Earth and Planetary Sciences ETDs

Publication Date



The Pennsylvanian Madera formation of Palomas Peak in the Sandia Mountains of central New Mexico is a sequence of marine limestone and minor sandstone that ranges in age from Desmoinesian to Virgilian. The limestone is predominantly clastic or bioclastic and the sandstone is arkosic. Lithologic and paleontologic evidence suggests an epineritic to infraneritic environment on a gently subsiding shelf during deposition of the Madera Sediments.

Rhythmic deposition at Palomas Peak is evidenced by alternating clastic and bioclastic limestones which may have resulted from: (1) eustatic changes in sea level, (2) tectonic fluctuations in the downwarping of the shelf, or (3) changes in temperature, salinity, oxygen content, or other factors which would hinder the growth of organisms.

The abundant silica present as chert nodules and siliceous lenses which parallel bedding planes is thought to have been transported in colloidal form and precipitated on the sea floor as a gel by electrolytic action.

The detritus of the Madera formation of Palomas Peak is thought to have come from Lamy positive to the east of the Penasco positive to the west.

Diagenetic changes observed within the Madera formation include: (1) syn-authigenic and epi-authigenic silicification, (2) epi-authigenic calification, (3) syn-authigenic and epi-authigenic dolomitization, (4) syn-authigenic and epi-authigenic limonitization and hemtitization, and (5) epi-authigenic recrystallization of calcite and conversion of fossil-shell aragonite to calcite.

Degree Name

Earth and Planetary Sciences

Level of Degree


Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Sherman Alexander Wengerd

Second Committee Member

J. Paul Fitzsimmons

Third Committee Member

Vincent Cooper Kelley



Document Type


Included in

Geology Commons