Left: Google Earth image showing location of Blue Beach – Avonport Station coastline. Right: aerial photo of the cliff (in the shade) and beach at low tide.
One of the world’s prime fossil locations, Nova Scotia’s iconic Blue Beach, hit the press recently (here and here) although readers outside Nova Scotia or readers not familiar with paleontology may not have noticed. As a result, confusion arose among the public and even among some of my followers, so here is a bit of background (NOTE: This post was originally published on March 17, 2014. On May 11, 2014, Blue Beach hit the press again in the Chronicla Herald (here) in relation to the research visit by world-renowned paleontologist Dr. Jenny Clack visited the site; on May 13, the Chronicle Herald published another piece here).
“Blue Beach” is informally named. Here is the Wikipedia entry, which is rather minimal but at least correct.
The cliffs along Blue Beach are exposed in rocks of the Tournaisian Horton Group which here represent shallow fluvio-lacustrine deposits forming the edge of the early Carboniferous Maritimes Basin which was located at a tropical latitude at the time. The Tournaisian lasted from 359-345 million years ago. It was a very interesting time interval in earth history, because this is when the first 4-footed vertebrate animals (I.e. with a spine just like us) set foot on land. A 4-footed vertebrate is generically known as a ‘tetrapod’ (‘tetra’ is Ancient Greek for ‘4’, ‘pod’ means ‘foot’). If you don’t find the whole animal, but just its footprints, then you usually can’t tell whether the animal is an amphibian or a reptile (or a mammal, for that matter, but mammals didn’t exist yet in the Carboniferous) so you call it a tetrapod. If you find a whole series of footprints of what obviously was a 4-footer wandering through life, you call it a ‘trackway’, as in ‘tetrapod trackway’.
Tetrapod trackway from Blue Beach. Figure from Mossman and Grantham, 2008
This short 15 million year time interval is also known as ‘Romer’s Gap’. It’s named after the scientist (Alfred Romer) who identified the interval as a crucial period in earth history: few 4-footed vertebrates existed earlier than 360 million years ago and many of them went extinct at the end of the Devonian, the period during which fishes were especially abundant (the UNESCO World Heritage site at Miguasha in Quebec is testimony to that ‘age of fishes’). The first true reptiles are found in sedimentary rocks younger than 345 million years. In fact, the world’s oldest reptile (fossil) is also from Nova Scotia – it was found at Joggins Fossil Cliffs, now a UNESCO World Heritage Site (www.jogginsfossilcliffs.net). It’s called Hylonimus Lyelli and is Nova Scotia’s provincial fossil. The oldest sedimentary rocks at Joggins are ca. 345 million years old. So big evolutionary changes happened in a relatively short period of time. Fishes went on land, amphibians evolved, reptiles evolved, all in the blink of an eye – that’s putting it a bit too simplistic, but you get the idea. Unfortunately, the world doesn’t have a lot of exposed sedimentary rocks from that period, so our understanding suffers from a gap. Hence “Romer’s Gap” (the Wikipedia entry is really good).
The rocks exposed between Blue Beach and Avonport Station are one of the few locations on earth that represent exactly that time interval. The paleo-environment was ideal for capturing life at the time: it was a shoreline at the mouth of probably multiple river systems. The body of water in which these rivers emptied may have been fully saline, it may have been brackish to fresh. In other words, a fertile environment. Lush vegetation grew on land, much of which wasn’t eaten, as there were no large land animals and no birds. As the vegetation died (and much of the dead vegetation that became buried eventually became coal), it supplied the soils with organic detritus and thus with plenty of nutrients, so the area teemed with life. Rapid sedimentation ensured that dead bodies (plant or animal) were quickly buried: an ideal condition for preservation. In addition, the area was subsiding as it was part of a rapidly opening and deepening sedimentary basin, so the thick sediment packages became quickly buried, out of reach of other destructive forces.
So the rocks at Blue Beach – Avonport Station are the showcase for an entire ecosystem. Amazing!
Fast forward 360 million years to today: the rocks are exposed along the Minas Basin, a side arm of the Bay of Fundy, which experiences the world’s highest tides. Along this stretch, the average tide range is about 12 m. This makes for a perfect 3D exposure along km-wide low-tide rocky and muddy beaches and in the cliff, which is up to 20 m high in places. The tides erode these soft shales rapidly – new discoveries are constant.
Blue Beach – excellent 3D outcrop! There is minor faulting and deformation in the shales, but virtually no diagenetic alteration.
Protecting our geoheritage
Nova Scotia has an amazing geodiversity, covering about 1 billion years of earth history. Not all of this geohistory contains evidence of evolution of life (fossils), but a lot of it does. The province has been the hunting ground of professional paleontologists for nearly 200 years! Realizing that much of our unique fossil heritage could be carted away easily, the province created a law in 1974 called the ‘Special Places Protection Act’. Without going in to too much detail, this law basically declares every fossil the ownership of the people of Nova Scotia, i.e. the province. No fossil can be private property. Now, there are lots of fossils that the province is not interested in, such as gazillions of raindrop imprints or mud-cracks or fish scales. But it’s worded in an extreme way so that you can’t take off with any fossil (raindrop or tetrapod trackway) and claim that you didn’t know about that being an illegal act. I live approximately 4 km from Blue Beach, so have wandered there frequently and found 1 special fossil, most likely the tail piece of a trilobite. I handed it over to the Nova Scotia Museum of Natural History, where it is catalogued and where anyone can come to study and admire it.
Most likely a trilobite pygidium (tailpiece) from Blue Beach
Such a law is difficult to police, of course, especially in a thinly populated place with wild coastlines. I remember visiting Arizona’s Petrified Forest and every visitor is essentially guarded by an interpreter / park warden to make sure that nobody picks up anything. Excellent. But we can’t do that here, it is logistically and financially impossible. (there was a sentence here that stated that Neil Shubin et al, who found the most important early dinosaur bones at Nova Scotia’s Parrsboro shore in the early 1980s, collected these bones and took them to Chicago without further ado, but I was notified by Neil Shubin himself that I was wrong, so that sentence is no longer here. Do read the comments below and do read his ‘your inner fish’).
So the law is good, but its operationalization is weak.
Only a few people have properties on top of the Blue Beach cliff. If you own property on the coast in Nova Scotia, you own it to the high tide line. So even if your property borders a site such as Blue Beach, those fossils aren’t even close to being yours (the law aside) because the highest high tide comes halfway up the cliff.
Sonja Wood and Chris Mansky own a property on top of the cliff at the entrance to Blue Beach. In fact, the dirt track that gives access to Blue Beach is their private road (access at Avonport Station is from a public road). Chris Mansky is a well-known amateur fossil hunter and I don’t mean amateur in a negative way. He is one of those rare individuals without formal training and with an extremely keen eye. Two other equally famous amateur fossil collectors in Nova Scotia are Don Reed at Joggins and Eldon George at Parrsboro. Over the decades, Chris has rescued an amazing array of unique fossils from being destroyed by the tides. He and Sonja have stored these fossils in a Quonsett hut on their property and have shared their findings generously with anyone who wished to see them – a lot of those were school kids but Chris also is co-author on a number of scientific articles. They only asked for donations. The fossils are not theirs, as they make very clear on their website (http://www.bluebeachfossilmuseum.com). They can’t be sold.
Sonja and Chris have made various attempts at creating a visitor and interpretation centre on their land, including getting money promised by the county. An architect created a design for a museum. But the money didn’t come through so I can only assume that none of these plans is considered viable any longer, so they have put their property up for sale. That’s too bad.
The question is, of course, what will happen to the collection. The collection belongs to the province and could – theoretically – be moved to the provincial storage facility at Stellarton, a good 3 hours driving away. That would be really sad, because while the province (Nova Scotia Department of Communities, Culture and Heritage through the Nova Scotia Museum of Natural History) would of course (as they are mandated by law to do) provide access to the collection to scientists, it would be less accessible to the general public, unless the Museum organizes a specific exhibit. Our small and thinly populated province doesn’t have money for remote interpretation centres. Such initiatives require separate funding.
Sites such as Blue Beach are important for public education and for furthering the collective understanding of our the history and evolution of life on earth and they are part of our geoheritage (the province’s Department of Natural Resources is actively working on developing a provincial geoheritage list, see for example here and here). While the Blue Beach-to-Avonport stretch of coastline is unaffected by all this uproar, it would be a really good idea if there was an interpretation centre that conserves and showcases the fossil collection in the area itself rather than somewhere further away where visitors can’t relate to the environment. The museums and interpretation centres at Joggins and at Parrsboro are testimony to that principle. They each get tens of thousands of visitors each year and are not only visitor sites, but also research facilities. The beach at Joggins is now more protected from illegal fossil hunting than before there was a funded interpretation centre because paid interpreters can be on the beach during the warmer part of the year, helping visitors and poring over their finds. This is a positive development.
So I do hope the collection made possible by Sonja and Chris’s efforts can be made available for public viewing in a centre somewhere as close as possible to Blue Beach itself. Since Sonja and Chris do not own the collection, it’s clear that the location of an interpretation centre doesn’t have to be on their property, because the collection isn’t theirs. Also, the cliffs and beach are not endangered by the intended sale of their property.
Calder, J.H., 1998, The Carboniferous evolution of Nova Scotia. In: Blundell, D.J. And A.C. Scott (eds.), Lyell, the past is the key to the present. Geological Society, London, Special Publications , v.143, p. 261-302
Clack, J. A., 2002, An early tetrapod from “Romer’s Gap”. Nature, v. 418, 4 July 2002, p. 72-76.
Gibling, M.R., N. Culshaw, M.C. Rygel and V. Pascucci, 2008, The Maritimes Basin of Atlantic Canada: basin creation and destruction in the collisional zone of Pangea. In: Sedimentary Basins of the World, V. 5, p. 211-244 (Elsevier).
Hunt, A.P., S.G. Lucas, J.H. Calder, H.E.K. Van Allen, E. George, M.R. Gibling, B.L. Herbert, C. Mansky and D. Reid, 2004. Tetrapod footprints from Nova Scotia: the Rosetta Stone for Carboniferous tetrapod ichnology. Geological Society of America, Abstracts with Programs, v. 36, no. 5, p. 66
Martel, A.Th. and M.R. Gibling, 1992, Wave dominated lacustrine facies and tectonically controlled cyclicity in the lower Carboniferous Horton Bluff Formation, Nova Scotia, Canada. In: Anadon, P., L.L. Cabrera, K. Kelts, Lacustrine Facies Analysis, Int’l Assoc. of Sedimentologists special publication no. 13, p. 223-240.
Martel, A.Th. and M.R. Gibling, 1996, Stratigraphy and tectonic history of the upper Devonian to lower Carboniferous Horton Bluff Formation, Nova Scotia. Atlantic Geology, v. 32, p. 13-38
Mossman, D.J. and R.G. Grantham, 2008, Eochelysipus horni, a new vertebrate trace fossil from the Tournaisian Horton Bluff Formation, Nova Scotia. Atlantic Geology, v. 44, p. 69-77
Tibert, N. E. And D.B. Scott, 1999, Ostracodes and agglutinated foraminifera as indicators of paleoenvironmental change in an early Carboniferous brackish bay, Atlantic Canada. Palaios, v. 14, p. 246-260.