Wavelets spectrum of 1.txt (size 63-125 μm). Y-axis periods are approximate: exact values are 2=30.4; 4=60.8; 8=121.6; 16=243.2; 32=486.4; 64=972.8; 128= 1945.6 years, due to the 15.2 years step (or 0.0152 Kyr) on X-axis (data digitized at 1-pixel step or 15.2-yr). 220, 400, 690 yr periods are outlined and apparently they do not exist before 800 BCE