Physical Sciences and Mathematics Commons^™

Sedimentology And Community Structure Of Reefs Of The Yucatan Peninsula, Mexico, Matthew J. Novak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Holocene carbonate sediments from Mexican reefs in the Caribbean and Gulf of Mexico display variations in constituent composition, texture and mineralogy which are related to their locations on the reefs. Samples were collected at barrier reef environments at Akumal and Chemuyil, on the northeast coast of the Yucatan Peninsula; at the oceanic atoll of Chinchorro, off the southeast coast of the peninsula; and at the shelf atoll of Alacranes, in the Gulf of Mexico. Samples were collected through a depth range of 0-40 m, which encompasses back reef, shallow fore reef, and deeper fore reef environments.

Constituent-particle analysis of reef …

The Petrology And Mineralogy Of Tertiary(?) Olivine Trachyte In The Harrington Peak Quadrangle, Southeastern Idaho, Amanda Shearer-Fullerton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Harrington Peak Quadrangle is located within the Caribou National Forest of southeast Idaho. Within this quadrangle are outcrops of olivine trachyte of Pliocene(?) age overlying sedimentary rocks of Mississippian to Tertiary age. The region contains thrust faults and later normal faults (generally trending north-south} formed during Basin and Range extension.

The Largest outcrop of olivine trachyte (approximately1 1/2 X 3 km) probably formed as the result of a fissure eruption. Two other outcrop areas show evidence of being sites of local extrusion.

Whole-rock chemical analyses revealed the olivine trachyte to have moderate amounts of SiO₂ and Al_{2O …}

Petrology And Mineralogy Of Tertiary(?) Volcanic Rocks West And Southwest Of Kelton (Box Elder Co.), Utah, R. L. Voit

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Kelton, Utah, area has numerous, isolated basaltic outcrops of probable Tertiary age mostly in the form of cuestas with steep faces displaying columnar joints. One ash-flow tuff is located in the southeastern part of the study area. Basaltic fragments in the tuff indicate that pyroclastic activity was preceded by extrusion of basalt.

Effects of Lake Bonneville on the basaltic outcrops include wave­cut terraces, scarps, and other wave-built forms in low lying areas. Massive carbonate deposits formed at levels of former shorelines of Lake Bonneville. Tertiary and Quaternary deposits cover the low- lying areas between basaltic flows, and consist of …

Petrology And Mineralogy Of Tertiary(?) Volcanic Rocks Of Snowville Area, Utah, And Tertiary-Quaternary(?) Volcanic Rocks Of Table Mountain And Holbrook Areas, Idaho, Yunshuen Wang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Basalt flows occur in the Snowville area of north-central Utah and the Table Mountain and Holbrook areas of south-central Idaho. All basalt flows are aphanitic in groundmass, and contain olivine, plagioclase, augite, and opaque oxides. They can be distinguished by texture. Snowville basalt has predominantly subophitic to intergranular textures. Table Mountain basalt is fine grained, with stumpy groundmass plagioclase and equant ilmenite crystals. Holbrook basalt has pilotaxitic to intergranular textures, with the presence of plagioclase phenocrysts and characteristic exsolution lamellae in Fe-Ti oxides. The olivine grains in Holbrook area are intensely oxidized to Fe-Ti oxides.

Snowville basalt contains olivine phenocrysts …

Petrology And Mineralogy Of Tertiary Volcanic Rocks In The Vicinity Of The Rozel Hills And Black Mountain, Box Elder County, Utah, Elizabeth R. Greenman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two basalt flows and an andesite fissure eruption occur in the Rozel Hills - Black Mountain area in Box Elder County, Utah. Both basalt flows are aphanitic, and contain olivine, plagioclase, augite, and opaque oxides. They may be distinguished both chemically and on the basis of their textures. Unit 2 basalt is finer grained, and appears to be associated with a fault in the Black Mountain area. Chemically, it is similar to high-iron lavas in the Craters of the Moon, Idaho area. It has higher alkali, total iron, and titanium contents that Unit 1 basalt. Unit 1 basalt is similar …

Mineralogy And Petrology Of Lava Flows (Tertiary-Quaternary) In Southeastern Idaho And At Black Mountain, Rich County, Utah, Barbara J. Puchy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lava flows of Tertiary-Quaternary age occur in Enoch Valley, Upper Valley, and Slug Valley in southeastern Idaho. The basalts in Upper Valley and Enoch Valley contain olivine (Fo₆₉ to Fo₃₇), plagioclase (An₆₂ to An₃₉), augite and Fe-Ti oxides. The lava in Slug Valley lacks plagioclase, but contains sanidine (Or₇₀ to Or₅₆) with a trace of biotite and amphibole, and thus, has been termed alkali trachyte.

Black Mountain, on the eastern side of Bear Lake, northeastern Utah, is capped by basalt. Minerals present include olivine (Fo₈₃ to Fo₇₂), plagioclase …

Petrology And Mineralogy Of Quaternary Basalts, Gem Valley And Adjacent Bear River Range, Southeastern Idaho, William D. Perkins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Quaternary basalts of Gem Valley, Idaho, are present as valley fill (Group 1) and as well defined flows in the Bear River Range (Group 2) east of Gem Valley. Minerals present in both groups of basalts include olivine (Fo₇₃ -Fo₃₉), augite (Wo₄₁ En₃₉ Fs₂₀), plagioclase (An₇₅ -An₄₀), and Fe-Ti oxides. Coexisting pairs of magnetite and ilmenite, and olivine and clinopyroxene in several samples indicate temperatures of crystallization from 958°c to 1167°c. The Group 2 basalts exhibit a cumulate texture with abundant large (2 cm) phenocrysts of plagioclase.

Chemically, the Gem …

Some Aspects Of Geochemistry And Mineralogy Of Bear Lake Sediments, Utah-Idaho, Dean F. Davidson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bear Lake is located in southeastern Idaho and north-central Utah. The lake has a maximum altitude of 5923 feet and an area of approximately 110 square miles. Surrounding the lake are carbonates, shales, and sandstones of lower Paleozoic through middle Mesozoic ages. The many streams and springs that originate in these rocks are probably the main contributors to the chemistry of the lake. Water from Bear River, which flows into the north end of the lake, also contributes to its chemistry.

Quartz, aragonite, dolomite, calcite and clay minerals are the main minerals in the lake-bottom sediments. Quartz is generally the …