The mineralogy and geochemistry of the ela y fraction ( <2f.!) of the Quater nary deposits in... more The mineralogy and geochemistry of the ela y fraction ( <2f.!) of the Quater nary deposits in the Numedal area, southern Norway, have been studied. The Numedal clays contain considerable amounts of illite, but chlorite, vermiculite, mixed layer minerals, quartz, microcline, and acid plagioclase are also usually found. Amphibole is present in most of the samples. Traces of montmorillonite are occasionally found. During weathering the amount of vermiculite and mixed layered illite vermiculite increases at the expense of trioctahedral illite and chlorite. The average chemical composition of the clay fraction ( <2!!) corresponds to that of coarse clays. The clay material is only slightly weathered, and the residual indexes correspond to those of fresh rocks. Comparison of the mineralogical and chemical data shows the physico chemical variations during weathering, transport and sedimentation, and the composition of the parent material to be of significant importance to the clay ...
A description is given of overconsolidated sub-tiU day sediments situated about 260 m a.s.l., i.e... more A description is given of overconsolidated sub-tiU day sediments situated about 260 m a.s.l., i.e. 90 m above the 1ocal marine limit ofi the last deglaciation. The clay sediments contain neither macro- nor micro-fossils. Textural, mineralogical and geochemical investigations, strongly supported by the Ce deficient lanthanide abundance pattern, indicate marine depositional environment. The clay sediments are assumed to be of Middle-Weichseli an age and are thus correlated with the Sandnes Interstadial, described from SW-Norway, and its analogues. E. Roaldset, Institutt for geologi, Universitetet i Oslo, Boks 1047, Blindern, Oslo 3, Norway. In the Numedal river basin sub-till sediments have previously been described from the north em parts of the area (Roaldset 1973a, Rosenqvist 1973). This paper presents data on the ftrst sub till clays in the lower part of the Numedal river basin, where in 1973 in the valley Herlandsdalen, overconsolidated sub-till clays situated 260 m a.s.l. (Fig...
Argau, James Wright, and so many others through the seven year journey. It takes a village to dev... more Argau, James Wright, and so many others through the seven year journey. It takes a village to develop one PhD and mine was filled with the best and most caring collection of individuals, starting with an outstanding committee of scholars: Kyle Peck, my advisor and chair, who showed consistent dedication to helping, along with the faithful service of Barbara Grabowski, Frank Dwyer, and Peggy Van Meter. Thank you, Ed Yoder, for a piece of valuable insight given at the crucial eleventh hour. Thanks to the village at Penn State with the many colleagues who have "walked" before me: Heeyoung Kim (a true friend!),
DURING our investigations of the genesis of Scandinavian glacial loams and clays, we have examine... more DURING our investigations of the genesis of Scandinavian glacial loams and clays, we have examined some gneisses in upper Numedalen, Eastern Norway. These rocks have undoubtedly been exposed to glacial erosion, but they seem to represent deeper parts of the preglacial (tertiary) weathering profile. We are particularly interested in the rare Earth elements (yttrium + lanthanides) which these rocks contain. The determinations were carried out by spark mass spectrometer1, which is well suited for all rare Earth elements except Tm. The micaceous fractions were found to be extremely enriched in lanthanides. Whereas micas of magmatic and highly metamorphosed rocks normally have lower rare Earth content than the host rock, we have found the opposite in these weathered gneisses. Thus a slightly weathered mylonite gneiss (from Smadola) has a total rare Earth content of 525 p.p.m. The light mica fraction (degraded muscovite), which made up approximately 2% of the rock, contained 3,755 p.p.m. and the dark mica fraction (chlorite and vermiculized biotite), which made up approximately 8% of the rock, contained 1,584 p.p.m. of rare Earth elements.
Rare earth elements (REE) in the clay fraction ( < 2~) of the Quaternary deposits in the Numedal ... more Rare earth elements (REE) in the clay fraction ( < 2~) of the Quaternary deposits in the Numedal area, southern Norway, have been determined by a spark source mass spectrome~,Tic method. The REE content was studied in relation to weathering and sedimentolog/cal factors. The total REE content vr,_ries from 100 to 1300 ppm. An average of the ,imilar fraction of 16 non-marine days, mostly tillitic, gave 527 ppm REE. An average of 38 glacial and postglacial marine clays from the lower part of the Numedal valley gave 335 ppm REE (max. 781 ppm). After removal of adsorbed ions the average total REE content of morainian and marine clays decreased to 186 ppm. The content and distribution of the REE in the Numedal days are strongly influe, lced by environmental factors. Under neutral and alkaline conditions the REE are accumulated by adsorption on c:ay minerals, and by increasing the hydroger, ion concentration the adsorbed ions are readil removed.
Introduction: Following a bright fireball and a loud explosion the Moss meteorite fell on 14 July... more Introduction: Following a bright fireball and a loud explosion the Moss meteorite fell on 14 July 2006 at approximately 10:20am in the Moss-Rygge area on the east side of Oslofjord [1]. 5 stones were subsequently recovered with a total mass of nearly 4 kg [1]. Petrography, mineralogy and oxygen isotope analysis confirm that Moss is a carbonaceous chondrite of the Ornans group (CO3) [1]. Ornans-type chondrites are a distinct group with a characteristic texture consisting of a high density of small (0.2 -0.5 mm) chondrules, inclusions and lithic fragments enclosed by a dark matrix. They also have a significantly lower matrix to chondrule ratio than other carbonaceous chondrites . As a consequence of this textural coherence, CO3 chondrites are thought to represent samples from a single asteroid. Unique among the carbonaceous chondites, the Ornans group show textural, mineralogical and isotopic evidence for a metamorphic series analogous to that seen in the ordinary chondrites [4,. In discussing the metamorphic grade of CO3 chondrites the scheme of [5] is used throughout. Moss is only the sixth fall in the CO3 group and the first since Kainsaz in 1937. In view of the importance of the Ornans group in understanding early Solar System processes, an integrated study of Moss has been undertaken to investigate further the metamorphic conditions that prevailed on the CO3 parent asteroid. Analytical techniques: Mineral analyses were undertaken using a Quanta 200 FIB-SEM and a Cameca SX-50 WDS microprobe operated at 20kV and 2nA. Oxygen isotope analyses were performed by infrared laser-assisted fluorination . C, N, and Ar isotopes were analyzed by stepped combustion using the Finesse fully automated mass spectrometer [8]. Organic analysis was undertaken using a Pegasus 4D (GCxGC) TOFMS (LECO Corporation) fitted with a Pyrola 2000 (Pyrolab, Sweden) for pyrolysis under the conditions described in [9]. Results: Petrography and mineral analysis: The results of petrographic studies confirm the classification of Moss as 3.4/3.5 . Fe-Mg zoning profiles in type 1A chondrule olivines suggest that Moss is closest to 3.5 in grade. Oxygen isotopes: Analysis of two replicates gave the following whole-rock oxygen isotope composition for Moss: 17 O = -5.90‰ ± 0.08, 18 O = -2.21‰ ± 0.
Decompaction may be defined as a process to reconstruct the palaeothickness and the palaeoporosit... more Decompaction may be defined as a process to reconstruct the palaeothickness and the palaeoporosity distributions of a sedimentary column. This process is normally realized by computation of pore volume reduction in sedimentary histories (Perrier and Quiblier 1974). Decompaction modelling has been a subject of interest because of its uses in quantitative geohistory analysis, reservoir evaluation and fluid migration studies in sedimentary basins (Sclater and Christie 1980; Bessis 1985; Bertram and Milton 1989). Petroleum geologists, while preparing palaeogeographic or palaeostructural reconstructions, must consider how thicknesses of strata were modified during depositional history.
This paper reports the organic constitution of the CO3 chondrites identified by 4D TOFMS in order... more This paper reports the organic constitution of the CO3 chondrites identified by 4D TOFMS in order to decipher the composition, structure and alteration history of the CO3 parent asteroid.
Sedimentological, mineralogical, geochemical and some geotechnical properties of Holocene clay an... more Sedimentological, mineralogical, geochemical and some geotechnical properties of Holocene clay and silt sediments of the inner Skagerrak and outer Oslofjord are reported. Close to the Norwegian coast the sea bottom has an irregular relief reflecting the rough features of the crystalline basement. Here the sediment thickness varies from 0 to 50 m. At water depths greater than 150 m the sediment layer becomes thicker and continuous. Generally, the sedimentation rates in the Oslo0ord and inner Skagerrak are high, normally I-2 mm/yr. Areas with higher deposition as well as with non-deposition and/or erosion occur. The inner fjord sediments have high contents of illite and chlorite, reflecting that they have been derived from the glacial deposits of Scandinavia. These clay minerals are also present in the outer i~ord and Skagerrak sediments, which in addition contain smectite and kaolinite, that originate from the Mesozoic and Cenozoic sediments in Denmark/southern Sweden and/or from sediments within the North Sea basin. These clay minerals are transported to the inner Skagerrak mainly by the Jutland and Baltic currents. The diagenetic zonation of most bottom sediments consists of an oxic layer on top of an incipient reducing anoxic, non sulphidic layer. In the oxic top layer of the Skagerrak sediments diagenetic calcite grows on foraminiferal tests. At depth the calcite dissolves. Zinc has been used as element reflecting anthropogenic pollution. The flux of zinc to the Osloi~ord-Skagerrak sediments started to increase about 120-140 years ago. Today the most polluted waters are locked fjords and coastal waters inside the archipelago. As the isostatic rebound still goes on in Scandinavia, the polluted sediment particles will not deposit in the river, but in the fjord and coastal areas. Except for a few near-shore areas and restricted fjord basins, the degree of pollution is low.
Geological Society, London, Special Publications, 1986
Summary A prograding sequence of near shore sediments is identified at the border of the northern... more Summary A prograding sequence of near shore sediments is identified at the border of the northern North Sea plateau (water depth 135 m) and the western slope of the Norwegian Trench. In Late Weichselian time (probably about 15 000 years bp) the relative sea level was approximately 180 m lower than today. During this low sea-level stand, the older consolidated glaciomarine sediments in the slope area were exposed to coastal erosion, leading to a prograding unit of sand fining outwards to silt and clay. During rising sea-level the coastal erosion gradually reached a lodgement till deposited at the top of the plateau, resulting in coarser sediments such as stones and gravel, fining outwards to sand down the slope. The plateau area was transgressed shortly after 13 000 years bp.
Mass spectrometric analyses for rare earth elements (REE) have been carried out on some Precambri... more Mass spectrometric analyses for rare earth elements (REE) have been carried out on some Precambrian mica schists, gneisses and granites from the Precambrian Numedal area, Norway and on their phyllosilicates. The rocks, which are metamorphosed in the upper greenschist to amphibolite facies, were originally partly sedimentary, partly magmatic. The total REE contents for rocks varies from 145 to 761 ppm. An average of 16 phyllosilicate samples gave 417 ppm REE (max. of 1809 ppm, min. of ca. 50 ppm). Coexisting light and dark phyllosilicates have similar abundances of REE. For the micas of high REE content most of the REE was extractable by rinsing with EDTA. The data thus support the possibility of an extensive adsorption of REE ions on micaceous minerals. The REE distribution patterns do not provide a clear distinction between the sedimentary and magmatic origin for the rocks examined.
Fourteen rare-earth elements (REE) have been determined in metavolcanics and metagabbros from the... more Fourteen rare-earth elements (REE) have been determined in metavolcanics and metagabbros from the island of Leka, Norway. The overall REE content of these rocks ranges from about 3ppm, with strong light REE depletion, for the metagabbros to 170ppm with light REE enrichment, for porphyritic greenstones and pillow lavas. Based on regional geological features, lithology, and the REE abundances it is concluded that rocks of the island Leka constitute a part of an ophiolite complex.
The mineralogy and geochemistry of the ela y fraction ( <2f.!) of the Quater nary deposits in... more The mineralogy and geochemistry of the ela y fraction ( <2f.!) of the Quater nary deposits in the Numedal area, southern Norway, have been studied. The Numedal clays contain considerable amounts of illite, but chlorite, vermiculite, mixed layer minerals, quartz, microcline, and acid plagioclase are also usually found. Amphibole is present in most of the samples. Traces of montmorillonite are occasionally found. During weathering the amount of vermiculite and mixed layered illite vermiculite increases at the expense of trioctahedral illite and chlorite. The average chemical composition of the clay fraction ( <2!!) corresponds to that of coarse clays. The clay material is only slightly weathered, and the residual indexes correspond to those of fresh rocks. Comparison of the mineralogical and chemical data shows the physico chemical variations during weathering, transport and sedimentation, and the composition of the parent material to be of significant importance to the clay ...
A description is given of overconsolidated sub-tiU day sediments situated about 260 m a.s.l., i.e... more A description is given of overconsolidated sub-tiU day sediments situated about 260 m a.s.l., i.e. 90 m above the 1ocal marine limit ofi the last deglaciation. The clay sediments contain neither macro- nor micro-fossils. Textural, mineralogical and geochemical investigations, strongly supported by the Ce deficient lanthanide abundance pattern, indicate marine depositional environment. The clay sediments are assumed to be of Middle-Weichseli an age and are thus correlated with the Sandnes Interstadial, described from SW-Norway, and its analogues. E. Roaldset, Institutt for geologi, Universitetet i Oslo, Boks 1047, Blindern, Oslo 3, Norway. In the Numedal river basin sub-till sediments have previously been described from the north em parts of the area (Roaldset 1973a, Rosenqvist 1973). This paper presents data on the ftrst sub till clays in the lower part of the Numedal river basin, where in 1973 in the valley Herlandsdalen, overconsolidated sub-till clays situated 260 m a.s.l. (Fig...
Argau, James Wright, and so many others through the seven year journey. It takes a village to dev... more Argau, James Wright, and so many others through the seven year journey. It takes a village to develop one PhD and mine was filled with the best and most caring collection of individuals, starting with an outstanding committee of scholars: Kyle Peck, my advisor and chair, who showed consistent dedication to helping, along with the faithful service of Barbara Grabowski, Frank Dwyer, and Peggy Van Meter. Thank you, Ed Yoder, for a piece of valuable insight given at the crucial eleventh hour. Thanks to the village at Penn State with the many colleagues who have "walked" before me: Heeyoung Kim (a true friend!),
DURING our investigations of the genesis of Scandinavian glacial loams and clays, we have examine... more DURING our investigations of the genesis of Scandinavian glacial loams and clays, we have examined some gneisses in upper Numedalen, Eastern Norway. These rocks have undoubtedly been exposed to glacial erosion, but they seem to represent deeper parts of the preglacial (tertiary) weathering profile. We are particularly interested in the rare Earth elements (yttrium + lanthanides) which these rocks contain. The determinations were carried out by spark mass spectrometer1, which is well suited for all rare Earth elements except Tm. The micaceous fractions were found to be extremely enriched in lanthanides. Whereas micas of magmatic and highly metamorphosed rocks normally have lower rare Earth content than the host rock, we have found the opposite in these weathered gneisses. Thus a slightly weathered mylonite gneiss (from Smadola) has a total rare Earth content of 525 p.p.m. The light mica fraction (degraded muscovite), which made up approximately 2% of the rock, contained 3,755 p.p.m. and the dark mica fraction (chlorite and vermiculized biotite), which made up approximately 8% of the rock, contained 1,584 p.p.m. of rare Earth elements.
Rare earth elements (REE) in the clay fraction ( < 2~) of the Quaternary deposits in the Numedal ... more Rare earth elements (REE) in the clay fraction ( < 2~) of the Quaternary deposits in the Numedal area, southern Norway, have been determined by a spark source mass spectrome~,Tic method. The REE content was studied in relation to weathering and sedimentolog/cal factors. The total REE content vr,_ries from 100 to 1300 ppm. An average of the ,imilar fraction of 16 non-marine days, mostly tillitic, gave 527 ppm REE. An average of 38 glacial and postglacial marine clays from the lower part of the Numedal valley gave 335 ppm REE (max. 781 ppm). After removal of adsorbed ions the average total REE content of morainian and marine clays decreased to 186 ppm. The content and distribution of the REE in the Numedal days are strongly influe, lced by environmental factors. Under neutral and alkaline conditions the REE are accumulated by adsorption on c:ay minerals, and by increasing the hydroger, ion concentration the adsorbed ions are readil removed.
Introduction: Following a bright fireball and a loud explosion the Moss meteorite fell on 14 July... more Introduction: Following a bright fireball and a loud explosion the Moss meteorite fell on 14 July 2006 at approximately 10:20am in the Moss-Rygge area on the east side of Oslofjord [1]. 5 stones were subsequently recovered with a total mass of nearly 4 kg [1]. Petrography, mineralogy and oxygen isotope analysis confirm that Moss is a carbonaceous chondrite of the Ornans group (CO3) [1]. Ornans-type chondrites are a distinct group with a characteristic texture consisting of a high density of small (0.2 -0.5 mm) chondrules, inclusions and lithic fragments enclosed by a dark matrix. They also have a significantly lower matrix to chondrule ratio than other carbonaceous chondrites . As a consequence of this textural coherence, CO3 chondrites are thought to represent samples from a single asteroid. Unique among the carbonaceous chondites, the Ornans group show textural, mineralogical and isotopic evidence for a metamorphic series analogous to that seen in the ordinary chondrites [4,. In discussing the metamorphic grade of CO3 chondrites the scheme of [5] is used throughout. Moss is only the sixth fall in the CO3 group and the first since Kainsaz in 1937. In view of the importance of the Ornans group in understanding early Solar System processes, an integrated study of Moss has been undertaken to investigate further the metamorphic conditions that prevailed on the CO3 parent asteroid. Analytical techniques: Mineral analyses were undertaken using a Quanta 200 FIB-SEM and a Cameca SX-50 WDS microprobe operated at 20kV and 2nA. Oxygen isotope analyses were performed by infrared laser-assisted fluorination . C, N, and Ar isotopes were analyzed by stepped combustion using the Finesse fully automated mass spectrometer [8]. Organic analysis was undertaken using a Pegasus 4D (GCxGC) TOFMS (LECO Corporation) fitted with a Pyrola 2000 (Pyrolab, Sweden) for pyrolysis under the conditions described in [9]. Results: Petrography and mineral analysis: The results of petrographic studies confirm the classification of Moss as 3.4/3.5 . Fe-Mg zoning profiles in type 1A chondrule olivines suggest that Moss is closest to 3.5 in grade. Oxygen isotopes: Analysis of two replicates gave the following whole-rock oxygen isotope composition for Moss: 17 O = -5.90‰ ± 0.08, 18 O = -2.21‰ ± 0.
Decompaction may be defined as a process to reconstruct the palaeothickness and the palaeoporosit... more Decompaction may be defined as a process to reconstruct the palaeothickness and the palaeoporosity distributions of a sedimentary column. This process is normally realized by computation of pore volume reduction in sedimentary histories (Perrier and Quiblier 1974). Decompaction modelling has been a subject of interest because of its uses in quantitative geohistory analysis, reservoir evaluation and fluid migration studies in sedimentary basins (Sclater and Christie 1980; Bessis 1985; Bertram and Milton 1989). Petroleum geologists, while preparing palaeogeographic or palaeostructural reconstructions, must consider how thicknesses of strata were modified during depositional history.
This paper reports the organic constitution of the CO3 chondrites identified by 4D TOFMS in order... more This paper reports the organic constitution of the CO3 chondrites identified by 4D TOFMS in order to decipher the composition, structure and alteration history of the CO3 parent asteroid.
Sedimentological, mineralogical, geochemical and some geotechnical properties of Holocene clay an... more Sedimentological, mineralogical, geochemical and some geotechnical properties of Holocene clay and silt sediments of the inner Skagerrak and outer Oslofjord are reported. Close to the Norwegian coast the sea bottom has an irregular relief reflecting the rough features of the crystalline basement. Here the sediment thickness varies from 0 to 50 m. At water depths greater than 150 m the sediment layer becomes thicker and continuous. Generally, the sedimentation rates in the Oslo0ord and inner Skagerrak are high, normally I-2 mm/yr. Areas with higher deposition as well as with non-deposition and/or erosion occur. The inner fjord sediments have high contents of illite and chlorite, reflecting that they have been derived from the glacial deposits of Scandinavia. These clay minerals are also present in the outer i~ord and Skagerrak sediments, which in addition contain smectite and kaolinite, that originate from the Mesozoic and Cenozoic sediments in Denmark/southern Sweden and/or from sediments within the North Sea basin. These clay minerals are transported to the inner Skagerrak mainly by the Jutland and Baltic currents. The diagenetic zonation of most bottom sediments consists of an oxic layer on top of an incipient reducing anoxic, non sulphidic layer. In the oxic top layer of the Skagerrak sediments diagenetic calcite grows on foraminiferal tests. At depth the calcite dissolves. Zinc has been used as element reflecting anthropogenic pollution. The flux of zinc to the Osloi~ord-Skagerrak sediments started to increase about 120-140 years ago. Today the most polluted waters are locked fjords and coastal waters inside the archipelago. As the isostatic rebound still goes on in Scandinavia, the polluted sediment particles will not deposit in the river, but in the fjord and coastal areas. Except for a few near-shore areas and restricted fjord basins, the degree of pollution is low.
Geological Society, London, Special Publications, 1986
Summary A prograding sequence of near shore sediments is identified at the border of the northern... more Summary A prograding sequence of near shore sediments is identified at the border of the northern North Sea plateau (water depth 135 m) and the western slope of the Norwegian Trench. In Late Weichselian time (probably about 15 000 years bp) the relative sea level was approximately 180 m lower than today. During this low sea-level stand, the older consolidated glaciomarine sediments in the slope area were exposed to coastal erosion, leading to a prograding unit of sand fining outwards to silt and clay. During rising sea-level the coastal erosion gradually reached a lodgement till deposited at the top of the plateau, resulting in coarser sediments such as stones and gravel, fining outwards to sand down the slope. The plateau area was transgressed shortly after 13 000 years bp.
Mass spectrometric analyses for rare earth elements (REE) have been carried out on some Precambri... more Mass spectrometric analyses for rare earth elements (REE) have been carried out on some Precambrian mica schists, gneisses and granites from the Precambrian Numedal area, Norway and on their phyllosilicates. The rocks, which are metamorphosed in the upper greenschist to amphibolite facies, were originally partly sedimentary, partly magmatic. The total REE contents for rocks varies from 145 to 761 ppm. An average of 16 phyllosilicate samples gave 417 ppm REE (max. of 1809 ppm, min. of ca. 50 ppm). Coexisting light and dark phyllosilicates have similar abundances of REE. For the micas of high REE content most of the REE was extractable by rinsing with EDTA. The data thus support the possibility of an extensive adsorption of REE ions on micaceous minerals. The REE distribution patterns do not provide a clear distinction between the sedimentary and magmatic origin for the rocks examined.
Fourteen rare-earth elements (REE) have been determined in metavolcanics and metagabbros from the... more Fourteen rare-earth elements (REE) have been determined in metavolcanics and metagabbros from the island of Leka, Norway. The overall REE content of these rocks ranges from about 3ppm, with strong light REE depletion, for the metagabbros to 170ppm with light REE enrichment, for porphyritic greenstones and pillow lavas. Based on regional geological features, lithology, and the REE abundances it is concluded that rocks of the island Leka constitute a part of an ophiolite complex.
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