scholarly journals K-Ar ages of a Late Cretaceous granitic ring complex around southern Lake Biwa. Southwest Japan. Cooling history of a huge cauldron.

1993 ◽  
Vol 99 (12) ◽  
pp. 975-990 ◽  
Author(s):  
Yoshihiro Sawada ◽  
Tetsumaru Itaya
Keyword(s):  
Late Cretaceous ◽  
Lake Biwa ◽  
Southwest Japan ◽  
Cooling History ◽  
Ring Complex ◽  
History Of

Sericitization of plagioclase in the Rosses Granite Complex, Co. Donegal, Ireland

1996 ◽  
Vol 60 (403) ◽  
pp. 927-936 ◽  
Author(s):  
Meideno Que ◽  
Alistair R. Allen
Keyword(s):  
Fluid Inclusion ◽  
Early Stage ◽  
Alkali Feldspar ◽  
Hydrothermal Fluids ◽  
Cooling History ◽  
Fluid Inclusion Data ◽  
Low Salinity ◽  
Ring Complex ◽  
History Of ◽  
Granite Complex

AbstractSericitization in three separate pulses of the Rosses Granite Ring Complex, Co. Donegal, Ireland, has been investigated texturally and chemically using electron microscopy, electron microprobe and fluid inclusion thermometry. The sericitization, which is restricted to the cores of plagioclase, is associated with pores which are abundant in the cores, but absent in the margins. Alkali feldspar, although porous, is unaltered. Associated with the sericitization is alteration of the adjacent primary plagioclase within the cores of grains to a more sodic composition.It is postulated that the sericitization resulted from the action of externally derived secondary hydrothermal fluids, which gained access to the pores in the plagioclase via now sealed microfractures, formed either by contraction during cooling of the Rosses Complex, or more likely by hydraulic fracturing by the fluids themselves. Limited fluid/rock ratios restricted the degree of sericitization within the host plagioclase, whilst an absence of alteration in alkali feldspar may have been due to the inaccessibility of pores in the alkali feldspar to the hydrothermal fluids at the time of alteration. Fluid inclusion data suggest that the fluids were of low salinity, and that the sericitization took place at an early stage in the cooling history of the Rosses Complex at temperatures between 400 and 600°C. It is further contended that greisenization in the Rosses Complex predated the sericitization and that the greisenization may have been due solely to volatile-rich late-stage magmatic fluids.

U-Pb zircon and K-Ar geochronology reveal the emplacement and cooling history of the Late Cretaceous Beypazarı granitoid, central Anatolia, Turkey

2014 ◽  
Vol 56 (9) ◽  
pp. 1138-1155 ◽  
Author(s):  
Cahit Helvacı ◽  
Yeşim Yücel Öztürk ◽  
Muharrem Satır ◽  
Cosmas Kongnyuy Shang
Keyword(s):  
Late Cretaceous ◽  
Central Anatolia ◽  
Cooling History ◽  
History Of ◽  
Ar Geochronology

scholarly journals A Cretaceous granitic ring complex and the Koto Cauldron around the southern part of Lake Biwa, Southwest Japan.

1994 ◽  
Vol 100 (3) ◽  
pp. 217-233 ◽  
Author(s):  
Yoshihiro Sawada ◽  
Hiroo Kagami ◽  
Ichiro Matsumoto ◽  
Kanji Sugii ◽  
Satoshi Nakano ◽  
...  
Keyword(s):  
Lake Biwa ◽  
Southwest Japan ◽  
Ring Complex

Petrogenetic application of Mg-Fe2+ order-disorder in orthopyroxene to the cooling history of rocks

1983 ◽  
Vol 106 (4) ◽  
pp. 443-449 ◽  
Author(s):  
Surendra Kumar Saxena ◽  
Alberto Dal Negro
Keyword(s):  
Cooling History ◽  
History Of
Sign in / Sign up

Export Citation Format

Share Document