Diagram of all 316 mortar samples

1
BUILDING ROMA AETERNA MORTAR DATING AND ROMAN
POZZOLANA, RESULTS AND INTERPRETATIONS
2
Diagram of Mortar samples from the Åland
Islands, 140 samples
Correct or plausible results 81,4
Correct results Plausible results Results wrong,
but reason known Wrong results
3
Åland mortars from securily dated structures,
compared to dendrochronologi and 14C dated wood
structures A total of 50 samples
42 correct 84 5 wrong, but reason known 10 3
results wrong 6
4
Sampling at the Roman villa of Torre de
Palma Portugal was done in 1997-2000. It
resulted in a chronology of the site
Beginning with The East Bath in the first
century AD
5
Ending with the large font of the Baptistery
6
Rome
Samples from Trajans market, from 1999
and Hadrianic Samples from Ostia
7
Carolingian construction at Nervas Forum,
analyzed in two fractions in 1998. Result of the
first fraction plausible.
8
Santo Urbano, excavated under Via dei Fori
Imperiali
9
Trajans Forum,Basilica Ulpia, calibrated
result 60AD-140 AD
10
Rome, Torre delle Milizie, analyzed in Aarhus
in two CO2 fractions, and in Oxford in
five. Calibrated age AD 1260-1285.
To begin with, in 1998, three samples from Torre
delle Milizie were analyzed in two CO2 fractions
in Aarhus
11
Sample Rome 007 was later analyzed in five
fractions by The Oxford Radiocarbon Accelerator
Unit. It confirmed the results yielded by the
first fractions. Calibrated age Ca 1205 AD-1260
AD
12
The Colosseum, erected ca 80 AD, four different
profiles agree on the first fractions with the
estimated age
13
The temple of Jupiter Anxur, Terracina
14
Sampling at Terracina, a candidate for early
pozzolana, from a spot which had been exposed to
maximal erosion. The concrete still had imprints
of the wooden moulding construction. Not
hydraulic according to the hydraulic index. It
reached a plausible age with the first CO2
fraction of the profile.
15
The identical sample from the harbour
construction at Portus, plausible result revealed
at the joining point between the two profiles,
one from Oxford and the other from Aarhus.
16
Pompeii, Casa di Marcus Lucretius, sampling in
Collaboration with the EPUH (Excavationes
Pompeii Universitatis Helsinkiensis). All
samples from Pompeii and Herculaneum went wrong
17
The Suburban Baths at Herculaneum, with
optimistic group in May 2006...
18
The horse-shoe shape Basilica of SantAgnese,
founded by Constantine the Great, during the
pontificate of Silvester I (314-335 AD). The
rotunda of Santa Costanza is not bonded with
SantAgnese, and the pozzolana concrete is very
different. Controversial date of Santa Costanza
a) Between 337-351 built by Constantina, daughter
of Constantine the Great b) later half of the 4th
C. C) around 400 AD.
19
Rome 017, Santa Costanza, 14C AMS-analysis
perfor-med in Aarhus, calibrated result, AD
330-390.
20
However, an independent source seems to support
our initial results. 14C AMS-analysis of the
wood ashes embedded in the mortar of the
foundation of Santa Costanza has been implement,
with interesting results. According to David J.
Stanley, who had wood ashes embedded in the
concrete at the foundation level of Santa
Costanza dated with 14C analysis, the result
yielded was AD 412 43, or 369-455 AD (David J.
Stanley, 2004). However, using mechanical
calculation with 43 as margin errors, can be
problematic. To reach the suggested date the
uncalibrated BP age of 163243 comes close,
without being identical. The original BP age, is
at present unknown.
21
Further samples from Santa Costanza were analyzed
to confirm the earlier result. The first 14C
fraction of Rome 046 does coincide with the
earlier plateau, but the profile of Rome 042 is
just strange. A narrow horizontal line along the
agreeing fractions can, with good will, suggest
the date of AD 340-395.
22
The results of two samples of three from
SantAgnese look even more problematic
23
SantAgnese the interpretation of the results
suggests two possible dates, one too ancient and
the other one too recent
Delta 13C values of samples from Santa Costanza
and SantAgnese

• Possible explanations bad sampling!
• Re-crystallization with rejuvinating effect on
  044
• The Delta 13C value of Rome 043 is different from
  the others, and
• anomal 18O delta values of the same sample may
  indicate that
• something could be wrong with the ancient
  horizontal level of the
• profile.

24
Diagram of all mortar samples, Classical and
Medieval
1. Correct results 2. Plausible results 3.
Results wrong, but reasons known 3. Results wrong
Correct plausible 72
25
Statistical diagram from Torre de Palma,
non-hydraulic Classical mortar, 65 samples
analyzed in two fractions
Correct Plausible Wrong, but reason known Wrong
Correct or plausible 83
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Diagram of Pozzolana mortars, 63 samples
Pozzolana mortars
Correct 19 samples Plausible 14 samples Wrong
but reasons known 19 samples Totally wrong 11
samples
Correct or plausible 52
27
Pozzolana mortars, results wrong, reasons known

1. Buried under volcanic ashes
2. Too few fractions dated
3. Crushed bricks in the aggregate
4. Bad sampling (secondary repairs)
5. Delayed hardening

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• 11 samples went wrong without us as yet
  understanding why.
• However as a rule samples that go wrong are
  easily recognized,
• even if the patterns may vary
• The profile created no horizontal plateau
• All the fractions yielded different results, all
  of them too recent
• In three cases horizontal plateaux were created
  in the wrong
• place of the profile, either far too recent or
  far too ancient, or
• possibly correct, secondary repair!

29
The team, in different constellations, trying to
work out how to proceed with pozzolana mortars