The Eocene geology at Harwich is very interesting. South of the shorter of the two lighthouses is the Harwich Stone Band (Eocene ~50 mya), which is well exposed at the upper part of the foreshore directly south of the lighthouse, and further south where it outcrops again along the lowest part of the foreshore. Between the two exposures, there is a fault in which the London Clay (which is from Division A1), has cut through the Harwich Formation.
The Harwich Formation is marked by patches of silty clay with blocks of sandstone and beds of black pebbles. The latter beds are normally only exposed during low spring tides. The same bed contains attractive veins of calcite and also volcanic ash from explosive volcanic eruptions in Scotland and Scandinavia during Eocene times, but tends to yield few fossils.
Fossils come from both the London Clay (Eocene ~50 mya) faulted at the Southern end, and also from the dredging of London Clay deposits from the riverbed. Material can be dumped on the beach or stirred up after dredging the river. This used to be a location that was highly rich in fossils, but since dredging has stopped, the number of fossils has dramatically decreased and the beach has become more silted up.
Fossils from Harwich have been noted for about 300 years. Several nautiloids, large turtles and fossil mammals were recorded in 1796. Recent finds include many different types of fish, reptiles (including turtles), crocodiles, bird bones and occasional mammals.
The most common finds are the highly polished sharks’ teeth and ray palate fragments from the London Clay, with whale bones and shell fragments derived from the Red Crag of the Pliocene. Pine cones, (Platycarya richardsoni) have also been found from the London Clay.
To find fossils at Harwich, you need to collect on a low or falling tide. Collecting is best further out from the promenade. In addition, fossils often get trapped around the large areas of shingle. However, sometimes the beach can be covered with sand and so collecting is poor. The best area is the beach around the shorter of the two lighthouses, and you will need to get on your hands and knees to find the fossils.
Equipment: Harwich is a foreshore location, where most fossils are collected by crawling along the beach on your hands and knees. However, remember to take something to put your finds in, such as a small plastic container or specimen bags.
Safety: Common sense when collecting at all locations should be used and prior knowledge of tide times is essential, but, it is virtually impossible to get cut off by the tide. Sometimes, pieces of metal junk can be seen sticking up from the beach, so one should take care, as these can be quite sharp. However, generally, Harwich is ideal for children to collect fossils.
Further information: View public discussions and other people's finds, or add your own reports and photos by going to our Discussion Board. Check out our other guides for more locations in Essex, or visit similar locations: Steeple, Burnham-on-Crouch, Isle of Sheppey, Maylandsea. If you like collecting sharks teeth you could also try Bracklesham Bay, Herne Bay, Barton-on-Sea or Taddiford Gap which are also Eocene age.