Embedded Files
SSSIs are Sites of Special Scientific Interest.
You can find brief information about the sites we manage using the map below.
Fuller details are given in the main listing below the map.
How to use this map
How to use this map
click on any of the map icons to find out more about a particular site
access the complee list of sites by clicking on the icon next to Hertfordshire Geology the map header
toggle complete categories on or off by checking/unchecking category headings
zoom in or out by using the +/- in the bottom left hand corner of the map
(if it's concealed by the list of sites then toggle the list off again)
CASTLE LIME WORKS QUARRY
CASTLE LIME WORKS QUARRY
TL 229026
Adjoins a Scheduled Ancient Monument
Boundary of chalk and overlying Tertiary deposits, with large solution pipes. Disused quarry, one face retained.
Status as at 2008, not visited since.
DOWNFIELD PIT, WESTMILL
DOWNFIELD PIT, WESTMILL
TL 349165
Former gravel pit. Nr Ware. Gravel & boulder clay from Pliestocene proto-Thames & Anglian glaciation.
Status as at 2008, not visited since.
HILLCOLLINS PIT
HILLCOLLINS PIT
Location: TL 442267.
This small pit exposes the earliest gravels (Westland Green Gravels) laid down by the ancestral River Thames (proto-Thames) about 1,600,000 – 1,800,000 years ago. The extent of these gravels indicates that the proto-Thames flowed from Oxford through the Goring Gap and then north-eastwards to Norwich. The original site where these deposits were first found has become completely degraded, so the Hillcollins Pit is of considerable significance for reconstructing the evolving geography of southern Britain. The site is discussed in detail by Bridgland (1994, pp. 115- 117).
LITTLE HEATH PIT
LITTLE HEATH PIT
Location – Grid Reference TL 01650825
Car Parking – on Bullbeggars Lane which starts from the A4251 at the eastern edge of Berkhamsted and rises up the hill to Potten End. The site is on the right hand side as the road starts to level at the top of the hill and you can park on the roadside or at the crossroads just beyond the site.
Catering options – Martins’ Pond pub in Potten End, or numerous cafes, pubs and restaurants in Berkhamsted
The site is in an area of regenerated woodland, owned and managed by the National Trust as part of the Ashridge Estate. It is one of many pits which were dug during WWI to obtain road stone. The beds of sands and gravels were first described by Charles Gilbert in 1919 as mostly beach deposits of Pliocene age, but no fossils have been found so the age and origin have been subject to much debate.
This unique site was designated a Site of Special Scientific Interest (SSSI) in 1954. It was excavated again in 1978, the results of which are summarised in Hertfordshire Geology and Landscape (2010) book, edited by John Catt. It was excavated again in 2012 to take samples to determine the age by Cosmogemic Isotope Analysis, the full results of which are still to be published, but preliminary analysis indicate a date in line with Charles Gilberts original paper.
Site during the 2012 excavation
This video describes the history of the site, the 2012 excavation, the interpretation of the stratigraphy, the provisional results and ongoing geoconservation.
The vegetation continues to be cleared each year by members of HGS. The main face of the 2012 excavation has deteriorated, and will only be fully exposed again as and when further scientific analysis is undertaken with the agreement of the National Trust and Natural England .
See Geoconservation – HGS Active Sites for blog on HGS activity on the site.
References
Catt JA. 2010 – Hertfordshire Geology & Landscape. Hertfordshire Natural History
Society
Gilbert, CJ 1919. On the occurrence of extensive deposits of High-level sands
and gravels resting on the chalk at Little Heath near Berkhamsted. Quarterly
Journal of the Geological Society, London
Moffat, AJ & Catt, JA. 1983 A new excavation in Plio-Pleistocene Deposits at
Little Heath. Hertfordshire Natural History Society.
MOOR MILL QUARRY WEST
MOOR MILL QUARRY WEST
TL 145027
Access issue Industrial Site. Gravels (oldest 470-500ka) and clays from diversion of proto Thames during Anglian glaciation.
Status as at 2008, not visited since.
OUGHTONHEAD LANE
OUGHTONHEAD LANE
Location: TL 172299
Interglacial tufa (probably Hoxnian Interglacial 300-420ka). Not exposed at the surface.
Oughtonhead Lane looking westwards
Oughtonhead Lane runs downhill westwards between overgrown banks, with a drop in elevation of some 10 m along its length; it has been roughly paved in the past. It lies on the margin of a major glacio-fluvial channel running N-S through Hitchin, and the neighbouring field margins show patches of coarse flint-rich gravel.
This is an important tufa site thought to date from the Hoxnian interglacial, containing a rich assemblage of fossil land snails and small mammals which provide significant evidence for Quaternary environmental reconstruction and dating. However, the tufa is not exposed at the surface. It was originally discovered in a trench dug for laying a water pipe, and has more recently been investigated by means of test pits and augering.
Car Parking Roadside parking at top of Redhill Road, Hitchin.
Herts Geology & Landscape p.164
Nearby Attractions
At its lower, westward end, the lane leads to Oughtonhead Common, a Local Nature Reserve containing the headwaters of the River Oughton (one of the few Hertfordshire chalk streams flowing northwards into the Ouse catchment) and various other springs. It was designated for its variety of habitats – marsh, rough grazing, and drier chalk grassland. On the far bank of the Oughton is a Nature Reserve managed by HMWT, containing fen woodland dominated by alder carr, but not open to the public.
WATER END SWALLOW HOLES
WATER END SWALLOW HOLES
A Walk at Water End…
Over several months in 2022 Liam Gallagher, an HGS member, visited Water End near Welham Green in Hertfordshire a number of times to gather information to update our records for this SSSI and to photograph the position of swallow holes at various times of the year under various hydrological conditions.
The geological aspects of the site are discussed in some detail here.
In addition a ‘self-guided walk’ around the site, with less geological ‘detail’ but with information on how to best access the whole of the site and how to enjoy the hydrogeology and geomorphology in a wider sense can be found here so you can enjoy the features of the Potterells Stream and Mimmshall Brook swallow holes ‘estate’.
Water End Mimmshall Brook – small pot beyond sink point.
Taken by Liam Gallagher on 10 April 2022 at 10:28
Water End Mimmshall Brook – small pot beyond now upstream of sink point.
Taken by Liam Gallagher on 10 April 2022 at 12:41.
GREAT WESTWOOD QUARRY
GREAT WESTWOOD QUARRY
TQ 071993
Proto-Thames deposit when flowing through Vale of St Albans (800-900 ka) pre Anglian glaciation Includes volcanic pebbles from north Wales.
Status as at 2008, not visited since.
Page updated
Google Sites
Report abuse