimens of Disotropites plinii (MOJS.) You can see them visible in the side view on the top right. The Disotropites plinii subzone is the lower ammonoid subzone of the Tuvalian III.

The second picture here shows Hypocladiscites subtornatus from when it was first described as Arcestes subtornatus, in Mojs, 1873.

In the North American literature (after Tim Tozer) the Tuvalian is split into three Zones; starting with the Dilleri Zone, then the Welleri Zone and finally the Macrolobatus Zone on the very top.

The Dilleri zone is characterized by the rise of the genus Tropites sp. together with later members of the genus Neoprotrachyceras sp.

In the Welleri zone, Neoprotrachyceras sp. disappears and Tropites becomes a very common faunal element. The Macrolobatus zone is named after Klamathites macrolobatus, an endemic ammonite of the North American strata. Other genera of this zone are comparable to the time frame of the latest Tuvalian and the earliest Norian of the Alps. In the Hallstatt (Tethys) realm the following Division is made:

Dilleri Zone= Tuvalian I (literature gives little evidence for this zone). Subbullatus Zone = Tuvalian II — corresponding in most parts to the North American Welleri Zone. These are followed by the Anatropites Zone or Tuvalian III — corresponding in part to the North American Macrolobatus Zone.

In the Alps, the strata are divided between Tuvalian II and Tuvalian III. It is up for debate if all three North American zones can be included in these two alpine zones. It has been postulated by Spatzenegger that there is little evidence for a time gap in the lower Tuvalian of the Alpine strata.

Discotropites sandlingense is in the North America zone — a clear Dilleri faunal element. In the Alps, it is ranged into Tuvalian II (Welleri Zone). The same is true for the genus Traskites sp. — corresponding to alpine Sandlingites sp. Some ammonites of the upper part of the Macrolobatus zone are also placed within the alpine Norian stage. The correlation between the North American and Alpine zones is problematic and matching up the Tuvalian fauna is a tricky business.

Sirenites sp., Upper Triassic, Lower Carnian Julian Zone
Tuvalian 1 is recognizable in the Alps by the composition of the faunal spectrum — the quantity of some special genera. We see more of some, less of others, and this gives us a general sense of time.

In some strata, Trachysagenites sp. Sagenites inermis, Sandlingites sp. occur frequently together, with scarce Tropites sp. and Sirenites sp. and (very rarely) Neoprotrachyceras cf. thyrae.

The transition from Tuvalian to the Norian is confirmed only in one location in the Hallstatt limestone. Clustered onto blocks, the ammonoids show us the faunal mix and allow us to place them in time. The bedded profile of Tuvalian fauna (which is overlain by a Norian fauna) hails from the Feuerkogel near Hallstatt. Here we also find the lower transition of Julian to Tuvalian. Not far from this site are limestone outcrops that show the transition between the Carnian and Norian. Here the latest Tuvalian and lowermost Norian are confirmed only by the microfossil fauna.

The Hallstatt Limestone is the world's richest Triassic ammonite unit, yielding specimens of more than 500 ammonite species. Along with diversified cephalopod fauna — orthoceratids, nautiloids, ammonoids — we also see gastropods, bivalves (esp. halobiids), brachiopods, crinoids and a few corals.

Along with an amazing assortment of macrofossils, we see microfauna that are incredibly helpful in teasing out the geologic history of the area. Fossil conodonts, foraminifera, sponge spicules, radiolaria, floating crinoids and the bizarre holothurian sclerites — polyp-like, soft-bodied invertebrate echinozoans often referred to as sea cucumbers because of their similarities in size, elongate shape, and tough skin over a soft interior — can be found here.

Eduard Suess, Gondwana / Tethys Sea
Franz Ritter von Hauer’s exhaustive 1846 tome describing Hallstatt ammonites inspired renowned Austrian geologist Eduard Suess’s detailed study of the area’s Mesozoic history.

That work was instrumental in Suess being the first person to recognize the supercontinent of Gondwana (proposed in 1861) and the existence of the Tethys Sea, which he named in 1893 after the sister of Oceanus, the Greek god of the ocean.

Suess Land in Greenland, as well as the lunar crater Suess and Suess crater on Mars, are named after him.

The Hallstatt-Meliata Ocean was one such back-arc basin. As it continued to expand and deepen during the Triassic, evaporation ceased and reefs flourished; thick limestone deposits accumulated atop the salt. When the Hallstatt-Meliata Ocean closed in the Late Jurassic, the compression squeezed the low-density salt into a diapir that rose buoyantly, injecting itself into the Triassic limestones above.

This area has a rich and interesting geological and human history. I'm sure more studies will be done on the fossil marine fauna to untangle and standardize the Carnian subdivisions. For now, we'll muddle along with regional stratigraphies employing a two-substage subdivision, the Julian and Tuvalian. Others will continue to employ a three-substage organization of the stage: Cordevolian, Julian and Tuvalian. As I've pieced together this interesting Tuvalian tale, I have to thank Andreas Spatzenegger from Salzburg, Austria for his insights, work and amazing photos of the area. Kudos to you, my friends. I'd be mesmerized but still well confused about the Carnian subdivisions if not for you!

The genus Hypocladiscites ranges from the base Carnian to the lower Norian stage of the Upper Triassic. Photos and collection of the deeply awesome Andreas Spatzenegger of Salzburg, Austria.

Superfamilia: Arcestaceae MOJSISOVICS, 1875; Familia: Cladiscitidae ZITTEL, 1884; Subfamilia: Cladiscites GAMSJÄGER, 1982; Genus: Hypocladiscites MOJSISOVICS, 1896

Photo: A spectacular example of Sirenites sp., Upper Triassic, Lower Carnian, Julian Zone of Trachyceras aonoides. From Hallstatt Limestone of Austria. This specimen is about 5cm. Photo and collection of the deeply awesome Andreas Spatzenegger.

Photo: Eduard Suess (1831–1914), lithograph by Josef Kriehuber (1800–1876) c. 1869 by Josef Kriehuber - File:Eduard Sueß.jpg (cropped), Public Domain https://commons.wikimedia.org/w/index.php?curid=31526345

Wednesday, 29 January 2020

HALLSTATT LIMESTONE AND SALT

Hallstatt Salt Mines, Austria / Permian Salt Diapir
The Hallstatt Limestone is the world's richest Triassic ammonite unit, yielding specimens of more than 500 ammonite species.

Along with diversified cephalopod fauna  — orthoceratids, nautiloids, ammonoids — we also see gastropods, bivalves, especially the late Triassic pteriid bivalve Halobia (the halobiids), brachiopods, crinoids and a few corals. For microfauna, we see conodonts, foraminifera, sponge spicules, radiolaria, floating crinoids and holothurian sclerites —  polyp-like, soft-bodied invertebrate echinozoans often referred to as sea cucumbers because of their similarities in size, elongate shape, and tough skin over a soft interior. Franz von Hauer’s exhaustive 1846 tome describing Hallstatt ammonites inspired renowned Austrian geologist Eduard Suess’s detailed study of the area’s Mesozoic history.

That work was instrumental in Suess being the first person to recognize the former existence of the Tethys Sea, which he named in 1893 after the sister of Oceanus, the Greek god of the ocean. As part of the Northern Limestone Alps, the Dachstein rock mass, or Hoher Dachstein, is one of the large karstic mountains of Austria and the second-highest mountain in the Northern Limestone Alps. It borders Upper Austria and Styria in central Austria and is the highest point in each of those states.

Parts of the massif also lie in the state of Salzburg, leading to the mountain being referred to as the Drei-Länder-Berg or three-state mountain. Seen from the north, the Dachstein massif is dominated by the glaciers with the rocky summits rising beyond them. By contrast, to the south, the mountain drops almost vertically to the valley floor. The karst limestones and dolomites were deposited in our Mesozoic seas. The geology of the Dachstein massif is dominated by the Dachstein-Kalk Formation ("Dachstein limestone"), which dates back to the Triassic.

Hallstatt and the Hallstatt Sea, Austria
There were several phases of mountain building in this part of the world pushing the limestone deposits 3,000 metres above current sea level. The rock strata were originally deposited horizontally, then shifted, broken up and reshaped by the erosive forces of ice ages and erosion.

The Hallstatt mine exploits a Permian salt diapir that constitutes some of this area’s oldest rock. The salt accumulated by evaporation in the newly opened, and hence shallow, Hallstatt-Meliata Ocean.

This was one of several small ocean basins that formed in what is now Europe during the late Paleozoic and early Mesozoic when the world’s landmasses were welded together to form the supercontinent Pangea. Pangea was shaped like a crescent moon that cradled the famous Tethys Sea. Subduction of Tethyian oceanic crust caused several slivers of continental crust to separate from Pangea, forming new “back-arc basins” (small oceans formed by rifting that is associated with nearby subduction) between the supercontinent and the newly rifted ribbon continents.

The Hallstatt-Meliata Ocean was one such back-arc basin. As it continued to expand and deepen during the Triassic, evaporation ceased and reefs flourished; thick limestone deposits accumulated atop the salt. When the Hallstatt-Meliata Ocean closed in the Late Jurassic, the compression squeezed the low-density salt into a diapir that rose buoyantly, injecting itself into the Triassic limestones above.

The Hallstatt salt diapir and its overlying limestone cap came to rest in their present position in the northern Austrian Alps when they were shoved northward as nappes (thrust sheets) during two separate collision events, one in the Cretaceous and one in the Eocene, that created the modern Alps. It is from the Hallstatt salt diapir that Hallstatt, like so many cities and towns, gets its name.

Deposits of rock salt or halite, the mineral name of sodium chloride with the chemical formula of NaCl, are found and mined around the globe. These deposits mark the dried remains of ancient oceans and seas. Names of rivers, towns and cities in Europe — Salzburg, Halle, Hallstatt, Hallein, La Salle, Moselle — all pay homage to their connection to halite and salt production. The Greek word for salt is hals and the Latin is sal. The Turkish name for salt is Tuz, which we see in the naming of Tuzla, a salt-producing region of northeastern Bosnia-Herzegovina and in the names of towns that dot the coast of Turkey where it meets the Black Sea. Hallstatt with its salt diapir is no exception.

The salt-named town of Hallstatt sits on the shores of the idyllic Hallstätter Sea at the base of the Dachstein massif. Visiting it today, you'd experience a quaint traditional fishing village built in the typical style of upper Austria. Tourism drives the economy as much as salt.

Space is at a minimum in the town. For centuries, every ten years the local cemetery exhumes the bones of those buried there and moves them to an ossuary to make room for new burials. The Hallstatt Ossuary is called Karner, Charnel House, or simply Beinhaus (Bone House). Karners are places of secondary burials. They were once common in the Eastern Alps, but that custom has largely disappeared.

Hallstatt Beinhaus Ossuary, Hallstatt, Austria
A collection of over 700 elaborately decorated skulls rest inside the ossuary. They are lined up on rows of wooden shelves that grace the walls of the chapel. Another 500 undecorated skulls, bare and without any kind of adornment, are stacked in the corners.

Each is inscribed and attached to a record with the deceased's name, profession and date of death. The Bone House is located in a chapel in the basement of the Church of Saint Michael. The church dates from the 12th century CE. Decorating the skulls was traditionally the job of the local gravedigger. At the family's request, garlands of flowers were painted on the skulls of deceased as decorative crowns if they were female. The skulls of men and boys were painted wreaths of oak or ivy.

Every building in Hallstatt looks out over the Hallstätter Sea. This beautiful mountain lake considered one of the finest of Austria's Salzkammergut region. It lies at the northern foot of the Dachstein mountain range, sitting eight-and-a-half kilometres long and two kilometres wide. The shoreline is dotted by the villages of  Obertraun, Steeg, and Hallstatt.

The region is habitat to a variety of diverse flora and fauna, including many rare species such as native orchids, in the wetlands and moors in the south and north.

Linked by road to the cities of Salzburg and Graz, Hallstatt and its lake were declared one of the World Heritage sites in Austria in 1997 and included in the Hallstatt-Dachstein Salzkammergut Alpine UNESCO World Heritage Site. The little market village of Hallstatt takes its name from the local salt mine.

Hallstatt, Salzkammergut region, Austria
The town is a popular tourist destination with its quaint shops and terraced cafes. In the center of town, the 19th-century Evangelical Church of Hallstatt with its tall, slender spire is a lakeside landmark. You can see it here in the photo on the left.

Above the town are the Hallstatt Salt mines located within the 1,030-meter-tall Salzburg Salt Mountain. They are accessible by cable car or a three-minute journey aboard the funicular railway. There is also a wonderful Subterranean Salt Lake.

In 1734, there was a corpse found here preserved in salt. The fellow became known as the Man in Salt. Though no archaeological analysis was performed at the time — the mummy was respectfully reburied in the Hallstatt cemetery — based on descriptions in the mine records, archaeologists suspect the miner lived during the Iron Age. This Old Father, Senos ph₂tḗr, 'ɸatīr 'father' may have been a local farmer, metal-worker, or both and chatted with his friends and family in Celtic or Proto-Celtic.

Salt mining in the area dates back to the Neolithic period, from the 8th to 5th Centuries BC. This is around the time that Roman legions were withdrawing from Britain and the Goths sacked Rome. In Austria, agricultural settlements were dotting the landscape and the alpine regions were being explored and settled for their easy access to valuable salt, chert and other raw materials.

The salt-rich mountains of Salzkammergut and the upland valley above Hallstatt were attractive for this reason. The area was once home to the Hallstatt culture, an archaeological group linked to Proto-Celtic and early Celtic people of the Early Iron Age in Europe, c.800–450 BC.
Bronze Age vessel with cow and calf

In the 19th century, a burial site was discovered with 2,000 individuals, many of them buried with Bronze Age artifacts of amber and ivory.

It was this find that helped lend the name Hallstatt to this epoch of human history. The Late Iron Age, between around 800 and 400 BC, became known as the Hallstatt Period.

For its rich history, natural beauty and breathtaking mountainous geology, Hallstatt is a truly irresistible corner of the world.

Salzbergstraße 1, 4830 Hallstatt.  https://www.salzwelten.at/en/home/

Photo: Bronze vessel with cow and calf, Hallstatt by Alice Schumacher - Naturhistorisches Museum Wien - A. Kern – K. Kowarik – A. W. Rausch – H. Reschreiter, Salz-Reich. 7000 Jahre Hallstatt, VPA 2 (Wien, 2008) Seite 133 Abbildung 6. Hallstatt Village & Ossuary Photos: P. McClure Photography ca. 2015.

Bernoulli D, Jenkyns HC (1974) Alpine, Mediterranean, and Central Atlantic Mesozoic facies in relation to the early evolution of the Tethys. Soc Econ Paleont Mineral Spec Publ 19:129–160

Bernoulli D, Jenkyns H (2009) Ancient oceans and continental margins of the Alpine-Mediterranean Tethys: deciphering clues from Mesozoic pelagic sediments and ophiolites. Sedimentology 56:149–190

Tuesday, 28 January 2020

GRAPTOLITES: DARLINGS OF THE DARRIWILIAN

Back in 2009, Jörg Maletz from St. Francis Xavier University, Antigonish, Nova Scotia, did a paper looking at the Les Méchins region in Quebec to compare the Darriwilian graptolite succession found there against other outcrops of eastern North America.

The graptolite faunas of the upper member of the Anse au Crapaud Formation include the Arienigraptus gracilis, Oncograptus upsilon, Undulograptus austrodentatus, and Holmograptus spinosus biozone faunas and, thus, complement the well known Darriwilian faunas of the Cow Head, Table Head, and Goose Tickle groups of western Newfoundland. In particular, the Holmograptus spinosus Biozone interval of calcarenitic limestones bears a rare combination of benthic (shelly) and planktic (graptolitic) faunas with conodonts, brachiopods, ostracods, sponge spicules, and algal remains associated with common graptolites that allow an inter-continental correlation.

The Holmograptus spinosus Biozone is introduced for the interval based on a diverse and characteristic graptolite fauna. The fauna includes among others, Atopograptus woodwardi, recognized for the first time in North America. The Holmograptus spinosus Biozone fauna can be found worldwide and is easily correlated into the conodont biofacies using species of the genus Histiodella. He looked at ties between graptolite and conodont biozonations for the Darriwilian. Some lovely silicified ostracods were illustrated for the first time from the interval and a new species, Hustedograptus quebecensis, was introduced.

The Darriwilian or late Middle Ordovician time interval shows a dramatic re-organization of graptolite faunas, both in their taxonomic composition and in their rhabdosome developmental style.

The Early Ordovician graptolite faunas, composed of multiramous to pauciramous “Dichograptaceans” (Bulman 1970), are slowly replaced by dipleural biserial graptolites of the “Diplograptaceans” (Mitchell et al. 1995, 2007) or Axonophorans (Maletz et al. 2009).

This shift started with the introduction of the reclined isograptids and glossograptids in the Dapingian and culminated with the extinction of multiramous sinograptids and stem reclinatids in the Darriwilian (Da 2 – Da 3), leaving but few survivors to reach the Late Ordovician. The monopleural glossograptids, as a second clade of the Bireclinata, enjoyed moderate success in the mid and Late Ordovician, but never attained the high diversity of the Axonophorans.

The Darling Darriwilian


The Darriwilian is a significant stage in the Middle Ordovician. It is here we see the first land plants and the introduction of the Undulograptus austrodentatus graptolite zone. These graptolite outcrops from around the world help us establish the base of the Darriwilian as an easily correlatable marker in time. Yet, for so many reasons, the charming Darriwilian has not received the attention in graptolite studies it deserves and little is known about many of the graptolites from the interval.

The biostratigraphy within this time interval remains only partially explored due to a scarcity of uninterrupted successions. The Darriwilian in Victoria, Australia (Vandenberg and Cooper 1992) is based on numerous spot collections, but successions spanning more than a single graptolite zone are not available. The base of the Darriwilian is now defined at the first appearance datum (FAD) of Undulograptus austrodentatus in the Huangnitang section (Zhejiang, China), but the graptolitic succession is less detailed and complete in the higher part of the interval (see Chen et al. 2006).

The northern Appalachian successions in Quebec and western Newfoundland provide numerous successions from which detailed biostratigraphical data are available, but most sections are poorly studied. Recent advances show the presence of good Darriwilian graptolite faunas in the Cow Head, Table Head, and Goose Tickle groups of western Newfoundland (Williams and Stevens 1988; Maletz 1992c; Taylor 1997) and China (Chen et al. 2006) that provide a better insight into the biostratigraphy and evolutionary history of graptolites in this interval.

Lithostratigraphic Succession at Les Méchins


The southern shore of the St. Lawrence River along the coast of the Gaspé Peninsula of Quebec exposes Cambrian to Ordovician continental slope sequences, representing the allochthonous thrust slices of the Humber tectonostratigraphic zone of Williams (1979). The successions were thrust westwards across the eastern rim of Laurentia during the Taconic Orogeny in the Middle Ordovician. Because of the complexity of the successions, the stratigraphy is only well defined in part and detailed biostratigraphic work is lacking for most regions.

Bernstein et al. (1992) described the lithostratigraphic succession at Les Méchins and provided detailed information on the location of the sections along the northern side of route 132, directly west of the entrance to Les Méchins.

As graptolites are the most important biostratigraphic indicators, their record can shed light on the structural complexity of the successions and help us to understand the geological evolution of this region. Newly discovered faunal successions at Les Méchins, Quebec have provided important biostratigraphical and biogeographical data and yielded taxa not previously found in North America.

Maletz, Jörg. Holmograptus spinosus and the Middle Ordovician (Darriwilian) graptolite biostratigraphy at Les Méchins (Quebec, Canada) Canadian Journal of Earth Sciences, 2009, 46:739-755, https://doi.org/10.1139/E09-048.

Albanesi, G., Hünicken, M.A., and Barnes, C.R. 1998. Bioestratigrafia de conodontes de las secuencias ordovicicas del Cerro Potrerillo, Precordillera central de San Juan, R. Argentina. Actas XII Academia Nacional de Ciencias., Córdoba, 12, pp. 7–72.

Bulman, O.M.B. 1970. Graptolithina with sections on Enteropneusta and Pterobranchia. In Treatise on invertebrate paleontology, Part V. 2nd ed. Edited by K. Teichert and R.C. Moore. Geological Society of America and University of Kansas Press, Boulder, Colo. and Lawrence, Kans., pp. 1–163.

Chen X, Zhang YD, Bergström SM, Xu H-G. 2006. Darriwilian graptolite and conodont zonation in the global stratotype section of the Darriwilian stage (Ordovician) at Huangnitang, Changshan, Zhejiang, China. Palaeoworld 15(2): 150-170.

Monday, 27 January 2020

ARIENIGRAPTUS OF BOLIVIA

Graptolites (Graptolita) are a group of colonial animals known primarily from Ordovician deposits. The biological affinities of the graptolites have always been debatable.

Originally regarded as being related to the hydrozoans, graptolites are now considered to be related to the pterobranchs, a rare group of modern marine animals.

The graptolites are classed as hemichordates (phylum Hemichordata), a phylum of marine deuterostome animals and come in a variety of weird and wonderful designs. They were a major component of the zooplankton in our early Paleozoic ecosystems, most likely living as suspension feeders, drifting freely on the surface of ancient seas or attached to floating seaweed by means of a slender thread. Some forms of graptolite lived attached to the sea-floor by a root-like base. The deceased planktonic graptolites would sink down to and settle on the seafloor, eventually becoming entombed in the sediment and are thus well-preserved.

Graptolite fossils are often found in shales and slates and can be mistaken for scratches on the rock. The name graptolite comes from the Greek graptos meaning "written", and lithos meaning "rock." It is a very suitable name as many graptolites look very much like hieroglyphs written on rock and not the impressions of animals.

Graptolites are common fossils and have a worldwide distribution. The preservation, quantity and gradual change over a geologic time scale of graptolites allow the fossils to be used to date strata of rocks throughout the world. They are important index fossils for dating Palaeozoic rocks as they evolved rapidly with time and formed many different species.

We find graptolite fossils flattened along the bedding planes of the rocks in which they occur. My first graptolite finds were from roadcuts up near Cranbrook, British Columbia, Canada. I was on a fossil field trip looking for Cambrian trilobites. It was a thrilling experience and completely unexpected when the first graptolite met my eyes.

They vary in shape, but are most commonly dendritic or branching (such as Dictoyonema), saw-blade like, or "tuning fork" shaped, such as Didymograptus murchisoni. The lovely specimen of Arienigraptus sp. you see here is from the Lower Darriwilian of Bolivia and in the collections of the deeply awesome Gilberto Juárez Huarachi‎. The second photo is from the Encyclopaedia Brittanica - From the Encyclopaedia Brittanica, Public Domain, https://commons.wikimedia.org/w/index.php?curid=6886878

Sunday, 26 January 2020

PERSISTISTROMBUS LATUS

A beautiful example of two water-worn specimens of the gastropod Persististrombus latus (Gmelin, 1791) captured after a storm captured by the deeply awesome José Juárez Ruiz from Palma De Mallorca, Spain.

In his original description of Strombus latus, Gmelin describes this new species in his paper from 1791, page 3520: "latus. 35. Str. testae labro prominulo inferne bis emarginato, spirae anfractu primo medio laevi utrinque transversim striato, reliquis nodis obtusis coronatis."

Persististrombus latus is the most iconic representative of the Senegalese fauna, a fossil assemblage of tropical water organisms thought to have colonized the Mediterranean Sea during the last interglacial period.

Persististrombus latus has become an important stratigraphic marker of Marine Isotope Stage (MIS) 5.5, which allows for the correlation of raised coastal deposits, useful in studying sea-level variations and tectonic uplift.

Persististrombus latus is found in shallow marine sediments of Tyrrhenian age (∼124 ka) in several localities of the Italian peninsula. Gmelin's early work on the species is from upper Pleistocene deposits of the marine terraces of the Crotone peninsula of southern Italy. If you fancy a visit to this locality, head to: N38°45'00" - N39°04'60", E17°04'60" - E17°19'60".

Commonly known as the Bubonian Conch, this species of sea snail is a marine gastropod mollusk in the family Strombidae, the true conchs. These fellows are herbivorous, dining on wee bits of algae, seagrass and other detritus found along the seafloor. They grow to around 2.76" - 6.5" (7cm - 16.5cm). We find them in the fossil record and also as modern shells in the Atlantic Ocean along West Africa, Senegal, Gabon, Cape Verde, Ascension Island and Angola. They like it warm, preferring seas of 57.2 °F - 68 °F (14°C - 20°C).

Ronald Nalin, Valentina Alice Bracchi, Daniela Basso, Francesco Massari; Persististrombus latus (Gmelin) in the upper Pleistocene deposits of the marine terraces of the Crotone peninsula (southern Italy). Italian Journal of Geosciences ; 131 (1): 95–101. doi: https://doi.org/10.3301/IJG.2011.25

Gmelin J.F. (1791). Vermes. In: Gmelin J.F. (Ed.) Caroli a Linnaei Systema Naturae per Regna Tria Naturae, Ed. 13. Tome 1(6). G.E. Beer, Lipsiae [Leipzig]. pp. 3021-3910.

Saturday, 25 January 2020

LATE JURASSIC PHYLLOCERAS

Phylloceras consanguineum (Gemmellaro 1876) a fast-moving carnivorous ammonite from Late Jurassic (Middle Oxfordian) deposits near Sokoja, Madagascar, off the southeast coast of Africa.

This classical Tethyan Mediterranean specimen is very well preserved, showing much of his delicate suturing in intricate detail. Phylloceras were primitive ammonites with involute, laterally flattened shells.

They were smooth, with very little ornamentation, which led researchers to think of them resembling plant leaves and gave rise to their name, which means leaf-horn. They can be found in three regions that I know of.  In the Jurassic of Italy near western Sicily's Rosso Ammonitico Formation, Lower Kimmeridgian fossiliferous beds of Monte Inici East and Castello Inici (38.0° N, 12.9° E: 26.7° N, 15.4° E) and in the Arimine area, southeastern Toyama Prefecture, northern central Japan, roughly, 36.5° N, 137.5° E: 43.6° N, 140.6° E. And in Madagascar, in the example seen here found near Sokoja, Madagascar, off the southeast coast of Africa at 22.8° S, 44.4° E: 28.5° S, 18.2° E.

Friday, 24 January 2020

EOCENE CRYPTODIRAN TURTLE

An Eocene Cryptodiran Fossil Turtle, Baena arenosa, from fine-grained lime mud outcrops in the Green River Formation, Wyoming, USA.

This fellow, with the extra-long tail, marks the last of his lineage. The now extinct family Baenidae appeared first in the Jurassic and died out at the end of the Eocene. We've found specimens of Baena, along with 14 other species of turtles in seven genera and five families in the Lower Eocene San Jose Formation, San Juan Basin of New Mexico.

This specimen is from the Green River Formation of Wyoming which was once the bottom of one of an extensive series of Eocene lakes. The Green River Formation is particularly abundant in beautifully preserved fossil fish, eleven species of reptiles including a 13.5ft crocodile, an armadillo-like mammal, Brachianodon westorum, bats, birds and other fresh-water aquatic goodies.

This specimen of a beautiful Baena was found and prepped by the Green River Stone Company. They purchased their private 12-acre quarry about 20 years ago. It's at the Eocene lake's centre, shared with Fossil Butte National Monument about 24 kilometres (15 miles) west of Kemmerer, Lincoln County, Wyoming.

Thursday, 23 January 2020

BAETIC CORDILLERA

This beautiful ammonite is Neocomites (Teschenites) flucticulus (Thieuloy, 1977) sharing a large boulder with a delicate, straight-shelled, heteromorph ammonite Bochianites. These beauties were found on a fossil field trip to Hauterivian, Early Cretaceous deposits in the Baetic Cordillera in the Spring of 2019. The Baetic Cordillera is one of the main systems of mountain ranges in Spain along the southern and eastern Iberian Peninsula. There are several productive outcrops here that yield lovely Cretaceous ammonites and other marine species.

Neocomites are known from about a dozen offshore marine deep subtidal Cretaceous deposits in France, Hungary, Italy, Romania, Slovakia and Ukraine. We also find Neocomites in the Cretaceous of British Columbia, Canada.

This lovely specimen is the first Neocomites I've seen come out of fossil deposits in Spain. It was found and prepped by the talented Manuel Peña Nieto of Córdoba, Spain.

Wednesday, 22 January 2020

RHACOLEPSIS AND CARDIAC OUTFLOW

This concretion contains a partially exposed Rhacolepis Buccalis, an extinct genus of ray-finned fossil fish in carbonate concretion from the Lower Cretaceous, Santana Formation, Brazil.

These ancient fish swam our Cretaceous seas 122-109 million years ago. Interestingly, we've been able to recover complete fossilized hearts from this species using X-ray synchrotron microtomography.

Lara Maldanis and her team published a paper on this back in 2016. They were looking at the evolution of cardiac outflow tracts in vertebrates and had a breakthrough moment when an x-ray revealed enough detail to show that Rhacolepis hearts contain a conus arteriosus containing at least five-valve rows making them a transitional morphology between the primitive, multivalve, conal condition and the derived, monovalvar, bulbar state of the outflow tract in modern actinopterygians.

Le premier et unique géoparc mondial UNESCO est situé dans le Cariri du Ceará (géoparc Araripe), dans l'intérieur semi-aride de la région Nordeste, Brésil. Reference: Maldanis et al. (2016) Heart fossilization is possible and informs the evolution of cardiac outflow tract in vertebrates.

Tuesday, 21 January 2020

SONGS OF THE CETACEAN

A mother humpback and her young charge. Mothers show a tremendous amount of affection and love to their young, often swimming so close together they touch noses.

The calves nurse for almost a year, growing slowly. Once nursed, they keep growing for another 8-10 years before reaching their full adult length. They grow up to 19 metres long and can weigh up to 40 tons (36 metric tons). Male humpbacks are known for their singing. They produce some of the most complex “songs” in the animal kingdom. We've recorded them making high-pitched squeals, whistles and low, rumbling gurgles. Perhaps the males believe that those with the best vocal abilities attract the best mates. They certainly increase the connectedness of those living in their pod.

Monday, 20 January 2020

CETACEANS OF WASHINGTON STATE

Fossil Whale Bone
Oligocene Fossil Whale vertebrae from Majestic Beach, Olympic Peninsula, Washington State, USA.

These lovely water-worn specimens are difficult to ID to species with certainty but they likely hail from an early baleen whale. Found amongst the beach pebbles on the Olympic Peninsula, they are definitely cetacean and very likely baleen as this area is home to some of the earliest baleen whales in the Pacific Northwest.

In 1993, a twenty-seven million-year-old specimen was discovered in deposits nearby that represents a new species of early baleen whale. It is especially interesting as it is from a stage in the group’s evolutionary history when baleen whales transitioned from having teeth to filtering food with baleen bristles. Visiting researcher Carlos Mauricio Peredo studied the fossil whale remains, publishing his research to solidify Sitsqwayk cornishorum (pronounced sits-quake) in the annals of history.

Baby Gray Whale Eschrichtius robustus showing his baleen
The earliest baleen whales clearly had teeth, and clearly still used them. Modern baleen whales have no teeth and have instead evolved baleen plates for filter feeding. I've included a rather good close-up of a baby Gray Whale here that shows the baleen to good effect.

The baleen is the comb-like strainer that sits on the upper jaw of baleen whales and is used to filter food.

We have to ponder when this evolutionary change —moving from teeth to baleen — occurred and what factors might have caused it. Traditionally, we have sought answers about the evolution of baleen whales by turning to two extinct groups: the aetiocetids and the eomysticetids.

The aetiocetids are small baleen whales that still have teeth, but they are very small, and it remains uncertain whether or not they used their teeth. In contrast, the eomysticetids are about the size of an adult Minke Whale and seem to have been much more akin to modern baleen whales; though it’s not certain if they had baleen. Baleen typically does not preserve in the fossil record being soft tissue; generally, only hard tissue, bones & teeth, are fossilized.

Sunday, 19 January 2020

UNLIKELY RHINOCEROS

The Miocene pillow basalts from the Lake Roosevelt National Recreation Area of central Washington hold an unlikely fossil mould of a small rhinoceros, preserved by sheer chance as it's bloated carcass sunk to the bottom of a shallow lake just prior to a volcanic explosion.

We've known about this gem for a long while now. The fossil was discovered by hikers back in 1935 and later cast by the University of California paleontologists in 1948. These were the Dirty Thirties and those living in Washington state were experiencing the Great Depression along with the rest of the country and the world. Franklin D. Roosevelt was President of the United States, navigating the States away from laissez-faire economics. Charmingly, Roosevelt would have his good name honoured by this same park in April of 1946, a few years before researchers at Berkeley would rekindle interest in the site.

Both hiking and fossil collecting was a fine answer to these hard economic times and came with all the delights of discovery with no cost for natural entertainment. And so it was that two fossil enthusiast couples were out looking for petrified wood just south of Dry Falls on Blue Lake in Washington State. While searching the pillow basalt, the Frieles and Peabodys came across a large hole high up in a cave that had the distinctive shape of an upside-down rhinoceros.

This fossil is interesting in all sorts of ways. First, we so rarely see fossils in igneous rocks. As you might suspect, both magma and lava are very hot. Magma, or molten rock, glows a bright red/orange as it simmers at a toasty 700 °C to 1300 °C (or 1300 °F to 2400 °F) in hot chambers beneath the Earth's surface.

During the late Miocene and early Pliocene, repeated basaltic lava floods engulfed about 63,000 square miles of the Pacific Northwest over a period of ten to fifteen million years. After these repeated bathings the residual lava accumulated to more than 6,000 feet.

As the magma pushes up to the surface becoming lava, it cools to a nice deep black. In the case of our rhino friend, this is how this unlikely fellow became a fossil. Instead of vaporizing his remains, the lava cooled relatively quickly preserving his outline as a trace fossil and remarkably, a few of his teeth, jaw and bones. The lava was eventually buried then waters from the Spokane Floods eroded enough of the overburden to reveal the remains once more.

Diceratherium tridactylum (Marsh, 1875)
Diceratherium (Marsh, 1875) is known from over a hundred paleontological occurrences from eighty-seven collections.

While there are likely many more, we've found fossil remains of Diceratherium, an extinct genus of rhinoceros, in the Miocene of Canada in Saskatchewan, China, France, Portugal, Switzerland, and multiple sites in the United States.

He's also been found in the Oligocene of Canada in Saskatchewan, and twenty-five localities in the US, specifically in Arizona, Colorado, Florida, Nebraska, North Dakota, Oregon,  South Dakota, Washington and Wyoming. We know a bit about him. He roamed a much warmer, wetter Washington state some 15 million years ago. By then, the Cascades had arrived and we'd yet to see the volcanic eruptions that would entomb whole forests up near Vantage in the Takama Canyon of Washington state. Diceratherium was a scansorial insectivore with two horns and a fair bit of girth. He was a chunky fellow, weighing in at about one tonne (or 2,200 lbs).

You are welcome to go see his final resting site beside the lake but it is difficult to reach and comes with its own risks. Head to the north end of Blue Lake in Washington. Take a boat and search for openings in the cliff face. You'll know you're in the right place if you see a white "R" a couple hundred feed up inside the cliff. Inside the cave, look for a cache left by those who've explored here before you. Once you find the cache, look straight up. That hole above you is the outline of the rhino.

If you don't relish the thought of basalt caving, you can visit a cast of the rhino at the Burke Museum in Seattle, Washington. They have a great museum and are pretty sporting as they've built the cast hardy enough to let folk climb inside. The Burke Museum recently underwent a rather massive facelift and has re-opened its doors to the public. You can now explore their collections in the New Burke, a 113,000 sq.ft. building at 4300 15th Ave NE, Seattle, WA 98105, United States. Or visit them virtually, at https://www.burkemuseum.org/

Photo: Robert Bruce Horsfall - https://archive.org/details/ahistorylandmam00scotgoog, Public Domain, https://commons.wikimedia.org/w/index.php?curid=12805514

Reference: Prothero, Donald R. (2005). The Evolution of North American Rhinoceroses. Cambridge University Press. p. 228. ISBN 9780521832403.

Reference: O. C. Marsh. 1875. Notice of new Tertiary mammals, IV. American Journal of Science 9(51):239-250

Saturday, 18 January 2020

FOSSIL FAUNAS OF THE PACIFIC NORTHWEST

Some water-worn samples of the fossil bivalve Vertipecten fucanus from Lower Miocene deposits in the Clallam Formation.

These were collected on the foreshore near Clallam Bay, Olympic Peninsula, northwestern Washington. Range zones of pectinid bivalves provide a principal means of age determination and correlation of shallow-water, inshore facies for Washington state. Until Addicott's study from 1976, the area was considered middle Miocene. The new Lower Miocene designation can be credited in large part to the restricted stratigraphic range of Vertipecten fucanus (Dall) and the restricted and overlapping ranges of several other fossil mollusks collected from Alaska to California.

Neogene marine sediments of the West Coast of North America were deposited in a series of widely spaced basins that extended geographically from the western and northern Gulf of Alaska (60°N) to southern California (33°N). Rich molluscan faunas occur extensively throughout these deposits and form the basis for biostratigraphic schemes that are useful for correlating within and between individual basins.

Early biostratigraphic work was concerned with faunas from particular horizons and with the stratigraphic range of diverse taxa, such as Pecten and Turritella, without reference to other fossil groups. Succeeding work increasingly dealt with the relationships of molluscan zones to benthic and, later, planktonic foraminiferal stages. In recent years the age limits of Neogene molluscan stages have become better documented by reference to planktonic microfossils from dated DSDP cores and onshore faunas.

Neogene molluscan faunas from California, the Pacific Northwest states (Oregon and Washington), and southern Alaska have been treated separately due to differences in faunal composition and geographic isolation. As a result, a different biostratigraphic sequence has been described for each region.

Pacific Northwest stages have been formally named and defined, and their names are also used informally for Alaskan faunas. California Neogene stages were proposed early in this century, are in need of redescription, and their usage is informal. Precise correlations between the three regional sequences have not yet been achieved, due to the low number of co-occurring species and the general lack of planktonic microfossils in these largely shallow-water faunas. The objectives of ongoing research include the documentation of the faunas of California and Pacific Northwest stages; formal description of California stages; an improved correlation between regional stage sequences; refinement of age estimates for stage boundaries; and, the establishment of Neogene stages for Alaskan faunas.

Friday, 17 January 2020

PANOPEA ABRUPTA OF CLALLAM

This lovely large fossil bivalve is Panopea abrupta (Conrad) an extinct species of marine mollusc in the family Hiatellidae, subclass Heterodonta.

This specimen was collected from lower Miocene deposits in the Clallam Formation on the foreshore bordering the Strait of Juan de Fuca near Clallam Bay, Olympic Peninsula, northwestern Washington.

Clallam Bay is a sleepy little town on the northwestern edge of the Olympic Peninsula. It was founded back in the 1880s as a steamboat stop and later served as a Mill town. If you are planning to visit the fossil exposures, head to the edge of town where it meets the sea.

Once at the water's edge, head east along the shore until you can go no further. You'll find marine fossils in the sandstone on the shore and cliffs. Mind the tide as access to the fossil site is only possible at low or mid-tide. You'll have to swim for it if you time it poorly. Clallam Bay: 48°15′17″N 124°15′30″W. Near this site, there are many additional fossil localities to explore. In Sequim Bay, you can find Pleistocene vertebrates as well as Miocene cetacean bones near Slip Point. Near the Twin Post Office, you can find Oligocene nautiloids and bivalves (2.5km west in the bluff); You can find crabs including, Branchioplax in the Eocene limestone concretions from Neah Bay.

References: Addicott, Warren. Molluscan paleontology of the lower Miocene Clallam Formation, northwestern Washington, Geological Survey Paper 976.

Thursday, 16 January 2020

EXPLORING THE OLYMPIC PENINSULA

One of the most beautiful in the Pacific Northwest is the Olympic Peninsula from Port Angeles to Neah Bay.

This stretch of coastline is home to the Clallam Formation, a thick, mainly marine sequence of sandstones and siltstones that line the northwestern margin of western Washington. These beachfront exposures offer plentiful fossils for those keen to make the trek.

The beautifully preserved clams, scallops and gastropods found here are mostly shallow-water marine from the late Eocene to Miocene. Time, tide and weather permitting, a site well worth visiting is the south flank of a syncline at Slip Point, near Clallam Bay. Head to the most Northwestern tip of the lower 48, visiting Cape Flattery on the Makah Reservation located 75 miles NW of PA on Hwy 112. Cape Flattery is located approx 7 miles from Neah Bay. The newly constructed wooden walkway takes you to some of the most gorgeous, rugged and wild scenery on the Pacific Coast.

Be sure to take time to explore the internationally known Makah Museum. The museum is open every day during the summer months and closed Mondays and Tuesdays from Sept. 16 through May 31. The hours are 10AM-5PM. The Makah Museum is the nation's sole repository for archaeological discoveries at the Makah Coastal village of Ozette. The centuries-old village was located 15 miles south of present-day Neah Bay. Ozette served the Makah people as a year-around home well into the 20th century.

In 1970, tidal erosion exposed a group of 500-year-old Ozette homes that have been perfectly preserved in an ancient mudslide. The thousands of artifacts subsequently discovered have helped recreate Makahs' rich and exciting history as whalers, fishermen, hunters, gatherers, craftspeople, basket weavers, and warriors. Lake Ozette is located off of Hwy 112 on the Hoko-Ozette Road and follows the road 21 miles to the Ozette Ranger Station.

Three miles of planked trail leads you to Sand Point, one of the most beautiful and primitive beaches on the coast. Continuing north along the beach you will find dozens of Indian petroglyphs at Wedding Rocks, ask for the interpretive handout at the ranger station. The northern point of this 9-mile triangular trail is Cape Alava, with a rocky shore and reefs to explore at low tide. Cape Alava is also the site of an ancient Makah village. The site is now closed and marked with a small sign. Be sure to check a tide table and carry the 10 essentials - and lots of film as seals, deer, eagles and perhaps osprey, otters and whales may be there, rain or shine! Hike north to Cape Alava along the beach to keep the ocean breeze at your back, and avoid Vibram-soled shoes as the cedar plank walkway can be slick!

Salt Creek County Park located on the Strait of Juan de Fuca west of Port Angeles offers fascinating tidal pools, (ask your hosts regarding tide tables). The Dungeness Spit and Wildlife Refuge offers great beach hiking and wildlife. The Olympic Game Farm in Sequim is great for children of all ages. Ediz Hook in Port Angeles provides great views of the Olympic and Cascade mountains. Ediz Hook is part of the 5.5 miles of Waterfront Trail; perfect for jogging, walking, biking, or rollerblading.
The Elwha Valley west of Port Angeles is a beautiful drive along the rushing Elwha River. Madison Falls is an easy hike. Further up the valley beyond Lake Mills is the trailhead to the Olympic Hot Springs.

Port Townsend, known as "Washington's Victorian Seaport" is less than an hour east of Sequim. Victorian homes and commercial buildings erected during the late 1800s are still the city's trademark, along with Fort Worden State Park.

Park fee: A pass is required to enter the Olympic National Park. The fee is $10.00 per carload and is good for 7 days. It can be attained at any of the Park entrances. No pass is required during the winter months for the Elwha Valley or the Sol Duc Valley. Phone # for Olympic National Park Visitors Center in Port Angeles is 360-452-2713.

Getting here…

Directions: From Vancouver, it is a 5-6 hour drive to the Olympic Peninsula. Head South on Oak or Knight to connect up with Hwy 99 to the US border and continue South on Hwy 5, past Bellingham, take Hwy 20 to Anacortes.Head South on Hwy 20 until you get to the Keystone Jetty. Take the ferry from Keystone to Port Townsend. From Port Townsend take Hwy 20 until it connects with Hwy 101. Turn right onto Hwy 101 and head West.

You will pass through Port Angeles. This is an excellent place for you to top up your food stores and fill up with gas. Just after Port Angeles, look for a sign for Hwy 112 (towards Joyce, Neah Bay & Seiqu). Turn right and head West. It is about another 30 km from Port Angeles to Whiskey Creek. From the turn-off, it is about 10 miles to Joyce.

This little town has restaurants and gas stations. From Joyce, it is another 3 miles to the campsite at Whiskey Creek where Joe or Ronee can help direct you to your cabin or campsite.

Wednesday, 15 January 2020

UPTHRUSTING PLATES: WASHINGTON GEOLOGY

Two hundred million years ago, Washington was two large islands, bits of the continent on the move westward, eventually bumping up against the North American continent and calling it home. The shifting continues, subtly changing the landscape like a breath. We only notice when pockets of resistance manifest as earthquakes, some newsworthy, some all but unnoticed. For now, the more extreme movement has subsided laterally and continues vertically, pushing California towards the North Pole. Hello Baja-BC.

The upthrusting of plates move our mountain ranges skyward – the path of least resistance. And it is this dynamic movement that's created the landscape we see today.

The 3,000 meters of the stratigraphic section of the Chuckanut Formation along Chuckanut Drive span an age range of just a few million years. The lower part is late Paleocene with a radiometric age of around 56 million years. The upper part of the section is early Eocene. The fossils found here lived and died very close to where they are now but in a much warmer, wetter, swampy setting. The exposures of the Chuckanut Formation were once part of a vast river delta; imagine, if you will, the bayou country of the Lower Mississippi. The siltstones, sandstones, mudstones and conglomerates of this formation were laid down during a time of luxuriant plant growth in the subtropical flood plain that covered much of the Pacific Northwest.

This ancient wetland provided ideal conditions to preserve the many trees, shrubs and plants that thrived here giving us a lot of information about climate, temperature, the water cycle and humidity of the region. The Chuckanut flora is made up predominantly of plants whose modern relatives live in tropical areas such as Mexico and Central America. While less abundant, evidence of the animals that called this ancient swamp home are also found here. Rare bird, reptile, and mammal tracks have been immortalized in the outcrops of the Chuckanut Formation.

Sumas Eocene Shorebird Trackway
Tracks of a type of archaic mammal of the Orders Pantodonta or Dinocerata (blunt foot herbivores), footprints from a small shorebird, and tracks from an early equid or webbed bird track give evidence to the vertebrates that inhabited the swamps, lakes and riverways of the Pacific Northwest 50 million years ago.

Fossil mammals and bird trackways from Washington State have caused great excitement over the past few years. Many new trackways have been discovered since the 2009 slides near Sumas. George Mustoe and team collected these important finds, bringing them to the Burke Museum in Washington State to study and make available for display.

The movement of these vertebrates was captured in the soft mud on the banks of an ancient river, one of the only depositional environments favourable for track preservation. The terrestrial paleontological record of Washington State at sites like Chuckanut and Racehorse Creek (U-Pb 53 Ma.) is primarily made up of plant material with some wonderfully enticing mammal, shorebird (seen here) and large Diatryma bird tracks on rare occasions.

Tuesday, 14 January 2020

AMMONITES FROM THE GAULT

The chunky ammonite Proeuhoplites subtuberculatus, bed II (iv), Folkstone Gault Clay, county of Kent, southeast England.

This matrix you see here is the Gault Clay, known locally as the Blue Slipper. This fine muddy clay was deposited 105-110 million years ago during the Lower Cretaceous (Upper and Middle Albian) in a calm, fairly deep-water continental shelf that covered what is now southern England and northern France.

Lack of brackish or freshwater fossils indicates that the gault was laid down in open marine environments away from estuaries. The maximum depth of the Gault is estimated 40-60m a figure which has been reached by the presence of Borings made by specialist Algal-grazing gastropods and supported by a study made by Khan in 1950 using Foraminifera. Estimates of the surface water temperatures in the Gault are between 20-22°c and 17-19°c on the seafloor. These estimates have been reached by bulk analysis of sediments which probably register the sea surface temperature for calcareous nanofossils.

It is responsible for many of the major landslides around Ventnor and Blackgang the Gault is famous for its diverse fossils, mainly from mainland sites such as Folkestone in Kent.

Folkestone, Kent is the type locality for the Gault clay yielding an abundance of ammonites, the same cannot be said for the Isle of Wight Gault, however, the south-east coast of the island has proved to be fossiliferous in a variety of ammonites, in particular, the Genus Hoplites, Paranahoplites and Beudanticeras.

While the Gault is less fossiliferous here on the island it can still produce lovely marine fossils, mainly ammonites and fish remains from these muddy mid-Cretaceous seas. The Gault clay marine fossils include the ammonites (such as Hoplites, Hamites, Euhoplites, Anahoplites, and Dimorphoplites), belemnites (such as Neohibolites), bivalves (notably Birostrina and Pectinucula), gastropods (including the lovely Anchura), solitary corals, fish remains (including shark teeth), scattered crinoid remains, and crustaceans (look for the crab Notopocorystes).

Occasional fragments of fossil wood may also be found. The lovely ammonite you see here is from the Gault Clays of Folkstone. Not all who name her would split the genus Euhoplites. There’s a reasonable argument for viewing this beauty as a very thick form of E. loricatus with Proeuhoplites being a synonym of Euhoplites. Collected, photographed and prepped by Thomas Miller. Approx 35mm across.

Jack Wonfor shared a wealth of information on the Gault and has many lovely examples of the ammonites found here in his collections. If you wish to know more about the Gault clay a publication by the Palaeontological Association called 'Fossils of the Gault clay' by Andrew S. Gale is available in Dinosaur Isle's gift shop.

There is a very good website maintained by Fred Clouter you can look at for reference. It also contains many handy links to some of the best fossil books on the Gault Clay and Folkstone Fossil Beds. Check it out here: http://www.gaultammonite.co.uk/

Monday, 13 January 2020

BREWERICERAS OF HAIDA GWAII

Brewericeras hulenense (Anderson 1938) a fast-moving, nektonic (no idle floating here!) carnivorous ammonite from the Lower Cretaceous (Albian) of Haida Gwaii (Queen Charlotte Islands), British Columbia, Canada.

This specimen is just over 12cm in length, a little under the average of 13.4cm. There are several localities in the Queen Charlotte Islands where Brewericeras can be found (six that I know of and likely plenty more!)

Brewericeras can also be found in Albian deposits in Svedenborgfjellet, Ulladalen, Norway (Cretaceous of Svalbard and Jan Mayen - så fin!) (77.7° N, 15.2° E: paleo-coordinates 66.6° N, 13.6° E) and Matanuska-Susitna County, Alaska, 62.0° N, 147.7° W: paleo-coordinates 57.3° N, 85.6° W (112.6 to 109.0 Ma.)

Sunday, 12 January 2020

JURASSIC COAST BEAUTIES

Charmouth Nodule; Photo and prep: Lizzie Hingley
The talented Lizzie Hingley of Stonebarrow Fossils found this beautiful chock-a-block nodule on Charmouth beach last year.

The nodule contains a couple of Caenisites turneri, along with some Promicroceras and Cymbites ammonites, but there was also a wee surprise just outside the nodule proper. Look closely and you'll see a very well preserved fish!

When she began to prep this nodule, Lizzie had no idea there was going to be a lovely little fish associated with it. Luckily, she caught a glimpse of it when her pen was just millimetres away. The fish is incredibly fragile but looks complete. I'm not sure which species this little fellow is but he shows nice detail in his preservation. A little over fifty fossil fish species are known from the area, including some early teleost fish— a group that includes over 23,000 living species.

The coast and the cliffs around Charmouth and Lyme Regis are famous for their fossils around the world. These are the same beaches that the famous Mary Anning explored as a youngster years ago and Lizzie and many of the locals walk today, all hunting for fabulous Jurassic finds. The most common fossils along the Jurassic coastline in this area are ammonites and belemnites.

Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells. Like other cephalopods, ammonites had sharp, beaklike jaws inside a ring of tentacles that extended from their shells to snare prey such as small fish and crustaceans. We see and collect their beautiful coiled shells but often forget the squid-like fellow who was living inside.

Some ammonites grew more than three feet (one meter) across — tasty snacks for the giant marine reptiles of the day. Most, though not all, ammonites have coiled shells. The chambered part of the shell is called a phragmocone.  It contains a series of progressively layered chambers called camerae, which were divided by thin walls called septae. The last chamber is the body chamber. As the ammonite grew, it added new and larger chambers to the opened end of the shell. A thin living tube called a siphuncle passed through the septa, extending from the body to the empty shell chambers.

Fish detail, Photo: Lizzie Hingley
Beautiful ammonites can be found along the coast at Charmouth and Lyme Regis in southwestern England. Some are in nodules on the beach, brought in as erratics or washed down from the cliffs. Sometimes the tides do all the work and you find the fossils perfectly prepped out, loose in the beach gravels.

Other Jurassic fossils found here include occasional partial or complete marine reptiles — such as Ichthyosaurus and Plesiosaurus. Fossilized fish, as you see here, also pop up on occasion.

As you travel to Charmouth from the east the coastline changes, from the chalk cliffs west of Poole, through the unique rock formations of Lulworth and Durdle Door, to the 28 kilometres (18 miles) and 180 billion pebbles of Chesil Beach and the Fleet Lagoon. The cliffs at West Bay will be particularly familiar to fans of the television series Broadchurch. To the west of Charmouth there is the Lyme Regis ‘ammonite pavement’ on Monmouth beach, with many exposed ammonites in the rocks. And further west you move into the Triassic red cliffs of Devon and the historic pretty coastal villages of Beer and Branscombe.

Photo and fossil preparation: Lizzie Hingley, Stonebarrow Fossils. She has workshops in Dorset and Oxfordshire. Check out more of her work here: https://www.stonebarrowfossils.co.uk/

If you're looking to head to Charmouth, check out the Charmouth Heritage Coast Centre. They also have a well-designed website with the local weather and tide tables.  You can visit it here: https://charmouth.org/chcc/fish/