Details
| Original language | English |
|---|---|
| Pages (from-to) | 632-647 |
| Number of pages | 16 |
| Journal | Geological magazine |
| Volume | 152 |
| Issue number | 4 |
| Publication status | Published - 4 Jul 2015 |
Abstract
Studies dealing with the response of the continental biosphere to the environmental perturbations associated with Cretaceous oceanic anoxic events (OAEs) are comparatively rare. Here, a quantitative spore-pollen record combined with clay mineral data is presented, which covers the entire early Aptian OAE 1a interval (Forcall Formation, Maestrat basin, east Spain). The well-expressed OAE 1a carbon-isotope anomaly is paralleled by changes in the clay mineral assemblage and by a stepwise decline in the normalized frequency of Classopollis pollen (produced by xerophytic Cheirolepidiaceae) with lowest contents occurring during the positive δ13C shift. In contrast, Araucariacites and Inaperturopollenites pollen show a pronounced increase in relative abundance from low background values to become a significant component of the palynological assemblage during the Classopollis minimum. The observed changes in clay minerals and pollen distribution patterns are interpreted to reflect a major change in the composition of the hinterland vegetation of the Maestrat Basin, most probably due to short-lived but pronounced climatic cooling and changes in humidity. Temperature anomalies driven by organic carbon burial and associated CO2 decline have been postulated for all major Mesozoic OAEs. The palynomorph record from the Iberian Maestrat basins indicates that the climax of this cooling episode was significantly delayed in comparison to the end of organic carbon-rich deposition in the world oceans.
Keywords
- clay minerals, early Aptian, Maestrat Basin, oceanic anoxic event 1a, palynology
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geology
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In: Geological magazine, Vol. 152, No. 4, 04.07.2015, p. 632-647.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Climatic evolution across oceanic anoxic event 1a derived from terrestrial palynology and clay minerals (Maestrat Basin, Spain)
AU - Cors, Jean
AU - Heimhofer, Ulrich
AU - Adatte, Thierry
AU - Hochuli, Peter A.
AU - Huck, Stefan
AU - Bover-Arnal, Telm
PY - 2015/7/4
Y1 - 2015/7/4
N2 - Studies dealing with the response of the continental biosphere to the environmental perturbations associated with Cretaceous oceanic anoxic events (OAEs) are comparatively rare. Here, a quantitative spore-pollen record combined with clay mineral data is presented, which covers the entire early Aptian OAE 1a interval (Forcall Formation, Maestrat basin, east Spain). The well-expressed OAE 1a carbon-isotope anomaly is paralleled by changes in the clay mineral assemblage and by a stepwise decline in the normalized frequency of Classopollis pollen (produced by xerophytic Cheirolepidiaceae) with lowest contents occurring during the positive δ13C shift. In contrast, Araucariacites and Inaperturopollenites pollen show a pronounced increase in relative abundance from low background values to become a significant component of the palynological assemblage during the Classopollis minimum. The observed changes in clay minerals and pollen distribution patterns are interpreted to reflect a major change in the composition of the hinterland vegetation of the Maestrat Basin, most probably due to short-lived but pronounced climatic cooling and changes in humidity. Temperature anomalies driven by organic carbon burial and associated CO2 decline have been postulated for all major Mesozoic OAEs. The palynomorph record from the Iberian Maestrat basins indicates that the climax of this cooling episode was significantly delayed in comparison to the end of organic carbon-rich deposition in the world oceans.
AB - Studies dealing with the response of the continental biosphere to the environmental perturbations associated with Cretaceous oceanic anoxic events (OAEs) are comparatively rare. Here, a quantitative spore-pollen record combined with clay mineral data is presented, which covers the entire early Aptian OAE 1a interval (Forcall Formation, Maestrat basin, east Spain). The well-expressed OAE 1a carbon-isotope anomaly is paralleled by changes in the clay mineral assemblage and by a stepwise decline in the normalized frequency of Classopollis pollen (produced by xerophytic Cheirolepidiaceae) with lowest contents occurring during the positive δ13C shift. In contrast, Araucariacites and Inaperturopollenites pollen show a pronounced increase in relative abundance from low background values to become a significant component of the palynological assemblage during the Classopollis minimum. The observed changes in clay minerals and pollen distribution patterns are interpreted to reflect a major change in the composition of the hinterland vegetation of the Maestrat Basin, most probably due to short-lived but pronounced climatic cooling and changes in humidity. Temperature anomalies driven by organic carbon burial and associated CO2 decline have been postulated for all major Mesozoic OAEs. The palynomorph record from the Iberian Maestrat basins indicates that the climax of this cooling episode was significantly delayed in comparison to the end of organic carbon-rich deposition in the world oceans.
KW - clay minerals
KW - early Aptian
KW - Maestrat Basin
KW - oceanic anoxic event 1a
KW - palynology
UR - http://www.scopus.com/inward/record.url?scp=84937643946&partnerID=8YFLogxK
U2 - 10.1017/S0016756814000557
DO - 10.1017/S0016756814000557
M3 - Article
AN - SCOPUS:84937643946
VL - 152
SP - 632
EP - 647
JO - Geological magazine
JF - Geological magazine
SN - 0016-7568
IS - 4
ER -