Middle Miocene to Oligocene sedimentary rocks (AZTsm;0)

Con-glomerate, sandstone, mudstone, limestone, and rock-avalanche breccia (sheet-like deposits of crushed rock) deposited and tilted during widespread normal faulting and basin development. Sediments, mostly conglomerate and sandstone, are commonly medium to dark brown, reddish brown, or brownish gray; younger strata are generally lighter colors. Most deposits are 20 to 30 Ma in southeastern Arizona and 15 to 25 Ma in central and western Arizona. (11-32 Ma)

State	Arizona
Name	Middle Miocene to Oligocene sedimentary rocks
Geologic age	Oligocene to Middle Miocene
Original map label	Tsm
Comments	Middle Tertiary syntectonic or synextensional sucpracrustal rocks
Primary rock type	conglomerate
Secondary rock type	sandstone
Other rock types	sedimentary breccia; siltstone; limestone; mudstone; landslide
Lithologic constituents	Major Sedimentary > Clastic > Sandstone (Bed) Sedimentary > Clastic > Conglomerate (Bed) Minor Sedimentary > Clastic > Sedimentary-breccia (Bed) Incidental Sedimentary > Clastic > Sandstone (Tuffaceous) Sedimentary > Clastic > Conglomerate (Tuffaceous) Sedimentary > Clastic > Sedimentary-breccia (Tuffaceous) Sedimentary > Chemical > Evaporite > Gypsum (Bed) Sedimentary > Carbonate > Marlstone (Bed) Sedimentary > Carbonate > Limestone (Bed) Sedimentary > Clastic > Mudstone (Bed) Sedimentary > Clastic > Siltstone (Bed)
Map references	Richard, S. M., Reynolds, S.J., Spencer, J. E., and Pearthree, P. A., 2000, Geologic Map of Arizona: Arizona Geological Survey Map 35, 1 sheet, scale 1:1,000,000.
Unit references	Richard, S. M., Reynolds, S.J., Spencer, J. E., and Pearthree, P. A., 2000, Geologic Map of Arizona: Arizona Geological Survey Map 35, 1 sheet, scale 1:1,000,000. Spencer, J.E., and Reynolds, S.J., 1989, Middle Tertiary tectonics of Arizona and adjacent areas, in Jenney, J.P., and Reynolds, S.J., editors, Geologic evolution of Arizona: Arizona Geological Society Digest 17, p. 539-574.
Geographic coverage	Cochise - Gila - Graham - Greenlee - La Paz - Maricopa - Mohave - Pima - Pinal - Santa Cruz - Yavapai - Yuma