It is believed that these frequent changes helped to deposit material in craters and other low places. The amount of atmospheric dust also has increased and decreased. Because of these variations of climate, at times the atmosphere of Mars would have been much thicker and contained more moisture. These climate variations are due to the tilt of the planet’s rotational axis. Martian climate changes probably helped greatly in the formation of these layers. On the Earth most layers have formed under lakes, seas, and oceans. Finding layered rocks is significant because layered materials usually need water to form. Some locations in the Argye quadrangle show layers. Layers exposed in Nereidum Montes, as seen by HiRISE under HiWish program The light-toned layers may contain sulfates which are good for preserving traces of ancient life. However, some concede that liquid water may have been involved in the past. So, today the scientific community mostly supports the idea that the gullies that are forming today are doing so with dry ice moving down steep slopes. Changes in gullies were seen on Mars when the temperature was just right for such movements of dry ice. Experiments on the Earth showed that gullies can be made with the movement of chunks of dry ice moving down steep slope. The weather conditions on present day Mars are such that sufficient liquid water cannot exist to cause gullies to form. But after many more observations it was found that gullies are being formed today which cannot happen with liquid water. For many years, researchers thought the gullies were made by running water. Usually, each gully has an alcove, channel, and apron. Moreover, they sometimes are on top of sand dunes which themselves are considered to be quite young. Gullies are believed to be relatively young because they have few, if any craters. Gullies occur on steep slopes, especially on the walls of craters. Most Martian gullies are found on the walls of craters or troughs, but Charitum Montes, a group of mountains, has gullies in some locations. Gullies are common in some latitude bands on Mars-usually in midlatitudes. Wide view of gullies in Arkhangelsky Crater, as seen by HiRISE under HiWish program This region shows a great deal of evidence of glacial activity with flow features, crevasse-like fractures, drumlines, eskers, tarns, aretes, cirques, Glacial horns, U-shaped valleys, and terraces. The deepest part of the lake may have taken more than a hundred thousand years to freeze, but with the help of heat from the impact, geothermal heating, and dissolved salts, it may have had liquid water for many millions of years. The lake's volume was equal to the Mediterranean Sea. That great impact melted the ice and formed a giant lake that eventually sent water to the North. Many researchers argue that the impact that formed the Argyre basin probably stuck an ice cap or a thick permafrost layer. Eskers are formed from streams moving under glaciers. After it froze solid, the ice formed eskers which are still visible today. As soon as water entered the basin, it began to freeze.
![smiley face of mars smiley face of mars](https://s.hdnux.com/photos/35/43/02/7745682/4/920x920.jpg)
At least three river valleys (Surius Vallis, Dzigal Vallis, and Palacopus Vallis) drain into it from the south. It contained a lake early in the history of Mars. It was formed by a giant impact that occurred 70 million years after the Hellas impact, the other giant impact in the Southern hemisphere. The real big feature of the Argyre quadrangle is the Argyre basin, called Argyre Planitia in the geological language of Mars. The word Argyre is named after a legendary silver deposit at the mouth of the Ganges-Arakan, Berma.