Historical clue formulations

• Earthy deposit — 2014-08-10
• Clayey deposit — 2012-07-01
• Earthy deposit — 2009-06-19
• Clayey sediment — 2008-04-16
• Soil fertilizer — 2005-04-08
• Earthy deposit — 2004-07-08
• Clayey deposit — 1999-11-28
• Soil fertilizer — 1996-10-22
• Common fertilizer — 1995-07-06
• Clayey deposit — 1995-05-21