Table 1. Bulk (trisilver phosphate) δ¹⁸O_phos data from the Comley Limestones and SSTs exploring the influence of different values for δ¹⁸O_sw.

Temperatures calculated from Eq. 1 (22). T₁ δ¹⁸O_sw = −6.5‰, the most reasonable value; T₂ δ¹⁸O_sw = −6‰, assumes no latitudinal P-E effects; T₃ δ¹⁸O_sw = −1‰, the most commonly used Paleozoic value; T₄ δ¹⁸O_sw = −8‰, incorporating the maximum likely latitudinal P-E effect of −2‰. Temperature uncertainty (2 SD T₁) calculated from δ¹⁸O measurement SDs, assuming that δ¹⁸O_sw = −6.5‰. See data S1.

Sample	Triplicate mean δ18Ophos (‰ VSMOW)	Triplicate 1 SD (‰ VSMOW)	T1 (°C)	T2 (°C)	T3 (°C)	T4 (°C)	2 SD T1 (°C)
Pristine brachiopods
Aa-Br-L	15.17	0.18	20	22	45	13	1.6
Ad-Br-L	15.06	0.03	20	23	45	14	0.3
La2-Br-L	13.93	0.22	25	28	50	19	2.0
Lb-Br-L	14.63	0.14	22	25	47	16	1.3
Sa-Br-L	14.62	0.15	22	25	47	16	1.3
Pristine Torellella
Lb-To-To	14.70	0.14	22	24	47	15	1.3
Sa-To-To	14.59	0.07	22	25	47	16	0.6
Altered brachiopods
La2-Br-D	13.33	0.17	28	30	53	21	1.5
Lb-Br-D	14.31	0.23	24	26	49	17	2.1
Sa-Br-D	13.94	0.18	25	28	50	19	1.7
Sedimentary phosphate
HG-A	13.95	0.05	25	28	50	19	0.5
HG-A-DC	14.07	0.21	25	27	50	18	1.9
HG-B	12.77	0.09	31	33	55	24	0.8
HG-B-DC	12.78	0.20	31	33	55	24	1.8