BULL. GEOL. SOC. AM. 



VOL. 26, 1914, PL. 25 



Figure 1. — Yegua ox Trimty River above We.st.moeelaxd Bluff 

 Photograph by C. r.. I'.ake.- 







KiouiJK 2. — Voi-Canic A.sii i.\ Jacksox. Wiini: Uock ('i!eek, 'I'uinitv fouxTY 



I'h'jtograiili li.v < '. 1,. I'.nkiT 



YEGUA FORMATION AND VOLCANIC ASH 



