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
Geology of the Yosemite area the area. These igneous deposits blanketed the region north of the Yosemite area. Some lava associated with this activity poured into the Grand Canyon of the Tuolumne and formed Little Devils Postpile (a smaller but much older version of the columnar basalt palisades in nearby Devils Postpile National Monument). In the late Cenozoic, extensive volcanism occurred east of the park area. Within the Yosemite region, andesitic lava flows and lahars flowed north of the Grand Canyon of the Tuolumne and volcanic dikes and plugs developed from faults on the flanks of Mount Dana. There is also evidence for a great