Washover deposits related to tsunami and storm surge along the north coast of the Shimokita Peninsula in northern Japan

Progress in Earth and Planetary Science

Table 4 Major element compositions of volcanic glass shard samples and the AT tephra working standard

Sample	SiO₂	TiO₂	Al₂O₃	FeO"	MnO	MgO	CaO	K₂O	Na₂O	n	Total^""	Remark
B-Tm ash in SKN-W (1)	75.0	0.2	10.9	4.0	0.1	~ ~ 01	0.3	4.3	5.1	8	96.5
	0.6	0.1	0.3	0.1	0.1	0.0	0.1	0.2	0.1		0.6
B-Tm ash in SKN-W (2)	67.6	0.4	15.1	4.5	0.2	0.2	1.1	5.1	5.6	12	97.5
	1.2	0.1	0.5	0.2	0.1	0.1	0.3	0.2	0.2		0.5
88–89 cm in depth of SKN-GS1 (1)	74.8	0.2	11.0	4.0	0.1	0.1	0.3	4.5	5.0	6	96.0
B-Tm	0.7	0.1	0.3	0.1	0.1	0.0	0.2	0.3	0.2		0.9
88–89 cm in depth of SKN-GS1 (2)	67.8	0.4	15.0	4.6	0.2	0.2	1.1	5.1	5.6	14	97.4
B-Tm	1.1	0.1	0.5	0.2	0.1	0.1	0.2	0.2	0.1		0.7
170–172 cm in depth of SKN-GS5	74.7	0.5	13.6	2.5	0.2	0.7	2.6	1.2	4.0	19	96.6
To-Cu	0.3	0.1	0.3	0.3	0.1	0.1	0.1	0.1	0.2		0.7
170–172 cm in depth of SKN-GS5	77.9	0.2	12.5	1.4	0.1	0.3	1.7	2.5	3.4	11	97.4
Other tephra	0.4	0.1	0.4	0.3	0.1	0.0	0.3	0.4	0.1		1.6
AT	78.0	0.1	12.5	1.3	0.1	0.2	1.1	3.2	3.5	24	93.9
Working standard	0.4	0.1	0.1	0.1	0.1	0.0	0.1	0.1	0.1		1.4
To-Cu ash in SKN-E	74.5	0.5	13.5	2.5	0.2	0.7	2.7	1.2	4.0	16	98.7	Ishimura and Hiramine (2020)
	0.3	0.1	0.3	0.1	0.1	0.1	0.1	0.1	0.1		0.6

The number on the upper line is the mean value and that on the lower line is the standard deviation. Measured values were recalculated to 100% on a water-free basis. FeO*, total iron oxide as FeO. Total**, raw data before recalculation