The resilient exine of the pollen and spores is preserved in anaerobic environments, such as lakes and bogs, and some acidic and dry soils, as in caves.
Rainwater in the soil zone reacts with soil CO Over time the accumulation of these precipitates form stalagmites, stalactites, and flowstones, which compose the major categories of speleothems.
The pollen grains of trees, shrubs, grasses, and flowers are preserved in either anaerobic conditions or in acid soils.
Samples can be taken from the deposits by means of a core or from individual layers at frequent intervals in a section face on an .
In the excitement of the widely publicized new finds of Aurignacian art from Chauvet, from the Swabian Jura and from as far afield as Pestera Coliboaia in Romania, it has almost been forgotten that a rich corpus of Aurignacian wall painting, engraving and bas-relief sculpture had been recognized and studied before World War I in the Vézère Valley of SW France.
Scientific knowledge of the chronological and cultural context of that early-discovered graphic record has been limited by the crude archaeological methods of that pioneering era, and the loss and dispersal of many of the works discovered.