Physical Sciences and Mathematics Commons^™

An Experimental Investigation Of Highly Undercooled Magnesium Silicate Chondrule-Like Spherules, Harry Nicholas Planner

Earth and Planetary Sciences ETDs

A series of experiments, involving molten magnesium silicate spherules that were subjected to high initial cooling rates and allowed to nucleate at high temperatures (985-1350°C), were performed so as to compare their thermal histories to the resulting internal features. Such comparisons could be used to decipher the thermal history of chondrules and the conditions surrounding their formation based on their mineralogy, crystal morphology, and overall texture. Various features of the spherules were correlated with the initial high cooling rate process, nucleation temperature, and the maximum temperature attained during the recalescance to demonstrate the restrictions resulting from or their sensitivities to …

Geochemistry And Petrology Of The Orbicular Rocks, Sandia Mountains, New Mexico, Robert David Enz

Earth and Planetary Sciences ETDs

Orbicular rock located on the west side of the Sandia Mountains, New Mexico, at W. long. 106° 29' 30", N. lat. 35° 13' 04", was first reported by Fitzsimmons (1966). Recently Thompson and Giles (1974) published a paper describing.three types of orbicular rock in the locality which they believed to have been formed by a metasomatic process. Without knowledge of the work of Thompson and Giles, this thesis was initiated as a detailed field, petrographic, geochemical and geochronologic study of these orbicular rocks.

Four types of orbicular rock, including another previously unreported occurrence of orbicular granite about 2 km north …

Unusual Lavas From Molokai, Hawaii: Alkalic Olivine Basalts Transitional To Hawaiites And Strontium-Rich Mugearites, Paul Frank Hlava

Earth and Planetary Sciences ETDs

ABSTRACT

Systematic data has recently been published on the compositions of major mineral phases in rocks of the tholeiitic, alkalic, and nephelinic suites from the island of Maui, Hawaii. The present study was initiated to provide similar data from the rocks of Molokai, Hawaii, from which the nature of interisland variations could be established. During the study, it became obvious that many of the rocks were unusual and so this study also provides information on the bulk rock, trace element, and mineral compositions of alkalic olivine basalts transitional to hawaiites and Sr-rich mugearites.

From a total of 14 basalts collected …

Geology Of The Northern Part Of The Sierra Cuchillo, Socorro And Sierra Counties, New Mexico, Florian Maldonado

Earth and Planetary Sciences ETDs

The northern Sierra Cuchillo, Socorro and Sierra Counties, New Mexico is approximately 32 miles northwest of Truth or Consequences, New Mexico. The Sierra Cuchillo is a narrow fault-block range in the Basin-Range province and is a structurally high element west of the Rio Grande trough. It is bordered on the west by the Winston graben and the Black Range and on the east by Monticello graben and the San Mateo Mountains.

Permian rocks consist of the Yeso and San Andres Formation, with an aggregate thickness of 2100 ft (640 m). Upper Cretaceous rocks, 40 ft (10 m) thick, consist of …

Growth Line Analysis Of A Recent Scallop Population And It's [Sic] Potential For Paleoecology, John F. Dillon

Earth and Planetary Sciences ETDs

Periodic growth lines can be used to construct a record of variations in the growth rate of a fossil or recent shell. Because growth rate is largely dependent upon environmental conditions, such a record serves also as an indication of variations in the environment during the lifetime of the shell. Although the very presence of such variations is of some paleoecologic interest, the main potential of growth lines in paleoecology lies in an extension of this argument. This is the concept that the contemporaneity of fossil organisms could be tested by examining their growth rate records for similarities; these would …

A Petrologic And Quantitative Compositional Study Of Four Rocks From The Mid-Atlantic Ridge, Jonathan A. Green

Earth and Planetary Sciences ETDs

The composition of major mineral phases in four rocks from the equatorial Mid-Atlantic Ridge, as determined by electron microprobe analysis and supplemented by additional mineralogic and petrographic study, have provided data for comparison with continental mafic assemblages. The compositional range of coexisting minerals in the samples: a nepheline-normative gabbro (teschenite), an olivine tholeiite, and two uralitized norites, is similar to the ranges of comparable continental suites. The teschenite contains pyroxene (Wo_48-46 En_37-23Fs_15-31) with high amounts of CaO (20.3-22.2 wt %), Al₂O₃ (2.9-6.8 wt. %), and Ti02 (1.2-2.9 wt. %) characteristic of continental …

Geology Of The White Oaks Mining District Lincoln County, New Mexico, James R. Grainger

Earth and Planetary Sciences ETDs

The White Oaks mining district is 12 km northeast of Carrizozo, in Lincoln County, New Mexico. Hydrothermal gold and tungsten mineralization occurs in north-trending veins and breccia zones in portions of the central district. Permian sandstones, limestones, and gypsum of the San Andres Formation are upwarped marginal to and by the Lone Mountain intrusive in the northwest portion of the map area. Triassic Santa Rosa and Chinle sandstones and shales are inclined to the south with Cretaceous Dakota, Mancos, and Mesaverde sediments. Approximately 640 m of sedimentary strata is exposed in the district.

Igneous rocks in the map area range …