Depositional facies and cyclic patterns in a subtidal-dominated ramp during the Early-Middle Ordovician in the western Tarim Basin (NW China)

Palaeoecological features of Lower Asselian (Lower Permian) carbonate skeletal mounds in the Pisanyi Kamen’ section (Un’ya River, Northern Urals)

“…Some of them were better developed in the shallower Asselian-Sakmarian sequences of the PLD (Zhemchugova, 2002;Zhemchugova et al, 2020). However, in the Un'ya River Basin, in the Buzgalskiy Kamen' section (Figure 4), evidence for high-frequency oscillation in the relative sea level is lacking which is probably caused by the 'subtidal missed beats' effect (Elrick, 1995;Goldhammer et al, 1990Goldhammer et al, , 1993Guo et al, 2018;Osleger & Read, 1991), possibly due to deeper sedimentation in the Verkhnaya Pechora sedimentary basin.…”

Depositional facies and sequence architecture of the Yijianfang Formation in the Shuntuoguole Low Uplift, Tarim Basin, NW China

“…The sequence interface (unconformity or related integration interface) is the key to defining third‐order sequences (Mitchum, Vail, & Thompson III, 1977; Van Wagoner et al, 1988). The sequence interface is roughly located at the lowest point of the descending limb of the Fischer plot, and the maximum flooding surface (MFS) is located at the turning point at the highest point of the Fischer plot to the beginning of the descent (Guo, Chen, Song, et al, 2018a; Guo, Chen, Zhou, et al, 2018b). Long‐term surface exposure may result in the loss of high‐frequency sea‐level fluctuation records (e.g., Goldhammer et al, 1990).…”

“…Our cuttings thin sections observations from the three key wells showed no notable surface exposure in the third‐order sequence interface, while the sequence interface is mainly transitional (Colombié & Strasser, 2005; Osleger & Read, 1991; Overstreet, Oboh‐Ikuenobe, & Gregg, 2003; Strasser, Pittet, Hillgärtner, & Pasquier, 1999). The transitional zones appear as cycles with thicknesses larger than the average cycle thickness, directly overlaying cycles with smaller‐than‐average thicknesses (Figures 8, 9 and 10; Guo, Chen, Song, et al, 2018a; Guo, Chen, Zhou, et al, 2018b). In general, the “lost beat” effect of the high‐frequency sea‐level change was limited during the deposition of the Yijianfang Formation (Laya, Tucker, & Perez‐Huerta, 2013).…”

“…Fischer plots were first proposed by Fischer in 1964 when studying the Lofer cycles of the Dachstein Limestone section of the Triassic tidal flat facies in Austria (Fischer, 1964). Subsequently, they were eventually utilized by many scholars for studies of carbonate cyclic sequences (Gale et al, 2002; Guo et al, 2018a, 2018b; Mei, 1995). Traditionally, Fischer plots have been used to determine long‐term changes and the magnitude of fluctuations in relative sea level (e.g., Osleger & Read, 1991; Read & Goldhammer, 1988).…”

“…Fischer plots were first proposed by Fischer in 1964 when studying the Lofer cycles of the Dachstein Limestone section of the Triassic tidal flat facies in Austria (Fischer, 1964). Subsequently, they were eventually utilized by many scholars for studies of carbonate cyclic sequences (Gale et al, 2002;Guo et al, 2018aGuo et al, , 2018bMei, 1995).…”