Ceren village in El Salvador is perfectly preserved by ash:
http://www.dailymail.co.uk/sciencetech/article-3302791/The-ancient-Salvadoran-village-perfectly-preserved-ash-Study-reveals-1-400-year-old-community-lived.html
I've found two articles from SOTT also:
http://www.sott.net/article/187311-Maya-Intensively-Cultivated-Manioc-1400-Years-Ago
http://www.sott.net/article/235932-CU-Boulder-team-discovers-ancient-road-at-Maya-village-buried-by-volcanic-ash-1400-years-ago
http://www.dailymail.co.uk/sciencetech/article-3302791/The-ancient-Salvadoran-village-perfectly-preserved-ash-Study-reveals-1-400-year-old-community-lived.html
I've found two articles from SOTT also:
http://www.sott.net/article/187311-Maya-Intensively-Cultivated-Manioc-1400-Years-Ago
http://www.sott.net/article/235932-CU-Boulder-team-discovers-ancient-road-at-Maya-village-buried-by-volcanic-ash-1400-years-ago