Measurement of Cl⁻ : Br⁻ Ratios in the Porewater of Clay-Rich Rocks—A Comparison of the Crush-and-Leach and the Paper-Absorption Methods

Table 2

Masses (μg) of Cl⁻ and Br⁻ extracted by the crush-and-leach and paper-absorption methods.

Crush and leach			Paper absorption
Sample	Cl^−	Br^−	Sample	Cl^−	Br^−
Michigan Basin
463a	53928	630	463a	641	15
463b	63586	744	463b	1109	26
495a	45262	562	495a	5355	129
495b	49897	584	495b	4434	112
522	49783	615	522	4224	107
531	20635	261	531	4057	93
571a	70851	884	571a	5739	117
571b	80998	874	571b	4119	87
571c	79415	875	571c	3667	76
626a	53887	620	626a	5077	125
626b	54301	659	626b	5718	131
634a	53411	615	634a	1474	35
634b	55397	635	634b	1420	33
634c	54416	612	634c	1761	40
634d	59462	678	634d	4242	95
634e	55150	637	634e	3290	82
Lorraine Group Shales
F7-1	289	2.71	F7-3	109	1.59
F7-2	295	2.75	F7-4	91	1.32
F8-1	80	0.38	F8-3	24	0.20
F8-2	78	0.39	F8-4	16	0.16
F20-1	1162	9.87	F20-3	148	2.5
F20-2	1209	10.4	F20-4	287	5.13
444-1	121	1.66	444-2	55	1.08
Opalinus Clay
115.1	542	1.63	115	77	0.28
115.2	550	1.73
115.3	493	1.51
115.4	625	1.92
119.1	1061	3.54
119.2	984	3.32
119.3	948	3.12
119.4	996	3.37
121.1	1163	3.85	128.1	85	0.33
121.2	1185	3.85	128.2	83	0.34
121.3	1239	4.14
121.4	1131	3.72
132.2	1454	4.74	144a	73	0.30
132.2	1554	4.90	144b	70	0.35
132.3	1576	5.00
132.4	1467	4.47
161.1	2899	9.39
161.2	2832	9.00
161.3	3049	9.70
161.4	2539	8.02
166.2	3418	10.84
166.3	3367	10.73
166.4	2886	9.21
172.1	2469	7.86
172.2	2581	8.36
172.3	2517	8.11
172.4	2519	7.94
174.1	2702	8.42
174.2	2857	8.97
174.3	2555	7.82
174.4	2587	8.22
179.1	1684	5.15	178a	185	0.74
179.2	1715	5.37	178b	177	0.75
179.3	1613	5.04
179.4	1601	4.96
190.2	1473	4.81
190.3	1467	4.78
190.4	1462	4.79
192.1	3318	10.62
192.2	3228	10.42
192.3	3065	10.05
192.4	3222	10.28
203.1	3767	11.98	204a	179	0.77
203.2	3712	11.78	204b	170	0.70
203.3	3768	12.01	204c	165	0.71
203.4	3698	11.96	204d	163	0.81
209.1	4002	12.82
209.2	3608	11.59
209.3	3351	10.87
209.4	3365	10.73
220.2	2880	9.05
220.3	2752	8.54
220.4	2751	8.59