weathering / mechanical weathering means breaking down rocks / surface materials from a larger whole into smaller pieces by weather / mechanical means
weathering is not becoming. weathering is not physical_event. snowing is precipitation_process. snowing is not precipitation_process. weathering is physical_event. phosphate_weathering is erosion. phosphate_weathering is not erosion. weathering is becoming. stand_underneath_when is raining_or_snowing. weather_vane is not mechanical_device.