Skip to main content Accessibility help
×
Hostname: page-component-77c89778f8-5wvtr Total loading time: 0 Render date: 2024-07-17T02:58:56.133Z Has data issue: false hasContentIssue false

6 - Middle Ordovician Trenton Group of New York, USA

Published online by Cambridge University Press:  10 November 2010

Hans Hess
Affiliation:
Basel Natural History Museum, Switzerland
William I. Ausich
Affiliation:
Ohio State University
Carlton E. Brett
Affiliation:
University of Cincinnati
Michael J. Simms
Affiliation:
Ulster Museum, Belfast
Carlton E. Brett
Affiliation:
University of Cincinnati, Ohio
Get access

Summary

A QUARRY FOR COLLECTING TRILOBITES AND ECHINODERMS

Classic outcrops of the Middle Ordovician Trenton Beds are exposed along the Trenton Gorge of West Canada Creek and in Mill, Cincinnati, and other creeks tributary to the Mohawk River at the town of Trenton, Madison County, New York, north of the Mohawk River valley (Fig. 71). A small hand-operated quarry on the property of W. Rust, about 1 km east of Trenton Falls, was opened by the Rust family and Charles Walcott for the purpose of collecting spectacular trilobite and echinoderm fossils from the upper beds of the Trenton Group.

Limestones of the Trenton Group are of late Middle Ordovician age (Trentonian or Caradocian Series, Mohawkian Stage), about 460 million years before present. The productive strata for crinoids occur in the Rust Member of the Denley Formation (Figs. 72, 73).

SHALLOW PLATFORM, RAMP AND BASIN

The Trenton Group comprises some 100–130 m of highly fossiliferous, thin-bedded, grey limestones with thin interbeds of dark grey calcareous shale. Limestones include a variety of lithologies, such as pelmatozoan-rich skeletal and rubbly nodular limestones with remains of bryozoans and pelmatozoans and tabular, graded micritic limestone. The latter have sharp bases, internal planar to cross-lamination and, in some instances, perfectly preserved fossils, including crinoids.

The coarser skeletal limestone facies are considered to have been deposited in shallow shelf settings. These beds show various amounts of winnowing by storm-generated waves and currents. Nodular calcarenites have undergone thorough bioturbation and, in some cases, early diagenetic cementation. The fine-grained lime mudstone beds reflect rapid deposition from low-density turbidity or gradient currents.

Type
Chapter
Information
Fossil Crinoids , pp. 63 - 67
Publisher: Cambridge University Press
Print publication year: 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×