Frank Lisker - Academia.edu (original) (raw)
Papers by Frank Lisker
Geotemas ( Madrid ), 2002
Sor Rondane occupies a key position for reconstructing the late Neoproterozoic to early Paleozoic... more Sor Rondane occupies a key position for reconstructing the late Neoproterozoic to early Paleozoic geodynamic evolution in eastern Dronning Maud Land (DML) since it appears to be located close to the supposed intersection of the East African-Antarctic Orogen (EAAO) and the Kuunga Orogen. The western part of Sor Rondane is dominated by two distinct terranes. The amphibolite to granulite-facies NE terrane is mainly composed of metasupracrustal rocks, showing Pan-African overprint provided by new SHRIMP zircon data from metamorphic rims with ages of ca. 560 Ma. The SW terrane is subdivided by the Main Shear Zone (MSZ) into two lithothectonic units, i.e. Pan-African greenschist- to granulite-facies metamorphic rocks with ―East African‖ affinities in the N and a Rayner-age early Neoproterozoic gabbro- tonalite-trondhjemite-granodiorite (GTTG) complex with ―Indo-Antarctic‖ affinities in the S. The GTTG complex has suffered Pan-African greenschist- to lower amphibolite-facies thermal overpr...
<p>Eastern North Greenland is a key area for studying the reorganisation of... more <p>Eastern North Greenland is a key area for studying the reorganisation of the North Atlantic-Arctic Realm during the Cenozoic. Due to its crucial position at the intersection of Atlantic Ocean, Arctic Ocean, and the West Greenland Rift Basin this area was significantly involved in the Eureka Orogeny leading to intracontinental compression/transpression observed on the Svalbard-Barents margin and the Canadian Archipelago as well as Northern Greenland. In the Neogene the final breakup occurred in this area, leading to the deep-water connection of the Arctic and North Atlantic Oceans.</p><p>It is characterized by the Carboniferous-Paleogene deposits of the Wandel Sea Basin overlaying Mesoproterozoic to early Palaeozoic supracrustal rocks. They occur in a series of pull apart basins along a zone of NE-SW-oriented faults. These faults are part of the DeGeer Shear Zone, along which the lateral offset of Greenland and Spitsbergen occurred during the Eureka Orogeny. In accordance the deposits are deformed, but the timing and the structural context of the deformation is much debated. Also, some deposits show unusually high thermal maturities of which the origin and geodynamic context is unclear.</p><p>We took samples across the Tolle-Land-Fault-Zone from the coast in the NE into the Caledonian basement in SW and applied apatite fission tack analysis and (U-Th-Sm)/He thermochronology to reconstruct the thermal history of the respective segments of the fault zone and their thermal evolution in respect to the deformation and opening of the northern Atlantic. Preliminary results will be presented and the exhumation history and timing of deformation and thermal anomalies in eastern North Greenland and influence of the breakup will be discussed.</p>
The Eisenhower Range is a N-S trending mountain range in the Transantarctic Mountains (TAM) adjac... more The Eisenhower Range is a N-S trending mountain range in the Transantarctic Mountains (TAM) adjacent to the NW Ross Sea Embayment. New AFT and apatite (U-Th-Sm)/He (AHe) data from vertical basement profiles supplemented by paleotemperature and pressure estimates derived from Beacon sandstones provide new quantitative results on regional burial evolution and first regional constraints on basin inversion and exhumation processes. AFT ages between 32 ± 2 and 259 ± 18 Ma and AHe ages of 37 ± 3-173 ± 16 Ma correlate positively with sample elevations. Thermal history modeling of these data and complementary thermal indications detect heating of the paleosurface on the Eisenhower Range to temperatures >= 80 °C subsequent to Ferrar magmatism, and constrain Late Eocene rapid cooling. Regression of modeled paleotemperatures against sample elevations refers to a high Jurassic (~ 45 °C/km) and a moderate Cretaceous-Eocene (28 ± 8 °C/km) geothermal gradient. The texture of Beacon sandstones s...
Thermochronology data suggest Eocene high-latitude rapid exhumation and topography formation. Enh... more Thermochronology data suggest Eocene high-latitude rapid exhumation and topography formation. Enhanced exhumation of northern Ellesmere Island occurred ~67-59 Ma, ~55-48 Ma, 44-38 Ma, and 34-26 Ma. These exhumation periods largely correlate with changes of spreading rates and movement directions of the Norwegian-Greenland Sea. Main topographic growth along the Eurekan belt was temporally coincident with deposition of ice-rafted debris off eastern Greenland. We suggest that Eurekan topography growth was an important trigger for glacier formation in Greenland. Exhumation of northern Ellesmere Island was episodic and was presumably controlled by strike-slip movements along the De Geer Fracture Zone between Svalbard and Greenland. The cessation of rapid exhumation at ~26 Ma can be explained by continental separation between Greenland and Svalbard, which decoupled northern Ellesmere Island from strike-slip movements along the De Geer Fracture Zone, eventually leading to the opening of the Fram Strait.
East Antarctica consists of a number of cratonic fragments that amalgamated along distinct orogen... more East Antarctica consists of a number of cratonic fragments that amalgamated along distinct orogenic belts in late Neoproterozoic to early Palaeozoic times. These mobile belts include the c. 640 to 500 Ma old East African-Antarctic Orogen (EAAO) and the Kuunga Orogen, which seem to converge in Dronning Maud Land in the Atlantic sector of Antarctica. The polymetamorphic basement of Dronning Maud Land is characterized by rocks with Grenville-age protolith ages of c. 1130 to 1000 Ma in the west and rocks with early Neoproterozoic protolith ages of c. 1000 to 900 Ma in the east. These two provinces are separated by the prominent Forster Magnetic Anomaly, which is therefore interpreted to represent a suture zone. Four joint AWI-BGR international expeditions within the WEGAS (West-East Gondwana Amalgamation and Separation) and GEA (Geodynamic Evolution of East Antarctica) programmes between 2010 and 2015 have provided new combined geological and geophysical data that reveal a complex crust...
West Antarctica combines one of the largest active rift systems with one of the largest ice sheet... more West Antarctica combines one of the largest active rift systems with one of the largest ice sheets on Earth. Complete melting of the West Antarctic Ice-Sheet (WAIS) would result in a global sea level rise of about 5 m. Understanding ice-sheet dynamics is of major importance for predicting future deglaciation processes in Antarctica. Generally, it is assumed that the geodynamic activity of Western Antarctica as the cradle of the WAIS exerts a strong influence on ice sheet dynamics, but coupling and feedback mechanisms are poorly understood. This project aims to apply geophysical and thermochronological methods for unravelling the geodynamic evolution of Marie Byrd Land (West Antarctica) in terms of crustal structure, exhumation and erosion rates, fault activities, and (paleo-)geothermal gradient. Furthermore, we will use cosmogenic nuclide analysis for reconstructing thinning rates and glacial retreat in Marie Byrd Land. The combination of both data sets provides information on spati...
The geology of Sor Rondane has been the focus of intense research and occupies a key position for... more The geology of Sor Rondane has been the focus of intense research and occupies a key position for reconstructing the late Neoproterozoic to early Paleozoic geodynamic evolution in eastern Dronning Maud Land (DML). Sor Rondane appears to be located close to the supposed intersection of the East African-Antarctic Orogen (EAAO) and the Kuunga Orogen. The western part of Sor Rondane is subdivided in two distinct terranes. The amphibolite to granulite-facies NE terrane is mainly composed of metasupracrustal rocks, with detrital zircon ages in part younger than 750 Ma, deposited on older basement of unknown, possibly Rayner-type, crust (Shiraishi et al., 2008). Metamorphism has been dated by U-Pb on zircon at ca. 640-600 Ma and amphibolite-facies retrogression dated at ca. 590-530 Ma. The SW terrane is subdivided by the Main Shear Zone (MSZ) into two lithothectonic units, i.e. Pan- African greenschist- to granulite-facies metamorphic rocks with “East African” affinities in the N and a Ray...
Gondwana Research, 2017
Abstract The Terra Nova Bay region of the Transantarctic Mountains hosts three N–S to NNW–SSE ext... more Abstract The Terra Nova Bay region of the Transantarctic Mountains hosts three N–S to NNW–SSE extending mountain ranges, Deep Freeze Range, Eisenhower Range and northern Prince Albert Mountains. All ranges consist of basement rocks locally overlain by Permo-Triassic sediments and Jurassic volcanic rocks. Recent thermochronological studies recognized that the Eisenhower Range was originally covered by a kilometre-thick Jurassic–Eocene sedimentary sequence. Here we present a comprehensive apatite fission track (AFT) and U-Th-Sm/He (AHe) data set of vertical sample profiles from the Terra Nova Bay to reconstruct architecture, extension and geometry of this depocentre and place its evolution in the context of supraregional geodynamic processes. The study comprises new data and thermal history models from the Deep Freeze Range and new thermal history models of published data from the northern Prince Albert Mountains. New AFT and AHe ages of 25–275 Ma from the Deep Freeze Range correlate tightly with sample elevations. Thermal history modelling of these data and complementary proxies detects common heating of the Jurassic surface and rapid late Eocene cooling. Regression of vertical paleotemperature profiles reveals an increased Jurassic and a moderate Cretaceous–Eocene geothermal gradient of 45° and 25 °C/km, respectively. Paleotemperatures and gradients used in tandem infer basement burial increasing from ~ 2 km in Deep Freeze and Eisenhower Ranges to ~ 3.4 km in the Prince Albert Mountains. Such a varying overburden probably reflects regional differences in the Jurassic basement topography. Subsequently, sediment thickness uniformly increased in the order of 1 km until late Eocene. Mid-Jurassic basin initiation and subsequent sediment accumulation is explained by extension of a Mesozoic Victoria Basin during Gondwana breakup between Antarctica and Australia. Late Eocene/early Oligocene basin inversion is associated with the formation of the West Antarctic Rift System while differential final exhumation represents the change from downwearing to backstepping incision.
East Antarctica formed by amalgamation of a number of cratons along distinct Ediacaran mobile bel... more East Antarctica formed by amalgamation of a number of cratons along distinct Ediacaran mobile belts. They include the ca. 600-500 Ma old East African-Antarctic Orogen (EAAO) and the Kuunga Orogen, which seem to converge in the region of Dronning Maud Land. In central Dronning Maud Land, the major Forster Magnetic Anomaly separates rocks with Grenville-age protolith ages (ca. 1130-1000 Ma) to the West from rocks with Early Neoproterozic protolith ages (ca. 1000-930 Ma) to the East. The Forster Magnetic Anomaly is therefore interpreted as a suture between these two provinces. New field work during three recent international expeditions, Geodynamic Evolution of East Antarctica (GEA) I to III, and first geoscientific results reveal a complex tectonic architecture between central Dronning Maud Land and Sor Rondane in eastern Dronning Maud Land. East of the Forster Magnetic Anomaly, the magnetic anomaly pattern changes significantly and typical Maud-type crust is apparently lacking. Particularly, the GEA II campaign targeted a range of previously unvisited nunataks between Sor Rondane and central Dronning Maud Land (from Blaklettane and Bergekongen in the East to Urna and Sorsteinen in the West). These nunataks are dominated by medium- to high-grade metasedimentary and metavolcanic rocks of possibly Neoproterozoic age, including abundant marble and graphite schists. Sor Rondane in eastern Dronning Maud Land, on the other hand, is dominated by two distinct blocks separated by the dextral Main Shear Zone. The northwestern block appears as part of the EAAO or the Kuunga Orogen, where new SHRIMP zircon data from metamorphic rims provide ages of ca. 560 Ma. The southeastern block is made up of a TTG terrane, which provides 12 new zircon crystallization ages ranging from 1000-930 Ma. The TTG terrane has predominantly oceanic affinities and the wide range of ages might indicate long-lasting accretionary tectonics. The TTG terrane shows in part limited tectonic overprint and could be the southeastern foreland of the EAAO or the Kuunga Orogen. Close to the contact of the two blocks, grey gneisses and augen-gneisses gave zircon crystallization ages of ca. 750 Ma. Such ages were previously unknown from the EAAO. The Forster Magnetic Anomaly therefore separates distinctly different parts of the EAAO. These are (i) a reworked, mainly Grenville-age crust to the West representing the overprinted margin of the Kalahari Craton, and (ii) a part of the orogen dominated by Neoproterozoic accretionary tectonics to the East. This difference is also reflected in the geochemistry of voluminous late-tectonics granitoids across the whole belt.
Geotemas ( Madrid ), 2002
Sor Rondane occupies a key position for reconstructing the late Neoproterozoic to early Paleozoic... more Sor Rondane occupies a key position for reconstructing the late Neoproterozoic to early Paleozoic geodynamic evolution in eastern Dronning Maud Land (DML) since it appears to be located close to the supposed intersection of the East African-Antarctic Orogen (EAAO) and the Kuunga Orogen. The western part of Sor Rondane is dominated by two distinct terranes. The amphibolite to granulite-facies NE terrane is mainly composed of metasupracrustal rocks, showing Pan-African overprint provided by new SHRIMP zircon data from metamorphic rims with ages of ca. 560 Ma. The SW terrane is subdivided by the Main Shear Zone (MSZ) into two lithothectonic units, i.e. Pan-African greenschist- to granulite-facies metamorphic rocks with ―East African‖ affinities in the N and a Rayner-age early Neoproterozoic gabbro- tonalite-trondhjemite-granodiorite (GTTG) complex with ―Indo-Antarctic‖ affinities in the S. The GTTG complex has suffered Pan-African greenschist- to lower amphibolite-facies thermal overpr...
<p>Eastern North Greenland is a key area for studying the reorganisation of... more <p>Eastern North Greenland is a key area for studying the reorganisation of the North Atlantic-Arctic Realm during the Cenozoic. Due to its crucial position at the intersection of Atlantic Ocean, Arctic Ocean, and the West Greenland Rift Basin this area was significantly involved in the Eureka Orogeny leading to intracontinental compression/transpression observed on the Svalbard-Barents margin and the Canadian Archipelago as well as Northern Greenland. In the Neogene the final breakup occurred in this area, leading to the deep-water connection of the Arctic and North Atlantic Oceans.</p><p>It is characterized by the Carboniferous-Paleogene deposits of the Wandel Sea Basin overlaying Mesoproterozoic to early Palaeozoic supracrustal rocks. They occur in a series of pull apart basins along a zone of NE-SW-oriented faults. These faults are part of the DeGeer Shear Zone, along which the lateral offset of Greenland and Spitsbergen occurred during the Eureka Orogeny. In accordance the deposits are deformed, but the timing and the structural context of the deformation is much debated. Also, some deposits show unusually high thermal maturities of which the origin and geodynamic context is unclear.</p><p>We took samples across the Tolle-Land-Fault-Zone from the coast in the NE into the Caledonian basement in SW and applied apatite fission tack analysis and (U-Th-Sm)/He thermochronology to reconstruct the thermal history of the respective segments of the fault zone and their thermal evolution in respect to the deformation and opening of the northern Atlantic. Preliminary results will be presented and the exhumation history and timing of deformation and thermal anomalies in eastern North Greenland and influence of the breakup will be discussed.</p>
The Eisenhower Range is a N-S trending mountain range in the Transantarctic Mountains (TAM) adjac... more The Eisenhower Range is a N-S trending mountain range in the Transantarctic Mountains (TAM) adjacent to the NW Ross Sea Embayment. New AFT and apatite (U-Th-Sm)/He (AHe) data from vertical basement profiles supplemented by paleotemperature and pressure estimates derived from Beacon sandstones provide new quantitative results on regional burial evolution and first regional constraints on basin inversion and exhumation processes. AFT ages between 32 ± 2 and 259 ± 18 Ma and AHe ages of 37 ± 3-173 ± 16 Ma correlate positively with sample elevations. Thermal history modeling of these data and complementary thermal indications detect heating of the paleosurface on the Eisenhower Range to temperatures >= 80 °C subsequent to Ferrar magmatism, and constrain Late Eocene rapid cooling. Regression of modeled paleotemperatures against sample elevations refers to a high Jurassic (~ 45 °C/km) and a moderate Cretaceous-Eocene (28 ± 8 °C/km) geothermal gradient. The texture of Beacon sandstones s...
Thermochronology data suggest Eocene high-latitude rapid exhumation and topography formation. Enh... more Thermochronology data suggest Eocene high-latitude rapid exhumation and topography formation. Enhanced exhumation of northern Ellesmere Island occurred ~67-59 Ma, ~55-48 Ma, 44-38 Ma, and 34-26 Ma. These exhumation periods largely correlate with changes of spreading rates and movement directions of the Norwegian-Greenland Sea. Main topographic growth along the Eurekan belt was temporally coincident with deposition of ice-rafted debris off eastern Greenland. We suggest that Eurekan topography growth was an important trigger for glacier formation in Greenland. Exhumation of northern Ellesmere Island was episodic and was presumably controlled by strike-slip movements along the De Geer Fracture Zone between Svalbard and Greenland. The cessation of rapid exhumation at ~26 Ma can be explained by continental separation between Greenland and Svalbard, which decoupled northern Ellesmere Island from strike-slip movements along the De Geer Fracture Zone, eventually leading to the opening of the Fram Strait.
East Antarctica consists of a number of cratonic fragments that amalgamated along distinct orogen... more East Antarctica consists of a number of cratonic fragments that amalgamated along distinct orogenic belts in late Neoproterozoic to early Palaeozoic times. These mobile belts include the c. 640 to 500 Ma old East African-Antarctic Orogen (EAAO) and the Kuunga Orogen, which seem to converge in Dronning Maud Land in the Atlantic sector of Antarctica. The polymetamorphic basement of Dronning Maud Land is characterized by rocks with Grenville-age protolith ages of c. 1130 to 1000 Ma in the west and rocks with early Neoproterozoic protolith ages of c. 1000 to 900 Ma in the east. These two provinces are separated by the prominent Forster Magnetic Anomaly, which is therefore interpreted to represent a suture zone. Four joint AWI-BGR international expeditions within the WEGAS (West-East Gondwana Amalgamation and Separation) and GEA (Geodynamic Evolution of East Antarctica) programmes between 2010 and 2015 have provided new combined geological and geophysical data that reveal a complex crust...
West Antarctica combines one of the largest active rift systems with one of the largest ice sheet... more West Antarctica combines one of the largest active rift systems with one of the largest ice sheets on Earth. Complete melting of the West Antarctic Ice-Sheet (WAIS) would result in a global sea level rise of about 5 m. Understanding ice-sheet dynamics is of major importance for predicting future deglaciation processes in Antarctica. Generally, it is assumed that the geodynamic activity of Western Antarctica as the cradle of the WAIS exerts a strong influence on ice sheet dynamics, but coupling and feedback mechanisms are poorly understood. This project aims to apply geophysical and thermochronological methods for unravelling the geodynamic evolution of Marie Byrd Land (West Antarctica) in terms of crustal structure, exhumation and erosion rates, fault activities, and (paleo-)geothermal gradient. Furthermore, we will use cosmogenic nuclide analysis for reconstructing thinning rates and glacial retreat in Marie Byrd Land. The combination of both data sets provides information on spati...
The geology of Sor Rondane has been the focus of intense research and occupies a key position for... more The geology of Sor Rondane has been the focus of intense research and occupies a key position for reconstructing the late Neoproterozoic to early Paleozoic geodynamic evolution in eastern Dronning Maud Land (DML). Sor Rondane appears to be located close to the supposed intersection of the East African-Antarctic Orogen (EAAO) and the Kuunga Orogen. The western part of Sor Rondane is subdivided in two distinct terranes. The amphibolite to granulite-facies NE terrane is mainly composed of metasupracrustal rocks, with detrital zircon ages in part younger than 750 Ma, deposited on older basement of unknown, possibly Rayner-type, crust (Shiraishi et al., 2008). Metamorphism has been dated by U-Pb on zircon at ca. 640-600 Ma and amphibolite-facies retrogression dated at ca. 590-530 Ma. The SW terrane is subdivided by the Main Shear Zone (MSZ) into two lithothectonic units, i.e. Pan- African greenschist- to granulite-facies metamorphic rocks with “East African” affinities in the N and a Ray...
Gondwana Research, 2017
Abstract The Terra Nova Bay region of the Transantarctic Mountains hosts three N–S to NNW–SSE ext... more Abstract The Terra Nova Bay region of the Transantarctic Mountains hosts three N–S to NNW–SSE extending mountain ranges, Deep Freeze Range, Eisenhower Range and northern Prince Albert Mountains. All ranges consist of basement rocks locally overlain by Permo-Triassic sediments and Jurassic volcanic rocks. Recent thermochronological studies recognized that the Eisenhower Range was originally covered by a kilometre-thick Jurassic–Eocene sedimentary sequence. Here we present a comprehensive apatite fission track (AFT) and U-Th-Sm/He (AHe) data set of vertical sample profiles from the Terra Nova Bay to reconstruct architecture, extension and geometry of this depocentre and place its evolution in the context of supraregional geodynamic processes. The study comprises new data and thermal history models from the Deep Freeze Range and new thermal history models of published data from the northern Prince Albert Mountains. New AFT and AHe ages of 25–275 Ma from the Deep Freeze Range correlate tightly with sample elevations. Thermal history modelling of these data and complementary proxies detects common heating of the Jurassic surface and rapid late Eocene cooling. Regression of vertical paleotemperature profiles reveals an increased Jurassic and a moderate Cretaceous–Eocene geothermal gradient of 45° and 25 °C/km, respectively. Paleotemperatures and gradients used in tandem infer basement burial increasing from ~ 2 km in Deep Freeze and Eisenhower Ranges to ~ 3.4 km in the Prince Albert Mountains. Such a varying overburden probably reflects regional differences in the Jurassic basement topography. Subsequently, sediment thickness uniformly increased in the order of 1 km until late Eocene. Mid-Jurassic basin initiation and subsequent sediment accumulation is explained by extension of a Mesozoic Victoria Basin during Gondwana breakup between Antarctica and Australia. Late Eocene/early Oligocene basin inversion is associated with the formation of the West Antarctic Rift System while differential final exhumation represents the change from downwearing to backstepping incision.
East Antarctica formed by amalgamation of a number of cratons along distinct Ediacaran mobile bel... more East Antarctica formed by amalgamation of a number of cratons along distinct Ediacaran mobile belts. They include the ca. 600-500 Ma old East African-Antarctic Orogen (EAAO) and the Kuunga Orogen, which seem to converge in the region of Dronning Maud Land. In central Dronning Maud Land, the major Forster Magnetic Anomaly separates rocks with Grenville-age protolith ages (ca. 1130-1000 Ma) to the West from rocks with Early Neoproterozic protolith ages (ca. 1000-930 Ma) to the East. The Forster Magnetic Anomaly is therefore interpreted as a suture between these two provinces. New field work during three recent international expeditions, Geodynamic Evolution of East Antarctica (GEA) I to III, and first geoscientific results reveal a complex tectonic architecture between central Dronning Maud Land and Sor Rondane in eastern Dronning Maud Land. East of the Forster Magnetic Anomaly, the magnetic anomaly pattern changes significantly and typical Maud-type crust is apparently lacking. Particularly, the GEA II campaign targeted a range of previously unvisited nunataks between Sor Rondane and central Dronning Maud Land (from Blaklettane and Bergekongen in the East to Urna and Sorsteinen in the West). These nunataks are dominated by medium- to high-grade metasedimentary and metavolcanic rocks of possibly Neoproterozoic age, including abundant marble and graphite schists. Sor Rondane in eastern Dronning Maud Land, on the other hand, is dominated by two distinct blocks separated by the dextral Main Shear Zone. The northwestern block appears as part of the EAAO or the Kuunga Orogen, where new SHRIMP zircon data from metamorphic rims provide ages of ca. 560 Ma. The southeastern block is made up of a TTG terrane, which provides 12 new zircon crystallization ages ranging from 1000-930 Ma. The TTG terrane has predominantly oceanic affinities and the wide range of ages might indicate long-lasting accretionary tectonics. The TTG terrane shows in part limited tectonic overprint and could be the southeastern foreland of the EAAO or the Kuunga Orogen. Close to the contact of the two blocks, grey gneisses and augen-gneisses gave zircon crystallization ages of ca. 750 Ma. Such ages were previously unknown from the EAAO. The Forster Magnetic Anomaly therefore separates distinctly different parts of the EAAO. These are (i) a reworked, mainly Grenville-age crust to the West representing the overprinted margin of the Kalahari Craton, and (ii) a part of the orogen dominated by Neoproterozoic accretionary tectonics to the East. This difference is also reflected in the geochemistry of voluminous late-tectonics granitoids across the whole belt.