UKAFH were fortunate to gain access to this remarkable mile-wide working quarry on Saturday 13th October. A small group of us gathered on this unseasonably mild but breezy day for an excursion into the Middle Jurassic. We assembled in the site canteen for a briefing from UKAFH leader Sam Caethoven and the site management, taking time to enjoy the displays of some of the more exceptional finds to have been previously found at the quarry, before heading into the quarry itself.
Ketton Quarry is an enormous site which provides an extensive exposure of the middle Jurassic from rocks of Bathonian age (dating to around 165 million years ago) to Bajocian age (around 175 million years old). The mile-wide quarry has been worked for many decades and is now 115.6 hectares in size. With full access, this huge quarry provides opportunities to collect fossils from many different beds, however we were limited to an area of spoil where operations were not currently ongoing for safety and practical reasons. Despite this, fossils were still abundant.
The geology at Ketton is complex, with a range of Jurassic-aged rocks recorded. Mostly, three formations are visible in the quarries: the lowest is the oolitic Lincolnshire Limestone which was laid down in the middle Jurassic about 160 million years ago. This large, blocky, rock was formed from small grains of calcium carbonate which were deposited under a warm, shallow sub-tropical sea which was subject to reasonably strong currents. Above this is the Rutland Formation – bands of delta and shoreline muds and sands carried by rivers. Each band, with shelly remains at its base and tree roots at the top, was formed when sea-level rise topped the layer below. Many colours can be seen in fresh exposures of this formation. The exposures at the working quarry (Ketton Main Quarry) are the type formation for the Rutland Formation. Above the Rutland Formation is the Blisworth Limestone, laid down under quiet, shallow, warm conditions during a marine transgression. The Blisworth limestone is full of fossil corals and shells.
Ammonites can be found but bivalves, corals, brachiopods, gastropods, echinoids (such as Clypeus ploti), shark teeth and fish remains are more common. In the past, dinosaur footprints have been seen, along with fragments of their bones, but we were not that fortunate on this occasion.
Blocks of limestone are often full of bivalves, brachiopods, or corals but you need a good geological hammer and a chisel to extract them as they can be very solid, although some rocks will have weathered to the point that fossils can be easily picked out. There were also many loose fossils to collect. Throughout our time on site we were able to find many bivalves and echinoids as well as a few brachiopods and gastropods. Special mention goes to James who took the time to carefully search the fine matrial for quasi-microfossils and found numerous echinoid spines, fish teeth and an Acrodus sp. shark tooth.
At the end of our hunt we gathered in the canteen for refreshments and to enjoy seeing each thers’ finds. It’s quite unusual on a UKAFH hunt for us all to finish together and have somewhere to gather for show-and-tell afterwards and it is always a highly enjoyable part of the day. As well as seeing all the finds and learning more about the site, the quarry staff can also see what we have found, both to share in our enjoyment and to ensure that anything rare is reported and recorded.
UKAFH would like to thank Hanson Cement and the staff at Ketton quarry for allowing us to visit and taking care of us throughout the day, including briefing us, showing us the site and allowing us the use of their facilities.
The 2nd July was a momentous day in UKAFH history being the last hunt that founder Craig Chapman would lead before stepping down from leadership duties and we were very hopeful it would be a good hunt. We weren’t disappointed!
I had only been to King’s Dyke once before on a blisteringly hot day and got quite pink in the sun! So I was relieved that there was some cloud cover and we didn’t have to worry about people getting sunburnt.
The hunt was very well attended with about 30 or so people eager to pick through the clay in search of ancient treasure. I must thank the quarry owners for having refilled the area the day before giving us 2 large areas of fresh clay to pick through. After a brief introduction at the identification board we headed up to the smaller heap just up the hill and the hunt was on!
One of the best features of this locality is that is suitable for all the family and is productive enough that hunters are guaranteed to go home with something, and everyone who wanted one of the plentiful (and beautiful) flat ammonites found at least one. Belemnites are also very common and range in size from a few centimetres to several inches (sorry about mixing metric and imperial!) The largest complete ones are not to be found everywhere and are quite the prize and I was lucky enough to find a couple of beauties. James found the biggest most complete one and was justifiably delighted with it!
After about an hour or so at the secondary heap we headed down into the main larger fossil hunting area where we were hoping to find some of the other things that can be found from this section of the Jurassic. Fish, crocodiles, ichthyosaurs and plesiosaurs are all known from here but are not common and are a major highlight if you are lucky enough to spot them. Between us we found 5 Lepidotes fish scales and even a couple of fish coprolites.
I am deliberately leaving the best till last, and chronologically they were found last, all within the last 30 minutes of our time hunting. It wouldn’t have been a proper UKAFH hunt in the Jurassic without Craig finding a vertebra and he duly obliged with a lovely ichthyosaur vertebra. I chipped in with 20 minutes to go with my most spectacular UK find – a plesiosaur vert which truly made my day. Then just as we were packing up, a random family who weren’t even part of our group arrived and the young man hunting with his Mum and sisters found a “weird belemnite” that we were not at all jealous to identify as a plesiosaur tooth! They were on their first ever fossil hunt so I shamelessly plugged UKAFH as a great group to join!! Maybe we’ll see them again on a hunt another time, who knows.
Either way it was a great day and the feedback was very positive. Thanks again to the quarry owners for the fresh clay to hunt through and I look forward to hunting there again next month with a new group.
On Sunday the 15th July UKAFH met at the world famous Smokejacks Pit – a large clay pit situated just outside Ockley in Surrey. The pit is famous for the near complete dinosaur specimens that have been discovered there including Iguanodonts and the first discovery of the spinosaurid Baryonyx in 1983.
The pit cuts through a section of the Wealden group, specifically the Weald Clay. The clay was deposited in a lake and floodplain environment during the Barremian stage of the Cretaceous period about 129-128 million years ago. At this time, the environment was warm and moist due to England’s then position in mid-latitudes but the climate was exceptionally seasonal with ground scorching dry seasons and intensely stormy wet seasons. Although this weather system may sound inhospitable, the cycle of organic deposition provided by the flood waters created a fertile ecosystem rich in both aquatic and terrestrial fauna and flora – perfect for giant dinosaurs! The diversity of fossils to be found here is quite extraordinary; some beds are extremely rich in plant material, others are ripe with insect remains. Fish, shark and shrimp are common too in the right layers and crocodile, pterosaur and of course dinosaur remains can be unearthed here with a good eye and a bit of luck.
Weald Clay expert Peter Austen provided us with a fantastic, in depth presentation on the Weald Clay and showed us examples of what could be found in the pit. Peter’s roadshow introduced us to the diversity of insects for which the pit is known (7 new orders of insects and numerous species). He covered in detail the discovery of Baryonyx and also a juvenile Iguanodont which was found together with Baryonyx teeth, suggesting predation or scavenging, which was later recognised as Mantellisaurus atherfiedensis. Smokejacks is also known for a very rare, early flowering plant called Bevhalstia Pebja. We also saw articulated fish death assemblages, an arthropod trackway, gastroliths (the stomach stones swallowed by dinosaurs to aid digestion) and plant remains and the well-known concostracans, small shrimp-like creatures which bear superficial similarity to bivalves. Peter provided a handout and a stratigraphical column to assist the group members in finding the various fossil beds. This was particularly beneficial in helping members determine where to look for certain fossils.
We entered the pit very excited and eager to see what we could found. We were lucky with the weather on this occasion; although rain threatened it remained dry – any downpour could soon turn the clay into mud – and we were grateful for it being overcast as the site is extremely exposed and will become uncomfortably hot in the sunshine very quickly, especially when traversing the steep quarry sides.
We began by walking the quarry slopes in search of any fossils visible on the surface. This proved fruitful for Chris Tait, who stumbled across several pieces of crocodile tooth enamel, and Mark Goble who found a broken block containing a large amount of fish material thought to be Lepidotes. Some then headed to the base of the quarry in search of rocks containing insect remains. Sam Caethoven struck lucky with a beautiful wing and wing case side by side in the same block. Some headed for the middle of the slope in search of fish remains: Dan Slidel, who is a geoscientist, took time to investigate the stratigraphy and found fish scales and an abundance of concostracans while Betsy Ooms found the most exquisitely preserved shark tooth.
By the end of the hunt many of us were digging in a bed high up the slope which is full of plant material and is known for an abundance of dinosaur remains. Notable finds include a large piece of bone found by Mary Bite, a beautifully detailed bone found by Seth Cook, an Iguanodont vertebra found by Katherine Combe and a huge crocodile tooth found by Mark Goble, as well as many other bone fragments. However; the prize of the hunt and possible of the year so far goes to Nicky Parslow who found a huge Theropod tooth about 5 cm in length. The tooth was rushed to the Natural History Museum for identification and was examined the very same day.
NHM staff advised: “Your find was of immediate interest, with the curator, Paul Barrett, coming down to identify it this afternoon. He has identified it as the tooth of a large theropod. He considers it an exceptional find as they are not commonly found. It is not from a Baryonyx but is from an indeterminate large theropod. Unfortunately, it can’t be identified any further as the teeth of these animals are all very similar and there are not enough identifying features to distinguish it from the various other species.”
Peter Austin has since confirmed that this is the only theropod tooth to have been found at Smokejacks apart from Baryonyx so it is a very significant find from the pit! We hope to seek further advice on the tooth in case more information can be found and we are all really excited to try and learn what large, ferocious beast this may have come from.
Smokejacks pit is not always as productive as this hunt assumed so I am really proud that everyone made some varied and exceptional finds on this occasion.
Thank you so much to everyone who came and made the day incredible. A huge and special thank you goes to Peter Austen and Joyce for sharing their expertise and organising access at such short notice.
We will, of course, keep everyone posted on the theropod tooth.