Historical building dating: A multidisciplinary study of the Convento de São Francisco (Coimbra, Portugal)

Giuseppe Stella; Luis Almeida; Lilia Basílio; Stefania Pasquale; Jorge Dinis; Miguel Almeida; Anna M. Gueli

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Historical building dating: A multidisciplinary study of the Convento de São Francisco (Coimbra, Portugal)

| 04 juil. 2018

Édition 45 (2018): Edition 1 (January 2018)

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Article Category: Regular Articles

Publié en ligne: 04 juil. 2018

Pages: 119 - 129

Reçu: 12 mai 2017

Accepté: 20 févr. 2018

DOI: https://doi.org/10.1515/geochr-2015-0089

Mots clés
brick dating, mortar dating, XRD, colorimetry, characterization, archaeological stratigraphy

© 2017 G. Stella, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Plan of the 2nd Floor of the Convento de São Francisco with construction phases and sampling points.

ED distribution obtained with radial plots for mortar samples.

Semi-quantitative mineral composition of mortar samples obtained by XRD analysis.

Sample grouping after the plot of binder vs aggregate proportions.

Level of brightness (L∗) associated to hue angle (h) for mortar samples.

Dates obtained for mortar and brick samples.

Color data in the CIELAB 1976 space both rectangular L, a, b* (respectively Lightness, red-green color component and yellow-blue color component) and cylindrical, C*, h (respectively chroma and hue angle) coordinates with the related uncertainties.

Sample	L^*	a^*	b^*	C^*	h
CSFL3	66.10 ± 1.67	4.63 ± 0.12	22.73 ± 0.58	23.19 ± 0.82	78.52 ± 2.77

CSLF7	55.67 ± 1.54	8.21 ± 0.23	25.57 ± 0.71	26.86 ± 1.01	72.25 ± 2.72

CSFL14	59.63 ± 1.33	11.45 ± 0.25	32.88 ± 0.73	34.82 ± 1.12	70.83 ± 2.28

CSFL12	56.72 ± 1.60	9.23 ± 0.26	26.69 ± 0.75	28.24 ± 1.08	70.95 ± 2.71

CSFL11	64.25 ± 1.52	3.46 ± 0.08	20.32 ± 0.48	20.62 ± 0.69	80.39 ± 2.70

Dating of bricks: k-value, Qβ e qβ values obtained by TL measurements.

Sample	k-value	Q_β (Gy)	q_β (Gy)
CSLF2	0.259 ± 0.011	2.09 ± 0.19	0.13 ± 0.02

CSLF6	0.232 ± 0.018	2.87 ± 0.23	0.05 ± 0.01

CSLF10	0.220 ± 0.010	3.18 ± 0.28	0.09 ± 0.02

Dating of samples: Sample name, sample material, technique, method with ED, annual dose rate, the individual dating results (referred to the year of the TL measurements) and the corresponding calendar dates obtained for both bricks and mortars.

Sample	Material	Technique	Method	ED (Gy)	Annual dose rate (mGy/a)	Age/2016 (a)	Age (AD)
CSFL2	Brick	TL	Added dose	2.22 ± 0.19	11.43 ± 0.85	194 ± 22	1822 ±22

CSFL3	Mortar	OSL	SAR	1.17 ± 0.10	5.41 ± 0.37	216 ± 24	1800 ±24

CSFL6	Brick	TL	Added dose	2.92 ± 0.23	8.62 ± 0.66	339 ± 37	1677 ± 37

CSFL7	Mortar	OSL	SAR	2.03 ± 0.21	6.67 ± 0.47	304 ± 38	1712 ± 38

CSFL10	Brick	TL	Added dose	3.27 ± 0.28	9.44 ± 0.63	346 ± 38	1670 ± 38

CSFL11	Mortar	OSL	SAR	1.13 ± 0.11	5.76 ± 0.37	196 ± 23	1820 ± 23

CSFL12	Mortar	OSL	SAR	2.41 ± 0.15	7.47 ± 0.44	322 ± 28	1694 ± 28

CSFL14	Mortar	OSL	SAR	2.61 ± 0.18	7.81 ± 0.48	344 ± 31	1672 ± 31

Contributions to the annual dose rate: Sample name, sample material, porosity factor W, alpha and beta internal dose rates (Dαint and Dβint) and environmental component (Denv).

Sample	Material	W	D_αint(mGy/a)	D_βint(mGy/a)	D_env(mGy/a)
CSFL2	Brick	0.16 ± 0.01	29.65 ± 1.25	3.22 ± 0.08	1.22 ± 0.05

CSFL3	Mortar	0.21 ± 0.02	22.71 ± 0.93	1.71 ± 0.04

CSFL6	Brick	0.15 ± 0.01	22.24 ± 0.95	2.53 ± 0.06	1.37 ± 0.05

CSFL7	Mortar	0.22 ± 0.02	22.36 ± 0.90	2.18 ± 0.05

CSFL10	Brick	0.17 ± 0.01	24.95 ± 1.01	2.94 ± 0.07	1.57 ± 0.05

CSFL11	Mortar	0.27 ± 0.02	21.38 ± 0.89	1.80 ± 0.05

CSFL12	Mortar	0.25 ± 0.02	23.31 ± 0.39	2.87 ± 0.06	1.75 ± 0.05

CSFL14	Mortar	0.23 ± 0.02	24.78 ± 0.28	2.86 ± 0.05	1.65 ± 0.05

XRD semi-quantitative mineralogical composition of mortars (%) and aggregate/binder ratio (Qz – quartz; K-felds – potassium feldspars; Na-plag – sodium plagioclases; Cal – calcite; Dolo – dolomite; Phyl – phyllossilicates; * – traces).

Sample	Qz	K-felds	Na-plag	Cal	Dolo	Phyl	Aggregate (A)	Binder (B)	A/B Ratio
CSFL3	65	21	1	13	^*	^*	86	13	6.62

CSFL7	65	5	^*	26	2	2	70	26	2.69

CSFL11	71	14	1	13	1	^*	85	13	6.54

CSFL12	59	12	10	18	1	^*	71	18	3.94

CSFL14	66	11	1	21	1	^*	77	21	3.67

Details of the samples studied in this work with ID number, material and sampling point description.

		Sampling point (floor 2)

Sample	Material	Architectural element	Height height above planking level (cm)
CSLF2	Brick	Arc (east)	350
CSLF3	Mortar	Arc (east)	350

CSLF6	Brick	Arc (south)	80
CSLF7	Mortar	Arc (south)	80

CSLF10	Brick	Arc (west)	235
CSLF11	Mortar	Arc (west)	235

CSLF12	Mortar	Wall (west)	145

CSLF14	Mortar	Wall (north)	150

Plateau temperature range and preheating (Ph) temperature choose for ED evaluation.

Sample	Plateau ED range (°C)	Ph temperature (°C)
CSLF3	180–220	200

CSLF7	180–240	210

CSLF11	180–220	200

CSLF12	180–220	200

CSLF14	180–240	210

Number of aliquots (n), luminescence efficiency coefficient (k-value), Equivalent Dose (ED) Value and relative standard deviations (SD) obtained, respectively, by radial plot (ED Central Value, see Fig. 2) and from ED frequency distributions (Mean ED) for mortar samples.

Sample	Number of aliquots (n)	k-value	ED Central Value from Radial Plot (Gy) SD	Mean ED from ED frequency distributions (Gy) SD
CSFL3	39	0.125 ± 0.010	1.17 0.10	1.18 0.18

CSFL7	47	0.161 ± 0.012	2.03 0.21	2.02 0.26

CSFL11	41	0.134 ± 0.010	1.13 0.11	1.12 0.17

CSFL12	38	0.148 ± 0.010	2.41 0.15	2.42 0.22

CSFL14	44	0.157 ± 0.010	2.61 0.18	2.63 0.25

Radioactive measurements: Sample name, sample material with U, Th, K contents obtained by high gamma spectrometry and 238U/226Ra ratio.

Sample	Material	²³⁸U/²²⁶Ra	U (ppm)	Th (ppm)	K (%)
CSFL2	Brick	1.03 ± 0.11	4.54 ± 0.22	23.26 ± 1.49	2.46 ± 0.07

CSFL3	Mortar	0.97 ± 0.08	3.76 ± 0.18	16.57 ± 1.07	0.90 ± 0.03

CSFL6	Brick	1.02 ± 0.12	3.26 ± 0.16	18.00 ± 1.15	2.00 ± 0.06

CSFL7	Mortar	0.97 ± 0.09	3.91 ± 0.19	15.70 ± 1.00	1.51 ± 0.05

CSFL10	Brick	0.98 ± 0.10	4.30 ± 0.21	17.75 ± 1.14	2.33 ± 0.07

CSFL11	Mortar	1.05 ± 0.08	3.40 ± 0.16	16.30 ± 1.04	1.10 ± 0.03

CSFL12	Mortar	0.99 ± 0.08	3.52 ± 0.06	18.48 ± 0.49	2.37 ± 0.07

CSFL14	Mortar	0.97 ± 0.10	3.70 ± 0.06	19.80 ± 0.31	2.27 ± 0.07

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Historical building dating: A multidisciplinary study of the Convento de São Francisco (Coimbra, Portugal)

Article Category: Regular Articles

Publié en ligne: 04 juil. 2018

Pages: 119 - 129

Reçu: 12 mai 2017

Accepté: 20 févr. 2018

DOI: https://doi.org/10.1515/geochr-2015-0089

Mots clés
brick dating, mortar dating, XRD, colorimetry, characterization, archaeological stratigraphy

© 2017 G. Stella, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Color data in the CIELAB 1976 space both rectangular L, a, b* (respectively Lightness, red-green color component and yellow-blue color component) and cylindrical, C*, h (respectively chroma and hue angle) coordinates with the related uncertainties.

Dating of bricks: k-value, Qβ e qβ values obtained by TL measurements.

Dating of samples: Sample name, sample material, technique, method with ED, annual dose rate, the individual dating results (referred to the year of the TL measurements) and the corresponding calendar dates obtained for both bricks and mortars.

Contributions to the annual dose rate: Sample name, sample material, porosity factor W, alpha and beta internal dose rates (Dαint and Dβint) and environmental component (Denv).

XRD semi-quantitative mineralogical composition of mortars (%) and aggregate/binder ratio (Qz – quartz; K-felds – potassium feldspars; Na-plag – sodium plagioclases; Cal – calcite; Dolo – dolomite; Phyl – phyllossilicates; * – traces).

Details of the samples studied in this work with ID number, material and sampling point description.

Plateau temperature range and preheating (Ph) temperature choose for ED evaluation.

Number of aliquots (n), luminescence efficiency coefficient (k-value), Equivalent Dose (ED) Value and relative standard deviations (SD) obtained, respectively, by radial plot (ED Central Value, see Fig. 2) and from ED frequency distributions (Mean ED) for mortar samples.

Radioactive measurements: Sample name, sample material with U, Th, K contents obtained by high gamma spectrometry and 238U/226Ra ratio.

Historical building dating: A multidisciplinary study of the Convento de São Francisco (Coimbra, Portugal)

Article Category: Regular Articles

Publié en ligne: 04 juil. 2018

Pages: 119 - 129

Reçu: 12 mai 2017

Accepté: 20 févr. 2018

DOI: https://doi.org/10.1515/geochr-2015-0089

Mots clésbrick dating, mortar dating, XRD, colorimetry, characterization, archaeological stratigraphy

© 2017 G. Stella, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Color data in the CIELAB 1976 space both rectangular L*, a*, b* (respectively Lightness, red-green color component and yellow-blue color component) and cylindrical, C*, h (respectively chroma and hue angle) coordinates with the related uncertainties.

Dating of bricks: k-value, Qβ e qβ values obtained by TL measurements.

Dating of samples: Sample name, sample material, technique, method with ED, annual dose rate, the individual dating results (referred to the year of the TL measurements) and the corresponding calendar dates obtained for both bricks and mortars.

Contributions to the annual dose rate: Sample name, sample material, porosity factor W, alpha and beta internal dose rates (Dαint and Dβint) and environmental component (Denv).

XRD semi-quantitative mineralogical composition of mortars (%) and aggregate/binder ratio (Qz – quartz; K-felds – potassium feldspars; Na-plag – sodium plagioclases; Cal – calcite; Dolo – dolomite; Phyl – phyllossilicates; * – traces).

Details of the samples studied in this work with ID number, material and sampling point description.

Plateau temperature range and preheating (Ph) temperature choose for ED evaluation.

Number of aliquots (n), luminescence efficiency coefficient (k-value), Equivalent Dose (ED) Value and relative standard deviations (SD) obtained, respectively, by radial plot (ED Central Value, see Fig. 2) and from ED frequency distributions (Mean ED) for mortar samples.

Radioactive measurements: Sample name, sample material with U, Th, K contents obtained by high gamma spectrometry and 238U/226Ra ratio.

Mots clés
brick dating, mortar dating, XRD, colorimetry, characterization, archaeological stratigraphy

Color data in the CIELAB 1976 space both rectangular L, a, b* (respectively Lightness, red-green color component and yellow-blue color component) and cylindrical, C*, h (respectively chroma and hue angle) coordinates with the related uncertainties.