Unified Soil Classification System group symbol. For example, GW-GM corresponds to "well-graded gravel "with silt"." If the soil has more than 15% by weight retained on a #4 sieve (R > 15%), there is a significant amount of gravel, and the suffix "with gravel" may be added to the group name, but the group symbol does not change. For example, SP-SM could refer to "poorly graded SAND with silt" or "poorly graded SAND with silt and gravel." Unified Soil Classification System The Unified Soil Classification System (USCS) is a soil classification system used in engineering and geology to describe the texture and grain size
Gravel Run (Black Creek) by acid mine drainage in the early 1900s. The acid mine drainage came from mines in and near the city of Hazleton. Gravel Run is entirely within the United States Geological Survey quadrangle of Hazleton. It drains a portion of the northwestern part of the city of Hazleton. It drains the older part of the city as well as the Green Ridge Territory. Gravel Run is one of eleven officially named streams in the watershed of Nescopeck Creek that has not been assessed by the Pennsylvania Fish and Boat Commission. Gravel Run was entered into the Geographic Names Information System