The silurian age pdf download

Finney, P. Gibbard, and J. Fan, Episodes 36 3 , — Krogh, Geochim. Acta 37 , — Acta 46 , — Ludwig, Isoplot 3. A Geochronological Toolkit for Microsoft Excel. Berkeley Geochronological Center Spec. Center, Berkeley, CA, Open-File Rep. Stacey and I. Kramers, Earth Planet. Steiger and E. Jager, Earth Planet. Download references. Degtyarev, A. Tretyakov, M. Petersburg, , Russia. You can also search for this author in PubMed Google Scholar. Correspondence to K. Tretyakov, A. Kotov, E. Salnikova, M.

Luchitskaya, V. Kovach, K. Wang, , published in Doklady Akademii Nauk, , Vol. Reprints and Permissions. Degtyarev, K. Earth Sc. Download citation. Received : 05 April Published : 23 April Issue Date : March Anyone you share the following link with will be able to read this content:.

Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative. Skip to main content. Search SpringerLink Search. References 1. Google Scholar 3. It is in most places separated from the underlying Ordovician System by a minor erosional unconformity. It is separated from the overlying Devonian System by a major erosional unconformity along which the entire Silurian section has been removed in some areas.

The Silurian is divided into five formations, which are, from lowest to highest: 1 Brassfield Dolomite or Formation , composed of dolomite in the south and both limestone and dolomite in the north; 2 Osgood Formation, shale and minor dolomite; 3 Laurel Dolomite, dolomite; 4 Waldron Shale, shale and minor dolomite; and 5 Louisville Limestone, calcitic dolomite and dolomitic limestone. The main outcrop area of the rocks considered in this re- port extends about 85 miles south from the Ohio River and has a maximum width of about 20 miles.

The rocks in this belt generally dip westward about 30 feet per mile. Part of this dip was imparted to the rocks prior to the cutting of the overlying unconformity, but most of it came later. Minor tectonic movement along west-northwest and east-northeast trends probably took place during Silurian time. Thickening of the Brassfield and Osgood southward across the westnorthwest-trending Bardstown monocline and thickening of the Brassfield in the axial zone of the east-northeast-trending Lyndon syncline indicate that movement took place along these structures during or immediately before the deposition of these formations.