Stratigraphy Commons^™

Chemostratigraphy Of The Early Pliocene Diatomite Interval From Mis And-1b Core (Antarctica): Paleoenvironment Implications, Giovanna Scopelliti, Adriana Bellanca, Donata Monien, Gerhard Kuhn

ANDRILL Research and Publications

The AND-1B drill core (1285 m-long) was recovered, inside the ANDRILL (ANtarctic geological DRILLing) Program, during the austral summer of 2006/07 from beneath the floating McMurdo Ice Shelf. Drilling recovered a stratigraphic succession of alternating diamictites, diatomites and volcaniclastic sediments spanning about the last 14 Ma. A core portion between 350 and 480 mbsf, including a 80 m-thick diatomite interval recording the early Pliocene warming event, was investigated in term of opal biogenic content and element geochemistry. Across the diatomite interval, in spite of the lithological uniformity, a fluctuating biogenic opal profile mirrors the δ18O record, testifying a decrease ...

Evaluating Potential Post-Flood Boundaries With Biostratigraphy--The Pliocene/Pleistocene Boundary, Marcus R. Ross

Marcus R. Ross

Here I report a biostratigraphic analysis of 303 genera from 28 North American terrestrial mammalian families, in which all families contain members that are either extant or last appear in Pliocene or Pleistocene deposits. The distribution of these taxa within the Cenozoic rock record is used to evaluate proposed demarcations for the Flood/post-Flood boundary. A pronounced biostratigraphic break is expected at the Flood/post-Flood boundary since the final devastation and burial of pre-Flood nephesh creatures should be stratigraphically overlain by the arrival of post-Flood migrants. It is found that when the Flood/post-Flood boundary is placed at or near ...

Veins, Fluid Migration And Hydrocarbon Generation In The Utica Shale, Northern Appalachian Basin, New York, Julian Michaels

Colgate Academic Review

The Upper Ordovician Utica Formation of the Appalachian Basin is a potential target for natural gas development. This black shale outcrops throughout the Mohawk Valley in Central New York State. The lower Flat Creek Member is characterized by E-W Mode 2 (strike-slip) fractures, bedparallel thrusts, and N-S Mode 1 (tensile) fractures. E-W fractures and dilational jogs host the majority of calcite veins, some with hydrocarbon staining and methane-dominated low-salinity aqueous fluid inclusions. Mode 1 fractures host calcite veins and sand injectite dikes sourced from sand and dolomite sourced from underlying Paleozoic strata and Proterozoic basement. Volcanic ash beds from within ...

Stratigraphy Of Quaternary Dunes By Sand Mineralogy And Pedogenic Features, Los Osos, California, Lyssa A. Cousineau

Master's Theses and Project Reports

The goal of this study was to assess mineralogy and pedogenic features of sand dunes in a stratigraphic sequence. The purpose was to determine whether these features significantly differ to reflect age differences with depth within the sequence. This study was conducted in Montaña de Oro State Park, located on the central Californian coast eighteen kilometers northwest of San Luis Obispo in San Luis Obispo County.

Samples were collected from the vertical exposure of one dune face by stratified random sampling at 1.0-m vertical intervals. Particle size distribution was determined through particle-size analysis by hydrometer and sieve. Electrical conductivity ...

Provenance And Geological Significance Of Red Mud And Other Clastic Sediments Of The Mugnano Cave (Montagnola Senese, Italy), Francesco Iacoviello, Ivan Martini

International Journal of Speleology

The Mugnano cave is characterized by a thick clastic sedimentary fill showing a great variability of sedimentary facies, ranging from clay to coarse-grained sand deposits. This paper deals with combined sedimentological and mineralogical (XRD and SEM) studies of these sediments and bedrock insoluble residues in order to understand the origin and geological significance of cave deposits, with particular attention to red mud sediments, often considered as the residue of host rock dissolution. Three different sedimentary facies were recognized: i) YS, yellow sand with occasionally shell fragments, testifying the arrival of sediments from the surrounding landscape; ii) RS, red laminated mud ...