| ชื่อเรื่อง | : | Glass and mineral chemistry of northern central Indian ridge basalts: Compositional diversity and petrogenetic significance |
| นักวิจัย | : | Ray, Dwijesh , Banerjee, R. , Iyer, S.D. , Basavalingu, B. , Mukhopadhyay, S. |
| คำค้น | : | petrogenesis , crystallization , mineral composition , mid-ocean ridges |
| หน่วยงาน | : | National Institute Of Oceanography (NIO), India |
| ผู้ร่วมงาน | : | - |
| ปีพิมพ์ | : | 2552 |
| อ้างอิง | : | Acta Geologica Sinica, vol.83(6); 1122-1135 , http://drs.nio.org/drs/handle/2264/3472 |
| ที่มา | : | - |
| ความเชี่ยวชาญ | : | - |
| ความสัมพันธ์ | : | - |
| ขอบเขตของเนื้อหา | : | - |
| บทคัดย่อ/คำอธิบาย | : | The glass and mineral chemistry of basalts examined from the northern central Indian ridge (NCIR) provides an insight into magma genesis around the vicinity of two transform faults: Vityaz (VT) and Vema (VM). The studied mid-ocean ridge basalts (MORBs) from the outer ridge flank (VT area) and a near-ridge seamount (VM area) reveal that they are moderately phyric plagioclase basalts composed of plagioclase (phenocryst [An sub(60-90)] and groundmass [An sub(35-79)]), olivine (Fo sub(81-88)), diopside (Wo sub(45-51), En sub(25-37), Fs sub14-24)), and titanomagnetite (FeO sub(t) approx. 63.5 wt% and Ti0 sub(2) approx. 22.69 wt%). The whole-rock composition of these basalts has similar Mg [mole Mg/mole(Mg+Fe sup(2+))] (VT basalt: approx. 0.56-0.58; VM basalt: approx. 0.57), but differ in their total alkali content (VT basalt: approx. 2.65; VM basalt: approx. 3.24). The bulk composition of the magma was gradually depleted in MgO and enriched in FeO sub(t), Ti0 sub(2), P sub(2) O sub(5), and Na sub(2)0 with progressive fractionation, the basalts were gradually enriched in Y and Zr and depleted in Ni and Cr. In addition, the Sigma REE of magma also increased with fractionation, without any change in the (La/ Yb) sub(N) value. Glass from the VM seamount shows more fractionated characters (Mg: 0.56-0.57) compared to the outer ridge flank lava of the VT area (Mg: 0.63-0.65). This study concludes that present basalts experienced low-pressure crystallization at a relatively shallow depth. The geochemical changes in the NCIR magmas resulted from fractional crystallization at a shallow depth. As a consequence, spinel was the first mineral to crystallize at a pressure >10 kbar, followed by Fe-rich olivine at <10 kbar pressure |
| บรรณานุกรม | : |
Ray, Dwijesh , Banerjee, R. , Iyer, S.D. , Basavalingu, B. , Mukhopadhyay, S. . (2552). Glass and mineral chemistry of northern central Indian ridge basalts: Compositional diversity and petrogenetic significance.
: National Institute Of Oceanography (NIO), India. Ray, Dwijesh , Banerjee, R. , Iyer, S.D. , Basavalingu, B. , Mukhopadhyay, S. . 2552. "Glass and mineral chemistry of northern central Indian ridge basalts: Compositional diversity and petrogenetic significance".
: National Institute Of Oceanography (NIO), India. Ray, Dwijesh , Banerjee, R. , Iyer, S.D. , Basavalingu, B. , Mukhopadhyay, S. . "Glass and mineral chemistry of northern central Indian ridge basalts: Compositional diversity and petrogenetic significance."
: National Institute Of Oceanography (NIO), India, 2552. Print. Ray, Dwijesh , Banerjee, R. , Iyer, S.D. , Basavalingu, B. , Mukhopadhyay, S. . Glass and mineral chemistry of northern central Indian ridge basalts: Compositional diversity and petrogenetic significance. : National Institute Of Oceanography (NIO), India; 2552.
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