Sentences with phrase «layers of sediment»

The brief history is that in 2007, Firestone and others published an article in PNAS showing evidence of various materials that may be diagnostic of extraterrestrial origin (and hence an impact) in layers of sediment dating to 12.9 thousand years ago, just before the beginning of the Younger Dryas cold event.

Can Saharan dust be identified in stratographic layers of sediment elsewhere, for instance during the African mega drought (Yep, looks like there is «Davis et al, Andean ice core records... Annals of Glaciology 43, 34 - 41») An Africam mega-drought coincided with the LIA.

Then he examined layers of sediment in these deep cores, using a suite of techniques to calculate the age of the sand, other rocks, and organic matter in each layer.

THey then studied the layers of sediment deep from the earth using high - tech techniques to figure out the age of various media in each layer.

They found a shift toward types of plankton known to persist in sea - ice conditions in layers of sediment that dated to the collapse of this Viking colony in 1350.

«Ship - based observations show that methane concentrations in the air above the East Siberian Sea Shelf are nearly twice as high as the global average... Layers of sediment below the permafrost slowly emit methane gas, and this gas has been trapped for millennia beneath the permafrost.

Those layers were the layers of sediment in the lake and we saw really thick beds of moss.»

For example, Palynology is the reconstruction of changing environmental conditions through changing layers of sediment and the pollen they contain.

«One thing these layers of sediment enable us to do is to «read» when the sea ice reached that precise point,» Jochen Knies tells us.

The pressure from the layers of sediment and the heat from the earth's core convert the organic materials into natural gas, petroleum and coal.

Natural gas reserves come from large quantities of plant and animal remains that have accumulated between layers of sediment on the bottoms of lakes and oceans over millions of years.

Layers of sediment that date to times when the site was covered by ice are coarse grained and include large pieces of gravel (the geological term is «diamict»).

Robert Smithson is interested in modern types of industry, quarries and salt lakes, prehistoric layers of sediment and puzzling ruins of ancient and modern civilisation.

In these paintings which could have been created nowhere else, the conversation with nature intones layers of sediment and stone, the fall of rain, the path of the wind, and the swath of the haze of the Milky Way.»

Sedimentary rocks are formed when layers of sediment (minerals, other rocks, or organic material) are compressed over time.

Shaw and colleagues from the British Museum, University College London, University of Manchester and the University of Wales studied stone tools and bone fragments found in layers of sediment dating back to more than 240,000 years ago until after 40,000 years ago - when Neanderthals went extinct.

After deposition, sediments are compacted as they are buried beneath successive layers of sediment and cemented by minerals that precipitate from solution.

During its two - year expedition there, Opportunity drove to the edges of promontories along Victoria's serrated edge, allowing it to look across to the next ridge and image the layers of sediment.

She knew the layers of sediment she studied held a treasure trove of biological finds, but she didn't yet have the tools she needed to unearth them.

To figure out why, Stern examined layers of sediment accumulated over time.

The deepest, oldest layers of sediment had hardened, yielding chunks with artifacts studding their surfaces.

Blueberries are thought to have formed by the precipitation of iron - bearing minerals when groundwater rose up through layers of sediment.

South Africa's fossils have been found mostly in caves and other protected sites, while the eastern African fossils tend to be discovered in layers of sediment along lakeshores and flood plains.

Without new layers of sediment, the delta eventually sinks below sea level.

But new images provide the first up - close look at stacked layers of sediment exposed near the base of Mount Sharp, the roughly 5 - kilometer - high outcrop at the center of the crater.

The team found layers of sediment and rocks that built up over time, recording the flow of the ice sheet and reflecting climate change.

Their goal was to examine layers of sediment from the cave, collected and preserved using a technique called micromorphology.

In contrast to glaciers and ice sheets, which sit on the ground, ground ice sits in the ground, mixed with frozen soil or buried under layers of sediment.

Thick layers of sediment tend to insulate deeply buried ground ice from sunlight and inhibit melting.

Such prints are preserved in a sandstone matrix when grains of sand fuse over the course of millions of years beneath the weight of accumulating layers of sediment.

Agricultural areas like St. George were hardest hit by the relentless rains and overflowing rivers that swamped roads, cut off power lines, washed away vineyards and fruit orchards, drowned thousands of head of cattle and other livestock, and covered homes and everything inside them in thick layers of sediment and mud.

Beth Shapiro at the University of California, Santa Cruz, gets first dibs on the samples since her team will take on the most sensitive test, at greatest risk of contamination during handling: the search for ancient mammoth DNA in the layers of sediment.

Generations of trees, ferns, and gargantuan reeds grew and fell before being submerged and then gradually buried under successive layers of sediment, like botanical specimens flattened between the pages of a book.

The rocks were of sandstone, siltstone, and shale: thin layers of sediment, each layer representing a year, or 10, or 100 — I had no idea — welded by time into varying degrees of solidity.

The clues for humanity's entrance into the Anthropocene, he says, lie in the traces we've left behind in layers of sediment and soil.

The remains of fish, algae, molluscs and small arthropods are preserved in the annual layers of sediment deposited in the bottom of Lake Tanganyika.

Allusion is the calling to mind of something without mentioning it, and its performance presupposes that the reader or hearer will be in possession of — and indeed be possessed by — layers of sedimented knowledge.

evolution is unable to explain where the layers of sediments in the strata came» try billions of years

Evolution never disproved Genesis because evolution is unable to explain where the layers of sediments in the strata came from without a global flood so the flood is still historical fact which means evolution never happened.

Every layer of sediment in experience would have its concernedness stubbornly inscribed in it, but each layer would also invite novel concernedness in the spontaneous forming of new layers.

Ambiguity ceases for an instant in the coming to be of a novel occasion with its novel layer of sediment and immediately is regenerated as that occasion perishes and yet remains as superject.

To determine when fire became a routine part of the lives of the cave dwellers, the team looked at flints from about 100 layers of sediments in the lowermost 16 meters of the cave deposits.

Sedimentary rock layers provide a more compressed view of climate, as each layer of sediment is made over a period of hundreds of thousands to millions of years.

Two meters (six and a half feet) below the surface he encountered a layer of sediment marked by coral fragments, mollusk shells and coarse beach sand that could only have come from the sea.

The study suggests that layers of sediments perhaps 10 to 20 meters thick can seal the sea floor and make seamounts the most important conduits for heat and fluid flow — especially on the sloping flank of a midocean ridge, says oceanographer John Sclater of the Scripps Institution of Oceanography in La Jolla, California.

«This ocean drilling expedition will for the first time drill scientific boreholes within the sediments entering this subduction zone, including the layer of sediment that eventually develops into the earthquake - generating fault,» Professor Henstock explained.

The key to Lambert Graben's history was found in layers of sediments just offshore, in Prydz Bay.

Each time the river flooded, it threw up a fresh layer of sediment onto the banks.

As Curiosity climbs Aeolis Mons, it should encounter layers of sediments revealing what mission leader John Grotzinger calls «the dimension of deep time».

In particular, deep down, the researchers identified a layer of sediment where the water had a lower salinity than the water in the sediment above or below.