Recharge and mineralization of groundwater of the Upper Cretaceous aquifer in Orontes basin, Syria

Figures & data

Fig. 1 Location map showing the main topographic features bounding the study area.

Fig. 2 (a) Simplified geological map of the study area; (b) schematic cross-section A–A′; and distribution of the sampling sites, nos. 1–40. Key: 1: Jurassic, 2: Upper Cretaceous aquifer (limestone and dolomites), 3: Upper Cretaceous (clay and limestone of Senonian to Maestrichtian), 4: Palaeogene (chalks and marls), 5: Neogene (conglomerates and limestone aquifer), 6: Basalt (Miocene/Pliocene) aquifer, 7: Quaternary, 8: Main faults, 9: Wells, 10: Cities.

Table 1 Mean chemical composition and field data of groundwater samples from the Upper Cretaceous aquifer in the Orontes basin. See Fig. 2 for location of sites

Site	T	pH	TDS	HCO3	Cl	NO3	SO4	Na	K	Mg	Ca
no.	(°C)		(mg/L)	(mg/L)	(mg/L)	(mg/L)	(mg/L)	(mg/L)	(mg/L)	(mg/L)	(mg/L)
Recharge area
1	19.5	7.36	401	286	11.9	4.4	8.4	7.3	0.9	28	54.0
2	16.2	7.48	367	255	7.3	14.4	5.6	4.5	0.3	19.9	60.2
3	16.7	7.30	163	105	7.0	11.4	1.9	11.6	1.6	8.9	15.1
4	16.0	8.37	155	108	6.0	3.5	1.7	16.1	1	8.1	10.5
5	22.1	8.47	202	130	11.7	6.4	2	31.1	2.4	8.1	10.2
Hama Uplift
6	20.0	7.13	430	288	14.8	11.7	12.1	9.4	0.9	28.9	64.0
7	20.9	7.20	532	263	64.9	39.2	30.2	55.2	0.7	20.3	58.0
8	36.8	7.00	1873	210	87.0	0.0	1105.2	85.7	8.3	107.9	266.0
9	27.2	6.76	1071	363	37.5	4.2	391.5	40.4	5.8	60.3	165.2
10	23.1	6.97	460	259	34.0	10.0	44.8	21.9	1.7	25.5	62.8
11	24.9	7.11	567	266	46.4	7.3	103.6	32.5	4.2	32.7	74.0
12	25.3	6.90	1476	356	152.2	2.2	564.4	108.4	5.6	77	208.9
13	23.6	6.95	493	239	40.2	20.1	70.1	25.1	2.5	33.7	62.1
14	24.4	6.90	740	281	54.3	16.2	191.3	44.1	3.8	42.5	106.1
15	30.0	7.23	608	191	72.6	2.1	187.1	47.4	4.9	29.4	72.9
16	23.4	6.93	1132	336	141.5	Nd	352.8	107.3	6.1	59.7	127.4
17	25.8	6.97	1031	241	125.4	1.0	376.4	97	7.1	52.1	129.3
18	26.2	7.16	355	192	36.4	8.1	26.7	29.6	2.4	20.8	39.0
19	26.7	7.82	532	206	117.9	35.1	20.8	50.3	2.4	39.4	56.6
20	26.4	7.50	364	202	33.2	11.5	24.9	27.5	2	21.9	41.1
21	22.5	7.15	602	408	19.5	27.4	5.6	11.8	1.4	36.2	92.4
22	21.0	7.30	564	331	61.8	12.7	21.1	30.6	1.2	34.5	70.3
23	20.7	7.18	580	333	77.4	7.2	22.4	35.8	1	37	66.0
24	21.0	7.70	461	184	70.3	61.5	21.1	58.4	2.6	25.3	37.3
Homs Depression
25	35.0	7.00	463	251	49.0	0.4	44.4	31.4	3.6	27.7	54.6
26	40.0	7.07	386	229	37.8	Nd	32.3	25	2.6	30.4	28.2
27	41.0	7.05	520	291	58.1	Nd	42.3	36.1	2.9	31.3	56.6
28	46.6	6.95	667	280	130.5	Nd	77.1	91	3.6	33.4	48.7
29	29.6	7.06	849	297	116.2	Nd	204.6	101.6	6.6	50	66.7
30	25.9	7.43	1280	320	214.8	Nd	379.6	158.5	8.8	61.7	130.1
31	26.4	7.64	732	368	61.9	Nd	115.4	46.7	4.1	44.4	86.8
32	20.2	7.30	3880	197	990.9	7.4	1221.2	571.1	37.8	191.8	292.0
33	43.2	7.23	1289	358	339.2	Nd	195.4	229.3	13.8	54.3	91.7
34	45.0	7.08	1423	210	120.2	2.2	699.7	92.3	12	73.3	206.4
35	38.3	6.80	958	226	92.7	Nd	382	71.2	9.4	49.6	123.3
36	40.0	7.32	909	256	282.5	Nd	95.1	164.9	5.3	35.7	61.8
37	29.8	7.31	1220	310	175.3	Nd	386.2	137	3.5	71.3	136.3
38	20.0	7.6	537	247	75.5	9.7	69.4	43.8	2.7	30.6	57.4
39	23.5	7.62	336	233	10.1	4.8	12.1	8.7	1	21.4	44.4
40	45.0	7.85	1298	318	492	1.6	41.9	344.3	10.4	30.7	43.6
Note: Nd: not detected.

Fig. 3 Average concentration and geochemical facies of the dominant groundwater groups in the study area.

Fig. 4 Relationship between different cations and anions in the groundwater of the studied area.

Fig. 5 Relationship between mineral and water saturation indexes (SI) of calcite, dolomite, gypsum and halite.

Table 2 Isotopic composition of groundwater samples collected from the Upper Cretaceous aquifer system in the Orontes basin. See Fig. 2 for location of sites

Site no.	Depth	Lat. N	Long. E	δ^18O	δ^2H	d-Excess	Tritium
	(m)			(‰)	(‰)	(‰)	(TU)
Coastal Mountains
1	500	35.06	36.34	−6.57	−32.70	19.86	4.40±0.2
2	560	35.17	36.31	−6.80	−33.81	20.59	2.59±0.2
3	560	34.89	36.37	−6.65	−30.01	23.19	1.77±0.2
4	430	34.80	36.38	−6.53	−28.68	23.56	4.37±0.2
5	537	34.78	36.46	−6.71	−29.70	23.98	n.m
Hama Uplift
6	250	35.15	36.57	−5.95	−29.47	18.13	2.53±0.2
7	700	35.31	37.07	−4.01	−26.64	5.44	0.84±0.2
8	500	35.35	36.97	−6.05	−39.10	9.30	0.60±0.2
9	336	35.31	36.80	−5.24	−33.10	8.82	0.60±0.2
10	200	35.26	36.67	−5.67	−30.89	14.47	1.97±0.2
11	350	35.21	36.72	−5.60	−32.13	12.67	0.98±0.2
12	258	35.44	36.62	−5.57	−35.46	9.10	0.60±0.2
13	225	35.43	36.50	−6.10	−35.11	13.69	0.60±0.2
14	130	35.44	36.40	−5.84	−33.91	12.81	0.91±0.2
15	350	34.99	36.76	−5.13	−28.68	12.36	0.60±0.2
16	280	35.12	36.87	−5.13	−32.63	8.41	0.0±0.2
17	250	35.12	36.94	−5.46	−34.87	8.81	0.60±0.2
18	200	34.96	36.68	−6.20	−34.34	15.26	0.60±0.2
19	200	34.55	36.83	−5.34	−34.02	8.70	0.60±0.2
20	225	35.06	36.72	−5.93	−28.96	18.48	0.60±0.2
21	380	35.00	36.50	−5.90	−29.24	17.96	1.09±0.2
22	190	35.25	36.47	−5.02	−26.45	13.71	0.83±0.2
23	250	35.25	36.47	−4.76	−26.47	11.61	n.m
24	300	34.65	36.65	−5.98	−34.45	13.39	n.m
Homs Depression
25	825	34.87	36.74	−7.86	−46.71	16.17	0.00±0.2
26	1130	34.82	36.8	−8.08	−44.14	20.50	0.00±0.2
27	1100	34.84	36.83	−8.24	−45.63	20.29	0.00±0.2
28	1027	34.88	36.87	−7.96	−49.39	14.29	0.00±0.2
29	1045	34.69	36.99	−7.71	−49.72	11.96	0.60±0.2
30	930	34.64	36.98	−8.67	−55.05	14.31	0.00±0.2
31	488	34.72	37.05	−6.86	−43.66	11.22	0.00±0.2
32	200	34.56	36.96	−6.88	−43.09	11.95	0.60±0.2
33	1380	34.81	36.94	−7.76	−47.53	14.55	0.00±0.2
34	910	35.00	36.97	−7.68	−44.10	17.34	0.00±0.2
35	400	35.01	36.75	−7.47	−42.87	16.89	0.60±0.2
36	1360	34.70	36.86	−8.39	−51.24	15.88	0.00±0.2
37	950	34.65	36.98	−8.74	−52.94	16.98	0.60±0.2
38	250	34.51	36.68	−7.15	−47.52	9.68	0.00±0.2
39	700	34.34	36.76	−8.49	−54.92	13.00	0.00±0.2
40	1659	34.72	36.79	−7.81	−51.29	11.19	0.00±0.2
Note: n.m: not measured.

Table 3 Mean isotopic composition values of the three groundwater clusters of the Upper Cretaceous aquifer in the Orontes basin

Name	δ^18O (‰)	δ^2H (‰)	d (‰)	n
Recharge area	−6.65 ± 0.10	−30.98 ± 2.17	22.2 ± 1.90	5
Hama Uplift	−5.52 ± 0.55	−31.89 ± 3.55	12.3 ± 3.70	19
Homs Depression	−8.01 ± 0.46	−48.78 ± 3.95	15.2 ± 3.16	16
Note: ± is the standard deviation; n: number of samples.

Fig. 6 δ¹⁸O–δ²H diagram of groundwater samples from the Upper Cretaceous aquifer in the Orontes basin. The mean and standard deviations of the δ values of the rainwater collected at the monitoring stations Bloudan and Kadmous are also shown.

Fig. 7 The δ¹⁸O (blue) and d_ex (green) values plotted vs groundwater ¹⁴C age (A₀ = 60 pmC) form six distinct clusters which are discussed in the text.

Table 4 Application of ¹⁴C age correction models for groundwater in the Orontes basin

Site no.	δ^13C (‰)	^14C (%)	Ages	Age correction models:
			A0 = 100%	Tamers	I&P	F&G	IAEA	Evans	Eichinger
Recharge area (Coastal Mts)
1	−11.6	53.4	5200	0.550	−00 100	3000	3950	−400	−700
2	−12.9	80.6	1800	−03 950	−02 600	1800	1700	−2800	−3000
3	−19.9	69.4	3000	−02 700	2200	6500	6400	2100	1900
Hama Uplift (unconfined aquifer)
12	−10.4	9.0	19 900	14 200	13 750	17 500	17 400	13 300	13 300
14	−10.4	23.8	11 850	6100	5700	9500	9500	5300	5200
17	−8.5	22.1	12 500	6750	4600	8300	8200	3950	3900
20	−12.0	17.2	14 600	8850	9500	13 200	13 100	9200	9200
Homs Depression (confined aquifer)
25	−10.3	3.9	26 800	21 100	20 500	23 700	23 600	19 900	20 000
26	−10.5	7.2	21 800	16 000	15 700	18 600	18 500	14 900	15 200
28	−10.4	5.6	23 800	18 100	17 600	20 200	20 100	16 700	17 000
29	−9.8	5.0	24 700	19 000	18 100	21 600	21 500	17 500	17 500
31	−10.6	3.6	27 600	21 900	21 500	25 200	25 100	21 100	21 000
33	−7.2	6.5	22 600	16 900	13 400	16 300	16 000	11 800	12 100
34	−6.9	4.6	25 500	19 800	15 800	18 800	18 400	14 000	14 400
39	−10.5	24.6	11 600	5900	5500	9300	9200	5100	5000
40	−8.7	5.9	23 400	17 700	15 800	18 500	18 400	14 600	14 900
Note: Tamers: Tamers (1975); I&P: Ingerson and Pearson (1964); F&G: Fontes and Garnier (1979); IAEA: Salem et al. (1980); Evans: Evans et al. (1979); Eichinger: Eichinger (1983).

Fig. 8 Evolution of ¹⁴C and δ¹³C values in the groundwater samples from the Upper Cretaceous aquifer in the study area.

Fig. 9 Relationship between δ¹⁸O and corrected age values for groundwater in the study area. Standard deviation shown by ± “whiskers” (5000 years for ¹⁴C age and 0.1‰ for δ¹⁸O).

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