[4] The sequence reflects assimilation and fractional crystallization (AFC) of a primitive basalt magma.

[3] The formation once formed an extensive thin veneer over the San Juan volcanic field before itself being eroded.

[5] The change to bimodal association coincided with the transition from Laramide compression to Rio Grande rift extension, a pattern seen elsewhere in the western United States.

[5] The rich mineralization of the San Juan Volcanic Field has been attributed to early intrusions of the Hinsdale Formation.

[2] Larsen redefined the unit as the Hinsdale Formation and included the Los Pinos Member.