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Volume 28 (2022): Issue 2 (August 2022)

Volume 28 (2022): Issue 1 (April 2022)

Volume 27 (2021): Issue 3 (December 2021)

Volume 27 (2021): Issue 2 (August 2021)

Volume 27 (2021): Issue 1 (April 2021)

Volume 26 (2020): Issue 3 (December 2020)

Volume 26 (2020): Issue 2 (August 2020)

Volume 26 (2020): Issue 1 (April 2020)

Volume 25 (2019): Issue 3 (December 2019)

Volume 25 (2019): Issue 2 (August 2019)

Volume 25 (2019): Issue 1 (April 2019)

Volume 24 (2018): Issue 3 (December 2018)

Volume 24 (2018): Issue 2 (August 2018)

Volume 24 (2018): Issue 1 (March 2018)

Volume 23 (2017): Issue 3 (December 2017)

Volume 23 (2017): Issue 2 (June 2017)

Volume 23 (2017): Issue 1 (March 2017)

Volume 22 (2016): Issue 3 (September 2016)

Volume 22 (2016): Issue 2 (June 2016)

Volume 22 (2016): Issue 1 (March 2016)

Volume 21 (2015): Issue 4 (December 2015)

Volume 21 (2015): Issue 3 (September 2015)

Volume 21 (2015): Issue 2 (June 2015)

Volume 21 (2015): Issue 1 (March 2015)

Volume 20 (2014): Issue 4 (December 2014)

Volume 20 (2014): Issue 3 (September 2014)

Volume 20 (2014): Issue 2 (June 2014)

Volume 20 (2014): Issue 1 (March 2014)

Volume 19 (2013): Issue 4 (December 2013)

Volume 19 (2013): Issue 3 (September 2013)

Volume 19 (2013): Issue 1-2 (May 2013)
Heavy-mineral analysis as a tool in earth-scientific research

Volume 18 (2012): Issue 4 (December 2012)

Volume 18 (2012): Issue 3 (October 2012)

Volume 18 (2012): Issue 2 (August 2012)

Volume 18 (2012): Issue 1 (March 2012)

Volume 17 (2011): Issue 4 (December 2011)

Volume 17 (2011): Issue 3 (September 2011)

Volume 17 (2011): Issue 2 (June 2011)

Volume 17 (2011): Issue 1 (April 2011)

Volume 16 (2010): Issue 4 (December 2010)

Volume 16 (2010): Issue 3 (October 2010)

Volume 16 (2010): Issue 2 (June 2010)

Volume 16 (2010): Issue 1 (April 2010)

Volume 15 (2009): Issue 3-4 (December 2009)

Journal Details
Format
Journal
eISSN
2080-6574
First Published
24 Dec 2009
Publication timeframe
3 times per year
Languages
English

Search

Volume 27 (2021): Issue 2 (August 2021)

Journal Details
Format
Journal
eISSN
2080-6574
First Published
24 Dec 2009
Publication timeframe
3 times per year
Languages
English

Search

8 Articles
Open Access

Field evidence suggests that the Palaeoproterozoic Gowganda Formation in Canada is non-glacial in origin

Published Online: 17 Sep 2021
Page range: 73 - 91

Abstract

Abstract

During more than a century since its original identification, the Gowganda Formation in Ontario (Canada) has gradually been reinterpreted from representing mainly subglacial tillites to secondary gravity flow and glaciomarine deposits. The main pieces of geological evidence advanced in favour of glaciation in recent articles are outsized clasts that have been interpreted as dropstones and patches of diamictites in a single small-sized area at Cobalt which is still interpreted as displaying subglacial basal tillites. The present research considers field evidence in the Gowganda Formation in the light of more recent work on gravity flows linked to tectonics. Detailed studies have demonstrated that the clasts which are interpreted to be dropstones rarely penetrate laminae and are commonly draped by sediments the appearance of which is similar to lonestones in gravity flows. The “subglacial area” at Cobalt displays evidence of tectonics and gravity flows, which can be traced from the underlying bedrock, and then further in the overlying sequence of diamictites and rhythmites. The sum of geological features displays appearances at odds with a primary glaciogenic origin, and there is no unequivocal evidence present of glaciation. The data indicate deposition by non-glaciogenic gravity flows, including cohesive debris flows for the more compact units, probably triggered by tectonic displacements.

Keywords

  • Debris flow
  • lonestone dropstone
  • lamination varve
  • non-glacial diamictite tillite
  • Snowball Earth
Open Access

Slumping as a record of regional tectonics and palaeoslope changes in the Satpura Basin, central India

Published Online: 17 Sep 2021
Page range: 93 - 103

Abstract

Abstract

Soft-sediment deformation structures play an important role in interpreting regional tectonics and basin evolution during slumping events. The Satpura Basin is interpreted as pull-apart with a monoclinal northerly palaeoslope throughout its evolution. The basin formed as a result of sinistral strike-slip faulting, induced by the ENE–WSW-trending Son-Narmada South fault in the north and the Tapti North fault in the south. We have analysed the slump folds within the basalmost Talchir Formation and related these to regional tectonics and palaeoslope changes in the Satpura Basin. The glaciofluvial strata of the Talchir Formation, exposed in the southern part of the Satpura Basin, record intricacies of folds created during slumping. Several fold styles can be distinguished, within alternations of competent sandstone and incompetent shale layers, some of which indicate buckling. Upright folds, resulting from pure shear, underwent rotation of their axial planes and fold axes during simple shear-dominated progressive deformation when the slump moved downslope. The soft-sediment deformation structures that we have studied show refolding patterns that closely resemble comparable folds known from lithified rocks. These layers with refolded structures are overlain by unde-formed sediments, which proves that they are the product of a single ongoing slumping process, rather than of successive deformation events. Our analysis of their fold axes and axial planes, together with fold vergences and thrust directions within the slumps, suggests a mean slumping direction towards the southwest. Analyses of slump folds and their relationship with regional tectonics have allowed us to reinterpret basin evolution history. The southwesterly trending palaeoslope of the basin suggest that the slope of the basin was not uniform throughout its evolution. At the opening, the oblique slip fault, which trended NE–SW, generated due to movement along the ENE–WSW basin bounding faults, was more active and triggered slumping event within the Talchir deposits in the basin. With progressive overlapping of the basin-bounding faults, the Satpura Basin gradually tilted towards the north.

Keywords

  • Soft-sediment deformation structures
  • fold analysis
  • refolding
  • slump folds
  • Talchir Formation
Open Access

Caves as geoheritage resource in remote desert areas: a preliminary evaluation of Djara Cave in the Western Desert of Egypt

Published Online: 17 Sep 2021
Page range: 105 - 113

Abstract

Abstract

Caves are rare in northeast Africa and, thus, deserve attention as potential geoheritage objects (geosites). Assessment of Djara Cave and its vicinity (Western Desert, Egypt) has permitted to document unique features, such as the cave itself as a peculiar subsurface landform, speleothems providing data for palaeoenvironmental reconstructions, rock art demonstrating elements of past landscapes, siliceous nodules weathered from Eocene limestones and a network of dry drainage channels indicative of wetter palaeoenvironments. These features are assigned to geomorphological, sedimentological and palaeogeographical types of geoheritage. Djara Cave and its vicinity are proposed as a geosite of national rank; it is vulnerable to anthropogenic stress and needs geoconservation measures and instalment of interpretative signs. This geosite is already popular among tourists, and can be used for further tourism development. More generally, the presence of caves in Egyptian desert areas makes possible the recognition of national speleological heritage that requires special country-level strategies of management.

Keywords

  • Desert cave
  • geomorphosite
  • rock art
  • siliceous nodules
  • tourism
Open Access

Burdigalian-Langhian foraminifera of the northwest High Zagros Thrust Belt, southwest Iran

Published Online: 17 Sep 2021
Page range: 115 - 126

Abstract

Abstract

The foraminiferal contents of the lower–middle Miocene succession exposed in three sections in north Nur Abad on the northwestern side of the High Zagros Thrust Belt were studied. Assemblages of larger foraminifera from these sections can be referred to Zone SBZ 25 (and the Miogypsina globulus and Miogypsina intermedia subzones), which correlates with the Burdigalian Stage. For the first time, planktonic foraminifera documented from the Nur Abad area document Lang-hian deposits in the High Zagros, the upper 20 metres of the upper Sayl Cheshmeh section being characterised by the occurrence of planktonic foraminifera such as Globigerina concinna (Reuss), Globigerina diplostoma (Reuss), Globigerinoides obliquus (Bolli), Orbulina bilobata (d’Orbigny) and O.universa (d’Orbigny). This association characterises the Orbulina suturalis Interval Zone.

Keywords

  • Miocene
  • biostratigraphy
  • correlation
  • protists
  • Middle East
Open Access

Methods of management of bottom sediments from selected water reservoirs – a literature review

Published Online: 17 Sep 2021
Page range: 127 - 134

Abstract

Abstract

Sediment accumulation is a process that is typical of all types of water reservoirs. The rate and pattern of such accumulation are related to processes taking place in catchments that produce the sediments and to those within reservoirs that determine the percentage of the inflowing load that is trapped and where it is deposited. To keep reservoirs in working order requires desilting and managing of such bottom sediments once they are removed. The choice of strategy for sediment management depends on chemical and physical properties which result from both natural and anthropogenic processes. To varying degrees, these sediments may be contaminated with chemical compounds, especially trace metals. Therefore, research is needed in order to assess the quality of sediments, which will allow to opt for the proper management strategy. Based on an analysis of the available literature, the possibility of using sediments from reservoirs has been determined, using quality criteria and in accordance with applicable law and regulations.

Keywords

  • reservoir sedimentation
  • contaminated sediments
  • legal aspects of management
Open Access

Book Review: Handbook of geotourism, by Ross Dowling and David Newsome (Eds.), 2018. Edward Elgar Publishing Limited, Cheltenham, UK. 520 pages. Hardback: price £190, ISBN: 9781785368851.

Published Online: 17 Sep 2021
Page range: 135 - 136

Abstract

Open Access

Book Review: Global groundwater: source, scarcity, sustainability, security, and solutions, by Abhijit Mukherjee, Bridget Scanlon, Alice Aureli, Simon Langan, Huaming Guo and Andrew McKenzie (Eds.), 2020. Elsevier, Amsterdam. 676 pages. Paperback: price $150.00, ISBN 9780128181720; e-Book: price $105.00, ISBN 9780128181737.

Published Online: 17 Sep 2021
Page range: 137 - 138

Abstract

Open Access

Book Review: The Anthropocene as a geological time unit: a guide to the scientific evidence and current debate, by J. Zalasiewicz, C.N. Waters, M. Williams & C.P. Summerhayes, 2019. Cambridge University Press, Cambridge, UK. 361 pages. Hardback: price £44.99, ISBN 9781108475235.

Published Online: 17 Sep 2021
Page range: 139 - 140

Abstract

8 Articles
Open Access

Field evidence suggests that the Palaeoproterozoic Gowganda Formation in Canada is non-glacial in origin

Published Online: 17 Sep 2021
Page range: 73 - 91

Abstract

Abstract

During more than a century since its original identification, the Gowganda Formation in Ontario (Canada) has gradually been reinterpreted from representing mainly subglacial tillites to secondary gravity flow and glaciomarine deposits. The main pieces of geological evidence advanced in favour of glaciation in recent articles are outsized clasts that have been interpreted as dropstones and patches of diamictites in a single small-sized area at Cobalt which is still interpreted as displaying subglacial basal tillites. The present research considers field evidence in the Gowganda Formation in the light of more recent work on gravity flows linked to tectonics. Detailed studies have demonstrated that the clasts which are interpreted to be dropstones rarely penetrate laminae and are commonly draped by sediments the appearance of which is similar to lonestones in gravity flows. The “subglacial area” at Cobalt displays evidence of tectonics and gravity flows, which can be traced from the underlying bedrock, and then further in the overlying sequence of diamictites and rhythmites. The sum of geological features displays appearances at odds with a primary glaciogenic origin, and there is no unequivocal evidence present of glaciation. The data indicate deposition by non-glaciogenic gravity flows, including cohesive debris flows for the more compact units, probably triggered by tectonic displacements.

Keywords

  • Debris flow
  • lonestone dropstone
  • lamination varve
  • non-glacial diamictite tillite
  • Snowball Earth
Open Access

Slumping as a record of regional tectonics and palaeoslope changes in the Satpura Basin, central India

Published Online: 17 Sep 2021
Page range: 93 - 103

Abstract

Abstract

Soft-sediment deformation structures play an important role in interpreting regional tectonics and basin evolution during slumping events. The Satpura Basin is interpreted as pull-apart with a monoclinal northerly palaeoslope throughout its evolution. The basin formed as a result of sinistral strike-slip faulting, induced by the ENE–WSW-trending Son-Narmada South fault in the north and the Tapti North fault in the south. We have analysed the slump folds within the basalmost Talchir Formation and related these to regional tectonics and palaeoslope changes in the Satpura Basin. The glaciofluvial strata of the Talchir Formation, exposed in the southern part of the Satpura Basin, record intricacies of folds created during slumping. Several fold styles can be distinguished, within alternations of competent sandstone and incompetent shale layers, some of which indicate buckling. Upright folds, resulting from pure shear, underwent rotation of their axial planes and fold axes during simple shear-dominated progressive deformation when the slump moved downslope. The soft-sediment deformation structures that we have studied show refolding patterns that closely resemble comparable folds known from lithified rocks. These layers with refolded structures are overlain by unde-formed sediments, which proves that they are the product of a single ongoing slumping process, rather than of successive deformation events. Our analysis of their fold axes and axial planes, together with fold vergences and thrust directions within the slumps, suggests a mean slumping direction towards the southwest. Analyses of slump folds and their relationship with regional tectonics have allowed us to reinterpret basin evolution history. The southwesterly trending palaeoslope of the basin suggest that the slope of the basin was not uniform throughout its evolution. At the opening, the oblique slip fault, which trended NE–SW, generated due to movement along the ENE–WSW basin bounding faults, was more active and triggered slumping event within the Talchir deposits in the basin. With progressive overlapping of the basin-bounding faults, the Satpura Basin gradually tilted towards the north.

Keywords

  • Soft-sediment deformation structures
  • fold analysis
  • refolding
  • slump folds
  • Talchir Formation
Open Access

Caves as geoheritage resource in remote desert areas: a preliminary evaluation of Djara Cave in the Western Desert of Egypt

Published Online: 17 Sep 2021
Page range: 105 - 113

Abstract

Abstract

Caves are rare in northeast Africa and, thus, deserve attention as potential geoheritage objects (geosites). Assessment of Djara Cave and its vicinity (Western Desert, Egypt) has permitted to document unique features, such as the cave itself as a peculiar subsurface landform, speleothems providing data for palaeoenvironmental reconstructions, rock art demonstrating elements of past landscapes, siliceous nodules weathered from Eocene limestones and a network of dry drainage channels indicative of wetter palaeoenvironments. These features are assigned to geomorphological, sedimentological and palaeogeographical types of geoheritage. Djara Cave and its vicinity are proposed as a geosite of national rank; it is vulnerable to anthropogenic stress and needs geoconservation measures and instalment of interpretative signs. This geosite is already popular among tourists, and can be used for further tourism development. More generally, the presence of caves in Egyptian desert areas makes possible the recognition of national speleological heritage that requires special country-level strategies of management.

Keywords

  • Desert cave
  • geomorphosite
  • rock art
  • siliceous nodules
  • tourism
Open Access

Burdigalian-Langhian foraminifera of the northwest High Zagros Thrust Belt, southwest Iran

Published Online: 17 Sep 2021
Page range: 115 - 126

Abstract

Abstract

The foraminiferal contents of the lower–middle Miocene succession exposed in three sections in north Nur Abad on the northwestern side of the High Zagros Thrust Belt were studied. Assemblages of larger foraminifera from these sections can be referred to Zone SBZ 25 (and the Miogypsina globulus and Miogypsina intermedia subzones), which correlates with the Burdigalian Stage. For the first time, planktonic foraminifera documented from the Nur Abad area document Lang-hian deposits in the High Zagros, the upper 20 metres of the upper Sayl Cheshmeh section being characterised by the occurrence of planktonic foraminifera such as Globigerina concinna (Reuss), Globigerina diplostoma (Reuss), Globigerinoides obliquus (Bolli), Orbulina bilobata (d’Orbigny) and O.universa (d’Orbigny). This association characterises the Orbulina suturalis Interval Zone.

Keywords

  • Miocene
  • biostratigraphy
  • correlation
  • protists
  • Middle East
Open Access

Methods of management of bottom sediments from selected water reservoirs – a literature review

Published Online: 17 Sep 2021
Page range: 127 - 134

Abstract

Abstract

Sediment accumulation is a process that is typical of all types of water reservoirs. The rate and pattern of such accumulation are related to processes taking place in catchments that produce the sediments and to those within reservoirs that determine the percentage of the inflowing load that is trapped and where it is deposited. To keep reservoirs in working order requires desilting and managing of such bottom sediments once they are removed. The choice of strategy for sediment management depends on chemical and physical properties which result from both natural and anthropogenic processes. To varying degrees, these sediments may be contaminated with chemical compounds, especially trace metals. Therefore, research is needed in order to assess the quality of sediments, which will allow to opt for the proper management strategy. Based on an analysis of the available literature, the possibility of using sediments from reservoirs has been determined, using quality criteria and in accordance with applicable law and regulations.

Keywords

  • reservoir sedimentation
  • contaminated sediments
  • legal aspects of management
Open Access

Book Review: Handbook of geotourism, by Ross Dowling and David Newsome (Eds.), 2018. Edward Elgar Publishing Limited, Cheltenham, UK. 520 pages. Hardback: price £190, ISBN: 9781785368851.

Published Online: 17 Sep 2021
Page range: 135 - 136

Abstract

Open Access

Book Review: Global groundwater: source, scarcity, sustainability, security, and solutions, by Abhijit Mukherjee, Bridget Scanlon, Alice Aureli, Simon Langan, Huaming Guo and Andrew McKenzie (Eds.), 2020. Elsevier, Amsterdam. 676 pages. Paperback: price $150.00, ISBN 9780128181720; e-Book: price $105.00, ISBN 9780128181737.

Published Online: 17 Sep 2021
Page range: 137 - 138

Abstract

Open Access

Book Review: The Anthropocene as a geological time unit: a guide to the scientific evidence and current debate, by J. Zalasiewicz, C.N. Waters, M. Williams & C.P. Summerhayes, 2019. Cambridge University Press, Cambridge, UK. 361 pages. Hardback: price £44.99, ISBN 9781108475235.

Published Online: 17 Sep 2021
Page range: 139 - 140

Abstract

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