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The Higdon deposit is located on the east flank of the St. Francois Mountains, approximately 11.5 km NE of Fredericktown, MO in the Mine LaMotte-Fredericktown district of the world renown Southeast Missouri (SEMO) region of Mississippi Valley-type (MVT) deposits. It was discovered in the 1950s and an attempt to mine the deposit was made in the 1960s. In the 2000s the importance of the Higdon deposit increased after extensive exploration by The Doe Run Mining Co. revealed a larger deposit, greater Ni-Co content than initially estimated and the presence of a low grade Unconformity-type Uranium deposit, similar to those of the Athabasca Basin in Canada. The overall paragenetic sequence, stratigraphy and stratigraphic controls of the Higdon deposit resembles those present in other SEMO MVT deposits located at the east flank of the St. Francois Mountains. The stratigraphy includes the Cambrian formations: Eminence, Potosi, Derby-Doe Run, Davis, Bonneterre and Lamotte which unconformably overlies Precambrian granitic intrusions. A common feature is the presence of collapse breccias especially at the base of the Bonneterre Formation and a relatively thin Lamotte Formation. Fine-grained, disseminated sulfides of Fe, Pb, Zn, Co and Ni are hosted in the lower one third of the Bonneterre Formation and upper two thirds of the Lamotte Formation, in a series of grainstone beds, open spaces in collapse breccias, near pinch outs of the Lamotte Formation against basement highs. Disseminations and nodules of pitchblende (uraninite) occur through the entire Lamotte Formation. The Higdon deposit differs in several important ways from the deposits of the Viburnum Trend on the west flank of the St. Francois Mountains. These differences include a distinctly lower stratigraphic interval of collapse breccias and mineralization, greater abundance of Co-Ni minerals, presence of pitchblende, and a significant fault control of mineralization. Several regionally extensive high angle faults aligned parallel to the NW-striking Simms Mountain and Mine LaMotte fault systems bound the deposit, especially the high Ni-Co-U portion. Petrographic and microprobe studies at Higdon revealed a mineral paragenetic sequence of uraninite (pitchblende, within a carbon matrix), pyrite, marcasite, chalcopyrite, bravoite, siegenite, gerdorsffite, sphalerite and galena. These minerals were deposited in four different stages: (1) a U dominated stage that precipitated the pitchblende during Early Ordovician to Permian time; (2) a Fe sulfide dominated sulfide characterized by pyrite, marcasite and bravoite; (3) a Cu-Co-Ni stage dominated by chalcopyrite and siegenite, and (4) a Zn-Pb stage characterized by the precipitation of sphalerite and galena. Precambrian uraniferous granitic intrusions in the vicinity of the Higdon deposit supplied the U for the pitchblende mineralization. At Higdon the U mineralization represents an overlapping deposit in an otherwise MVT system. This required leaching by fluids migrating through the basement along high angle faults and U precipitation in a reducing environment as the fluids encountered the Lamotte Formation. The Ni and Co were possibly leached from mafic and ultramafic intrusions along the Reelfoot Rift or from the Precambrian basement and transported to the Higdon area by fluids migrating along the regional NW-trending faults. Mixing with connate Pb-Zn brines moving laterally through the Lamotte Sandstone and other permeable units may have triggered the sulfide precipitation. Finally, the Higdon deposit is anomalous in the tonnage and grade of its Ni-Co resource (0.17 % Ni, 0.14 % Co) with significant values contained in siegenite (30.9 % Ni, 23.9 % Co), bravoite (0.04 % Ni, 6.3 % Co), gerdorsffite (26.1 % Ni, 8.0 % Co) and marcasite-pyrite (0.3 % Ni, 0.2 % Co).

Philadelphia has been a renowned center for musical development since the American Revolution. The city continues to produce influential composers who elevate the cultural tapestry of American art music. Women composers in Philadelphia have been writing innovative vocal music since the eighteenth century, including patriotic songs, children's songs, folk songs, parlor songs, musical farces, operettas, operas, cantatas, choral music, sacred music, art songs, and chamber music. The introduction of this monograph illuminates the lineage of a selected group of Philadelphian women composers. This includes biographical sketches, musical examples of their works, and a summary of their contributions, giving an inspiring account of their outstanding talent. An increasing number of women composers are producing large-scale vocal works including orchestral choral works and operas. Art songs, however, accompanied by piano or in collaboration with a variety of instruments, continue to be an integral part of the output of contemporary women composers. Solo vocal art song collaboration is popular, and rightly so, for several reasons. The result of using a combination of instruments not only creates multi-textural sonorities, but also allows for “conversation” among the different performers. Secondly, composers can assign an instrument to be played in a particular fashion to create a specific atmosphere. Thirdly, art song is an intimate medium that does not require a large performance venue, so the cost is minimal. Also, there is a theatrical element in ensemble art song that pleases the audience as they experience the collaboration between the musicians as they interact with one another. Finally, in today’s technologically advanced society there are more opportunities for ways of expression through various kinds of multimedia. Internationally acclaimed Philadelphia composer Andrea Clearfield has composed a large body of vocal works. She has written many arrangements of art song for a variety of voice types in collaboration with selected instruments. Her chamber work, A reminiscence sing for soprano, clarinet, and piano, is set to Walt Whitman’s “Out of the Cradle Endlessly Rocking” from his collection of twelve poems, Leaves of Grass (1855). The musical setting captures the essence of the American Romantic poet Walt Whitman, whose works celebrate nature, unity, and humanity. Through musical and textual analysis, I aim to offer performance goals for the singer. These include maintaining keen intonation while navigating dissonant open intervals, communication with the clarinetist throughout the work, and using Clearfield’s organized architecture of form to the utmost advantage to reveal the complex symbolism of Whitman’s poem. Pulitzer Prize-winning and three-time Grammy winner Jennifer Higdon composes music that creates a kaleidoscope of textures. Her chamber work for soprano, violin, cello, and piano, Love Sweet, comprises five poems by Imagist poet Amy Lowell. I intend to reveal how Higdon’s skillful use of prosody creates the images that Lowell expresses in her poetry. This skill ultimately aids the singer in successfully relaying the text. Higdon uses extended jazz harmonies, strong rhythmic motifs, and dampened string technique in the piano to provide the cycle’s cohesiveness. The city of Philadelphia has a rich musical heritage, to which women composers have contributed a great deal. As new vocal works composed by Philadelphia women continue to be an integral part of the mainstream classical repertoire, we must invest time and scholarship in understanding, performing, and teaching these new works. By studying the lineage of women composers in Philadelphia, one can learn about the significance of the city’s cultural landscape and discover the opportunities available to young composers. Through careful musical and poetic analysis, focusing on performance and interpretive strategies for collaborative art songs by Andrea Clearfield and Jennifer Higdon, I aim to prove these works accessible, enlightening, and fulfilling for performers and audiences alike. / Music Performance