When the lake drained (2 to 4 million years ago), the oolite was left behind, along with siltstone, volcanic tuffs and alluvium from adjacent mountain slopes. Wave action in the lake washed sediments back and forth in the shallows on the southwestern shore, forming ooids and depositing them on steeper benches near the shore in 2- to 40-foot thicknesses. Ten million years ago, the plain formed the bed of Lake Idaho. One of the world's largest freshwater lakebed oolites is the Shoofly Oolite, a section of the Glenns Ferry Formation on southwestern Idaho's Snake River Plain. The material consolidated and eroded during later exposure above the ocean surface. A particular type, Bath Stone, gives the buildings of the World Heritage City of Bath their distinctive appearance.The islands of the Lower Keys in the Florida Keys, as well as some barrier islands east of Miami bordering Biscayne Bay, are mainly oolitic limestone, which was formed by deposition when shallow seas covered the area between periods of glaciation. Some exemplar oolitic limestone, a common term for an oolite, was formed in England during the Jurassic, and forms the Cotswold Hills, the Isle of Portland with its famous Portland Stone, and part of the North Yorkshire Moors. The size of the oolite reflects the time they have had exposed to the water before they were covered with later sediment.
The oolites are commonly found in large current bedding structures that resemble sand dunes. Strong intertidal currents wash the 'seeds' around on the seabed, where they accumulate layers of chemically precipitated calcite from the supersaturated water. The mechanism of formation starts with a small fragment of sediment acting as a 'seed', e.g. They are usually formed in warm, supersaturated, shallow, highly agitated marine water intertidal environments, though some are formed in inland lakes. Oolitic hematite occurs at Red Mountain near Birmingham, Alabama, along with oolitic limestone. Dolomitic and chert ooids are most likely the result of the replacement of the original texture in limestone. The term oolith can refer to oolite or individual ooids.Ooids are most commonly composed of calcium carbonate (calcite or aragonite), but can be composed of phosphate, clays, chert, dolomite or iron minerals, including hematite.
Strictly, oolites consist of ooids of diameter 0.25–2 mm rocks composed of ooids larger than 2 mm are called pisolites.
The name derives from the Ancient Greek word for egg. Make it a goal for your fitness.Oolite or oölite (egg stone) is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. Pick up a copy of Boise Trail Guide and try to knock off even half the routes in one year. It also takes a peek into a few of my favorite trails in the Owyhees with the Oolite Interpretive Trail, the West Fork Shoofly Quick Loop, and the Wilson-Reynolds Loop, among others. The new edition spotlights newly built, popular trails such as the Around the Mountain Trail at Bogus Basin, Peggy’s Trail, Freddy’s Stack Rock Trail, Highlands-Corrals-Bob’s Loop, and the Watchman Loop. And then, cap it off with six, unforgettable Epic Mountain Trails that will test the best. Overall, the books builds your strength and endurance, starting with Greenbelt and Parks trails, then there are tons of Easy Mountain Trails, Moderate Mountain Trails and Strenuous Mountain Trails. The new edition features detailed routes and maps for the Boise Grand Slam Peaks. Now you can experience even more new trails close to home. Steve has produced a whole new edition of Boise Trail Guide, featuring 95 hiking and running trails in the greater Boise area – greenbelt trails, mountain trails in the Boise Foothills, Bogus Basin trails, new routes in the Owyhee Canyonlands, and sweet trails in the Boise National Forest near Idaho City, Garden Valley and Smith’s Ferry.īoise Trail Guide has such a rich diversity of trails that it will break you out of the mold of covering the same trails over and over again.
0 kommentar(er)
