Skip navigation

Visit to Pett Levels July 2016

The Grand Staircase Escalante USA

Bracklesham Bay

Beacon Limestone, Somerset

Beltinge, Herne Bay

Seasalter

Wye, Kent

Osmoy-Saint-Valery

Seaford

Betchworth

APRIL 2016

Field Trip to The Grand Staircase Escalante USA.

Our itinerary was as follows:

Las Vegas>Hoover Dam>Flagstaff (Sunset Crater and Meteorite Crater)>Grand Canyon>Gooseneck Canyon>Monument Valley>Lake Powell>Bryce Canyon>Zion National Park>Las Vegas

The general geological situation is summed up in this brilliant cross-section.

Stacking the rocks in terms of age:

Bryce Canyon

photo

Bryce Canyon

Lake Powell

Monument Valley

photo

Monument Valley

Zion Canyon

photo

Zion National Park

 

Grand Canyon (bottom of the Canyon goes right down to basement Vishnu rocks).  It’s all written in stone.

photo

Grand Canyon

July 2015

Visit to Bracklesham Bay.  Not the optimum time for a visit as the spring low water is not as low as in the spring and autumn and there is a lot of sand on the beach.  I was surprised to find that the Eocene reefs emerged as the tide went out.

photo

Bracklesham – Eocene reefs – four days before spring low tide – July 2015. Turitella packed glauconitic sands overly Venericor planicosta beds. Many of the bivalves are still articulated.

There was much better exposure of the reefs than I expected.  The Turitella packed beds were very clear, overlying the Venericor planicosta beds.

Some of the fossils collected:

photo

Venericor planacosta – articulated

photo

Sharks tooth , id’s as sand tiger shark.

photo

oyster shell – the operculum and shell were articulated when they were collected in situ. Id’s as Cubitostrea plicata.

photo

oyster-operculum. Id’s as Cubitostrea plicata

photo

Gastropod fossil. These shells are decalcified and extremely friable.

I need to get some proper id of these fossils. Alan Morton’s Collection of Eocene and Oligocene Fossils is a good place to start.

March/April 2015
Somerset further explorations. Having mapped the outcrop of the Beacon Limestone I went slightly further afield to explore other outcrops. I visited Seavington, Hurcott and Green Lane End. There are many places where fossiliferous pieces of this limestone can be collected. So I came back with more ammonite, nautiloid and rhychinellid specimens.

photo

A303 cuts right through the Beacon Limestone at this point.

March 2015

photo

Beach at Beltinge (Herne Bay)

Monday 23rd March – trip to Herne Bay. Low tide 8.32am GMT, 0.30m according to the Port of London Authority Tide Tables. Sunrise 6.00 am. Very cold morning, temperature 1.5 degrees celcius with a 6mph breeze blowing from WSW, ie. slightly offshore. Air pressure is about 1020 millibars.
Left Redhill at 4.15am and arrived at Herne Bay at 5.30am – much too early.
It’s very cold at Herne Bay so decided to go for a brisk walk towards Reculver to try to warm up.

Had a look at the ‘classic’ section at Bishopstone Glen.

photo

Bishopstone Glen – Tertiary section.

Went to look at the ‘Artica’ beds (Thanet Sands) close by but this part of the beach is largely obscured by sand and pebbles.

photo

Artica beds

I then went to the west of the normal sharks teeth hunting area, trying to identify the Beltinge Fish Bed.

photo

Trying to identify the Beltinge fish bed. I think that I overshot the fish bed!

Back to the normal sharks tooth hunting area and I met a man searching for micro sharks teeth fossils in a very specific glauconitic sand zone.

photo

Digging for the glauconitic sand zone. Reculver in the background.

I happened to pick up a bit of the glauconitic sand, it outcrops on the beach and contains numerous tiny bivalves.

photo

Tiny bivalves from the glauconitic sand zone.

I’m not sure which bed this monster bivalve came from – it was lying loose on the beach near the glauconitic sands.

photo

Monster bivalve lying loose on the beach.

Found the usual trawl of sharks teeth, mostly by sieving. Here’s a ‘Where’s Wally?’ spot the sharks tooth image.

photo

Spot the sharks tooth.

Managed to find the usual trawl of sharks teeth, though many are damaged, that’s usual here.

photo

Sharks teeth plus two ray plates.

When the tide had come up too far at Herne Bay I left. I decided to go and recce. Seasalter. The London Clay outcrops on this beach producing horrible mud-sucking mud-flats.

photo

Wellington boot deposit at Seasalter.

I walked across the mud in someone elses bootprints and was very lucks to find a fossil crab. This fossil is the star of the show – I’m so pleased to have found one after several searches on the Isle of Sheppey.

photo

Seasalter – fossil crab in phosphatic nodule from the London Clay.

Then it was a race back to the pebble part of the beach as the tide was coming up very fast behind me. It was about two and a half hours off high tide.

February 2015
Saturday 21st February – trip to Herne Bay. Low tide at 8.15am GMT, 0.21m according to the Port of London Authority tidal tables. Sunrise at 7.02am reveals a cold grey overcast morning 2-3 degrees Celsius ie. very cold! At the beach a 14mph WNW wind is blowing the sea up the shore. Just under 1000mb pressure doesn’t help either.

Arrived at the beach at 7am and am surprised by how few people are there. The wind blowing the sea up the beach is a real problem. Where the small ‘island’ would normally be visible above the waves there is nothing to be seen.

photo

Herne Bay Beach, Beltinge end, early in the morning.

We got down to searching for fossils as quickly as possible.

photo

Searching for fossils at Herne Bay.

photo

Checking the sieve for fossils, mainly sharks teeth.

Driving home it snowed for about an hour up on the North Downs. The snow only settled briefly though!

This is the worst low tide that I’ve ever seen at Herne Bay. The wind prevented the water from ebbing completely and when the tide turned it came back up the beach much more rapidly than usual. This is the lowest tide of 2015.

January 2015

Oh dear I seem to have created a high speed version!

Friday 23rd January 2015. Three days past the full moon – spring tides. Herne Bay – low water 08.28am, 0.28m, not the lowest of spring tides but with pressure of 1024mb and a slight offshore breeze, bright partly sunny morning and sunrise at 7.56am conditions are promising. Only thing is – it’s cold, very cold with the temperature of minus 2 degrees celsius at 6am.

Decided to give fossil hunting at Herne Bay a go. Leave home in the dark at 6am. The stars are out and the birds are waking up and singing the dawn chorus. It’s my favourite time of day. Slow journey to the coast with the M20 closed eastwards of Junction 7 and the lorries being stacked on the inside lane. Poor lorry drivers they face a delay of at least 3 hours to reach the ferries and eurotunnel.

Finally arrive at 7.50am, that was a very slow journey. Conditions on the beach are good and there are not many other people there. Spent about two hours collecting and got just over a hundred teeth with a larger number of complete specimens than usual.

photo

Herne Bay – sharks teeth

Notes from the Geology of England and Wales edited by P.McL./d.Duff & A.J.Smith, published in 1992.

The main outcrops of Palaeogene rocks in the UK is in the London and Hampshire Basins. Older Palaeocene beds(Thanet Formation) occur in Kent.

Tertiary stratigraphy is in a state of confusion but microfossil studies are clarifying the issues.

There was a large time gap (20Ma) separating the latest Mesozoic deposits from the earliest Tertiaries in the London and Hampshire Basins. The contact appears to be conformable with the basal beds comprising glauconitic sands with rounded flint pebbles sitting on a marine erosion surface. The Thanets of Kent comprise clayey silts and fine sands 30m thick. The middle and upper Thanets are present at Herne Bay. The Woolwich and Reading Beds yield the sharks teeth.

Western Europe was 10 degrees nearer the Equator at this time and the temperature in Britain was probably 10 degrees higher than at present. There was less ice at the poles and sea levels were higher than at present. The Late Cretaceous period was a time of marine transgression and only the ancient Massifs lay above sea level. The Palaeocene was a period of marine regression. In the upper Thanets the presence of Artica and Astarte indicate cooler seas less than 50m deep.

Nomenclature is a huge problem with this stratigraphy eg. woolwich and reading beds are called the upnor formation on some websites.

Now to try and identify some of the sharks teeth………….

April 2014

I’ve just spent a few days in the West Country having a look for fossils around Ilminster.  British Lower Jurassic stratigraphy:  an introduction, a defa publication, explains the stratigraphy.  Pages 23 and 24 discuss the Beacon Limestone Formation that outcrops/sub-crops in the Ilminster area.  These sedimentary rocks are Pliensbachian – Toarcian in age ie. 176 – 190 million years old according to The Geological Society of America 2009 stratigraphic table. 

Photo

Ploughed field near Ilminster.

The British Geological society have produced a Geology of Britain viewer that is very useful for identifying where outcrops/subcrops may occur.

Fossil hunting took several days.  First checking out the ground and then looking for the landowner.  I never did find out who owned and who farmed the land so I just confined my search to footpaths and the edges of fields.

photo

Searching for fossils along the edges of fields in the Ilminster area.

One field in particular was very productive.  There were numerous fossils and broken fossils on the surface of the soil with larger rocks towards the edges of the field.

photo

Ammonites and broken ammonites on the surface of a field near Ilminster, Somerset.

I collected numerous ammonites of several different species plus belemnites, nautiloids and bivalves.

photo

Ammonites and nautiloids from the Beacon Limestone, Ilminster.

We also went down to Branscombe to see how the Sea Shanty Caravan Park has fared after the winter storms.  The profile of the beach had changed with a channel scoured along the top of the beach undercutting some of the cabins.

photo

The top of the beach has been scoured allowing ground under the cabins to be undercut.

photo

The storms have removed the pebbles at the top of the beach allowing the ground behind to slip.

Somerset was followed by a visit to the North Downs near Wye, Kent.  Again a short look around a ploughed field yielded several Creatceous echinoids, sponges and corals,  all flint replacement and of Cenomanian age, 93.5 – 99.5 million years old.

photo

Searching for fossils in a ploughed field on the North Downs, Kent.

photo

Fossil echinoids, sponges and corals from the North Downs, Wye, Kent.

Interestingly the echinoids appear to be crushed before the organic matter was replaced by flint.

March 2012 (10th)
Yesterday and today were the two lowest spring tides of the year at Herne Bay. Perfect conditions for collecting fossil sharks teeth. Fine weather with high white cloud, air pressure of 1038 millibars, a cool north westerly breeze and a low tide of 0.8m. The ‘Island’ was visible but not high and dry. Two youngsters waded the short distance across to it but filled up their wellies in the process. The ‘Island’ is supposed to yield the best sharks teeth. I have found that digging and sieving is the most productive way of searching for sharks teeth. I need a sieve with a slightly smaller mesh than the garden sieve. Professional collectors seem to concentrate digging and sieving the Thanet/Reading-Woolwich boundary (‘Beltinge Fish Bed’).

photo

Fossil sharks teeth from Herne Bay

These tides were not as low as those of the previous year. Looks like 2020 is when the next extra low spring tides occur. ( based on National Oceanography Centre predictions for Sheerness)

June 2011
We passed a small chalk exposure on the side of the D77 south-west of Osmoy-Saint-Valery. Not sure what age this chalk is but it is very rich in fossil sponges.

photo

Chalkpit near Avenue Vert

April 2011 – I can’t remember exactly when – field trip to Barton-on-Sea to have a look at the Barton Beds, exposed at Highcliffe. The clays were dry when I visited, this is a classic welly boot deposit – I saw one trapped welly boot! Here is what I found, nice selection of shells from the warm, tropical seas of the Eocene:

photos

Fossils from the Barton Beds, Barton-on-Sea

22nd March 2011, could’nt resist another visit to Herne Bay! Another predicted spring low tide 0.1m with fair weather, a slight offshore breeze and pressure 1036 mb. Unfortunately low tide is at stupid o’clock (7.26am?) and we have to get up at 5am! Fabulous morning but foggy to start with. As the mist clears we are driving straight towards the rising sun. A few people are already on the beach. Armed with a shovel and sieve I started looking. Nothing – absolutely nothing! Nearby kid is having a field day finding loads of sharks teeth. The beach is very silty, like last time, an looks none too clean either. Start digging in the shallows. Digging and sieving seems to be quite productive. Nearby there is a collector in waders, with a floating sieve- good idea the water is very murky. He is digging where the stream joins the sea. The Island is still inaccessible. It would be good to collect here wearing a wetsuit. 40+ sharks teeth – more broken ones this time – was that caused by the shovel? Plus a crocodile tooth. Went to a small museum in town displaying good fossil finds at Bishopstone Glen area of the beach.

19th March 2011, nice clear night for the supermoon visit to the garden with tripod and binoculars. Moon looked very large and reddish as it rose – saw it from the Essex stretch of the M25. Later, it doesn’t look particularly large but is exceptionally bright.

9th March 2011, visited Seaford, Sussex to search for fossil sponges in the chalk. Unfortunately the tide was too high to get any further than the eastward end of the beach. The small part of the chalk that is exposed adjacent to the path shows great promise. Flint is abundant and so are fossil sponges. This location is well worth revisiting on a falling tide. Excellent exposure of late Cretaceous, Santonian chalk 83 – 86 MYA.

7th March 2011, went fossil hunting in Betchworth yesterday. I was hoping to find some fossil sponges but no luck, only found a few unsuitable odds and ends.

20th February 2011, field trip to Herne Bay, junction of Woolwich and Reading Beds (to the east) and the Oldhaven Beds (to the west). This is one of the predicted lowest spring tides for 2011. Unfortunately, low tide occurs just after dawn and the cold grey drizzly weather means that light levels are low. Although pressure is relatively high (1014mb) the wind is blowing slightly onshore and pushing the water up the beach. There is a lot of silt covering the beach but down on hands an knees (ouch!) sharks teeth are easy to spot.

pic

54 million year old sharks teeth collected at Herne Bay

One Trackback/Pingback

  1. By 22560 days old | Barbara Roberts - NON ART on 01 Aug 2015 at 10:04 pm

    […] Field Trips […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s