Báo cáo "Some results of discovering old vestiges in the vicinity of Kinh Thien Temple " doc
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VNUJournalofScience,EarthSciences23(2007)177‐186
177
Someresultsofdiscoveringoldvestiges
inthevicinityofKinhThienTemple
VuDucMinh
1
*,NguyenBaDuan
2
1
CollegeofScience,VNU
2
InstituteofGeophysics,VAST
Received14June2007
Abstract.Afterreportingtheresults ontheoldroad foundationsaroundDoan Monvestige,apart
frominvestigatingtodiscoveroldvestigesinthevicinityofKinhThienTemple,theauthorstryto
determine whether these old discovered road foundations still exist and direct from inside Doan
MontoKinhThienTempleornot?
Theresultsshowthatitcanbeimaginedthatwholeinvestigatedareacanlocateontheflathill,
withindicationsofthecultureoftheLeDynastyandoftheTranDynastyatthedepthofabout1m
and 2 m. The indications
of old road foundations and old roads are clearly seen. These road
foundations and roadshave a directionextended from Doan MonGate to Kinh Thien Temple. In
addition, small noticeable abnormal objects have been discovered in the investigated area. The
resultsarereportedinthispaper.
Keywords:GPR;MRI;Profile;Antennae;Wavepatterns.
1.Introduction
*
A difficult problem of archaeological work
isthatinordertodiscoveroldvestigesonehas
firsttorelyon signsonthegroundsurfaceand
thendoexcavationsbyhanddigging.Thisdoes
not always lead to a positive result, and
sometimes partly destroys the vestige. On the
other
hand, if a vestige has been found after
digging, its preservation is very difficult,
expensive,andloweffective.
Nowadays, geophysical archaeological
methods have been successfully used in the
world for the purpose of discovering, locating
and mapping archaeological objects buried in
_______
*
Correspondingauthor.Tel.:84‐4‐8587781.
E‐mail:
the ground. Among those, the Multi‐electrode
ResistivityImaging(MRI)method[1,3]andthe
Ground‐PenetratingRadar(GPR)[2,3]method
arenearearthsurfac eon es,wh ichareconsidered
asthemainmethods.
In Vietnam, geophysicists start to pay
attentiontothisproblem,especiallyleadersand
managershavebeenallowed
tousegeophysical
methodsintheworktodiscoveroldvestigesin
order not to destroy the scene as well as the
vestiges, to help the archaeologists to see
overall picture of the area under investigation,
andhencetodigonlynecessaryvestiges.
This paper presents some results of
discovering
old vestigesin thevicinity of Kinh
ThienTempleusingabove‐mentionedmethods.
VuDucMinh,NguyenBaDuan/VNUJournalofScience,EarthSciences23(2007) 177‐186
178
2.Featuresoftheareaunderinvestigationand
fieldmethods
Atpresent,theKinhThienTempleareaand
its vicinity (Fig. 1) have many houses in use.
Apart from these houses, internal roads are
concretedorasphalted.Therearenoanysignof
theoldvestigesonthegroundsurface.
However, above Kinh Thien Temple,
according to historical data, there is a house
which was built a long time ago and has been
restored. Below the King’s yard, there are two
stonedragonswithheadsalongthenorth‐south
direction.
BehindthehousesN6andN18tothesouth
isDoan
Monvestige.TheArchaeologicalInstitute
and Department of Culture and Information of
Hanoi have made archaeological excavations
inside Doan Mon vestige. They have found a
yard coveredby the brick, stone jetty ofthe Le
Dynasty at the depth of 1‐1.2m, a 1.3m‐wide
roadoftheTranDynasty
coveredbythelemon
flower‐colorbrickatthedepthof1.9‐2m,below
itthe roadfoundationsoftheLy Dynasty have
been found. In previous research on the area
around Doan Mon [3], we have discovered
these old road foundations behind Doan Mon
vestige.Therefore,apartfromourinvestigation
in order to discover old vestiges in the Kinh
Thien Temple area, we want to determine
whether these old road foundations still exist
and direct from inside the Doan Mon to the
KinhThienTempleornot?
We used two geophysical methods: GPR
and MRI. The measuring profiles have been
arranged so that they are co inciding with or
perpendicular to the directions of old road
foundations found inside Doan Mon vestige,
fromDoanMongatetotheKing’syardofKinh
Thien Temple, with two areas: area 1 between
Kinh Thien Temple and house N15, area 2
between houses N16, N17,
N6 and N18. In
these profiles, the MRI measuring profile with
distanceof1mbetweentheelectrodesisprofile
DIEN‐2 just in front of house N15 and the
King’syardandaplentyoftheGPRmeasuring
profiles with antennae of 80 MHz (denoted as
80,forexample80D11),200MHz(denotedas2,
for example 2D4) and 400 MHz (denoted as 4,
forexamp le4TEST1).Theseprofilesar epresented
inFig.1.
3.Resultsofanalysis
3.1.AreabetweenhousesN16,N17,N6,andN18
In this area, we have made seven GPR
measuringprofileswithantennaeof
80,200and
400 MHz. Among these profiles, five profiles
directedfrom Eastto West(profiles 80N30 and
4TEST1, which coincide with each other) and
two profiles directed from the south to the
north,whichcoincidewitheachotherbuthave
different depths. Due to technical reason, MRI
measurementshave
notbeencarriedout(Fig.1).
Fig.2showstheresultsofanalysisforthree
GPR profiles measured by 80 MHz antenna. In
the wave pattern of these profiles, a sign of
foundat ionlayersisnotseenbecausewavelength
of the 80 MHz antenna is large (about 1.25 m)
and,consequently,
manyobjectsofsmallersize
areneglected.However,from2Djoinedpicture
andwavepatternsweobserveratherclearlythe
geologicalstructureofthisarea(probablyitisa
broadandnothighhill).
Comparing the results of the GPR sections
of two coinciding GPR profiles 80D9N and
80D9N2 having
different depths (Fig. 3), one
can see that geological structure signs along
these profiles coincide with each other and are
atsmalldepth(about2.5m)inthebeginningof
theprofiles.
Fig.4presentstheresultsoftheGPRsections
with200MHzand400MHzantennae.Allthree
GPR
sections show similar characteristics,
namely many abnormal objects and strong
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179
reflectingborders.Asignoffoundationlayerat
1mdepthexistbutnotclearly;foundationlayer
at2mdepthisratherclearlyseenontheprofile
2TEST1but not clearlyonother profilesdueto
distanceisnotdeepenough.Intheendingpart
of the profiles (closed to house
N17 in the
scheme), there are strong reflecting geological
borders at small depth (only about 1.5 m)
sloping to the beginning of the profiles. This
canbeavestigeofahillarea.Itiscoveredbya
filledlandaffectedbyhumanactivities.
Especially, on two GPR sections 4TEST2
and
4TEST1 there is a sign of a road of the Le
Dynasty, on both sides of which there are two
stone jetties, in particular clear on the GPR
section 4TEST2, in the middle of which we
observe multiple reflections since radar waves
beatatstrongreflectingobjects(brick,sto n e et c. ).
This sign is clearly seen in Fig. 5. However,
these two profiles are about 10 m apart but
distance between two stone jetties is changed?
On the GPR section 4TEST2 it is from distance
at 5.5 to 10 m (4.5 m), on the GPR section
4TEST1fromdistanceat6.5to
9.5m(3m).This
problem should be clarified in the next
investigation.
Fig.1.Positionschemeofgeophysicalinvestigationprofiles.
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180
Fig.2.Wavepatternsand2Djoinedpicturesof80MHz‐antennaprofiles:
twoprofiles80N31,80N30andoneprofile80D9N2.
Fig.3.ComparisonoftheresultsoftheGPRsectionsoftheprofiles80D9N2(above)
and80D9N(below)coincidingwitheachotherbutwithdifferentdepths.
VuDucMinh,NguyenBaDuan/VNUJournalofScience,EarthSciences23(2007) 177‐186
181
Fig.4.Wavepatternsandresultsofanalysisforprofiles2TEST1(above),4TEST2(middle)and4TEST1(below).
3.2. Area in the front of the King’s yard of Kinh
ThienTemple
Inthisarea,wehavemade4GPRmeasuring
profiles with antennae of 80 MHz, 200 MHz
and one MRI profile (DIEN‐2). Among those,
profiles 80D11 and 2D4 coincide with each
other, in front of the King’s
yard; the profiles
80D12and2D5coincidewitheachot her,infront
of the yard of house N15 and nearly coincide
with the profile DIEN‐2. These profiles direct
from the east gate to the west gate (Fig. 1), or
fromtherighttotheleftinwavepatterns.
In
the wave pattern of the GPR measuring
profileswithantennaeof200MHz(Fig.6),one
can see two foundation layers at the depth of
about1mand2m,existingfromthebeginning
to the end of the profiles. Probably these two
foundation layers are related to the culture
of
the Le Dynasty and the Tran Dynasty. On the
GPRsection2D5(infront ofhouseN15) asign
of 2m‐foundation layer is weaker; on the GPR
section 2D4 (in front of the King’s yard), this
foundation layer is clearer and somewhat
sloping to east. On both profiles,
abnormal
objectsarediscovered.OntheGPRsection2D4,
there are several strong reflections at distance
of 11‐24 m (in the part in front of the King’s
yard)from groundsurfacetothedepthof1.7m.
This can be due to multiple reflections from
terraces in front of the
King’s yard under
ground.OntheGPRsection2D5,therearetwo
regionsatdistanceof4‐10mand15‐20m,atthe
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depth of 0.5‐1.2 m in which an indication of
inhomogeneousenvironmentexists. Especially,
betweenthesetworeg ions(atdistanceof10‐15m)
thereare verystrong reflectionsatthedepth of
1.2mandbelow.Thesemaybereflectionsfrom
aflagstoneorfromratherthickconcrete.
Fig.
7 presents a comparison of two wave
patterns of the same profile2D5 but measured
by RAMAC equipment with 500 MHz antenna
and by SIR 10B equipment with 200 MHz
antenna. One can see two inhomogeneous
regionson both sides andone strongreflecting
anomaly in the middle of which have
rather
clear and coinciding indications. One can
observe indicationofthisanomalyinthewave
pattern of profile 80D12 (Fig. 8) and
pseudoresistivitycross‐section(Fig.9).
In the wave pattern of the GPR profiles
(80D12 and 80D11) with antennae of 80 MHz
(Fig. 8) indications of foundation layers and
of
someabnormalobjectsarenotclearbecausethe
antennaoflowfrequency(80MHz)isusedand,
consequently, many objects with smaller size
are neglected. In addition, this type of antenna
does not havethe curtain that causes thewave
patterns to be strongly perturbed. However, in
the wave patterns
some large objects such as
geological borders and terraces in front of the
King’s yard on profile 80D11 near the King’s
yardareindicatedratherclearly. The geological
bordersstarttoappearatsmalldepth(about3m)
indicatingnon‐flatgeologicalstructures.Itmay
be a hill area, which
has been leveled or
depositedmanytimes.
Fig.5.Wavepatternsand2Djoinedpicturesofprofiles4TEST1and4TEST2.
VuDucMinh,NguyenBaDuan/VNUJournalofScience,EarthSciences23(2007) 177‐186
183
Fig.6.Wavepatternsandresultsofanalysisforprofiles2D5(above),
2D4(below)and2Djoinedpicture(middle).
Fig.7.Comparisonoftwowavepatternsofprofile2D5:obtainedbyRAMACequipment
with500MHzantenna(above)andbySIR10Bequipmentwith200MHzantenna(below).
VuDucMinh,NguyenBaDuan/VNUJournalofScience,EarthSciences23(2007) 177‐186
184
Fig.8.Wavepatternsandresultsofanalysisforprofiles80D12(above)and80D11(below).
Fig.9.ComparisonoftheGPRsection2D5(above)andMRIsectionDIEN‐2(below).
Fig. 9presents a comparison of GPR section
2D5 (above) and MRI section DIEN‐2 (below).
The positions of these two profiles are nearly
the same. One can see two inhomogeneous
regions on both sides and strong reflecting
anomaly in the middle of which described
above coincide well with three high
‐resistivity
regions on the pseudoresistivity cross‐section.
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With the resistivity scale, perhaps anomaly in
the middle is concrete. Below this anomaly,
there is a low‐resistivity, rather symmetrical
region. With these indications, it can be a
reservoir which is made of concrete. Below it,
there is a low‐resistivity region, this is the
reason of strong diminishing
of radar waves,
affectingpenetrabilityoftheGPRsignals.
4.Concludingremarks
‐ In the area between housesN16, N17, N6
and N18, results of analysis for the profiles by
GPR methods, through 2D joined picture and
the wave patterns of 80 MHz‐antenna profiles,
allow to observe rather clearly the
geological
structureat oldtimes.Itcan beaflathill.When
measuring by 200 and 400 MHz antennae,
results show indications of many abnormal
objects and several strong reflection borders,
especially the indications of the road of the Le
Dynasty, the stone jetties on both sides, the
indications of multiple
reflections due to
beating of radar waves at strong reflecting
objects (brick, stone etc.). The foundation layer
atthedepthof2misalsoclearlyseen.Closeto
houseN17,thereisageologicalborderofstrong
reflections at small depth (only about 1.5 m).
Thiscanbea
vestigeofahillarea.Itiscovered
byafilledlandaffectedbyhumanactivities.
‐InthefrontareaoftheKing’syardofKinh
Thien Temple, results of analysis for the
profiles by the GPR methods also show rather
clear indications of geological borders,
foundation layers on the
wave patterns and of
terraces in front of the King’s yard on profile
80D11closedtotheKing’syard.Thegeological
bordersstart toappe aratsmalldept h(about3m),
indicatingnon‐flatgeologicalstructures.Itmay
be a hill area, which has been leveled or
deposited many times. In
the wave patterns of
the 200 MHz antenna profiles, there are two
foundationlayersatthedepthofabout1mand
2 m. Probably these two foundation layers are
relatedtothecultureoftheLeDynastyandthe
Tran Dynasty. On both GPR sections, some
abnormalobjectshave
alsodiscovered.OnGPR
section 2D4 (in the part in front of the King’s
yard), there are several strong reflections at
distanceof 11‐24 mfromground surfacetothe
depth of 1.7 m. This can be due to multiple
reflections from terraces in front of the King’s
yard under
ground. On GPR section 2D5 (in
frontofhouseN15)at thedepthof0. 5‐1.2m,ther e
isanindicationofinhomogeneousenvironment.
Especially,atdistanceof10‐15mtherearevery
strongreflectionsatthedep thof1.2mandbelow.
These may be reflections from a
flagstone or
from rather thick concrete. Comparing GPR
section 2D5 and MRI section DIEN‐2 having
nearly the same position, one can see that
resultsobtainedbybothmethodsareveryclose
toeachother.It canbeexpectedthatanomalyin
themiddleisconcrete.Belowthisanomaly, there
is
alow‐resistivity,rathersymmetricalregion.
‐ Thus, it can be imagined that whole area
under investigation can be located on the flat
hill, with indications of the culture of the Le
Dynasty and of the Tran Dynasty at the depth
of about 1 m and 2 m. The indications of
old
road foundations and old roads are clearly
seen. Comparison with our previous results of
investigation around Doan Mon vestige shows
that these road foundations and roads have a
direction extended from Doan Mon Gate to
KinhThienTemp le.Inaddition,smallabnormal
objectshaveb eendisc overed,whicharescattered
ontheprofiles.
‐ Once again, it can be stated that the
application of GPR and MRI methods to
discoveroldvestigesin the groundin Vietnam
isveryfeasibleandeffective.However,inorder
toindicateexactlythe positionandstructureof
old vestiges, one has to select relevant
antennae,
to arrange the system of profiles so
VuDucMinh,NguyenBaDuan/VNUJournalofScience,EarthSciences23(2007) 177‐186
186
thata3Dpictureoftheareaunderinvestigation
can be constructed, to determine exact wave
propagation velocity of the environment under
investigation, to carry out measurem ent s and
investigationinmoredetail.
‐ We have improved and are continuing to
improve the MRI method in the direction of
selecting,improvingthe
electrodes, development
of ways and procedure of data collection as
well as programs for analysis in order to
increase the effectiveness of this method in
general and of application of combination of
the GPR and improved MRI methods in
particulartodiscoveroldvestiges.
Acknowledgements
The author would like to
thank BSc. Pham
Hoai Nam, MSc. Ta Quoc Khanh‐the staff
members of the Institute for Conservation of
MonumentsandMSc.DoAnhChung‐thestaff
of the Centre for Termite Control Research,
Institute for Water Resources Research for
helpingusduringmeasurementsinthefield.
References
[1] Geotomo Software, Res2dinv Manual Ver. 3.5.4,
Penang,Malaysia,2004.
[2] N. Stewart, H. Griffiths, Ground Penetrating
Radar, 2
nd
Edit io n, MPG Books Limited, Bodmin,
Cornwall,UK,2004.
[3] Vu DucMinh,Nguyen Ba Duan, Application of
methods of Ground Penetrating Radar and of
Multi‐electrode Resistivity Imaging to discover
oldroadfoundationsaroundDoanMonvestige,
VNU Journal of Science, Earth Sciences 23 (2007)
126.
