Biggs jasper

[1](p 56) Biggs jasper is found between two of the basalt lava flows that once covered the U.S. states of Oregon, Washington and parts of Idaho.

During this time, the volcanic ash decomposed into clay and was deposited by rain water in streams and lakes atop the cooled basalt.

As water escaped it in the form of superheated steam, pressure variations resulted in flexing and many short fluctuating changes, reflected in the jasper's many thin, parallel bands.

[1](p 59) Near Biggs jasper a stratum of white clay is sometimes found, locally named "wascoite" for the town of Wasco, Oregon.

Because of their different physical properties, water movement separated the two colloids from which the chert and Biggs jasper resulted from each other, so that both were deposited in nearly pure form.