نتایج جستجو برای: carbonate sand

تعداد نتایج: 52870  

Journal: :Journal of Geotechnical and Geoenvironmental Engineering 2021

This paper includes an investigation of the thermal conductivity biocemented soils to better understanding regimes heat transmission through treated by microbially induced calcium carbonate precipitation (MICP). A series tests using transient plane source method (TPS) was performed on silica sand specimens with different gradations, void ratios, and MICP treatment cycles. The results showed tha...

Journal: :Zootaxa 2013
Andreas Kroh Rich Mooi Claudia Del Río Christian Neumann

A new species of abertellid sand dollar, Abertella miskellyi n. sp., is described from the Miocene Camarones Formation of Patagonia, southern Argentina. The new taxon corroborates the existence of the genus in South America, given that Abertella is most common in the southeastern USA and the eastern coast of Central America. It is characterized by a unique basicoronal circle, in which the inter...

2017
Jasmin A. Godbold Rachel Hale Christina L. Wood Martin Solan

Fundamental changes in seawater carbonate chemistry and sea surface temperatures associated with the ocean uptake of anthropogenic CO2 are accelerating, but investigations of the susceptibility of biogeochemical processes to the simultaneous occurrence of multiple components of climate change are uncommon. Here, we quantify how concurrent changes in enhanced temperature and atmospheric pCO2, co...

ژورنال: :پژوهش های دانش زمین 0
سید احمد بابا زاده دانشگاه پیام نور تهران مریم علوی کارشناس ارشد چینه و فسیل، دانشکده علوم، دانشگاه پیام نور تهران

منطقه مورد مطالعه در حاشیه لوت، در استان خراسان جنوبی قرار دارد. دو برش چینه شناسی کبوده و آرک شمالی به منظور توصیف رخساره ها و تعیین محیط رسوبی مورد اندازه گیری و نمونه برداری قرار گرفت. برای هر برش سه دسته رخساره اصلی کربناته، آواری و مخلوط آواری-کربناته شناسایی گردید. هفت ریز رخساره برای برش کبوده و شش ریز رخساره برای برش آرک شمالی، تشخیص داده شد که از محیط های ساحلی تا ابتدای بخش خارجی پلتف...

2004
B. A. Welle A. C. Hirsch L. E. Davis

A sedimentological survey of the southwest arm of the Holocene Pigeon Creek tidal lagoon on San Salvador Island, Bahamas was conducted to determine the origin and distribution of calcareous sediments. Transect surveys, surface samples, and sediment cores were collected and examined to determine the abundance and distribution of sediments and sediment producers in the lagoon and associated tidal...

2011
Katerina Aggelopoulou Theofanis A. Gemtos

In the present paper the yield and soil spatial variability in an apple orchard was studied. Apples were collected manually and placed in plastic bins along the tree rows. Yield per ten trees was weighted and the geographical position in the centre of the ten trees was recorded, using a GPS, in order to create the yield map. The orchard was divided in management zones with the Management Zone A...

2004

Pliny the Elder recorded that Phoenician sailors came ashore and, not finding any local materials suitable for supporting their cooking pots above the sandy shore, used lumps of trona (natural soda or sodium carbonate) that formed part of their ship’s cargo. As the trona was heated in the fire it combined with the sand to give a material that flowed. This story may not be entirely accurate but ...

2006

Formation and Distribution of Beachrock Beachrock is defined by Scoffin and Stoddart (1987, 401) as "the consolidated deposit that results from lithification by calcium carbonate of sediment in the intertidal and spray zones of mainly tropical coasts." Beachrock units form under a thin cover of sediment and generally overlie unconsolidated sand, although they may rest on any type of foundation....

Journal: :Frontiers in Ecology and Evolution 2022

We conducted a 5-year field (2017–2021) and laboratory study of the relationship between type substrate hatching success, embryonic development, quality hatchlings in loggerhead turtle nests. Our site, island Maio archipelago Cabo Verde, one world’s largest nesting colonies, displays marked heterogeneity sand colouration, with dark, mixed, light sandy beaches. experimentally incubated eggs, com...

2017
V. Witt P. M. Ayris D. E. Damby C. Cimarelli U. Kueppers D. B. Dingwell G. Wörheide

Shallow-water coral reef ecosystems, particularly those already impaired by anthropogenic pressures, may be highly sensitive to disturbances from natural catastrophic events, such as volcanic eruptions. Explosive volcanic eruptions expel large quantities of silicate ash particles into the atmosphere, which can disperse across millions of square kilometres and deposit into coral reef ecosystems....

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