The relation between peak metamorphic temperatures and subsequent cooling during continent–continent collision (western Central Alps, Switzerland)

Swiss Journal of Geosciences

Table 3 Results of the zircon fission track analysis

Sample	U ppm	Cryst. No.	Spontaneous		Induced		P(χ)²	Dispersion	Age	Error
Sample	U ppm	Cryst. No.	ρ_s	N_s	ρ_i	N_i	%	Dispersion	Ma	Ma
LBS-05	653	20	52.8	259	102.2	482	71.3	0.02	17.5	± 1.7
LBS-07	704	20	57.7	289	109.7	550	63.9	0.01	17.8	± 1.7
LBS-10	421	18	145.1	428	66.1	195	33	0.1	73.8	± 7.9
LBS-11	339	20	172.7	594	52.6	181	65.4	0.02	109.7	± 11.5
LBS-17	1102	19	73.9	305	179.7	742	34.2	0.18	13.8	± 1.3
Lo-14-2	988	20	49.6	278	147.2	825	2.5	0.25	11.5	± 1.1
Lo-14-4	909	20	60.1	307	154.2	788	26	0.06	13.3	± 1.2
LB-13	699	20	24.1	356	110.3	1627	31.6	0.09	8.4	± 0.7

Ages were calculated using the zeta calibration method (Hurford and Green 1983), glass dosimeter IRMM541, and a zeta value of 101 ± 8 year/cm² (S. Erne-Schmid) calculated with Fish Canyon Tuff zircon standards
ρ_s: the spontaneous (induced) track density (105 tracks/cm²); N_s: the number of counted spontaneous (induced) tracks; ρ_d: the dosimeter track density (105 tracks/cm²); N_i: the number of tracks counted on the dosimeter; P(χ)²: the probability of obtained Chi-square value for n degree of freedom (where n is the number of crystals minus 1)