The Experts below are selected from a list of 72 Experts worldwide ranked by ideXlab platform
Carlton E. Breit - One of the best experts on this subject based on the ideXlab platform.
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placement of the wenlockian Ludlovian boundary in western new york state
Lethaia, 1991Co-Authors: Steven T. Loduca, Carlton E. BreitAbstract:Despite many years of detailed examination focused on the Silurian strata of New York State, the position of the Wenlockian/Ludlovian boundary has, to date, not been satisfactorily cstablished. Reccnt discovery of early Ludlovian graptoloid graptolites, however, provides the first conclusive biostratigraphic evidence for placement of this chronostratigraphic boundary within the New York sections. The carly Ludlovian genera Saetograptus and Spinograptus were recovered from a thin, but laterally persistent bed of argillaceous dolostone located near the base of the Goat Island Formation. This occurrencc indicates that the Wenlockian/Ludlovian boundary is at or near the contact between the Goat Island Formation and the underlying Gasport Formation, considerably lower than had previously been suspected. □Silurian, Wenlockian, Ludlovian, graptolites, stratigraphy. biostratigraphy.
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Placement of the Wenlockian/Ludlovian boundary in western New York State
Lethaia, 1991Co-Authors: Steven T. Loduca, Carlton E. BreitAbstract:Despite many years of detailed examination focused on the Silurian strata of New York State, the position of the Wenlockian/Ludlovian boundary has, to date, not been satisfactorily cstablished. Reccnt discovery of early Ludlovian graptoloid graptolites, however, provides the first conclusive biostratigraphic evidence for placement of this chronostratigraphic boundary within the New York sections. The carly Ludlovian genera Saetograptus and Spinograptus were recovered from a thin, but laterally persistent bed of argillaceous dolostone located near the base of the Goat Island Formation. This occurrencc indicates that the Wenlockian/Ludlovian boundary is at or near the contact between the Goat Island Formation and the underlying Gasport Formation, considerably lower than had previously been suspected. □Silurian, Wenlockian, Ludlovian, graptolites, stratigraphy. biostratigraphy.
Wang Ping - One of the best experts on this subject based on the ideXlab platform.
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Continental island from the Upper Silurian (Ludfordian Stage) of Inner Mongolia: Implications for eustasy and paleogeography
Geology, 2001Co-Authors: Markes E. Johnson, Rong Jia-yu, Wang Chengyuan, Wang PingAbstract:An unconformity between the Silurian Xibiehe Formation and Ordovician igneous rocks marks the perimeter of a small paleoisland near Bater Obo in north-central Inner Mongolia, 180 km northwest of the provincial capital of Hohhot. The stratigraphic position of the lower part of the Xibiehe Formation is correlated by means of conodonts with the upper part of the Ancoradella ploeckensis Zone in the basal Ludfordian Stage (corresponds to mid-Ludlovian Epoch, ca. 421 Ma). Elongate in plan (610 m × 200 m), the exhumed diorite core rises 30 m above the lowest elevations of surrounding Silurian strata. Paleoshores along the principal axis of the inlier delineate contrasting facies. Robust stromatoporoids are in growth position within silty limestones, some directly encrusting the unconformity surface of the sheltered southeast margin. A basal conglomerate of diorite cobbles and boulders characterizes the high-energy northwest margin. The depositional constraints and timing of transgressive facies associated with this continental paleoisland have implications for the eustatic and paleogeographic history of the parent Sino-Korean plate. Burial of the island corresponds to the beginning of a global rise in sea level that peaked in late Ludlovian time. Our interpretation of windward and leeward facies requires an approximate 90° clockwise rotation of the parent plate to accommodate the dominant pattern of low-latitude trade winds and storms.
Steven T. Loduca - One of the best experts on this subject based on the ideXlab platform.
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placement of the wenlockian Ludlovian boundary in western new york state
Lethaia, 1991Co-Authors: Steven T. Loduca, Carlton E. BreitAbstract:Despite many years of detailed examination focused on the Silurian strata of New York State, the position of the Wenlockian/Ludlovian boundary has, to date, not been satisfactorily cstablished. Reccnt discovery of early Ludlovian graptoloid graptolites, however, provides the first conclusive biostratigraphic evidence for placement of this chronostratigraphic boundary within the New York sections. The carly Ludlovian genera Saetograptus and Spinograptus were recovered from a thin, but laterally persistent bed of argillaceous dolostone located near the base of the Goat Island Formation. This occurrencc indicates that the Wenlockian/Ludlovian boundary is at or near the contact between the Goat Island Formation and the underlying Gasport Formation, considerably lower than had previously been suspected. □Silurian, Wenlockian, Ludlovian, graptolites, stratigraphy. biostratigraphy.
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Placement of the Wenlockian/Ludlovian boundary in western New York State
Lethaia, 1991Co-Authors: Steven T. Loduca, Carlton E. BreitAbstract:Despite many years of detailed examination focused on the Silurian strata of New York State, the position of the Wenlockian/Ludlovian boundary has, to date, not been satisfactorily cstablished. Reccnt discovery of early Ludlovian graptoloid graptolites, however, provides the first conclusive biostratigraphic evidence for placement of this chronostratigraphic boundary within the New York sections. The carly Ludlovian genera Saetograptus and Spinograptus were recovered from a thin, but laterally persistent bed of argillaceous dolostone located near the base of the Goat Island Formation. This occurrencc indicates that the Wenlockian/Ludlovian boundary is at or near the contact between the Goat Island Formation and the underlying Gasport Formation, considerably lower than had previously been suspected. □Silurian, Wenlockian, Ludlovian, graptolites, stratigraphy. biostratigraphy.
Markes E. Johnson - One of the best experts on this subject based on the ideXlab platform.
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Continental island from the Upper Silurian (Ludfordian Stage) of Inner Mongolia: Implications for eustasy and paleogeography
Geology, 2001Co-Authors: Markes E. Johnson, Rong Jia-yu, Wang Chengyuan, Wang PingAbstract:An unconformity between the Silurian Xibiehe Formation and Ordovician igneous rocks marks the perimeter of a small paleoisland near Bater Obo in north-central Inner Mongolia, 180 km northwest of the provincial capital of Hohhot. The stratigraphic position of the lower part of the Xibiehe Formation is correlated by means of conodonts with the upper part of the Ancoradella ploeckensis Zone in the basal Ludfordian Stage (corresponds to mid-Ludlovian Epoch, ca. 421 Ma). Elongate in plan (610 m × 200 m), the exhumed diorite core rises 30 m above the lowest elevations of surrounding Silurian strata. Paleoshores along the principal axis of the inlier delineate contrasting facies. Robust stromatoporoids are in growth position within silty limestones, some directly encrusting the unconformity surface of the sheltered southeast margin. A basal conglomerate of diorite cobbles and boulders characterizes the high-energy northwest margin. The depositional constraints and timing of transgressive facies associated with this continental paleoisland have implications for the eustatic and paleogeographic history of the parent Sino-Korean plate. Burial of the island corresponds to the beginning of a global rise in sea level that peaked in late Ludlovian time. Our interpretation of windward and leeward facies requires an approximate 90° clockwise rotation of the parent plate to accommodate the dominant pattern of low-latitude trade winds and storms.
Breit, Carlton E - One of the best experts on this subject based on the ideXlab platform.
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Placement of the Wenlockian/Ludlovian boundary in western New York State
'Wiley', 1991Co-Authors: Loduca, Steven T, Breit, Carlton EAbstract:Despite many years of detailed examination focused on the Silurian strata of New York State, the position of the Wenlockian/Ludlovian boundary has, to date, not been satisfactorily established. Recent discovery of early Ludlovian graptoloid graptolites, however, provides the first conclusive biostratigraphic evidence for placement of this chronostratigraphic boundary within the New York sections. The early Ludlovian genera Saetograptus and Spinograptus were recovered from a thin, but laterally persistent bed of argillaceous dolostone located near the base of the Goat Island Formation. This occurrence indicates that the Wenlockian/Ludlovian boundary is at or near the contract between the Goat Island Formation and the underlying Gasport Formation, considerably lower than had previously been suspected
