Sentences with phrase «glacial deposits»

Braided fluvial channels (inset) emerge from the edge of glacial deposits roughly 210 million years old on the martian volcano Arsia Mons, nearly twice as high as Mount Everest.

The Dry Valleys» most striking similarity to the Red Planet is in glacial deposits laid down by ice so cold that meltwater never reworks the surface features.

The tools were found beneath glacial deposits laid down during a period 450,000 years ago when the region was blanketed in ice, so they must be older than this.

When NASA's Mars Global Surveyor observed further evidence for ancient glacial deposits on Mars after it arrived in 1997, the idea became less outlandish.

During the Snowball Earth, the presence of which is indicated by glacial deposits with low paleolatitudes from the Transvaal Supergroup in South Africa, the entire planet may have been sheathed in ice for tens of millions of years.

In his mind, the site snuggled too closely to glacial deposits from the last ice age that lay atop the sloping Martian-esque hills.

Most models put Africa, North America, Australia and Europe near the equator in the late Precambrian, about 650 million years ago, which is why geologists have been puzzled to find glacial deposits on these continents.

When he started inspecting nearby craters to work out the direction of the sunlight and shadows, however, he realized that those channels weren't channels at all; they were ridges of material and possible evidence for glacial deposits.

* Chinese glacial deposits show that three of the oldest and coldest ice ages in Earth's history date from 600 to 750 million years ago.

They consist of blocks of horizontally layered glacial deposits, often complete with the overlying forest floor.

Lead author Martin Kennedy at the University of California, Riverside, and colleagues collected limestone and dolomite rocks from Precambrain glacial deposits in northern Namibia, central Australia and the North American Cordillera.

Moraine Creek is certainly an apt name; it has carved through an impressive cake of glacial deposits containing rocks of all origins and colors, ground together, mixed, and mashed by creeping glaciers.

Examples of this type of data include tree ring width and density measurements, fossilized plant remains, insect and pollen frequencies in sediments, moraines and other glacial deposits, marine organism fossils, and the isotope ratios of various elements.

There are a number of different types of proxy data types in this group including glacial deposits, glacial erosional features, shoreline features, aeolian deposits, lake sediments, relict soil deposits, and speleothems (depositional features like stalactites and stalagmites).

The continental glaciations of the Pleistocene left signatures on the landscape in the form of glacial deposits and landforms; however, the best knowledge of the magnitude and timing of the various glacial and interglacial periods comes from oxygen isotope records in ocean sediments.

One author, speculating about the coming of a new ice age, pointed to «evidence of (at least) five rapid hemispheric coolings of about 5 °C... each event spread over not more than about a century,» Flohn (1974), quote p. 385; one line of evidence was carbon - 14 studies of tree stumps in glacial deposits: Denton and Karlén (1973).

In fact, a popular bear viewing spot is at the edge of these glacial deposits.

The peat layer is embedded in a sandy deposit capped by a glacial deposit.

Sohl, L.E., N. Christie - Blick, and D.V. Kent, 1999: Paleomagnetic polarity reversals in Marinoan (ca. 600 Ma) glacial deposits of Australia: Implications for the duration of low - latitude glaciation in Neoproterozoic time.

The drill core penetrated 514 m of silts and silty clays (glacial deposits) punctuated by muds and episodic 0.02 — 1.2 m thick terrigenous sands (interglacial deposits) 22.