The elongated landform produced when glaciers move over older moraines is called a drumlin.

Here's a breakdown:

* Moraines: Moraines are piles of rock, gravel, and sediment deposited by glaciers.

* Drumlins: Drumlins are elongated, tear-drop shaped hills formed when a glacier moves over previously deposited moraine material. The "upstream" end (where the glacier came from) is typically rounded, while the "downstream" end (where the glacier moved towards) is more pointed.

Drumlins are often found in groups, providing valuable clues about the direction and flow of ancient glaciers.