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Beachrock along Réunion island seashore Detail showing fragments of coral and shells. Beachrock is a friable to well-cemented sedimentary rock that consists of a variable mixture of gravel-, sand-, and silt-sized sediment that is cemented with carbonate minerals and has formed along a shoreline.
An ophiolite is a section of Earth's oceanic crust and the underlying upper mantle that has been uplifted and exposed, and often emplaced onto continental crustal rocks. The Greek word ὄφις, ophis (snake) is found in the name of ophiolites, because of the superficial texture of some of them. Serpentinite especially evokes a snakeskin.
The exact origins of the rocks found in the ophiolite are a matter of debate; some geologists hypothesize that the rock primarily consists of mid-ocean lithosphere, while others assert different ideas related to island arc terranes associated with the Nevadan orogeny.
An accretionary prism or accretionary wedge is formed from sediments that are accreted onto the non-subducting tectonic plate at a convergent plate boundary.Most of the material in the accretionary wedge consists of marine sediments scraped off from the downgoing slab of oceanic crust but in some cases includes the erosional products of volcanic island arcs formed on the overriding plate.
Found in 1940 in San Joaquin County in a piece of Franciscan chert from the Coast Ranges washed into the Great Valley. Plesiosaurus: hesternus [23] Name means "one who is near to being a lizard of the West coast." Found in 1949 in San Luis Obispo County in a limestone concretion in Franciscan-Knoxville shales.
List of rocks on Mars – Alphabetical list of named rocks and meteorites found on Mars; Rock cycle – Transitional concept of geologic time; List of rock formations: for a list of unusual or culturally significant rock outcrops; Leaverite – Rock in the field that looks interesting but is actually not
Haystack Rock is a 235 ft-tall (72 m) sea stack in Cannon Beach, Oregon. The monolithic rock is adjacent to the beach and accessible by foot at low tide. The Haystack Rock tide pools are home to many intertidal animals, including starfish , sea anemone , crabs , chitons , limpets , and sea slugs .
The use of rock has had a huge impact on the cultural and technological development of the human race. Rock has been used by humans and other hominids for at least 2.5 million years. [22] Lithic technology marks some of the oldest and continuously used technologies. The mining of rock for its metal content has been one of the most important ...