http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Foland, (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Foland, K.A.,Gibb, F.G.F.,Henderson, C.M.B. CHOSUN UNIVERSITY 1997 Basic Science and Engineering Vol.1 No.2
The Shinat Isles Main Sill, of Tertialry age in the Outer hebrides, is a classical example of a composite, differentiated alkaline basic sill. The 170m thick body is composed of four intrusions, oldest to youngest;a 2m olivine teschenite; a 24m thick picrite sill; a subsequent intrusion into the picrite before it was completely solidified producing a 140m thick picrodolerite-crinanite unit; and, a 2m thick granular olivine picrodolerite, emplaced into the upper crinanites befor efull solidification of this host. nd and Sr isotopic study of the sill, from the bottom to top, clarifies the petrogenesis and the extensive sub-solidus alteration by hydrothermal fluids that produced extensive formation of analcime and zeolites. Overall, the initial 87Sr/86Sr ratios show considerable dispersion from about 0.7036 to about 0.7057 while initial 143Nd/144Nd ratios vary from about 0.51252 to 0.51285. Much of the scatter in 87Sr/86Sr for whole-rock samples reflects the uniquitous sub-solidus, aqueous alteration (as deduced by leaching rock samples to remove analcime) during which more radiogenic Sr was introduced into the sill rocks, especially along the margins. in contrast, Nd was immobile during fluid interaction so that the sill 143Nd/144Nd ratios were not affected by the alteratiohn reactions. These values along with the 87Sr/86Sr ratios for leached rock samples outline original magmatic signatures where 87Sr/86Sr and 143Nd/144Nd ratios are inversely and linarly well correlated. Samples cluster at the ends of this trend with only a few in between. The magmatic trend indicates the sill was formed by magmas with two distinct isotopic compositions ofr 143Nd/144Nd and 87Sr/86Sr; a more primitive magma at 0.51285 and 0.7035 that produced the teschenite and picrite, and a more evolved melt at 0.51252 and 0.7048 that produced the picrodolerite-crinanite. There was only very limited mixing of the two magmas which was restricted to the near the contacts between the intrusions and apparently occurred by intercumulus melt migration. The more evolved crinanitc magma was probably produced from the more primitive picritic one by a small degree of crustal contamination and crystal fractionation during a very short interval of residence in the deep crust prior to ascent and emplacement into the picritic intrusion.
-
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
