Here's why:

* Pressure: Rocks at the surface experience much lower pressure than rocks deep underground. This means they are less confined and have less stress.

* Temperature: Surface rocks are generally cooler than those deep within the Earth. This limits their ability to deform plastically.

* Confining pressure: The confining pressure from the weight of overlying rock is much lower near the surface. This makes the rocks more susceptible to fracturing.

Ductile deformation typically occurs at higher temperatures and pressures, such as those found deep within the Earth's crust and mantle. Under these conditions, rocks can bend and flow instead of breaking.

Examples of brittle deformation near the surface:

* Faults: Fractures in the Earth's crust where rocks have moved past each other.

* Joints: Fractures in rocks without movement.

* Shatter cones: Conical fractures caused by shock waves from impacts.

However, it's important to note that:

* Rock type plays a role: Some rocks, like shale and limestone, are inherently more brittle than others, like granite or basalt.

* Strain rate: Even at the surface, if the strain rate (how quickly the rock is deformed) is slow enough, some rocks might exhibit ductile behavior.

So, while rocks near the surface are generally brittle, there are always exceptions depending on the specific circumstances.