REE geochemistry of the Maltby Lakes Metavolcanics and Allingtown metadiabase, southwest Connecticut

Conference · Mon Mar 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5807010

Smith, R D; Lanzirotti, A; Hanson, G N ^[1]

---

1. State Univ. of New York, Stony Brook, NY (United States). Dept. of Earth and Space Sciences

The Maltby Lakes Metavolcanics and the Allingtown metadiabase are part of the Orange Milford Belt just west of New Haven. The Maltby Lakes Metavolcanics are dominantly fine- to medium-grained, commonly strongly deformed, mafic to intermediate metavolcanic rocks that range in metamorphic grade from lower greenschist to upper amphibolite facies. The Maltby Lakes samples are LREE depleted (Ce[sub N]/Yb[sub N] < 1, Sm[sub N]/Nd[sub N] > 1), are flat to slightly fractionated through the HREE's and have negative Eu anomalies that increase with increasing REE abundance. The most REE-enriched Maltby Lakes sample has an E[sub Nd] = +7.3 at 450 Ma. The REE and Nd isotopic composition of the Maltby Lakes Metavolcanics are consistent with being a mafic to intermediate volcanic suite derived from a long-lived, LREE depleted mantle source. The Allingtown metadiabase is to the east of the Maltby Lake Metavolcanics and is dominantly at greenschist facies. The metadiabase commonly displays relatively undeformed porphyritic textures and locally intrudes the Maltby Lakes Metavolcanics. A REE pattern for the Allingtown metadiabase is slightly LREE enriched (Ce[sub N]/Yb[sub N] = 1.4, Sm[sub N]/Nd[sub N] < 1), relatively HREE depleted and has no Eu anomaly. The LREE depleted patterns for the Maltby Lake Metavolcanics and the HREE depleted pattern for the Allingtown metadiabase suggest that the two rock types may have had different mantle sources.

• OSTI ID: 5807010
• Report Number(s): CONF-9303211--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:2
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
BASALT
CHEMISTRY
CONNECTICUT
DEVELOPED COUNTRIES
DIABASES
ELEMENTS
GEOCHEMISTRY
GEOLOGIC DEPOSITS
GEOLOGY
IGNEOUS ROCKS
MAGMATISM
METALS
METAMORPHIC ROCKS
METAMORPHISM
NORTH AMERICA
PETROLOGY
RARE EARTHS
ROCKS
TECTONICS
USA
VOLCANIC ROCKS