Filed from 25 published puzzles

STRATA

Set to 11 different clues across 25 published puzzles, most often “Layers” — The New York Times, Sunday, 9 January 2011.

6 letters

Every clue on record, most used first

  • Layers9 times

    The New York Times — Sunday, 9 January 2011

  • Levels4 times

    The New York Times — Sunday, 12 September 2010

  • Sheets3 times

    The New York Times — Saturday, 4 February 2006

  • Rock layers2 times

    The New York Times — Monday, 10 November 2008

  • Levels of societyonce

    The New York Times — Tuesday, 20 October 2009

  • Echelonsonce

    The New York Times — Saturday, 19 January 2008

  • Rock bands?once

    The New York Times — Wednesday, 18 July 2007

  • Geological formationsonce

    The New York Times — Saturday, 7 June 2003

  • Geologists' studiesonce

    The New York Times — Sunday, 26 August 2001

  • Geologic layersonce

    The New York Times — Tuesday, 4 November 1997

  • Class levelsonce

    The New York Times — Thursday, 12 January 1995

Other answers to these clues