Table T2. Amount (weight percent of weighed sample) of SiO2 biogenic extracted from selected samples from the site survey, Site EW9709-3PC.

Table T2. Amount (weight percent of weighed sample) of SiO_{2 biogenic}extracted from selected samples from the site survey, Site EW9709-3PC.


	Na₂CO₃ leach		KOH leach
Digestion time:	6.5 hr	14 hr	9 hr
Sample ID (cm):	Undigested opal in residue	Undigested opal in residue	No opal in residue
EW9709-3PC: 50-51	5.4	7.8	14.3
EW9709-3PC: 150-151	5.8	8.7	14.4
EW9709-3PC: 300-301	3.0	9.6	17.8
EW9709-3PC: 750-751	13.6	32.4	41.3
EW9709-3PC: 800-801	16.5	27.2	44.9
EW9709-3PC: 850-851	19.4	36.8	60.4

Note: The 2-M Na₂CO₃ digestion was incomplete after 6.5 and 14 hr, as evidenced by abundant fossils in the undigested solid residue. Essentially, no opal remained after a 9-hr 2-M KOH digestion.