Sentences with phrase «volcanic deposits»

The research suggests, for example, that finding pristine mantle material in the middle of the basin might be a bit tricky because of the large volcanic deposit.

Extensive underwater volcanism during ridge spreading led to rapid alteration of volcanic deposits and major changes in ocean chemistry.

Much of this clay is harvested from large volcanic deposits in Fort Benton, Wyoming (thus the name), but it is also harvested from the Montmorillon region in France (again, thus the name) and several smaller deposits worldwide.

NASA researchers have found that several volcanic deposits on Mercury's surface require mantle melting to have started close to the planet's core - mantle boundary, which lies only 400 km below the planets surface and making it unique in the solar system.

Almost all diamonds come from volcanic deposits called kimberlites.

For example, the researchers found higher - than - average concentrations of water in lunar volcanic deposits near the Moon's equator, where background water in the soil is scarce.

But geologists have found little evidence of activity in recent eons; the newest volcanic deposits date back millions of years.

A younger volcanic deposit lying in the rock above these fossils includes zircons, tiny bits of silicate mineral that often contain trace amounts of uranium.

Using radioisotopic dating of underlying volcanic deposits, researchers in 1993 estimated them to be 228 million years old.

«In contrast to most volcanic deposits, the melt inclusions are encased in crystals that prevent the escape of water and other volatiles during eruption.

age constraints on key volcanic deposits that are not directly dated,.

Thick volcanic deposits obliterated the rich farmland surrounding the volcano, and ash travelled as far as western Europe.

The geology of Belize can be divided broadly into the Northern Lowlands, the Maya Mountains, the Toledo Beds and the Pliestocene deposits, but there are other features including volcanic deposits of bentonite in the north and volcanic outcrops along the southern boundary of the Maya Mountains.

Like many earlier eruptions, we know they were tropical eruptions if volcanic deposits are found for the same year in ice cores at both the North and South Poles — that only happens if the aerosol makes it into the tropical stratosphere (where large - scale air currents ultimately distribute the aerosol cloud into both hemispheres — there are some really nice satellite images of this process for the ’91 Pinatubo eruption).

The climate in the Auvergne also contributes to their unique texture: a lack of humidity and abundant sunshine, courtesy of the surrounding mountains and volcanic deposits, ensures that the lentils dry on the plant all by themselves.