Graptolites as fossil geo-thermometers and source material of hydrocarbons: An overview of four decades of progress

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F20%3A00523769" target="_blank" >RIV/61389005:_____/20:00523769 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.earscirev.2019.103000" target="_blank" >https://doi.org/10.1016/j.earscirev.2019.103000</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.earscirev.2019.103000" target="_blank" >10.1016/j.earscirev.2019.103000</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Graptolites as fossil geo-thermometers and source material of hydrocarbons: An overview of four decades of progress

Popis výsledku v původním jazyce

The thermal maturity of lower Paleozoic graptolite-bearing marine sediments, which host many hydrocarbon deposits worldwide, has long been difficult to determine due to the absence of wood-derived vitrinite particles for conventional vitrinite reflectance. In 1976, graptolite reflectance was introduced as a new indicator for organic maturity of these deposits and has been used since in many regional studies. The majority of these studies, however, were done on a limited sample set and a limited range of thermal maturity, which resulted in a number of controversial views concerning the usefulness of graptolite reflectance as an alternative paleothermal indicator and its correlation with vitrinite reflectance through various proxies. In this paper, we review previous studies and combine those analyses with new data to assess the physical and chemical characteristics of graptolite periderm with increasing thermal maturity. We conclude that graptolite random reflectance (GR(or)) is a better parameter for the thermal maturity assessment than graptolite maximum reflectance (GR(omax)) due to the better quality of available data. Combining published data with results of our study of both natural and heat-treated graptolites and vitrinite, we present a new correlation between GFt(or) and equivalent vitrinite reflectance (EqVR(o)), as EqVR(o) = 0.99GR(or) + 0.08. Chemical composition of graptolite periderm is similar to vitrinite, graptolites are mainly kerogen Type II-III, are gas prone and have a substantial hydrocarbon potential. Lower Paleozoic graptolite-bearing organic-rich sediments are important shale gas source rocks and reservoirs globally and make a significant contribution to worldwide petroleum reserves.

Název v anglickém jazyce

Graptolites as fossil geo-thermometers and source material of hydrocarbons: An overview of four decades of progress

Popis výsledku anglicky

The thermal maturity of lower Paleozoic graptolite-bearing marine sediments, which host many hydrocarbon deposits worldwide, has long been difficult to determine due to the absence of wood-derived vitrinite particles for conventional vitrinite reflectance. In 1976, graptolite reflectance was introduced as a new indicator for organic maturity of these deposits and has been used since in many regional studies. The majority of these studies, however, were done on a limited sample set and a limited range of thermal maturity, which resulted in a number of controversial views concerning the usefulness of graptolite reflectance as an alternative paleothermal indicator and its correlation with vitrinite reflectance through various proxies. In this paper, we review previous studies and combine those analyses with new data to assess the physical and chemical characteristics of graptolite periderm with increasing thermal maturity. We conclude that graptolite random reflectance (GR(or)) is a better parameter for the thermal maturity assessment than graptolite maximum reflectance (GR(omax)) due to the better quality of available data. Combining published data with results of our study of both natural and heat-treated graptolites and vitrinite, we present a new correlation between GFt(or) and equivalent vitrinite reflectance (EqVR(o)), as EqVR(o) = 0.99GR(or) + 0.08. Chemical composition of graptolite periderm is similar to vitrinite, graptolites are mainly kerogen Type II-III, are gas prone and have a substantial hydrocarbon potential. Lower Paleozoic graptolite-bearing organic-rich sediments are important shale gas source rocks and reservoirs globally and make a significant contribution to worldwide petroleum reserves.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/EF16_019%2F0000728" target="_blank" >EF16_019/0000728: Výzkum ultrastopových izotopů a jejich využití v sociálních a environmentálních vědách urychlovačovou hmotnostní spektrometrií</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Earth-Science Reviews

ISSN

0012-8252

e-ISSN

—

Svazek periodika

200

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

28

Strana od-do

103000

Kód UT WoS článku

000514749100020

EID výsledku v databázi Scopus

2-s2.0-85074430454