title: Post-Triassic thermal history of the Tazhong Uplift Zone in the Tarim Basin, Northwest China: Evidence from apatite fission-track thermochronology

authors: Xiang, Caifu

subjects: Apatite fission track

abstract: The Tarim Basin is a representative example of the basins developed in the northwest China that are characterized by multiple stages of heating and cooling. In order to better understand its complex thermal history, apatite fission track (AFT) thermochronology was applied to borehole samples from the Tazhong Uplift Zone (TUZ). Twelve sedimentary samples of Silurian to Triassic depositional ages were analyzed from depths coinciding with the apatite partial annealing zone (∼60-120 °C). The AFT ages, ranging from 132 ± 7 Ma (from a Triassic sample) to 25 ± 2 Ma (from a Carboniferous sample), are clearly younger than their depositional ages and demonstrate a total resetting of the AFT thermometer after deposition. The AFT ages vary among different tectonic belts and decrease from the No. Ten Faulted Zone (133-105 Ma) in the northwest, the Central Horst Zone in the middle (108-37 Ma), to the East Buried Hill Zone in the south (51-25 Ma). Given the low magnitude of post-Triassic burial heating evidenced by low vitrinite reflectance values (Ro < 0.7%), the total resetting of the AFT system is speculated to result from the hot fluid flow along the faults. Thermal effects along the faults are well documented by younger AFT ages and unimodal single grain age distributions in the vicinity of the faults. Permian-early Triassic basaltic volcanism may be responsible for the early Triassic total annealing of those samples lacking connectivity with the fault. The above arguments are supported by thermal modeling results.

text: Post-Triassic thermal history of the Tazhong Uplift Zone in the Tarim Basin, Northwest China: Evidence from apatite fission-track thermochronology The Tarim Basin is a representative example of the basins developed in the northwest China that are characterized by multiple stages of heating and cooling. In order to better understand its complex thermal history, apatite fission track (AFT) thermochronology was applied to borehole samples from the Tazhong Uplift Zone (TUZ). Twelve sedimentary samples of Silurian to Triassic depositional ages were analyzed from depths coinciding with the apatite partial annealing zone (∼60-120 °C). The AFT ages, ranging from 132 ± 7 Ma (from a Triassic sample) to 25 ± 2 Ma (from a Carboniferous sample), are clearly younger than their depositional ages and demonstrate a total resetting of the AFT thermometer after deposition. The AFT ages vary among different tectonic belts and decrease from the No. Ten Faulted Zone (133-105 Ma) in the northwest, the Central Horst Zone in the middle (108-37 Ma), to the East Buried Hill Zone in the south (51-25 Ma). Given the low magnitude of post-Triassic burial heating evidenced by low vitrinite reflectance values (Ro < 0.7%), the total resetting of the AFT system is speculated to result from the hot fluid flow along the faults. Thermal effects along the faults are well documented by younger AFT ages and unimodal single grain age distributions in the vicinity of the faults. Permian-early Triassic basaltic volcanism may be responsible for the early Triassic total annealing of those samples lacking connectivity with the fault. The above arguments are supported by thermal modeling results.

year: 2013

title: The effects of ocean acidification on microbial nutrient cycling and productivity in coastal marine sediments

authors: Brandt, Shelly Mia Marie

subjects: Ocean acidification

abstract: Ocean Acidification (OA), commonly referred to as the “other CO₂ problem,” illustrates the current rise in atmospheric carbon dioxide (CO₂) levels, precipitated in large by human-related activity (e.g., fossil fuel combustion and mass deforestation). The dissolution of atmospheric CO₂ into the surface of the ocean over time has reduced oceanic pH levels by 0.1 units since the start of the pre-industrial era and has resulted in wholesale shifts in seawater carbonate chemistry on a planetary scale. The chemical processes of ocean acidification are increasingly well documented, demonstrating clear rates of increase for global CO₂ emissions predicted by the IPCC (Intergovernmental Panel on Climate Change) under the business-as-usual CO₂ emissions scenario. The ecological impact of ocean acidification alters seawater chemical speciation and disrupts vital biogeochemical cycling processes for various chemicals and compounds. Whereby the unidentified potential fallout of this is the cascading effects on the microbial communities within the benthic sediments. These microorganisms drive the marine ecosystem through a network of vast biogeochemical cycling processes aiding in the moderation of ecosystem-wide primary productivity and fundamentally regulating the global climate. The benthic sediments are determinably one of the largest and most diverse ecosystems on the planet. Marine sediments are also conceivably one of the most productive in terms of microbial activity and nutrient flux between the water-sediment interface (i.e., boundary layer). The absorption and sequestering of CO₂ from the atmosphere have demonstrated significant impacts on various marine taxa and their associated ecological processes. This is commonly observed in the reduction in calcium carbonate saturation states in most shell-forming organisms (i.e., plankton, benthic mollusks, echinoderms, and Scleractinia corals). However, the response of benthic sediment microbial communities to a reduction in global ocean pH remains considerably less well characterized.  As these microorganisms operate as the lifeblood of the marine ecosystem, understanding their response and physiological plasticity to increased levels of CO₂ is of critical importance when it comes to investigating regional and global implications for the effects of ocean acidification.

text: The effects of ocean acidification on microbial nutrient cycling and productivity in coastal marine sediments Ocean Acidification (OA), commonly referred to as the “other CO₂ problem,” illustrates the current rise in atmospheric carbon dioxide (CO₂) levels, precipitated in large by human-related activity (e.g., fossil fuel combustion and mass deforestation). The dissolution of atmospheric CO₂ into the surface of the ocean over time has reduced oceanic pH levels by 0.1 units since the start of the pre-industrial era and has resulted in wholesale shifts in seawater carbonate chemistry on a planetary scale. The chemical processes of ocean acidification are increasingly well documented, demonstrating clear rates of increase for global CO₂ emissions predicted by the IPCC (Intergovernmental Panel on Climate Change) under the business-as-usual CO₂ emissions scenario. The ecological impact of ocean acidification alters seawater chemical speciation and disrupts vital biogeochemical cycling processes for various chemicals and compounds. Whereby the unidentified potential fallout of this is the cascading effects on the microbial communities within the benthic sediments. These microorganisms drive the marine ecosystem through a network of vast biogeochemical cycling processes aiding in the moderation of ecosystem-wide primary productivity and fundamentally regulating the global climate. The benthic sediments are determinably one of the largest and most diverse ecosystems on the planet. Marine sediments are also conceivably one of the most productive in terms of microbial activity and nutrient flux between the water-sediment interface (i.e., boundary layer). The absorption and sequestering of CO₂ from the atmosphere have demonstrated significant impacts on various marine taxa and their associated ecological processes. This is commonly observed in the reduction in calcium carbonate saturation states in most shell-forming organisms (i.e., plankton, benthic mollusks, echinoderms, and Scleractinia corals). However, the response of benthic sediment microbial communities to a reduction in global ocean pH remains considerably less well characterized.  As these microorganisms operate as the lifeblood of the marine ecosystem, understanding their response and physiological plasticity to increased levels of CO₂ is of critical importance when it comes to investigating regional and global implications for the effects of ocean acidification.

year: 2022

title: What’s in a name? The sense of reference, the rigidity of designators and the history of causes when determining the names of the two main islands of Aotearoa/New Zealand

authors: Parker, Martin

subjects: New Zealand

abstract: The New Zealand Geographic Board recently revealed that the two main islands of Aotearoa/New Zealand have never been officially named. The revelation made both national and international news and led to a large number of publicly aired comments on the matter, suggesting that something so fundamental and seemingly innocuous as naming is in fact likely to generate a good deal of controversy, no more so than in a bicultural/bilingual context. This paper will examine the phenomenon of naming from a number of angles. After discussing a layperson’s idea of what is meant by the meaning of names, we shall attempt to apply a number of theoretical models from the field of Language Philosophy to the case of the main islands of Aotearoa/New Zealand: the Descriptivist approach of Frege and Russell, Kripke’s Rigid Designators, and Causal Grounding theory. We shall conclude that, in the case of applying the first two of these, there is a question mark over whether any of the current names for the two islands, both Māori and Pākehā, are in fact names at all; in terms of applying the theory of Causal Grounding, we are drawn to the conclusion that in history lies the key to the future.

text: What’s in a name? The sense of reference, the rigidity of designators and the history of causes when determining the names of the two main islands of Aotearoa/New Zealand The New Zealand Geographic Board recently revealed that the two main islands of Aotearoa/New Zealand have never been officially named. The revelation made both national and international news and led to a large number of publicly aired comments on the matter, suggesting that something so fundamental and seemingly innocuous as naming is in fact likely to generate a good deal of controversy, no more so than in a bicultural/bilingual context. This paper will examine the phenomenon of naming from a number of angles. After discussing a layperson’s idea of what is meant by the meaning of names, we shall attempt to apply a number of theoretical models from the field of Language Philosophy to the case of the main islands of Aotearoa/New Zealand: the Descriptivist approach of Frege and Russell, Kripke’s Rigid Designators, and Causal Grounding theory. We shall conclude that, in the case of applying the first two of these, there is a question mark over whether any of the current names for the two islands, both Māori and Pākehā, are in fact names at all; in terms of applying the theory of Causal Grounding, we are drawn to the conclusion that in history lies the key to the future.

year: 2010-02