“…Taken together, these lines of evidence point to overall arid conditions during the deposition of the lower Plattenkalk interval which were rapidly, though gradually, replaced by a moderately humid and warm climate during the upper Plattenkalk interval. The variable amount of millimetre‐sized charcoal within some marly interlayers of the middle and upper intervals suggests that wildfires were an active process in the coastal depositional setting of Pietraroja, likely promoted by high atmospheric oxygen concentration (Glasspool & Scott, 2010; Brown et al ., 2012; Mays et al ., 2017; Bartiromo et al ., 2019; Xu et al ., 2022).…”
This study reports the first high‐resolution, integrated facies analysis of the lowermost Albian Pietraroja Lagerstätten (Apennine Carbonate Platform) which yields the first dinosaur (Scipionyx samniticus) found in Italy and other terrestrial vertebrates and plants. Aiming to clarify the long‐debated palaeoenvironmental significance of the Pietraroja succession, the following have been carried out: (i) a field survey to establish stratigraphic position and number of the fossil Lagerstätten; (ii) the centimetre‐scale facies analysis of a new section, ca 15 m‐thick, consisting of two new lithostratigraphic units, the ‘Cyclically organized Limestones’ and the ‘Cherty Limestones’; (iii) the scanning electron microscopy – energy dispersive X‐ray spectroscopy and backscattered electron – energy dispersive X‐ray spectroscopy analyses of clay mineral proxies for palaeoclimate and non‐carbonate grains; and (iv) the regional and supra‐regional investigation of the event stratigraphical context of the fossil Lagerstätten, in order to elucidate the controls on their formation. The section includes two out of the three observed fossil‐rich Lagerstätten, each up to 1.5 m‐thick. The arrangement of lithofacies and early diagenetic overprint defines shallow‐water depositional cycles suggestive of precession and short‐eccentricity periodicities. The Middle Lagerstätte yielding Scipionyx samniticus consists of three intervals. The lower, paralic interval was deposited during arid conditions and passes gradually to the plant‐rich, coastal wetland carbonaceous marls of the upper interval. The ‘Cherty Limestones’, yielding the Upper Lagerstätte with terrestrial vertebrates, contains two spiculitic intervals suggesting the development of siliceous sponge meadows in a shallow, restricted lagoon. Genetic stratigraphy suggests that the Pietraroja Lagerstätten were formed during glacioeustatic lowstands; interestingly, the Middle Lagerstätte mirrors the earliest Albian sea‐level lowstand (KAl1 event, ca 111.2 Myr), during a semi‐continuous supply of windblown volcaniclastics. Findings herein substantiate the pivotal role of paralic‐continental Lagerstätten for deriving high‐frequency palaeoclimatic dynamics and glacioeustacy from carbonate platform archives. The origin of Tethyan continental bridges between Africa and Europe during the late Aptian–earliest Albian cold interval is discussed.
“…Taken together, these lines of evidence point to overall arid conditions during the deposition of the lower Plattenkalk interval which were rapidly, though gradually, replaced by a moderately humid and warm climate during the upper Plattenkalk interval. The variable amount of millimetre‐sized charcoal within some marly interlayers of the middle and upper intervals suggests that wildfires were an active process in the coastal depositional setting of Pietraroja, likely promoted by high atmospheric oxygen concentration (Glasspool & Scott, 2010; Brown et al ., 2012; Mays et al ., 2017; Bartiromo et al ., 2019; Xu et al ., 2022).…”
This study reports the first high‐resolution, integrated facies analysis of the lowermost Albian Pietraroja Lagerstätten (Apennine Carbonate Platform) which yields the first dinosaur (Scipionyx samniticus) found in Italy and other terrestrial vertebrates and plants. Aiming to clarify the long‐debated palaeoenvironmental significance of the Pietraroja succession, the following have been carried out: (i) a field survey to establish stratigraphic position and number of the fossil Lagerstätten; (ii) the centimetre‐scale facies analysis of a new section, ca 15 m‐thick, consisting of two new lithostratigraphic units, the ‘Cyclically organized Limestones’ and the ‘Cherty Limestones’; (iii) the scanning electron microscopy – energy dispersive X‐ray spectroscopy and backscattered electron – energy dispersive X‐ray spectroscopy analyses of clay mineral proxies for palaeoclimate and non‐carbonate grains; and (iv) the regional and supra‐regional investigation of the event stratigraphical context of the fossil Lagerstätten, in order to elucidate the controls on their formation. The section includes two out of the three observed fossil‐rich Lagerstätten, each up to 1.5 m‐thick. The arrangement of lithofacies and early diagenetic overprint defines shallow‐water depositional cycles suggestive of precession and short‐eccentricity periodicities. The Middle Lagerstätte yielding Scipionyx samniticus consists of three intervals. The lower, paralic interval was deposited during arid conditions and passes gradually to the plant‐rich, coastal wetland carbonaceous marls of the upper interval. The ‘Cherty Limestones’, yielding the Upper Lagerstätte with terrestrial vertebrates, contains two spiculitic intervals suggesting the development of siliceous sponge meadows in a shallow, restricted lagoon. Genetic stratigraphy suggests that the Pietraroja Lagerstätten were formed during glacioeustatic lowstands; interestingly, the Middle Lagerstätte mirrors the earliest Albian sea‐level lowstand (KAl1 event, ca 111.2 Myr), during a semi‐continuous supply of windblown volcaniclastics. Findings herein substantiate the pivotal role of paralic‐continental Lagerstätten for deriving high‐frequency palaeoclimatic dynamics and glacioeustacy from carbonate platform archives. The origin of Tethyan continental bridges between Africa and Europe during the late Aptian–earliest Albian cold interval is discussed.
“…In this study, the Cretaceous coals were formed from the angiosperm flora of the Shengli coalfield of Inner Mongolia. 36 The extrapolations from the Pennsylvanian and Permian coals to our Cretaceous coals have been made with caution.…”
“…The maceral-based coal facies indices have been frequently used to estimate the depositional environments of coal-bearing strata in different regions. − Their utilization has also been a subject of debate. , The Pennsylvanian and Permian coals studied by Calder and Diessel were formed from the Laurasian Westphalian flora of Nova Scotia and from the Permian Gondwana flora of New South Wales, respectively. In this study, the Cretaceous coals were formed from the angiosperm flora of the Shengli coalfield of Inner Mongolia . The extrapolations from the Pennsylvanian and Permian coals to our Cretaceous coals have been made with caution.…”
To provide a new perspective on the formation of the Ge-rich coals, the depositional environment of the Wulantuga coals was studied with the incorporation of coal maceral and geochemistry-based indicators. The results show that the No.6 coal seam in the Wulantuga mine was formed in a mire with a succession of swamps, fens, and marsh. The average contents of Ge in coals formed in different mires, from high to low, are swamp (220 μg/g), marsh (205 μg/g), and fen (185 μg/g). The accumulation of the No.6 seam has been divided into four stages from bottom to top based on the identified coal facies types. The reducing condition and gelification of the ecosystem environment ranged from strong to weak, to strong, and back to weak. The variation of Ge concentrations also occurs in the same way. Strong reduction and gelification of the ecosystem environments can favor Ge enrichments in the Wulantuga coals. Sufficient sources and favorable conditions are essential for the unusual Ge enrichments in coals. This study provides a new perspective for the depositional environment of Ge-rich coals and is useful for the exploration of Ge-rich coal resources.
“…68 Inertinite is mostly formed in peat swamps with shallow water cover, periodic exposure, and wildfire events. 69,70 Liptinite is a group of macerals derived from nonhumifiable plant matter and relatively hydrogen-rich remains such as sporopollenin, resins, waxes, and fats, which are closely related to the oxygenrich peat swamp environment where the lignocellular tissue of the plant remains can be oxidized and decomposed, and the stable components are relatively enriched. 71 Peat swamps in tidal flats are mostly water-covered low-lying swamps with strong reducibility, and the coal formed in this environment has high vitrinite contents and beneficial reservoir physical properties.…”
Section: Distribution Of the Cbm Contentmentioning
confidence: 99%
“…It is generally believed that vitrinite is mainly formed in a reducing environment, which is mostly related to peat swamps with higher water levels . Inertinite is mostly formed in peat swamps with shallow water cover, periodic exposure, and wildfire events. , Liptinite is a group of macerals derived from nonhumifiable plant matter and relatively hydrogen-rich remains such as sporopollenin, resins, waxes, and fats, which are closely related to the oxygen-rich peat swamp environment where the lignocellular tissue of the plant remains can be oxidized and decomposed, and the stable components are relatively enriched…”
The Zhuozishan coalfield
at the western margin of the
Ordos Basin
is one of the main coal-mining areas in China, and recent explorations
have revealed the great potential for coalbed methane (CBM) resources
in its Carboniferous and Permian strata. In this paper, the controlling
factors of CBM enrichment of the major coals are studied in this coalfield
and the CBM resources are estimated based on the analysis of the coal
petrology and compilation of literature data on the gas content. The
result of the coal petrology analysis of 10 samples shows that the
vitrinite content of No. 16 coal (71.9–77.3%) is higher than
that of No. 9 coal (59.1–65.1%), and the inertinite content
of No. 16 coal (18.9–23.5%) is lower than that of No. 9 coal
(30.1–34.9%). The R
o,max value
of No. 16 coal (1.18–1.35%) is higher than that of No. 9 coal
(1.04–1.13%), and both coals are of medium rank. Due to greater
thickness, deeper burial depth, and better coal petrology characteristics,
the No. 16 coal seam of the Taiyuan Formation is selected as the major
coal seam for CBM resource estimation, which has a thickness of 1–6
m and a present-day burial depth of 200–1100 m. The gas content
of this coal seam varies mostly between 4 and 10 m3/t.
Positive correlation between the coal seam thickness as well as present-day
burial depth and the gas content suggests that the thick and deeply
buried coal seams are favorable for CBM preservation. The ash yield
shows an insignificant negative correlation with the gas content,
indicating that ash yield is not an important factor for CBM enrichment.
The syncline hinges located below the thrust zones show higher gas
content due to greater burial depths. In contrast, the anticline hinges
at shallower depths tend to have lower gas contents. Based on the
combined information about sedimentary environments, structural patterns,
and hydrogeology, two CBM accumulation models are put forward in the
study area that include synclinehydraulic plugging below thrust
nappe and faultconfined aquifer plugging. The volumetric method
is used to estimate the CBM resources, and results indicate that the
CBM resource in the whole coalfield is 428.78 × 108 m3, and the total resource abundance is 0.74 × 108 m3/km2. Two favorable areas for the
CBM exploration are optimized based on the resource amount and resource
abundance. One of the favorable areas is the Kabuqi area in the northern
part of the coalfield, and another is the Baiyunwusu area in the central
part of the coalfield. These two areas will be the CBM priority exploration
areas at the western margin of the Ordos Basin.
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