Q.Glacial valleys show up many linear depositional forms. Give their locations and names.

Glacial valleys are carved out by moving ice, and as the glacier melts, it leaves behind a suite of linear depositional features that trace the ice's former path. These forms are not scattered randomly; each one occupies a specific position within the valley, telling you where the ice was and how it behaved.

The most prominent linear deposit is the esker, a long, winding ridge of sand and gravel. It forms in the tunnel of meltwater that ran beneath the glacier, so it snakes along the valley floor, often following the old course of the subglacial stream.

Another key form is the moraine, which is debris dumped directly by the ice. You get lateral moraines running along the valley sides, marking the glacier's former edges. Where two tributary glaciers met, their side moraines merge into a medial moraine running down the middle of the valley. At the glacier's snout, the dumped material forms a terminal moraine across the valley mouth. …

A glacier is not just a slow river of ice; it is a conveyor belt of rock. As it grinds down a valley, it plucks, scrapes, and carries tonnes of debris — boulders, gravel, sand, and clay — all mixed together as till. When the ice finally melts or retreats, it does not dump this load randomly. The debris is arranged into distinct, often strikingly linear, shapes that tell you exactly where the ice stood, where it flowed, and where meltwater ran. These are the linear depositional forms of a glacial valley, and each one has a name and a preferred home.

The most famous of these is the eskers. Picture a winding ridge of sand and gravel snaking across a valley floor, sometimes for kilometres, looking like an abandoned railway embankment. That is an esker. It forms inside a tunnel beneath the glacier, carved by meltwater streams that ran under the ice, under enormous pressure. The stream deposits its load of sand and gravel along its bed; when the ice melts away, that streambed is left behind as a long, sinuous ridge. So eskers are found along the valley floor, following the path of the old subglacial drainage — often meandering, sometimes branching, always linear.

Then there are the drumlins. These are not ridges but streamlined hills — elongated, teardrop-shaped mounds of till, with a steep blunt end facing the direction the ice came from and a gentler tapering tail pointing the way the ice was going. They look like a herd of giant inverted spoons lying on the valley floor. Drumlins form beneath the ice as it flows over the ground, moulding the till into these smooth, aerodynamic shapes. They occur in clusters or swarms, often called a "basket of eggs" landscape, and they are found on the valley floor and in the broader lowlands where the ice moved freely. Their alignment is a direct fossil of ice-flow direction.

The third family is the moraines, and these come in several linear flavours. A lateral moraine is a ridge of debris running along the side of the valley, at the glacier's edge — a long, straight bank of rock that marks where the ice rubbed against the valley wall. A medial moraine forms where two glaciers merge; their side moraines join and ride along the top of the combined glacier as a dark stripe, and when the ice melts, that stripe is dumped as a ridge down the middle of the valley floor. And a terminal moraine is the great curved rampart of till piled up at the glacier's snout — the furthest point the ice reached. It arcs across the valley mouth like a dam. A recessional moraine is a smaller version of the terminal moraine, left behind when the glacier paused during its retreat, so you get a series of parallel ridges marching up the valley. …