Skip to Main Content


Hot springs along Sulphur Creek in Colusa County, California, have been recognized for about 130 years. Several researchers have proposed that the hot spring fluid there is derived from mixing of “connate” or “evolved connate” water which is derived from ancient seawater deposited in the Mesozoic sedimentary rocks. This water, which is similar in composition to Complexion Spring, mixes with meteoric water to form Wilbur Springs and other hot spring waters along Sulphur Creek. A δD - δ18O plot shows that Complexion Spring really does not plot along this trend; it must be isotopically modified to plot along the trend. Tuscan Springs, which is located 140 km NNE of Wilbur Springs, just NE of Red Bluff, has chemical and isotopic characteristics which are similar to the Sulphur Creek hot springs. Tuscan Springs vent from the Chico Formation of the Great Valley sequence and indicate that Tuscan Springs and Wilbur Springs are both derived from waters originating in the Great Valley sequence. Also δ11B correlates well with Cl, δD and δ18O, which originate in the Great Valley sequence, suggesting a similar source for the higher d11B values. Chemical geothermometry of the Sulphur Creek hot springs indicates a reservoir temperature of ~ 180 °C. This temperature agrees with measured homogenization temperatures from fluid inclusion which range from 150 to 180 °C. The calculated cation geothermometer temperatures are affected by the presence of dissolved Mg, even though the concentrations appear low.

You do not currently have access to this chapter.

Figures & Tables




Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal