Salina Canyon, Utah, reveals a spectacular angular unconformity along an east-west transect throu... more Salina Canyon, Utah, reveals a spectacular angular unconformity along an east-west transect through the southern part of the Wasatch Plateau. This region of Utah is well known as the eastern extent of Sevier orogenesis, but it also includes subsequent extensional overprinting. Earliest descriptions of this unconformity were published by Dutton (1880) and Spieker (1946, 1949), and work continues today. Field relationships expose many classic stratigraphic and sedimentologic features of erosional surfaces. Due to the geometry of the progressive unconformity onto the topographic high of the Sanpete-Sevier Valley antiform, the angular discordance of strata results in a gap in time of greater than 107 million years in the west, decreasing toward the east to about 39 million years and finally to less than 17 million years. Paleosols and small-scale channels/scours with infilled basal conglomerates are also prominent along the unconformity, as are several mine adits. Because of its abundan...
Glaciovolcanic landforms provide global-scale records of paleoenvironmental conditions and yield ... more Glaciovolcanic landforms provide global-scale records of paleoenvironmental conditions and yield insights into subglacial eruption processes. Models for the formation of glaciovolcanic ridges, or tindars, are relatively simple, proposing a monogenetic eruption and a fairly uniform stratigraphy with or without a single transition from effusive pillow lavas to explosive fragmental deposits. Others have suggested that tindars are more complicated. To build a more robust model for tindar formation, we conducted a field and geochemical study of Undirhlíðar ridge on the Reykjanes Peninsula in southwestern Iceland. We show that the ridge was built through a complex sequence of eruptive and intrusive events under dynamically changing ice conditions. Quarry walls expose a continuous cross-section of the ridge, revealing multiple pillow and fragmental units. Pillow lava orientations record the emplacement of discrete pillow-dominated lobes and the migration of volcanic activity between erupti...
Logging data are measurements of physical properties of the formation surrounding a borehole, acq... more Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.
Logging data are measurements of physical properties of the formation surrounding a borehole, acq... more Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.
The site for CRP-3, 12 km east of Cape Roberts (77.006°S; 103.719°E)was selecte to overlap the lo... more The site for CRP-3, 12 km east of Cape Roberts (77.006°S; 103.719°E)was selecte to overlap the lower Oligocene strata cored in nearby CRP-2/2A, and to sample the oldest strata in the Victoria Land Basin (VLB) for Paleogene climatic and tectonic history. As it transpired there was ...
Ooimmuration is here defined as a taphonomic process by which fossils are preserved within ooids.... more Ooimmuration is here defined as a taphonomic process by which fossils are preserved within ooids. It is a form of lithoimmuration, although depending on the role of microbes in the formation of the ooid cortex, ooimmuration can also be considered a type of bioimmuration. Fossils enclosed within ooids are protected from bioerosion as well as the abrasion common in energetic depositional environments such as ooid shoals. Many taxa in some fossil assemblages may be known only because they were ooimmured. We describe as examples of ooimmuration fossils preserved in an oolite from the Middle Jurassic (Bajocian) Carmel Formation in southwestern Utah.
Salina Canyon, Utah, reveals a spectacular angular unconformity along an east-west transect throu... more Salina Canyon, Utah, reveals a spectacular angular unconformity along an east-west transect through the southern part of the Wasatch Plateau. This region of Utah is well known as the eastern extent of Sevier orogenesis, but it also includes subsequent extensional overprinting. Earliest descriptions of this unconformity were published by Dutton (1880) and Spieker (1946, 1949), and work continues today. Field relationships expose many classic stratigraphic and sedimentologic features of erosional surfaces. Due to the geometry of the progressive unconformity onto the topographic high of the Sanpete-Sevier Valley antiform, the angular discordance of strata results in a gap in time of greater than 107 million years in the west, decreasing toward the east to about 39 million years and finally to less than 17 million years. Paleosols and small-scale channels/scours with infilled basal conglomerates are also prominent along the unconformity, as are several mine adits. Because of its abundan...
Glaciovolcanic landforms provide global-scale records of paleoenvironmental conditions and yield ... more Glaciovolcanic landforms provide global-scale records of paleoenvironmental conditions and yield insights into subglacial eruption processes. Models for the formation of glaciovolcanic ridges, or tindars, are relatively simple, proposing a monogenetic eruption and a fairly uniform stratigraphy with or without a single transition from effusive pillow lavas to explosive fragmental deposits. Others have suggested that tindars are more complicated. To build a more robust model for tindar formation, we conducted a field and geochemical study of Undirhlíðar ridge on the Reykjanes Peninsula in southwestern Iceland. We show that the ridge was built through a complex sequence of eruptive and intrusive events under dynamically changing ice conditions. Quarry walls expose a continuous cross-section of the ridge, revealing multiple pillow and fragmental units. Pillow lava orientations record the emplacement of discrete pillow-dominated lobes and the migration of volcanic activity between erupti...
Logging data are measurements of physical properties of the formation surrounding a borehole, acq... more Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.
Logging data are measurements of physical properties of the formation surrounding a borehole, acq... more Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.
The site for CRP-3, 12 km east of Cape Roberts (77.006°S; 103.719°E)was selecte to overlap the lo... more The site for CRP-3, 12 km east of Cape Roberts (77.006°S; 103.719°E)was selecte to overlap the lower Oligocene strata cored in nearby CRP-2/2A, and to sample the oldest strata in the Victoria Land Basin (VLB) for Paleogene climatic and tectonic history. As it transpired there was ...
Ooimmuration is here defined as a taphonomic process by which fossils are preserved within ooids.... more Ooimmuration is here defined as a taphonomic process by which fossils are preserved within ooids. It is a form of lithoimmuration, although depending on the role of microbes in the formation of the ooid cortex, ooimmuration can also be considered a type of bioimmuration. Fossils enclosed within ooids are protected from bioerosion as well as the abrasion common in energetic depositional environments such as ooid shoals. Many taxa in some fossil assemblages may be known only because they were ooimmured. We describe as examples of ooimmuration fossils preserved in an oolite from the Middle Jurassic (Bajocian) Carmel Formation in southwestern Utah.
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