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Palynological investigation of coal-bearing deposits of the Thar Coal Field Sindh, Pakistan

Kumar, Pardeep LU (2012) In Dissertations in Geology at Lund University GEOR02 20121
Department of Geology
Abstract (Swedish)
Palynologiska och sedimentologiska studier av prover från en borrkärna från Thar-kolfältet (nedre Indus Bassängen), Pakistan har genomförts. De kenozoiska sedimenten ligger på det granitiska urberget (som utgör den Indiska skölden) och utgörs främst av kolavlagringarna vilka är mellanlagrade av sandsten och silt-sten.. Thar är namnet på det stora ökenområde som breder ut sig i gränsområdet mellan Indien och Pakistan och som överlagrar rika kolfyndigheter på båda sidor om gränsen. Genom att jämföra borrkärneloggen och resultaten av palynofaciesanalysen från denna studie så kan successionen indelas i tre paleoekologiska enheter; 1. våtmarksmiljö; 2. träskmiljö med kolbildning; 3. fluvial flodslättsavlagring. Den nedre delen av borrkärnan med... (More)
Palynologiska och sedimentologiska studier av prover från en borrkärna från Thar-kolfältet (nedre Indus Bassängen), Pakistan har genomförts. De kenozoiska sedimenten ligger på det granitiska urberget (som utgör den Indiska skölden) och utgörs främst av kolavlagringarna vilka är mellanlagrade av sandsten och silt-sten.. Thar är namnet på det stora ökenområde som breder ut sig i gränsområdet mellan Indien och Pakistan och som överlagrar rika kolfyndigheter på båda sidor om gränsen. Genom att jämföra borrkärneloggen och resultaten av palynofaciesanalysen från denna studie så kan successionen indelas i tre paleoekologiska enheter; 1. våtmarksmiljö; 2. träskmiljö med kolbildning; 3. fluvial flodslättsavlagring. Den nedre delen av borrkärnan med de kolbärande intervallen avsattes under anoxiska till måttligt anoxiska förhållanden medan den övre delen deponerades under helt oxiska förhållanden.De palynologiska associationerna består enbart av icke-marina palynomorfer, dvs. pollen spo-rer samt alger och svampsporer. Totalt identifierades 60 arter. Dessa utgörs främst av pollen och domineras av pol-len från blomväxter (angiospermer). De kolbärande sedimenten är intressanta då de uppvisar en hög mångfald av pollen och sporer, men i sedimenten i övergången mellan flodslättsavlagringen och kolavlagringarna är bevarings-graden dålig. Där utgörs den palynologiskaassociationen av en stor andel amorft organiskt material (AOM). Detta sammanfaller med ett intervall som visar på kraftigt reducerade (anoxiska) förhållanden och här innehåller sedi-menten även pyrit. I den basala delen av borrkärnan dominerar palm pollen representerat av pollen tillhörande släktet Spinizoncolpites och Proxapertites. Förekomst av dessa arter indikerar att sedimenten avsattes i en kustnära träskmiljö. Dessa resultat överensstämmer med andra studier från området och tyder på ett varmt och fuktigt klimat med en tropisk regnskog. Förekomsten av svampsporer och hyfer i proverna stöder dessa iakttagelser. (Less)
Abstract
A palynological and sedimentological study of samples from the Thar Coal Field (Lower Indus Basin), south eastern border of Sindh, Pakistan was performed. Thar is the name of the large desert extending into India and Pakistan and overlying rich coal deposits on both sides of the border. The Cenozoic coal deposits alternate with sandstones and in turn overlay the granitic basement rocks of the Indian shield.
The palynofacies is characterized by a gradual change of the relative abundance of structured components, i.e.; wood, and the amorphous organic matter (AOM), starting from the lower coal seam and increasing up-core. By matching the drill core log and the recorded palynofacies, three cycles were identified; fluvial, flood plain and... (More)
A palynological and sedimentological study of samples from the Thar Coal Field (Lower Indus Basin), south eastern border of Sindh, Pakistan was performed. Thar is the name of the large desert extending into India and Pakistan and overlying rich coal deposits on both sides of the border. The Cenozoic coal deposits alternate with sandstones and in turn overlay the granitic basement rocks of the Indian shield.
The palynofacies is characterized by a gradual change of the relative abundance of structured components, i.e.; wood, and the amorphous organic matter (AOM), starting from the lower coal seam and increasing up-core. By matching the drill core log and the recorded palynofacies, three cycles were identified; fluvial, flood plain and coal swamp deposits. Based on the palynofacies analysis, the coal swamp could further be sub divided into two, by the presence of fresh lacustrine grey claystone.
The palynomorphs, identified in the studied samples are predominantly terrestrial and 60 taxa of pollen and spores were identified characterized by a dominance of angiosperm pollen. The coal- bearing sediments show a high diversity of pollen and spores. However, the transition between the flood plain and coal swamp sediments are characterized by high percentages of AOM and with poorly preserved palynomorphs. This coincides with an interval indicating highly reduced (anoxic) conditions based on the occurrence of pyrite. The family Bombacaceae (herbaceous) and Arecaceae represented by (Spinozonocolpites spp., and Acanthotricolpites spp), are the most dominant pollen groups throughout the studied samples. In the basal part of the drill core the pollen species are predominant with Nypa palm pollen of the genus Spinizonocolpites and Proxapertites spp. Occurrence of these species indicates that the sediments were deposited in a coastal swamp. These results agree with other studies from the area on palynomorph assemblages indicating a warm and exceptionally humid climate in a coastal zone and with a tropical rainforest in the area of the depositional environment (Sahni 2006). The presence of fruiting bodies and epiphyllous fungi in the samples supports episodes of warm tropical-subtropical climate under high precipitation during deposition of the Thar sediments. The lower coal bearing interval and the middle transition (flood plain and coal swamp) were deposited under anoxic to moderate anoxic conditions whereas the upper part was deposited under the influence of completely oxic conditions. (Less)
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author
Kumar, Pardeep LU
supervisor
organization
alternative title
Palynologisk studie av kolbärande sediment från Thar-kolfältet i Sindh, Pakistan
course
GEOR02 20121
year
type
H2 - Master's Degree (Two Years)
subject
keywords
hydrocarbons, Eocene, Paleocene, pollen, coal, Pakistan, palynofacies
publication/series
Dissertations in Geology at Lund University
report number
322
language
English
id
3222714
date added to LUP
2013-01-07 10:14:20
date last changed
2013-01-07 10:14:20
@misc{3222714,
  abstract     = {A palynological and sedimentological study of samples from the Thar Coal Field (Lower Indus Basin), south eastern border of Sindh, Pakistan was performed. Thar is the name of the large desert extending into India and Pakistan and overlying rich coal deposits on both sides of the border. The Cenozoic coal deposits alternate with sandstones and in turn overlay the granitic basement rocks of the Indian shield. 
 The palynofacies is characterized by a gradual change of the relative abundance of structured components, i.e.; wood, and the amorphous organic matter (AOM), starting from the lower coal seam and increasing up-core. By matching the drill core log and the recorded palynofacies, three cycles were identified; fluvial, flood plain and coal swamp deposits. Based on the palynofacies analysis, the coal swamp could further be sub divided into two, by the presence of fresh lacustrine grey claystone.
 The palynomorphs, identified in the studied samples are predominantly terrestrial and 60 taxa of pollen and spores were identified characterized by a dominance of angiosperm pollen. The coal- bearing sediments show a high diversity of pollen and spores. However, the transition between the flood plain and coal swamp sediments are characterized by high percentages of AOM and with poorly preserved palynomorphs. This coincides with an interval indicating highly reduced (anoxic) conditions based on the occurrence of pyrite. The family Bombacaceae (herbaceous) and Arecaceae represented by (Spinozonocolpites spp., and Acanthotricolpites spp), are the most dominant pollen groups throughout the studied samples. In the basal part of the drill core the pollen species are predominant with Nypa palm pollen of the genus Spinizonocolpites and Proxapertites spp. Occurrence of these species indicates that the sediments were deposited in a coastal swamp. These results agree with other studies from the area on palynomorph assemblages indicating a warm and exceptionally humid climate in a coastal zone and with a tropical rainforest in the area of the depositional environment (Sahni 2006). The presence of fruiting bodies and epiphyllous fungi in the samples supports episodes of warm tropical-subtropical climate under high precipitation during deposition of the Thar sediments. The lower coal bearing interval and the middle transition (flood plain and coal swamp) were deposited under anoxic to moderate anoxic conditions whereas the upper part was deposited under the influence of completely oxic conditions.},
  author       = {Kumar, Pardeep},
  keyword      = {hydrocarbons,Eocene,Paleocene,pollen,coal,Pakistan,palynofacies},
  language     = {eng},
  note         = {Student Paper},
  series       = {Dissertations in Geology at Lund University},
  title        = {Palynological investigation of coal-bearing deposits of the Thar Coal Field Sindh, Pakistan},
  year         = {2012},
}