roberts & pope 2009 boxgrove qra field guide

7/31/2019 Roberts & Pope 2009 Boxgrove QRA Field Guide

1/12

94

Q u a t e r n a r y r e s e a r c h a s s o c i a t i o n

95

The QuaTernary of Th e SolenT BaS in an d WeS T SuSSex raiSedBeacheS

Reid, C. 1892 The Pleistocene deposits of the Sussex coast, and their equivalents

in other districts. Quarterly Journal of the Geological Society 48, 344365.

Seaward, D.R. 1982 Sea Area Atlas of the marine molluscs of Britain and Ireland.

Nature Conservancy Council, Shrewsbury.

Seaward. D.R. 1990Distribution of the marine molluscs of north west Europe.

Nature Conservancy Council, Peterborough, 114 pp.

Sparks, B.W. 1961 The ecological interpretation of Quaternary non-marineMollusca.Proceedings of the Linnean Society of London 172, 7180.

Stace, C. 1997 New Flora of the British Isles. 2nd edition. Cambridge University

Press, Cambridge 1130 pp.

Stinton, F. 1985. British Quaternary sh otoliths.Proceedings of the Geologists

Association 96, 199215.

Tebble, N. 1966British Bivalve Seashells. Royal Scottish Museum, Edinburgh,

212 pp.

West, R.G. 1980 Pleistocene forest history in East Anglia.New Phytologist 85,

571622.

West, R.G. and Sparks, B.W. 1960. Coastal interglacial deposits of the EnglishChannel.Philosophical Transactions of the Royal Society of London B306,

95133.

West, R.G., R.J.N. Devoy, B.M. Funnell, and J.E. Robinson. 1984. Pleistocene

deposits at Earnley, Bracklesham Bay, Sussex.Philosophical Transactions of

the Royal Society of London B 306, 137157.

Whatley, R.C. & Kaye, P. 1971. The palaeoecology of Eemian (Last Interglacial)

Ostracoda from Selsey, Sussex. In: Oertli, H.J. (ed.), Colloque sur la

Palocologie des Ostracodes, Pau 1970. Bulletin de Centre de Recherches

Pau-SNPA, Supplment 5: 311330.

Whittaker, J.E. 2003.A Micropalaeontological Analysis of the Lepe (Stone Point)

Pleistocene Deposits, Hampshire. The Natural History Museum, London.7pp.

6.The archaeological and sedimentary records from

Boxgrove and Slindon

Mark B. Roberts and Matthew I. Pope

Introduction: The Westbourne to Arundel Raised BeachBetween 2001 and 2006 the Boxgrove Project team undertook eldwork and

research to ascertain the total surviving extent of the sediments of the Slindon

Formation, which constitutes the bulk of the Boxgrove temperate depositional

sequence (Roberts et al. 1997; Roberts and Partt 1999): this work was entitled

the Raised Beach Mapping Project (Roberts 2003; Roberts and Pope in press).

The mapping project revealed that sediments of the Slindon Formation were

mappable over an east-west distance of 26 km, the resulting feature is now

known as the Westbourne to Arundel Raised Beach, reecting its two mapped

western and eastern extremities (Figure 6.1). The north to south survival

of the sediment stack, in front of the relict cliff line, was more variable. The

conformable sequence is best preserved in the eastern central area of the mappedextent (Figure 6.1), between the Valdoe and Slindon (Pope 2001; Pope et al. in

press); in this region the conformable sequence extends some 0.25 km south of

the cliff, with the unconformable sequence extending up to 0.80 km. Beyond

0.80 km the geliucted Palaeogene and Cretaceous regolith, together with the

gravel generated by cliff erosion and collapse, pinch out the marine Slindon Sand

Member and directly overlie the heavily weathered and dissected Chalk wave

cut platform. Elsewhere, preservation of the sediments is more variable, west

of the River Lavant between Trumley Copse and West Stoke the conformable

sequence is pinched out after less than 50 m in front of the cliff. West of Adsdean

Farm and east of Penfolds Pit at Slindon, the conformable sequence is lost as

the two ends of the beach begin to swing south and the cliff line diminishes

with the transition from Cretaceous to Palaeogene bedrock. Even in the central

areas, the conformable sequence is often disrupted by erosion associated with

slope processes and mass movement, such as at Goodwood, between Boxgrove

and the Valdoe, and Downs Farm, between Trumley and Adsdean (Figure 6.1).

The marine sediments of the Slindon Formation are also cut through by uvial

deposits of the Downland winterbournes, the Rivers Lavant and Ems (Figure

6.1), although the temporal relationship between these two sediment packages

has yet to be elucidated. The marine sediments are for the most part buried under

varying thicknesses of Head Gravel, that range from in excess of 15m in the


2/12

96


97


centre of the distribution to a few meters where the beach crosses the Reading

Beds Formation. At either end of its distribution the beach achieves surfaceexpression and outcrops. In the east the beach can be found on or just below the

surface for 2 km between Tortington and Racton, whilst in the west it outcrops

over its nal 1 km in the area around Westbourne Common (Figure 6.1).

A physical relationship between the early Middle Pleistocene sediments of the

Slindon Formation and deposits of the next surviving marine trangression in the

coastal plain sequence, the Aldingbourne Raised Beach (Figure 6.2), has not been

demonstrated: although the BGS map an outcrop to the south east of Slindon,

at Binsted, where the two are in contact (Figure 6.1, 6.9). The Aldingbourne

Beach cuts through the weathered platform of the Westboune-Arundel Raised

beach and shares the same east-west distribution; this constrained extent is quite

different from the younger Brighton-Norton Beach, which extends some 30kmeast of the River Arun and runs continuously westward, passing immediately

to the south of Portsdown Hill. An age estimation from OSL has been obtained

from the Aldingbourne Sand, which correlates with a position in MIS 7. If this

date is correct it means that the palaeogeography of the coastal plain had to

change radically, early in the stage (see below), with the Brighton Norton event

either representing a later intra stage transgression or a regressing but expanded

coastline. An alternative proposition is that the Aldingourne sediments are older

and were laid down during MIS 11 or MIS 9.

Figure 6.2. The Arundel-Westbourne cliff line running westwards fromBoxgrove, through Goodwood into west Stoke and on to

Westbourne. Q1 = Quarry 1.

The disposition of the sediments of the Slindon Formation is thought to be

constrained by the Middle Pleistocene palaeotopography, which in itself was

determined by the solid geology and its associated structures (Roberts and

Pope in press), and has been described as the extant anticline hypothesis. The

hypothesis develops that proposed by Martin (1938), to explain why there were

no higher raised beaches to the east of the River Arun. Essentially, it is proposed

that the Littlehampton and Portsdown Anticlines exhibited signicant relief and

covered an area more closely related to their current mapped distribution (Figure

6.3), thus creating another range of Downs to the south of the current South

Downs dipslope. The extant anticline hypothesis demonstrates that there was

therefore no connection, except a temporal one, between the c. 40 m beaches

of the western Portsdown Anticline and the Slindon Formation, similarly the

proposed role of the River Solent in terms of contribution to the sedimentary

and biological regimes of the Boxgrove embayment can now be correspondingly

reduced. Marine transgression through the distal ends of the anticlines resulted

in the formation of a semi-enclosed marine bay (Barnes 1980), which became

progressively enlarged through time. At either end of the bay, where the energy

Figure 6.1. Location map showing the distribution of the Slindon

Formation.


3/12

98


99


regime decreases, the littoral sediments arc southwards giving the entire sediment

package a gently parabolic shape. The wave cut platform within the bay includesPalaeogene sediments of the Reading and London Clay Formations to the south

and at the eastern and western extremity of the beach. In the centre of the bay

the platform extends across progressively older beds of the chalk in a classic

ofapping sequence. The time scale of eustatic sea level rise during an interglacial

is difcult to ascertain. However, the fact that fully interglacial faunas were able

to colonise the British Isles in successive temperate episodes, after the Anglian

breaching of the Weald-Artois Anticlinorum, suggests that there was a signicant

lag response between climatic amelioration and sea level heights, probably on

a 104 year scale. Erosion rates of the Palaeogene sediments were substantially

smaller than those of the Chalk but even with a time averaged retreat of 0.5m pa

in the relatively sheltered environment of the bay, the time required to achieve

the maximum point of transgression would only have been in the order of 6kyr. At the close of the interglacial, a similar but reverse lag response is visible,

whereby it appears that sea temperatures are cooling faster than the land. This

fact accounts for the more continental signature of the Boxgrove mammalian

faunas (Partt in Roberts et al. in prep) and also the presence of ice rafted exotic

rocks in all three members of the Slindon Formation (see below).

Explanations for the elevated height of Pleistocene raised beaches and

associated marine sediments above the present day sea level, have moved on

considerably since the formulation of simple eustatic and isostatic models, based

on Milankovitch cycle duration sea level rise and fall, and post continental

ice sheet depression and rebound, respectively. Current thinking links eustatic

and isostatic modeling with processes such as intraplate tectonics (Cloetingh

et al. 2005); crustal extension and shortening resulting in basin development

and basin inversion (Chadwick 1986; Lake and Karner 1986; Hopson 1999, in

press; Aldiss 2002); basement control of overlying Mesozoic structure though

reactivation of Variscan and older faults (Jones 1980, 1981, 1999a, 1999b; van

Vliet-Lano et al. 2000; Lagarde et al. 2003); post Cretaceous to Neogene upliftas a consequence of these aforementioned processes (Plint 1982; Mortimore and

Pomerol 1997; Gale et al. 1999; Evans and Hopson 2000; Blundell 2002); and

lithosphere controlled uplift related to sub crustal rheology, as a result of the

erosion and movement of proglacial continental sediment bodies coupled with

the effect of emplacement and displacement of glacial ice masses (Watts et al.

2005; Westaway et al. 2002, 2003; 2006). In an analysis of the structure and

uplift history of the Raised Beach Mapping Project survey area; all these process

will have played a role. The underlying geological structure of the survey area

and its associated tectonic activity is still active today and is responsible for

the preservation of the Westbourne Arundel Raised Beach, which since its

deposition has been uplifted somewhere in the region of 40m. (Maddy 1998;

Roberts and Partt 1999; Westaway et al. 2006). Although it is clear that uplift isa punctuated event, the 40m gure corresponds to c.8m per 100 kyr on average.

The combination of uplift and the eustatic rise in sea level in the ensuing

interglacial dictate whether raised beach sequences remain intact or are eroded

away and incorporated into the new beach. Similarly, intra interglacial sea level

uctuations can operate with the same effect.

The sediments of the Slindon Formation have been dated to the nal temperate

stage of the Cromerian Complex that in the United Kingdom is correlated with

MIS 13 (Roberts and Partt 1999; Preece and Partt 2000; Partt et al. 2007).

The overlying sediments of the Eartham Formation probably all belong to the

ensuing MIS 12 cold stage, the Anglian Glaciation. Other researchers such

as Bowen (Bowen and Sykes 1994); and Gard (1999) and Young (in Robertsand Pope in press) prefer a designation to MIS 11, based upon amino acid

racemisation and coccolith biostratigraphy, respectively. The MIS 11 age is

rejected because of the taxonomic composition of the Boxgrove mammal fauna

which contains species of both large and small mammals with regionally mapped

last occurrence data (LOD) in MIS 12 (Roberts and Partt 1999). Similarly, the

MIS 11 or Hoxnian Interglacial contains species with rst occurrence data that

almost certainly evolved from their Cromerian predecessors, in refugia, during

the Anglian. Boxgrove now heads a growing group of sites with a Cromerian

Figure 6.3. The coastline in the Boxgrove area at the end of MIS 13.


4/12


5/12

102


103


surrounding intact Slindon Silts, together with a small but signicant amount of

highly calcareous material carried by the spring water discharge. The calcareous

component becomes greater up the prole (Figures 6.5, 6.6), as the availability

of other sediment sources declines. The pond deposits are in part capped by Unit

5a the ferric manganese organic bed of the standard sequence and by colluvial

deposits derived from erosion of the chalk gravel scree slopes in front of the cliff

(Table 6.1) (Figure 6.5); these latter deposits are associated with climatic decline

at the end of the Cromerian Complex and the advent of the ensuing Anglian

Glaciation in Marine Isotope Stage 12 at c. 480 kyr bp.

The inuence of freshwater into the catchment around Q1/B only becomes

apparent after marine regression, although rare freshwater and some euryhalineostracods in the standard sequence might reect the overall contribution of

spring fed freshwater into the neritic environment and localised reduction in net

salinities. Evidence for the initial deposition of freshwater sediments is found

in the main northwest-south east trending channel that runs through the site

(Figure 6.5) and in the truncated surface of Unit 3, the Slindon Sand, this unit

also exhibits smaller scour channels that migrate southwards across the surface.

The main channel, which achieves a maximum depth of 0.8m, is inlled with a

Figure 6.4. (a) The classic Boxgrove marine-terrestrial sequence from the

western edge of area Q1/B (left) and (b) the freshwater terrestrial

sequence from the middle of the Q1/B waterhole (right).

Figure 6.5. The channel deposits, Unit 3c, underlying the calcareous silts of

Unit 4. Note the preservation of Unit 5a, the organic bed, at this

part of the waterhole.

Figure 6.6. The excavated landsurface at the top of the marine Slindon Sand,

Unit 3, at Q1/B. The surface of the sand has been reworked by

freshwater emanating from springs issuing from the base of the

cliff, some 50m to the north of the site.


6/12

104


105


coarse gravel deposit at the base, containing int beach pebbles, worked int and

bone fragments; the ne component of Unit 3c is largely arenaceous, with some

chalky clay deposition with ne to massive bedding (Macphail in Roberts et al.

in prep). Reworked and in situ lithics and faunal remains were found throughoutthe unit as well as chalk mud clasts and humic soil traces, indicating the erosion

of nearby landsurfaces. Outside of the main channel, the truncated surface of

Unit 3 has undergone pedogenesis and ripening prior to the deposition of Units

4u and 4 (Figures 6.6, 6.7), which constitute the main body of the freshwater

sediments. These processes along with an input of dung from mammals using

the waterhole, give rise to a phosphate-P concentration twice as great as that

encountered in the standard sequence at this stratigraphic level (Crowther in

Roberts et al. in prep). Similarly, the upper part of the sands at Q1/B contains

a signicantly higher silt component than elsewhere at the site, attesting to the

admixture of ner sediments from the Slindon Silt Member (Units 4a and 4b)

both during the truncation and subaerial weathering phase, and during the later

redeposition of the silts by the calcareous freshwater source.

The channel deposits are completely overlain by Unit 4u, the basal freshwater

unit of the waterhole sequence, and its associated sub-units 4us and 4.* (Table

6.1). Elsewhere in the waterhole Unit 4u only partially covers the Unit 3 surface,

whether this distribution mirrors its original deposition or if it has been partially

eroded, has yet to be elucidated. This unit is a massive silt with rare traces of

bedding, although in places a sandier facies, indicating higher energy deposition

has been noted. Unit 4u is overlain by Unit 4, the thickest and most extensive

Member

D

escriptionandInterpretation

Standard

Q1/B

Descriptionand

Interpretation

C

alcareousHead.Massmovement

deposit.

Unit10

Unit10

CalcareousHead.Massmovementdeposit.

EarthamUpperGravel

Pathgravel.Freezethawsortedint

gravel.

U

nit9

NotseenatQ1/B.

C

halk

pellet

gravel.

Waterlain,

w

eatheredandsortedchalkclasts.

U

nit8

Unit8

UpperChalkpelletgravel.Dewateringstructures

initiated.

EarthamLowerGravelC

liffcollapse.

U

nit7

NotseenatQ1/B,probably

toofarsouthofthecliff.

C

alcareous

muds/brickearth.

C

olluvialandwaterlainsilts.

Units5b,6

Unit6b

Calcareousmuds/brickearth

..Colluvialandwaterlain

silts.

M

ineralisedandcompressedorganic

deposits.Alder/fencarr.

Unit7

Unit5a

Unit5a

Mineralisedandcompresse

dorganicdeposits.Alder/

fencarr.

Soilhorizondevelopedontopofthe

silts.Poldertypesoil.

Unit4c

4d2,4d3,

5ac

Spring

dischargesedimen

tswith

colluvial,chalk

pellet,inputtowardsthetop

(5ac)

Unit4d1

Springdischargesediment.

Intraformationalcalcretes.

Unit4b

SlindonSilt

Intertidallaminatedmudslaiddown

in

a

Unit4

Massivesiltfrom

freshwaterreworkingofUnits4a

and4b.Heavilydeformed.

semi-enclosedmarinebay.

Unit4a

Unit4u

Massivenesiltfrom

freshwaterreworkingofUnits

4aand4b.Includessubunits

4usand4*

Units3/4,

3c

Freshwaterchannelsandfreshwaterscoured

landsurface,fromspringsatcliffbase.

Unit7

SlindonSand

N

ear-shoremarinesands.

U

nit3

Unit3

Nearshoremarine

sands

with

atruncated

upper

surface.

Table6.1.Stratigraphicrelationshipbetweenthestandard

Boxgrovesequenceandthatrecor

dedatQuarry1/B,the

springfedw

aterhole.Unit4canditschronostratigraphiccorrelativesareoutline

dinblack.Unit7isa

sedimentary

unitthatisincontinuousformatio

nuntiltheburialofthecliffbyma

ssmovementdeposits.

(Nottoscale).

Figure 6.7. Photomicrographs of M29, Q1B, Unit 3/4, showing detail

of curved pans of chalky mud at the base of a 80+ mm wide

depression (animal print?) that contains coarsely fragmented

sandy sediments; pans are also associated with the anomalous

concentrations of iron staining here that may be relict of inputs

of amorphous organic matter/dung. OIL and PPL frame widths

are ~4.62 mm.


7/12

106


107


of the waterhole deposits, it comprises a dense massive silt that is relatively

homgenous at both the macro and micro scale, the unit has been heavily disturbed

by pore water release deformation structures from dewatering (Figures 6.5, 6.7),

most especially towards its surface. Macphail (ibid) has identied three phases

of deposition; the rst of which involves erosion and redeposition of Unit 4u

material; the second is characterised by an increase in plant detrital material and

bioturbation; and the third is characterised by massive calcareous silting under

an increasingly wet depositional regime.

The upper pond deposits begin with Unit 4d1, a highly calcareous white silt of

variable thickness that contains intraformational calcrete nodules, the source of

the carbonate is likely to be from directly from the Cretaceous Chalk at the cliff

base. Unit 4d1 is overlain by the highly mixed sediments of Unit 5ac (Figures 6.5

& 6.7), this poorly sorted deposit is predominantly a coarse silt, with subrounded

chalk clasts and sand size quartz grains. Bedding is occasionally present along

with organic laminae similar to but thinner than Unit 5a. The origins are Unit

5ac are a mix of redeposited pond sediments combined with upslope colluvial

deposits. Unit 5ac is succeeded by a return to highly calcareous spring deposition

of Units 4d2 and 4d3, which are in turn overlain by the marker horizon and

upper bed of the Slindon Silt Member, Unit 5a. This bed, between 10 and 15mm

thick has recently been mapped over a distance of 15km by Roberts and Pope(in press). Unit 5a comprises many microlaminations of detrital organic material

and was deposit in an alder/fen carr environment that developed on top of the

Slindon Silts. The colluvial sedimentation that overlies Unit 5a sees a reversion

to the standard stratigraphic sequence seen elsewhere at Boxgrove, although at

this part of the sequence certain units are not represented.

The waterhole or pond sediments described here were deposited under fully

interglacial conditions, as demonstrated by the taxonomic composition of

the mammalian, herpeto and ostracod faunas. Evidence for drying out of the

waterhole either in its entirety or through a shrinking shoreline, is attested to

by the presence of earthworm granules and discrete horizons containing dead

freshwater ostracod tests. The locale, which would have been rich in terrestrialand aquatic vegetation was utilised by many elements of the Boxgrove fauna,

including hominins (Figure 6.8). The remains of butchered rhinoceroses, deer

and other animals point to it being a place of food procurement and processing

as well as a water source (Figure 6.6). The whole of the depositional sequence

at Q1/B from the basal channel deposits up to the surface of Unit 4d3 was time

equivalent and thus a chronostratigraphic correlative of Unit 4c, the soil bed that

developed on the surface of the Slindon Silts after marine regression (Roberts

and Partt 1999).

Slindon

The village of Slindon is located on the dip slope of the South Downs; some 4km east of Boxgrove, 9 km east of Chichester and 12 km north of the current

English Channel at Middleton (Figures 6.1, 6.8). Various Middle Pleistocene/

Palaeolithic sites have been revealed along the line of the relict cliff of the

Westbourne-Arundel Raised Beach, both by the research of the Raised Beach

Mapping Project team and by earlier workers (Prestwich 1859; Calkin 1934;

Jeffries 1959; Woodcock 1981; Roberts and Pope in press). The sites running

from west to east are: Everymans Pit; Slindon Bottom; Slindon Park; Gaston

Farm and Penfoldss Pit. The sedimentary sequence at Slindon Park and Gaston

Farm were revealed in cable percussion boreholes whilst at the other locations,

sections were available after cleaning.

The bedrock of the cliff and wave cut platform largely comprises the Tarrant andNewhaven Members of the Upper Chalk Formation. However, in places, part of

the cliff and the solid to the north of the cliffs is made up of an elongate outlier

of Reading Beds. The Palaeogene deposits are preserved in a c. 4 km long, strike

parallel, normal fault. The downthrow, to the north of the fault, is estimated to be

in the region of 10 m (Hopsonpers comm.), with the surface footprint extending

to a maximum extent of 150 m. The presence of the impermeable Reading Beds

in the cliff has had important implications for Pleistocene coastal morphology,

preservation of organic sediments and Anglian snow-melt drainage.

Figure 6.8. Pre-mortem cut-marked incisors from the waterhole sediments

at Q1/B.


8/12

108


109


Everymans Pit

This quarry contained the full sequence of Slindon and Eartham Formationdeposits and was very similar to that at Boxgrove, albeit further south of the cliff

and lacking the freshwater sediments (Woodcock 1981; Wessex Archaeology

1996; Wymer 1999). A handaxe was found on the oor of the pit by the Reverend

Fowler (1929) but there is little other lithic material recorded. In 2003 the authors

carried out a watching brief on a water transfer pipeline beginning at the Slindon

reservoir immediately to the north of Everymans Pit, and located the clifine

and raised beach, together with lithics and vertebrate microfauna (Roberts and

Pope 2004; Roberts et al. in prep).

Slindon Bottom

This site is probably the best known of all the Slindon exposures and until the

excavation of Boxgrove, produced the largest assemblage of Lower Palaeolithic

artefacts in Sussex. The site has been subject to sporadic collection by the likes

Jeffrey, and Zeuner who used to bring classes from the Institute of Archaeology

to the site; and focussed excavation by Calkin (1934), Woodcock (1981) and

Pope (2001). Excavation of the oor of Slindon Bottom by Pope (ibid), as part

of the RBMP rediscovered the original sections of Calkin and Woodcock along

with a handaxe and associated knapping debris. Previously, it had been proposedby Woodcock (1981) that Slindon Bottom represented a tidal inlet of the Slindon

Formation sea, that extended, through its connection with a downland valley

system, northwards beyond the relict cliff. However, test pitting across the valley

and to the north of the Slindon Eartham Road shows unequivocally that the cliff

and beach are extant in this area but have been reduced or removed by Pleistocene

snow melt discharge, leading to their preservation and exposure on either side of

the valley (Figure 6.14). It was the conguration and combination of the eastern

Eartham Valley and the Courthill Valley that therefore led to the formation of

Slindon Bottom, similar drainage patterns are also likely to be the precursors of

other substantial valley systems such as the Binsted Valley/Avisford Dell (Figure

6.9).

Slindon Park

Eleven boreholes were sunk in Slindon Park, immediately to the east of Slindon

Bottom (Figures 6.9-6.11). The boreholes proved a long 0.70 km north to south

sequence similar to that revealed by quarrying at Boxgrove and a west to east

sequence that revealed previously unrecorded organic deposits trending back into

the full conformable marine terrestrial sedimentary prole. The organic deposits

contain a late temperate pollen ora (Gibbard in Roberts and Pope in press)

(Figure 6.15), that includes Larch (larix) which appears to be an indicator species

for late Cromerian IV/ MIS 13 sites (Gibbard et al. 2003). Further examination

of selected levels of the organic deposits using micromorphology has revealed

well preserved plant detritus and wood charcoal (Macphail in Roberts and Pope

in press) (Figure 6.17) The stratigraphic correlation of these organic sediments

with the sequence recorded at sites such as the Valdoe, Boxgrove, Everymans

Pit and Slindon Park east requires further borehole work. However, they are

possibly a local continuation of the freshwater organic beds of Unit 5a that have

been mapped over a distance of 15 km between Adsdean and Slindon (Figure

6.1). The organic beds do however thicken to the west and achieve their greatest

extent in BHs 2 and 3, where they unconformably overlie the marine Slindon

Sand, it may be that they were deposited in a actively owing freshwater system

that was a prototype of the Slindon Bottom valley.

Figure 6.9. Geology of the area around Slindon showing the line of the

Slindon-Park Farm normal fault. Note the oulier of Reading

Beds preserved by the fault, to the south of Slindon Village.

SCk=Seaford Chalk; NCk=Newhaven Chalk; TCk=Tarrant

Chalk; SPCk=Spetisbury Chalk; ReaB=Reading Beds;

LClay=London Clay; URBs=Upper Raised Beaches; Lower

Raised Beaches; Cwf=Clay-with-ints; HGrvl=Head Gravel;

Be=Brickearth; TAlluv=Tidal Alluvium.


9/12

110


111


Figure 6.10. Slindon Park looking south from the downland dipslope to-

wards the coastal plain. Note the break of slope that indicates

the position of the buried cliff line.

Figure 6.11. Plan showing the location of boreholes in Slindon Park.

Figure 6.12. West to east borehole logs through the stratigraphy at

Slindon.

Figure 6.13. North to south borehole logs through the stratigraphy at

Slindon.


10/12

112


113


Figure 6.14. Geliucted Reading Beds and Chalk overlying the surface of

the beach at Slindon Bottom.

Figure 6.15. Pollen diagram from the organic deposits in Borehole 5 at

Slindon Park.

Figure 6.16 a-f. Examples of sediment micromorphology from Slindon Park

BH5.

Figure 6.16a. U100 from BH5.

Figure 6.16b. Scan of 50 mm long thin section

BH5-M.2B; contains many plant

fragments some large and well

preserved.

Figure 6.16e. Scan of 60 mm long thin section

BH5-M.3A; contains layer of

wood charcoal.

Figure 6.16c. Detail of Fig. 16b, long plant

fragment; Plane polarised light

(PPL), frame width is ~7.7 mm

Figure 6.16d Detail of Fig. 16c , well preserved

blue light autofuorescent plant

tissues. Frame width is ~1.6 mm.

Figure 6.16f Detail of wood charcoal in non-

calcareous iron-stained clay. PPL,

frame width is ~7.7 mm.


11/12

114


115


Gaston Farm

Three boreholes were sunk at Gaston Farm (Figure 6.17); the rst was abandoned

after less than 2m as it went directly into the Reading Beds, eighty metres to

the south BH2 was drilled down through almost 25m of relatively homogenous

silts before the hole was abandoned. However, a further seventy metres south of

BH2, BH3 passed back into the normal sequence. Whether the unique sequence

at BH2 is the result of snow melt run-off over the impermeable Reading beds

cliff creating a plunge pool or a feature of the fault line itself is as yet unknown.

Samples looking for mammals, freshwater invertebrates and pollen all proved

barren.

Penfolds Pit

The most easterly of the Slindon sites Penfolds Pit is at the northern end of

the Binsted Valley, which is the modern name of Prestwichs Avisford Dell

(1898). Penfolds Pit like Everymans Pit to the west, is located on the side of the

valley, and has produced numerous handaxes from residual contexts (Pyddoke1950; Woodcock 1981). Detailed records were made by Jeffrey (1957, 1960)

who recorded two levels of beach, a phenomenon noted in GTP 13 at Boxgrove

(Collcutt in Roberts and Partt 1999) and the fact that the pebbles from the basal

beach were sat in a pink clay like eggs in a box. It is now clear that the clay was

derived from the Reading beds that form part of the cliff at this site. Penfolds

Pit is now completely overgrown but would repay diligent section cleaning if the

opportunity arose.

Acknowledgements

The authors are grateful to English Heritage for their funding of the Raised Beach

Mapping Project and the Boxgrove Project. We extend our thanks to the many

landowners who facilitated our research by allowing access and investigation.We are indebted to Richard Macphail and Phillip Gibbard for their work on

the micromorphology and palynology, and most importantly to John Whittaker

for his work on the invertebrate microfauna, and his unstinting support of our

research.

References

Aldiss 2002

Barnes 1980

Blundell 2002

Bowen 1999

Bowen and Sykes 1994

British Isles (2003).

Calkin 1934

Cloetingh et al. 2005

Chadwick 1986;

Evans and Hopson 2000;

Gard (1999)

Gibbard et al. 2003

Hedberg 1986,

Figure 6.17. Boreholes at Gaston Farm revealing the great depth of inll

deposits in front of the cliff at BH2. Both axes scaled in metres,

Y axis is m OD.


12/12

116


117


Hopson 1999, in press;

Jeffries 1959

Jones 1980, 1981, 1999a, 1999b;

Lagarde et al. 2003

Lake and Karner 1986;

Macphail in Roberts et al. in prep

Maddy 1998;

Martin 1938

;Mortimore and Pomerol 1997;Partt et al. 2007

Plint 1982Gale et al. 1999;

Pope 2001

Pope et al in Press

Preece and Partt 2000;

Prestwich 1859

Pyddoke 1950;

Reverend Fowler (1929)

Roberts 2003

Roberts et al. 1997

Roberts and Partt 1999

Roberts and Pope in PressSalvadore 1994

van Vliet-Lano et al. 2000

Wessex Archaeology 1996

Watts et al. 2005;

Westaway et al. 2002, 2003; 2006

Westaway et al. 2006

Whittaker 1999

Woodcock 1981

Wymer 1999

roberts & pope 2009 boxgrove qra field guide

Documents