Geology of Kent into northern France. The fold arises from the continuing Alpine orogeny and results in the general northward dip of the rock strata in most of Kent. There are extensive spreads of coastal and estuarine alluvium on the Thames Estuary coast, in the low ground surrounding the Isle of Thanet and across Romney Marsh. Alluvium also floors the valleys of the River Medway and Stour. 'Clay-with-flints' is a commonly occurring deposit across the North Downs which is a product of periglacial conditions during the last ice age. Loessic deposists, of aeolian origin i.e. windblown, are common in east Kent, especially on
History of the west coast of North America example, it has been estimated that in 1492, one-third of all Native Americans in the United States were living in California. In the western half of Mesoamerica (that is, western portions of today's Mexico and northern Central America), the oldest known settlements date to approximately 2000 BCE. A succession of cultures started with the very early "Capacha" culture, which appeared on the Pacific coast of modern Mexico about 1450 BC and spread into the interior. The following cultures developed into "high civilizations" in Mesoamerica, with extensive urban areas, writing, astronomy and fine arts: Farther south, Panama was home to some