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Age and origin of the Cortlandt Complex, New York: Implications from Sm-Nd data

Contributions to Mineralogy and Petrology

By:
,
DOI: 10.1007/BF00371520

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Abstract

Sm-Nd systematics for nine whole-rock samples of hornblende norites, pyroxenites and a lamprophyre from various parts of the Cortlandt Complex were analyzed. Six of these samples from the central and eastern parts of the complex give an isochron age of 430??34 (2 ??) Ma with an e{open}Nd value of -2.9??0.5, and the other three samples from the western part, including the lamprophyre, define a similar age of 394??33 (2 ??) Ma but with a distinctly different e{open}Nd value of -1.4??0.4. The two different initial 143Nd/144Nd ratios corresponding to these e{open}-values are interpreted to reflect continental crustal contamination of the lamprophyric parental liquid prior to final emplacement and crystal fractionation to produce the different rock types of the complex. The intrusion age of 430 Ma for the complex clearly post-dates the major metamorphic event of the Taconic orogeny. The Nd-isotopic data also suggest a relationship between the Cortlandt Complex and a belt of lamprophyric dike rocks to the west, known as the Beemerville trend, which cuts across the metamorphic trends of the Taconic (Ratcliffe 1981). ?? 1982 Springer-Verlag.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Age and origin of the Cortlandt Complex, New York: Implications from Sm-Nd data
Series title:
Contributions to Mineralogy and Petrology
DOI:
10.1007/BF00371520
Volume
79
Issue:
3
Year Published:
1982
Language:
English
Publisher location:
Springer-Verlag
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
290
Last page:
294
Number of Pages:
5