Lance Black - Profile on Academia.edu (original) (raw)
Papers by Lance Black
Contributions to Mineralogy and Petrology, 1984
A moderate-to high-grade regionally metamorphosed paragneiss from Antarctica contains monazites o... more A moderate-to high-grade regionally metamorphosed paragneiss from Antarctica contains monazites of several different colours-brown, yellow and grey. Each colour type has a distinctive U-Pb isotopic composition which appears to result from different proportions of radiogenic Pb loss. Isotopic differences are neither related to La, Nd, Ce, P, Ca, Ti (and/or Ba), nor to U or Th content. All colour types have similar structures at the submicron scale, as determined by both conventional and high-resolution transmission electron microscopy (TEM). These show that the grains are essenttially non-metamict but are composed of 100 ~ crystalline domains misoriented from each other by no more than 2x 10-3 radians, and separated by narrow confused boundary regions where misorientation is probably accommodated by imperfect atomic arrangements. These regions of mismatch form potential zones of high permeability/diffusivity which are believed to be fundamental to the isotopic and colour differences between grains. Colour type is apparently related to the capacity of different minerals to shield included monazite grains from fluids circulating in the rock system. The well aligned monazite U-Pb analyses produce concordia intercepts of 2a20+17 Ma and 1087+29 Ma. Both ~-16 ages are comparable to those of major geological events in this part of Antarctica. They are interpreted in terms of isotopic resetting through Pb loss, and original monazite crystallisation is thought to have occurred somewhat earlier, possibly at the time this terrain first underwent granulite-facies metamorphism, about 3070 Ma ago.
Journal of Metamorphic Geology, 1983
Detailed geochronological, structural and petrological studies reveal that the geological evoluti... more Detailed geochronological, structural and petrological studies reveal that the geological evolution of the Field Islands area, East Antarctica, was substantially similar to that of the adjacent Archaean Napier Complex, though with notable differences in late and post Archaean times. These differences reflect the area's proximity to the Proterozoic Rayner Complex and consequent vulnerability to tectonic process involved in the formation of the latter. Distinctive structural features of the Field Islands are (I) consistent development of a discordant, pervasive S, axial-plane foliation; (2) reorientation of S, axial planes to approximate to the subsequent E-W tectonic trend of the nearby Rayner Complex; (3) selective retrogression by a post-D, static thermal overprint; and (4) relatively common development of retrogressive, E-Wtrending, mylonitic shear zones. Peak metamorphic conditions in excess of 800°C at 900 100 MPa (9 kbar) were attained at one locality following, but probably close to the time of D, folding. D, took place in late Archaean times when metamorphic temperatures were about 650°C and pressures were about 600 MPa (6 kbar). Later, temperatures of 600 f
Workshop on Antarctic geology 17–18 May 1979
Journal of the Geological Society of Australia, 1979
The Permian-Triassic boundary mass extinction in China
Episodes
The age of the Stuart Dyke Swarm and its bearing on the onset of late Precambrian sedimentation in central Australia
Journal of the Geological Society of Australia
The Harry Creek Deformed Zone, a retrograde schist zone of the Arunta Block, central Australia
Journal of the Geological Society of Australia
Rock lead isotopes in northeast Queensland
Journal of the Geological Society of Australia
Metamorphic zircon formation by solid-state recrystallization of protolith igneous zircon: SOLID-STATE RECRYSTALLIZATION OF ZIRCON
J Metamorph Geol, 2002
New U-Pb zircon ages from the Denman Glacier area, East Antarctica, and their significance for Gondwana reconstruction
Antarctic Science, Dec 1, 1992
Reply to N.C. Higgins' Comment on
Geochim Cosmochim Acta, 1990
The Mordor Complex: A highly differentiated potassic intrusion with kimberlitic affinities in central Australia
Contrib Mineral Petrol, 1978
The Mordor Complex: A Highly Differentiated Potassie Intrusion With Kimberlitic Affinities in Central Australia
Contrib Mineral Petrol, 1978
The Use of Multiple Reference Samples for the Monitoring of Ion Microprobe Performance During Zircon 207 Pb/ 206 Pb Age Determinations
Geostand Newslett J Geostand, 2005
The geochronology, structure and metamorphism of early Archaean rocks at Fyfe Hills, Enderby Land, Antarctica
Precambrian Research, 1983
Workshop on Antarctic geology 17–18 May 1979
Journal of the Geological Society of Australia, 1979
Lead and Thallium Isotopes in Mare Tranquillitatis Surface Material
Science, 1970
Isotopic resetting of U-Pb zircon and Rb-Sr and Sm-Nd whole-rock systems in enderby land, Antarctica: Implications for the interpretation of isotopic data from polymetamorphic and multiply deformed terrains
Precambrian Research, 1988
The Rayner Complex of East Antarctica: complex isotopic systematics within a Proterozoic mobile belt
Journal of Metamorphic Geology, 1987
Isotopic evidence for the dependence of recurrent felsic magmatism on new crust formation: An example from the Georgetown region of Northeastern Australia
Geochimica et Cosmochimica Acta, 1990
Isotopic Composition and Possible Genesis of Ore Leads in North-Eastern Queensland, Australia
Economic Geology, 1972
Contributions to Mineralogy and Petrology, 1984
A moderate-to high-grade regionally metamorphosed paragneiss from Antarctica contains monazites o... more A moderate-to high-grade regionally metamorphosed paragneiss from Antarctica contains monazites of several different colours-brown, yellow and grey. Each colour type has a distinctive U-Pb isotopic composition which appears to result from different proportions of radiogenic Pb loss. Isotopic differences are neither related to La, Nd, Ce, P, Ca, Ti (and/or Ba), nor to U or Th content. All colour types have similar structures at the submicron scale, as determined by both conventional and high-resolution transmission electron microscopy (TEM). These show that the grains are essenttially non-metamict but are composed of 100 ~ crystalline domains misoriented from each other by no more than 2x 10-3 radians, and separated by narrow confused boundary regions where misorientation is probably accommodated by imperfect atomic arrangements. These regions of mismatch form potential zones of high permeability/diffusivity which are believed to be fundamental to the isotopic and colour differences between grains. Colour type is apparently related to the capacity of different minerals to shield included monazite grains from fluids circulating in the rock system. The well aligned monazite U-Pb analyses produce concordia intercepts of 2a20+17 Ma and 1087+29 Ma. Both ~-16 ages are comparable to those of major geological events in this part of Antarctica. They are interpreted in terms of isotopic resetting through Pb loss, and original monazite crystallisation is thought to have occurred somewhat earlier, possibly at the time this terrain first underwent granulite-facies metamorphism, about 3070 Ma ago.
Journal of Metamorphic Geology, 1983
Detailed geochronological, structural and petrological studies reveal that the geological evoluti... more Detailed geochronological, structural and petrological studies reveal that the geological evolution of the Field Islands area, East Antarctica, was substantially similar to that of the adjacent Archaean Napier Complex, though with notable differences in late and post Archaean times. These differences reflect the area's proximity to the Proterozoic Rayner Complex and consequent vulnerability to tectonic process involved in the formation of the latter. Distinctive structural features of the Field Islands are (I) consistent development of a discordant, pervasive S, axial-plane foliation; (2) reorientation of S, axial planes to approximate to the subsequent E-W tectonic trend of the nearby Rayner Complex; (3) selective retrogression by a post-D, static thermal overprint; and (4) relatively common development of retrogressive, E-Wtrending, mylonitic shear zones. Peak metamorphic conditions in excess of 800°C at 900 100 MPa (9 kbar) were attained at one locality following, but probably close to the time of D, folding. D, took place in late Archaean times when metamorphic temperatures were about 650°C and pressures were about 600 MPa (6 kbar). Later, temperatures of 600 f
Workshop on Antarctic geology 17–18 May 1979
Journal of the Geological Society of Australia, 1979
The Permian-Triassic boundary mass extinction in China
Episodes
The age of the Stuart Dyke Swarm and its bearing on the onset of late Precambrian sedimentation in central Australia
Journal of the Geological Society of Australia
The Harry Creek Deformed Zone, a retrograde schist zone of the Arunta Block, central Australia
Journal of the Geological Society of Australia
Rock lead isotopes in northeast Queensland
Journal of the Geological Society of Australia
Metamorphic zircon formation by solid-state recrystallization of protolith igneous zircon: SOLID-STATE RECRYSTALLIZATION OF ZIRCON
J Metamorph Geol, 2002
New U-Pb zircon ages from the Denman Glacier area, East Antarctica, and their significance for Gondwana reconstruction
Antarctic Science, Dec 1, 1992
Reply to N.C. Higgins' Comment on
Geochim Cosmochim Acta, 1990
The Mordor Complex: A highly differentiated potassic intrusion with kimberlitic affinities in central Australia
Contrib Mineral Petrol, 1978
The Mordor Complex: A Highly Differentiated Potassie Intrusion With Kimberlitic Affinities in Central Australia
Contrib Mineral Petrol, 1978
The Use of Multiple Reference Samples for the Monitoring of Ion Microprobe Performance During Zircon 207 Pb/ 206 Pb Age Determinations
Geostand Newslett J Geostand, 2005
The geochronology, structure and metamorphism of early Archaean rocks at Fyfe Hills, Enderby Land, Antarctica
Precambrian Research, 1983
Workshop on Antarctic geology 17–18 May 1979
Journal of the Geological Society of Australia, 1979
Lead and Thallium Isotopes in Mare Tranquillitatis Surface Material
Science, 1970
Isotopic resetting of U-Pb zircon and Rb-Sr and Sm-Nd whole-rock systems in enderby land, Antarctica: Implications for the interpretation of isotopic data from polymetamorphic and multiply deformed terrains
Precambrian Research, 1988
The Rayner Complex of East Antarctica: complex isotopic systematics within a Proterozoic mobile belt
Journal of Metamorphic Geology, 1987
Isotopic evidence for the dependence of recurrent felsic magmatism on new crust formation: An example from the Georgetown region of Northeastern Australia
Geochimica et Cosmochimica Acta, 1990
Isotopic Composition and Possible Genesis of Ore Leads in North-Eastern Queensland, Australia
Economic Geology, 1972