Physical Sciences and Mathematics Commons^™

Hierarchical Segmentation Of The Malawi Rift: The Influence Of Inherited Lithospheric Heterogeneity And Kinematics In The Evolution Of Continental Rifts, Daniel A. Lao-Davila, Haifa S. Al-Salmi, Mohamed G. Abdel Salam, Estella A. Atekwana

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We used detailed analysis of Shuttle Radar Topography Mission-digital elevation model and observations from aeromagnetic data to examine the influence of inherited lithospheric heterogeneity and kinematics in the segmentation of largely amagmatic continental rifts. We focused on the Cenozoic Malawi Rift, which represents the southern extension of the Western Branch of the East African Rift System. This north trending rift traverses Precambrian and Paleozoic-Mesozoic structures of different orientations. We found that the rift can be hierarchically divided into first-order and second-order segments. In the first-order segmentation, we divided the rift into Northern, Central, and Southern sections. In its Northern Section, …

No Thermal Anomalies In The Mantle Transition Zone Beneath An Incipient Continental Rift: Evidence From The First Receiver Function Study Across The Okavango Rift Zone, Botswana, Youqiang Yu, Kelly H. Liu, M. Moidaki, Cory A. Reed, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Mechanisms leading to the initiation and early-stage development of continental rifts remain enigmatic, in spite of numerous studies. Among the various rifting models, which were developed mostly based on studies of mature rifts, far-field stresses originating from plate interactions (passive rifting) and nearby active mantle upwelling (active rifting) are commonly used to explain rift dynamics. Situated atop of the hypothesized African Superplume, the incipient Okavango Rift Zone (ORZ) of northern Botswana is ideal to investigate the role of mantle plumes in rift initiation and development, as well as the interaction between the upper and lower mantle. The ORZ developed within …

The Lithotectonic Setting And Paragenetic History Of Deposit No.1, Mary River District, North Baffin Island, Sean A. Fulcher

Electronic Thesis and Dissertation Repository

Baffinland Iron Mines Corporation is currently extracting the highest grade BIF-hosted direct shipping iron ore in the world from their flagship Deposit No.1 on north Baffin Island. This deposit and several other prospects are hosted within the isoclinally folded Mary River Group, a Neoarchean greenstone belt terrane hosting Algoma-type BIF, ultramafics volcaniclastics and sediment. Mary River Group supracrustals are juxtaposed against Mesoarchean basement gneisses due to a regional Transhudson Orogen overprint, forming a regional dome-keel tectonic framework.

Detail mapping and core logging of Deposit No.1 combined with geochemistry and geochronology reveal the footwall rocks, previously interpreted as gneisses, volcanics and …

Understanding The Contractional History Of Surprise Canyon, California Through Digital Field Mapping, 3d Modeling, And U-Pb Zircon Geochronology, Joshua A. Cobb

Open Access Theses & Dissertations

Detailed digital mapping of lower-middle Surprise Canyon has revealed a more complex structure than previously interpreted. Rock units derived from the metamorphosed equivalents of the Pahrump Group exposed in Surprise Canyon display juxtapositions inconsistent with stratigraphic variations suggested in previous studies. This study proposes a contractional history of the central Panamint Mountains defined by two kinematically distinct and geochronologically constrained deformation events. D1 is characterized by a shallow dipping, NNW striking L and LS tectonite fabric ubiquitously observed in all metasedimentary and basement units. F1 folds are mesoscopic in scale and isoclinal with an axial planar S1 foliation. A prominent …