Sentences with phrase «for calcite»

Decreasing the amount of carbonate ions in the water makes conditions more difficult for both calcite users (phytoplankton, foraminifera and coccolithophore algae), and aragonite users (corals, shellfish, pteropods and heteropods).

Finds that for calcite, undersaturation occurs when carbonate ion concentration drops below 42 µmol kg - 1

Not exact matches

A mix of red mineral stone and calcite balance the pH of the purified water and reincorporate minerals like magnesium and potassium that are good for your body and can actually improve the taste of your water.

The specific forms of each coccolith most likely evolved under pressure from zooplankton, the microscopic animal group a notch up the food chain that developed mandibles, claws, and other accoutrements for getting past the hard calcite coccoliths.

He then used the concentration of naturally occurring but unstable uranium in the calcite to estimate how much time had passed since the popcorn formed, giving him a minimum age for the art.

For example, Aubert and his team took 55 samples of the layers of the calcite popcorn, showing that they formed a sort of ministratigraphic sequence in which the layers closest to the art were oldest and the top layers were the youngest.

The researchers hope to get a rough age range for the fossils by dating flowstones — calcite structures formed slowly by dripping water — in adjacent rock layers.

The 14C ages were corrected for mass - dependent fractionation with measured δ13C values, 33 and compared with samples of Pleistocene whale bone or calcite (backgrounds, > 48 14C kyr BP), late Holocene bison bone (∼ 1,850 14C BP), late AD 1800s cow bone and OX - 2 oxalic acid standards for calibration.

Warning: While it's fine for most, some gems can't be submerged in water, which can actually dissolve the stone (e.g., gypsum, halite, pyrite, calcite).

- Extracts of Motherwort, Hawthorn, & St. John's - Gem essences of Carnelian, Jasper, & Orange Calcite - Healing for the second / sacral chakra.

Evoking the sea, sweet blue calcite centers a silver stud for pierced ears.

This morning, visit Barton Creek Cave and learn about how the cave served as a gateway to the underworld for the ancient Maya, and paddle a canoe along its aqueous passageways, studded with sparkling calcite crystals.

Its calcite crystals were originally mistaken for diamonds by British soldiers in the 19th century.

Kelly Hill Caves for a guided tour of the sinkholes and caverns that lead to caves of ornate calcite formations.

The cave was named after a shocking display showcasing the calcite - encrusted remains of a woman whom the Cave of the Stone Sepulchre was named for.

Stylistically, his work is all over the place; the wood, honeycomb calcite and steel installation «Hope for the Aw - A» is particularly unexpected.

Present - day ocean surface waters are supersaturated for the major carbonate mineral forms used by marine organisms, including the more soluble form aragonite (corals, many mollusks) and the less soluble form calcite (coccolithophores, foraminifera, and some mollusks).

The Antarctic ice sheet reached the coastline for the first time at ca. 33.6 Ma and became a driver of Antarctic circulation, which in turn affected global climate, causing increased latitudinal thermal gradients and a «spinning up» of the oceans that resulted in: (1) increased thermohaline circulation and erosional pulses of Northern Component Water and Antarctic Bottom Water; (2) increased deep - basin ventilation, which caused a decrease in oceanic residence time, a decrease in deep - ocean acidity, and a deepening of the calcite compensation depth (CCD); and (3) increased diatom diversity due to intensified upwelling.

At some times of year, acidification has already reached a critical threshold for organisms living on Alaska's continental shelves.145 Certain algae and animals that form shells (such as clams, oysters, and crab) use carbonate minerals (aragonite and calcite) that dissolve below that threshold.

For example across the tropical ocean, the ratio of net calcification to net photosynthesis for coccolithophores remained constant despite regions of widely varying surface pH and calcite saturation levels (Maranon 201For example across the tropical ocean, the ratio of net calcification to net photosynthesis for coccolithophores remained constant despite regions of widely varying surface pH and calcite saturation levels (Maranon 201for coccolithophores remained constant despite regions of widely varying surface pH and calcite saturation levels (Maranon 2016).

Here we present the first reconstruction of rainfall variability for the western tropical Atlantic that spans the past 8 centuries and is derived from the δ18O of speleothem calcite.

For example: how much of the O - 18 in the CO2 exchanges with O - 16 in the water used to process the calcite.

Would we for instance change the Mg / Ca ratio triggering shifts to a calcite rather than the modern aragonite state of the oceans?

The Mg - calcite composition of antarctic echinoderms: important implications for predicting the impacts of ocean acidification

The magnitude of sea - level estimates for the past 100 million years rely heavily on foraminiferal calcite oxygen isotopes (δ18O), which are influenced by temperature, evaporation and precipitation, and diagenesis2.