A petrographic and chemical analysis of Trinidad pre-colonial ceramics

Figures & data

Figure 1. Situation of Trinidad in the wider region.

Figure 2. Trinidad surface geology with discussed sites and clay sampling locations.

Figure 3. Summary pre-contact ceramic age chronological chart based on 14C dates. Adapted from Boomert 2000, 128.

Table 1. Overview of the thin sections.

Petrographic group	Petrofabric name	Sample code	Site
1	Shell inclusions	CB14BN483	Bontour
1	Shell inclusions	CB14BN466	Quinam, Excavation 1
1	Shell inclusions	CB14BN432	Cedros, Excavation 1
2	Sponge spicules	CB14BN459	Erin, Excavation 2
2	Sponge spicules	CB14BN452	Erin, Excavation 1
2	Sponge spicules	CB14BN480	Quinam, Excavation 4
3	Grog	CB14BN433	Cedros, Excavation 1
3	Grog	CB14BN442	Palo Seco, Excavation 1
3	Grog	CB14BN450	Erin, Excavation 1
3	Grog	CB14BN465	Quinam, Excavation 1
3	Grog	CB14BN470	Quinam, Excavation 2
3	Grog	CB14BN475	Quinam, Excavation 3
3	Grog	CB14BN478	Quinam, Excavation 4
3	Grog	CB15BN019	Red House
3	Grog	CB15BN022	Red House
3	Grog	CB14BN440	Palo Seco, Excavation 1
3	Grog	CB14BN445	Palo Seco, Excavation 2
3	Grog	CB15BN012	Red House
3	Grog	CB15BN018	Red House
3	Grog	CB14BN439	Cedros, Excavation 1
3	Grog	CB15BN014	Red House
3	Grog	CB15BN016	Red House
3	Grog	CB14BN456	Erin, Excavation 1
3	Grog	CB14BN476	Quinam, Excavation 3
3	Grog	CB15BN024	Red House
3	Grog	CB15BN025	Red House
3	Grog	CB15BN027	Red House
4	Micaschist/quartzite	CB14BN486	St. Joseph, Excavation 2
4	Micaschist/quartzite	CB15BN020	Red House
4	Micaschist/quartzite	CB15BN026	Red House
4	Micaschist/quartzite	CB15BN021	Red House
4	Micaschist/quartzite	CB15BN023	Red House
4	Micaschist/quartzite	CB15BN017	Red House

Note: The sections in bold italics are described in detail in this article.

Table 2. Relative frequencies of inclusions and voids.

Predominant	>70%	Few	5–15%
Dominant	50–70%	Very few	2–5%
Frequent	30–50%	Rare	0.5–2%
Common	15–30%	Very rare	<0.5%

Figure 4. From left to right and top to bottom: CB14BN483, CB14BN466 and CB14BN432 under XP.

Figure 5. From left to right and top to bottom: CB14BN59, CB14BN480 and CB14BN452 under XP.

Figure 6. From left to right and top to bottom: CB15BN014, CB15BN016, CB15BN012, CB15BN024 and CB14BN439 in XP.

Table 3. Major oxides of ceramics and clays.

Sample n°	Group	Location	Na2O	MgO	Al2O3	SiO2	P2O5	K2O	CaO	TiO2	MnO	Fe2O3	Total
TRI-06		TRI-06	1.06	0.31	19.24	69.02	0.05	2.65	0.01	1.12	0.01	6.52	100
TRI-10		TRI-10	1.09	2.38	19.85	59.50	0.43	2.44	4.61	0.91	0.07	8.71	100
TRI-11		TRI-11	1.21	2.62	17.67	66.18	0.18	2.95	0.75	1.03	0.12	7.26	100
TRI-12A		TRI-12A	1.09	1.95	15.32	73.98	0.11	2.36	0.71	0.90	0.02	3.54	100
TRI-12B		TRI-12B	1.08	2.29	17.04	70.92	0.10	2.66	0.68	1.08	0.02	4.13	100
TRI-12C		TRI-12C	1.06	2.39	17.10	70.96	0.09	2.54	0.57	1.06	0.02	4.18	100
TRI-13		TRI-13	0.33	1.17	17.92	73.35	0.24	1.96	0.48	1.07	0.06	3.36	100
TRI-14		TRI-14	0.77	1.77	19.69	65.44	0.11	2.49	0.25	0.97	0.02	8.45	100
TRI-15		TRI-15	0.54	2.48	21.20	63.81	0.08	2.99	0.57	0.97	0.06	7.27	100
TRI-17		TRI-17	0.55	2.65	20.22	62.43	0.15	3.14	0.42	0.95	0.07	9.36	100
TRI-18		TRI-18	0.35	2.06	22.24	60.60	0.17	2.52	1.17	0.85	0.14	9.85	100
TRI-19		TRI-19	0.38	1.01	19.96	61.99	0.11	2.09	0.60	1.03	0.11	12.69	100
TRI-20		TRI-20	0.38	1.05	20.50	65.38	0.11	2.32	0.44	1.12	0.07	8.59	100
TRI-21		TRI-21	0.62	1.27	15.49	73.56	0.11	2.05	0.43	0.79	0.07	5.61	100
TRI-22		TRI-22	0.44	2.00	19.47	68.11	0.07	2.50	0.55	1.01	0.06	5.77	100
Average			0.73	1.83	18.86	67.02	0.14	2.51	0.82	0.99	0.06	7.02
Standard Deviation			0.33	0.71	2.03	4.84	0.10	0.34	1.08	0.10	0.04	2.66
Sample n°	Group	Location	Na2O	MgO	Al2O3	SiO2	P2O5	K2O	CaO	TiO2	MnO	Fe2O3	Total
CB14BN483	1	Btr	0.52	1.51	12.75	39.21	0.84	1.95	35.67	0.83	0.02	6.70	100
CB14BN466	1	Qui	0.57	1.13	17.38	47.46	0.99	1.49	22.36	0.84	0.04	7.74	100
CB14BN432	1	Cedr	0.33	1.24	17.83	57.97	0.50	2.01	10.35	1.03	0.08	8.66	100
CB14BN459	2	Erin	0.06	0.69	18.03	72.97	1.66	1.41	0.60	0.98	0.11	3.49	100
CB14BN452	2	Erin	0.32	0.65	21.27	61.66	1.25	1.80	1.88	1.12	0.06	10.00	100
CB14BN480	2	Qui	0.13	0.55	16.38	72.49	1.75	1.67	0.45	0.98	0.16	5.42	100
CB14BN433	3	Cedr	0.30	0.91	20.69	61.83	0.80	2.33	2.99	1.20	0.08	8.89	100
CB14BN442	3	P.S.	0.40	1.40	21.18	59.43	0.91	2.29	2.45	1.01	0.02	10.90	100
CB14BN450	3	Erin	0.72	1.48	19.07	62.00	0.72	2.09	2.20	1.03	0.12	10.57	100
CB14BN465	3	Qui	0.37	1.37	19.66	62.32	1.30	2.49	2.29	1.01	0.08	9.11	100
CB14BN470	3	Qui	0.32	1.14	20.49	61.52	1.24	2.06	1.92	1.10	0.08	10.12	100
CB14BN475	3	Qui	0.51	1.62	20.78	60.43	0.22	2.72	2.77	1.04	0.24	9.68	100
CB14BN478	3	Qui	0.53	1.80	21.10	60.44	0.80	2.59	5.78	1.14	0.03	5.78	100
CB15BN019	3	R.H.	0.46	0.62	25.77	52.67	6.08	2.46	3.21	1.06	0.02	7.63	100
CB15BN022	3	R.H.	0.58	0.75	22.42	59.78	3.47	2.24	2.66	1.06	0.04	7.01	100
CB14BN440	3	P.S.	0.84	1.61	18.71	65.59	1.27	3.19	1.92	1.06	0.05	5.76	100
CB14BN445	3	P.S.	0.28	1.34	21.46	66.10	0.40	2.39	1.35	1.17	0.04	5.45	100
CB15BN012	3	R.H.	0.63	1.01	21.68	59.02	3.43	2.07	2.66	1.04	0.03	8.43	100
CB15BN018	3	R.H.	0.50	0.66	25.90	54.18	6.04	2.21	3.70	1.00	0.02	5.78	100
CB14BN439	3	Cedr	0.22	1.21	20.40	60.99	0.87	2.01	2.77	1.04	0.20	10.29	100
CB15BN014	3	R.H.	0.46	0.72	21.91	59.95	4.13	1.96	2.42	0.98	0.04	7.42	100
CB15BN016	3	R.H.	0.38	1.08	24.74	56.60	4.03	1.78	1.59	1.16	0.05	8.60	100
CB14BN456	3	Erin	0.54	1.04	20.07	65.47	0.70	1.90	1.91	1.09	0.06	7.22	100
CB14BN476	3	Qui	0.67	1.46	19.33	65.52	0.28	2.23	1.35	1.05	0.04	8.08	100
CB15BN024	3	R.H.	0.47	0.54	17.41	66.87	3.25	1.79	2.35	0.86	0.02	6.45	100
CB15BN025	3	R.H.	0.42	0.96	22.97	57.44	3.10	2.18	1.99	0.95	0.04	9.96	100
CB15BN027	3	R.H.	0.43	0.74	24.83	55.84	4.47	1.83	2.25	1.13	0.04	8.43	100
CB14BN486	4	St. J	0.51	1.03	16.06	67.59	2.61	2.25	1.57	0.73	0.03	7.61	100
CB15BN020	4	R.H.	0.41	0.79	21.51	63.77	1.32	2.66	2.19	0.87	0.03	6.44	100
CB15BN026	4	R.H.	0.43	0.36	19.09	61.92	4.27	2.01	2.05	0.89	0.06	8.92	100
CB15BN021	4	R.H.	0.62	0.90	16.34	71.27	0.59	1.91	0.92	0.82	0.05	6.59	100
CB15BN023	4	R.H.	0.35	0.33	15.77	69.75	2.83	1.11	1.42	0.80	0.03	7.61	100
CB15BN017	4	R.H.	0.46	0.84	20.15	63.63	1.81	2.20	1.94	0.92	0.06	8.00	100
Average			0.45	1.02	20.10	61.32	2.06	2.10	4.06	1.00	0.06	7.84
Standard Deviation			0.16	0.38	2.98	6.82	1.65	0.40	6.86	0.12	0.05	1.75

Figure 7. from left to right and top to bottom: CB14BN486, CB15BN020, CB15BN026, CB15BN021, CB15BN023 and CB15BN017 under XP.

Figure 8. MgO/Al₂O₃ vs. K₂O/Al₂O₃ scatterplot.

Figure 9. Na₂O vs. MgO scatterplot.

Figure 10. Cu vs. Zn scatterplot. Bulk of samples between 20–50 ppm for Cu and 90–250 ppm for Zn.

Figure 11. Cr vs. Ni scatterplot. Most samples between 50–160 ppm for Cr and 15–80 for Ni.

Figure 12. Zr vs. Ba scatterplot. Most samples between 100–270 ppm for Zr. For Ba, clays between 350–500 ppm and most ceramics 400–1000 ppm.

Figure 13. Sr vs. Y scatterplot. Most samples 90–400 ppm for Sr (some exceptions from groups 1 and 3). Most samples 20–50 ppm for Y with outliers from groups 1 and 4.

Boomert, A. 2000. Trinidad, Tobago and the Lower Orinoco Interaction Sphere. An Archaeological/Ethnohistorical Study. Leiden: Universiteit Leiden.

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