"a geologist is studying sediments on land that were originally deep sea sediments. she finds the minerals zircon and garnet in the sediments, which could only come from a continental region. these sediments must be"

Terrigenous

Explanation:

The sediments must have been land derieved.

Garnet and zircon are found associated with igneous and metamorphic rocks.

Weathering of these rocks release the minerals into sediments and are hereby transported into ocean basins. They can lithify in the sediments as they get carried along with them.

Terrigenous sediments originates from the land. They are made of rock materials and volcanic deposits. Some of them like volcanic dusts can travel into deeper parts of the oceans as they are lighter and can be carried very far into the ocean.