Monkwearmouth, North Dock, tufa

HER Number:
17548

District:
Sunderland

Site Name:
Monkwearmouth, North Dock, tufa

Place:
Monkwearmouth

Map Sheet:
NZ45NW

Class:
Water Supply and Drainage

Site Type: Broad:
Well

Site Type: Specific:
Petrifying Well

General Period:
Early Modern

Specific Period:
C19

Form of Evidence:
Natural Feature

Description:
The North Dock Tufa is a 4 x 4m dome-shaped structure of petrified calcareous material. It is accessed through the Marine Activities Centre. The tufa was found behind some old huts in 1992, when the Tyne and Wear Development Corporation were developing the marina. Tufa is a geological term for deposits of calcium carbonate. The water which flows through the tufa contains dissolved calcite. Over several decades the tufa developed as the calcite water covered roots and grasses to form stalactites and stalagmites. The wall to which the tufa is attached is part of North Dock, which opened in 1837, so the tufa is no earlier than that. The source of the water is unknown. It may originate from Fulwell Quarries. The water may be channelled through a buried valley or by the original dock railway (HER 2708) route. The Marine Activities Centre, which was built in 1993, was modified to preserve the tufa. A concrete foundation and supports hold up the tufa and steel rods prevent it from coming away from the wall. In 1995 the North Dock tufa was designated as a Regionally Important Geological Site (now a Local Geological Site). It is an outstanding example of its kind. It is still growing and becoming heavier each year.

Easting:
4063

Northing:
5856

Grid Reference:
NZ40635856

Lats/Lons:

Sources:
https://en.wikipedia.org/wiki/North_Dock_Tufa; http://www.liquisearch.com/north_dock_tufa/history_of_the_tufa; North East England Local Geological Site Field Record and Assessment Form, North Dock Tufa, Site Number 4; Fenwick, G.R. and McLean, S. (1996) In Bennett, M.R. (Ed) Geology on your Doorstep, The Geological Society. pp 128-137; Lawrence, D J D. (2009), Limestone Landscapes - a geodiversity audit and action plan for the Durham Magnesian Limestone Plateau. British Geological Survey Open Report, OR/09/007; Ulyett, L. (2004) Sunderland’s Secret in ‘ The Lady’, The Lady Magazine Limited, Nov. Issue.