Smokejack Clay Pit

Also within

Surrey County

Condition (Natural England)

Habitats

Saline lagoon

Geology & landscape

Rock Type: Sandstone, Siltstone

Description

Area, 76.32 ha. 188.51 ac. Description The site consists of a pit in the lower Weald Clay Group, probably near the Hauterivian Barremian boundary. Important for depositional environments and faunas, its dark to light grey and brown clays with siderite concretions have yielded insects, ostracods, molluscs, fish, articulated and disarticulated bones of reptiles and numerous gastroliths. The insects occur in siltstone concretions, the fossils not occurring as common debris as is often the case but in a fine grained matrix with fine detail preserved. Some six orders haveso far been recorded. The reptilian remains consist of crocodile teeth, coprolites and a partial skeleton of Iguanodon. The unique fish eating theropod dinosaur, Baronyx walkeri, was discovered at this site. It is the best Weald Clay reptile site currently available. The overlying Alford Sand Member BGS Bed 5c comprises lenticular bedded silty clay and silt, possibly the resins of a brackish tidal lagoon, passing up into a bioturbated sandstone with Ophiomorpha which is probably an old brackish lagoon lower shoreface. The sand is predominantly from Cornubia high K feldspar, tourmaline and tourmaline fine aggregates; low microcline, garnet and staurite < kyanite. While the sand's origin is similar to those of the preceding members e.g. at Billingshurst, the depositional environments are entirely different.

Plant communities