A new selected area electron diffraction (SAED) pattern was found from Fe-illite. The lattice of the ED pattern can be described as a compound tessellation of {3,6}[79{3,6}], which is based on a large coincidence-site...A new selected area electron diffraction (SAED) pattern was found from Fe-illite. The lattice of the ED pattern can be described as a compound tessellation of {3,6}[79{3,6}], which is based on a large coincidence-site lattice (CSL) with oriented crystal associations rotated by a non-crystallographic angle 26°. This phenomenon corresponds to the plesiotwinning of Fe-illite and has been never reported in the nature so far.展开更多
The SHRIMP zircon U-Pb dating was carried out and yielded 287±5 Ma (MSWD = 0.34) and 274±3 Ma (MSWD = 1.35) for the Kalatongke No. 1 and Huangshan- dong Cu-Ni-bearing mafic-ultramafic complexes. These ages a...The SHRIMP zircon U-Pb dating was carried out and yielded 287±5 Ma (MSWD = 0.34) and 274±3 Ma (MSWD = 1.35) for the Kalatongke No. 1 and Huangshan- dong Cu-Ni-bearing mafic-ultramafic complexes. These ages are much more precise than pre-existing rock-mineral Rb-Sr, Sm-Nd and Re-Os isochron ages for the two complexes and constrain the timing of not only the complexes but also the magmatic Cu-Ni sulfide deposits more reliably. It is neces- sary to carefully reevaluate the previous chronological data for the complexes. The Cu-Ni-bearing mafic-ultramafic com- plexes have the ages similar to those of postcollisional A-type granites in the same area, implying that they could be related to the delamination of lithospheric mantle and upwelling and partial melting of asthenospheric mantle in postcollisional setting. Therefore, the Cu-Ni-bearing mafic-ultramafic com- plexes are a direct indicator of vertical growth of the conti- nental crustal in the Central Asian Orogenic Belt.展开更多
The high pressure pelitic granulite with peak assemblage of garnet + kyanite + ternary feldspar + musco-vite + rutile was discovered in Qixia area in the Precambrian Jiaobei massif, where high pressure basic granulite...The high pressure pelitic granulite with peak assemblage of garnet + kyanite + ternary feldspar + musco-vite + rutile was discovered in Qixia area in the Precambrian Jiaobei massif, where high pressure basic granulites are widely distributed. The metamorphic peak conditions for the pelitic granulite were calculated as T = 800—840℃ and P = 1.0—1.25 GPa on the basis of P-T pseudosection. The post peak P-T path is characterized first by an isothermal de-compression (ITD) pattern and then by an isobaric cooling (IBC) pattern, indicating a geodynamic process related to thinning of thickened continental crust.展开更多
文摘A new selected area electron diffraction (SAED) pattern was found from Fe-illite. The lattice of the ED pattern can be described as a compound tessellation of {3,6}[79{3,6}], which is based on a large coincidence-site lattice (CSL) with oriented crystal associations rotated by a non-crystallographic angle 26°. This phenomenon corresponds to the plesiotwinning of Fe-illite and has been never reported in the nature so far.
文摘The SHRIMP zircon U-Pb dating was carried out and yielded 287±5 Ma (MSWD = 0.34) and 274±3 Ma (MSWD = 1.35) for the Kalatongke No. 1 and Huangshan- dong Cu-Ni-bearing mafic-ultramafic complexes. These ages are much more precise than pre-existing rock-mineral Rb-Sr, Sm-Nd and Re-Os isochron ages for the two complexes and constrain the timing of not only the complexes but also the magmatic Cu-Ni sulfide deposits more reliably. It is neces- sary to carefully reevaluate the previous chronological data for the complexes. The Cu-Ni-bearing mafic-ultramafic com- plexes have the ages similar to those of postcollisional A-type granites in the same area, implying that they could be related to the delamination of lithospheric mantle and upwelling and partial melting of asthenospheric mantle in postcollisional setting. Therefore, the Cu-Ni-bearing mafic-ultramafic com- plexes are a direct indicator of vertical growth of the conti- nental crustal in the Central Asian Orogenic Belt.
文摘The high pressure pelitic granulite with peak assemblage of garnet + kyanite + ternary feldspar + musco-vite + rutile was discovered in Qixia area in the Precambrian Jiaobei massif, where high pressure basic granulites are widely distributed. The metamorphic peak conditions for the pelitic granulite were calculated as T = 800—840℃ and P = 1.0—1.25 GPa on the basis of P-T pseudosection. The post peak P-T path is characterized first by an isothermal de-compression (ITD) pattern and then by an isobaric cooling (IBC) pattern, indicating a geodynamic process related to thinning of thickened continental crust.
