Details
| Original language | English |
|---|---|
| Article number | 104300 |
| Journal | Journal of African Earth Sciences |
| Volume | 182 |
| Early online date | 8 Jun 2021 |
| Publication status | Published - Oct 2021 |
| Externally published | Yes |
Abstract
The early Bajocian environmental crisis is marked by floral and faunal turnovers, and a positive carbon excursion recognized in both marine and continental archives. In the basinal setting of the Central High Atlas Basin, it is concomitant to a drastic drop of carbonate content, interpreted as a result of a severe carbonate demise event in neritic settings. In order to provide a carbonate platform perspective of this demise event, we have investigated a proximal–distal transect consisting of five sections of the Errachidia Platform, which represents upper neritic settings on the southern margin of the basin. New nannofossils and brachiopod findings, supported by organic matter carbon isotope chemostratigraphy, allow for the establishment of a high-resolution chronostratigraphic framework of the Errachidia Platform and a detailed reconstruction of carbonate factory evolution during the late Aalenian to middle Bajocian interval. The early Bajocian (Propinquans Zone) environmental crisis triggered a severe demise event which restricted carbonate production to supra-to intertidal settings, where microbial and peloidal limestones are the only trace of carbonate production. As a consequence, most of the platform is dominated by extended marl deposits that are usually interpreted as hemipelagic deposits. This observation demonstrates that caution must be exerted when interpreting the depositional environments of marl-dominated successions during time of neritic carbonate factory demise.
Keywords
- Brachiopods, Carbonate platform demise, Central High Atlas Basin, Chemostratigraphy, Middle Jurassic, Nannofossils
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geology
- Earth and Planetary Sciences(all)
- Earth-Surface Processes
Sustainable Development Goals
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In: Journal of African Earth Sciences, Vol. 182, 104300, 10.2021.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Tracking a drowning unconformity up to the peritidal zone: proximal expression of the early Bajocian carbonate crisis in Morocco
AU - Danisch, Jan
AU - Krencker, Francois-Nicolas Frédéric
AU - Malte, Mau
AU - Mattioli, Emanuela
AU - Fauré, Philippe
AU - Alméras, Yves
AU - Nutz, Alexis
AU - Kabiri, Lahcen
AU - El Ouali, Mohamed
AU - Bodin, Stéphane
N1 - Funding information: This research was financed by the Aarhus Universitets Forskningsfond (grant n° AUFF-E-2015-FLS-8-77 ) and the Independent Research Fund Denmark ( DFF , grant n° 9040-00188B ) to SB. We thank Sara Tomás and an anonymous reviewer for their constructive comments on an earlier version of this manuscript.
PY - 2021/10
Y1 - 2021/10
N2 - The early Bajocian environmental crisis is marked by floral and faunal turnovers, and a positive carbon excursion recognized in both marine and continental archives. In the basinal setting of the Central High Atlas Basin, it is concomitant to a drastic drop of carbonate content, interpreted as a result of a severe carbonate demise event in neritic settings. In order to provide a carbonate platform perspective of this demise event, we have investigated a proximal–distal transect consisting of five sections of the Errachidia Platform, which represents upper neritic settings on the southern margin of the basin. New nannofossils and brachiopod findings, supported by organic matter carbon isotope chemostratigraphy, allow for the establishment of a high-resolution chronostratigraphic framework of the Errachidia Platform and a detailed reconstruction of carbonate factory evolution during the late Aalenian to middle Bajocian interval. The early Bajocian (Propinquans Zone) environmental crisis triggered a severe demise event which restricted carbonate production to supra-to intertidal settings, where microbial and peloidal limestones are the only trace of carbonate production. As a consequence, most of the platform is dominated by extended marl deposits that are usually interpreted as hemipelagic deposits. This observation demonstrates that caution must be exerted when interpreting the depositional environments of marl-dominated successions during time of neritic carbonate factory demise.
AB - The early Bajocian environmental crisis is marked by floral and faunal turnovers, and a positive carbon excursion recognized in both marine and continental archives. In the basinal setting of the Central High Atlas Basin, it is concomitant to a drastic drop of carbonate content, interpreted as a result of a severe carbonate demise event in neritic settings. In order to provide a carbonate platform perspective of this demise event, we have investigated a proximal–distal transect consisting of five sections of the Errachidia Platform, which represents upper neritic settings on the southern margin of the basin. New nannofossils and brachiopod findings, supported by organic matter carbon isotope chemostratigraphy, allow for the establishment of a high-resolution chronostratigraphic framework of the Errachidia Platform and a detailed reconstruction of carbonate factory evolution during the late Aalenian to middle Bajocian interval. The early Bajocian (Propinquans Zone) environmental crisis triggered a severe demise event which restricted carbonate production to supra-to intertidal settings, where microbial and peloidal limestones are the only trace of carbonate production. As a consequence, most of the platform is dominated by extended marl deposits that are usually interpreted as hemipelagic deposits. This observation demonstrates that caution must be exerted when interpreting the depositional environments of marl-dominated successions during time of neritic carbonate factory demise.
KW - Brachiopods
KW - Carbonate platform demise
KW - Central High Atlas Basin
KW - Chemostratigraphy
KW - Middle Jurassic
KW - Nannofossils
UR - http://www.scopus.com/inward/record.url?scp=85107803932&partnerID=8YFLogxK
U2 - 10.1016/j.jafrearsci.2021.104300
DO - 10.1016/j.jafrearsci.2021.104300
M3 - Article
VL - 182
JO - Journal of African Earth Sciences
JF - Journal of African Earth Sciences
SN - 1464-343X
M1 - 104300
ER -