DATING THE METAMORPHISM OF PRECAMBRIAN MARBLES - EXAMPLES FROM PROTEROZOIC MOBILE BELTS IN GREENLAND

被引：53

作者：

TAYLOR, PN ^{[1
]}

KALSBEEK, F ^{[1
]}

机构：

[1] GEOL SURVEY GREENLAND,DK-1350 COPENHAGEN K,DENMARK

来源：

CHEMICAL GEOLOGY | 1990年 / 86卷 / 01期

关键词：

D O I：

10.1016/0168-9622(90)90003-U

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

Pb-isotope data yield whole-rock isochrons of 1881 +/- 20 Ma (mean square of weighted deviates, MSWD, 1.73), 1845 +/- 23 Ma (MSWD 1.12) and 1773 +/- 22 Ma (MSWD 3.96) on marbles from the Rinkian and Nagssugtoqidian mobile belts of West Greenland and the Ammassalik mobile belt in Southeast Greenland, respectively. The isochron dates are considered to represent the age of metamorphic recrystallisation of the marbles. For the Rinkian and Nagssugtoqidian belts the dates are in good agreement with published ages obtained from Rb-Sr and Pb/Pb data on the other rock types. For the Ammassalik belt there is disagreement with some but not all of the published information; it is possible that the data record two separate phases of metamorphism. The high precision of the dates is due to large variations in Pb-isotopic composition, which appear to be a common feature incarbonate rocks.

引用

页码：21 / 28

页数：8

共 22 条

[1]

ANDERSEN MC, 1985, B GEOLOGICAL SOC DEN, V34, P205

[2] NEW ELECTROCHEMICAL TECHNIQUE FOR SEPARATION OF LEAD AT TRACE LEVELS FROM NATURAL SILICATES [J].

ARDEN, JW ;

GALE, NH .

ANALYTICAL CHEMISTRY, 1974, 46 (01) :2-9

[3]

CHADWICK B, 1989, RAPP GRONLANDS GEOL, V146, P5

[4]

DAWES PR, 1989, RAPP GRONL GEOL UNDE, V146, P23

[5]

Escher A., 1976, GEOLOGY GREENLAND, P77

[6]

Escher A., 1976, GEOLOGY GREENLAND, P105

[7]

FRIEND CRL, 1989, RAPP GRONL GEOL UNDE, V146, P41

[8]

Garde A., 1976, RAPP GRONL GEOL UNDE, V80, P49

[9]

GARDE AA, 1978, MEDD GRONL, V200

[10]

GROCOTT J, 1990, IN PRESS SPEC PAP GE

← 1 2 3 →