A magnetostratigraphic record of landscape development in the eastern Ordos Plateau, China: Transition from Late Miocene and Early Pliocene stacked sedimentation to Late Pliocene and Quaternary uplift and incision by the Yellow River

Geomorphology ◽  
2011 ◽  
Vol 125 (1) ◽  
pp. 225-238 ◽  
Author(s):  
Baotian Pan ◽  
Zhenbo Hu ◽  
Junping Wang ◽  
Jef Vandenberghe ◽  
Xiaofei Hu
2020 ◽  
Author(s):  
Ke Zhang ◽  
Hao Liang ◽  
Zhongyun Li

<p>The Yellow River, as the one of the largest rivers in the world, is considered to be formed by connection of several gorges and basins in between triggered by uplift of Tibetan Plateau. The Junshan Gorge with 600km length is the longest one and it lower gorge, the Senmen Gorge, is the last one for the River feeds into the great north China fluvial plain. This two Gorges used to be the last obstacle for the river running into the sea. In order to better understand the river processes, the Hetao Basin-Jinshan Gorge-Fenwei Basin-Sanmen Gorge-fluvial plain is taken as a whole river-lake system. Under this idea, the unexpected but reasonable complex evolution history of the river-lake system has been reconstructed, and more general evolutional laws for the big river under the tectonic activity and climate change regimes are revealed. In the study area, the terraces can be classified into iso-chronological and meta-chronological ones. Tectonic uplift results in knickpoint headward migration and forms meta-chronological terrace covered by increasing younger paleosol-loess sequences upstream but in most chance by paleosol in Quaternary because of faster and stronger carving during interglacial than glacial periods. The connection between the paleo-lake and its lower gorge form iso-chronological terrace along the gorge but meta-chronological terrace ahead of the gorge. The drainage for the Fenwei paleo-lake into the Sanmen Gorge was earlier (ca. 200ka) than that of the Hetao paleo-lake into the Jinshan Gorge (ca. 100ka), leading to the iso-chronological terrace covered by the paleosol S<sub>2</sub> along the Sanmen Gorge while iso-chronological terrace covered by the paleosol S<sub>1</sub> from the Jinshan Gorge, Fenwei Basin to Sanmen Gorge. Drainage of the Fenwei Basin resulted in the base level lowering and affected all the rivers that fed into the basin, while drainage of the Hetao Basin only affected the main course of the Jinshan and Sanmen Gorges, resulting in many "suspended valleys" along the gorge where the tributaries fed into because they could not keep pace of the main course incision. The Yuncheng Salt Lake is a relic of Fenwei paleo-lake after the drainages. The Jinshan Gorge is superposed by the broad, V-shape and vertical valleys, respectively. The broad valley was formed by the ancient meandering channel shifting in Pliocene and initial incised in late Pliocene to early Pleistocene, leaving relic meta-chronological terraces covered by the late Pliocene red clay or early Pleistocene loess, and forming popular incised meanderings. The V-shape valley was formed by increasing down cutting initially in middle Early Pleistocene, leaving series of meta-chronological terraces covered by loess-paleosol sequence. The vertical valley was formed by the connection between the gorges and their upper paleo-lakes, leaving iso-chronological terraces covered by S<sub>2</sub> or S<sub>1</sub>. Before river-lake connection, the Jinshan and Sanmen Gorges were affected by slowly tectonic uplift plus periodic climate changes, forming several levels of meta-chronological terraces while after the connection, they were cut down quickly since sharp discharge increased. Comparing with this down cutting, the tectonic uplifts and periodic climate changes could be neglected.</p>


2019 ◽  
Vol 20 (3) ◽  
pp. 143
Author(s):  
Agus Handoyo Harsolumakso ◽  
Dardji Noeradi ◽  
Alfend Rudyawan ◽  
Dadan Amiarsa ◽  
Satryo Wicaksono ◽  
...  

The Tertiary stratigraphy of Situbondo was constructed by a series of volcanoclastic-carbonate turbidite facies of Menuran Formation with Pacalan limestone Member, and Leprak Formation. These formations formed a regional east-west trending circular anticlinorium. The Tertiary formations were covered by Quaternary volcano-clastic Ringgit Formation and subsequent younger Bagor volcanic products. The oldest Tertiary rock units are the Late Miocene-Pliocene Menuran Formation, with Pacalan Limestone Member. Formation is mainly composed of foram-rich marls and calcareous, sometimes tuffaceous sandstones, with conglomerate intercalations. Sedimentation of this formation is interpreted as to be a mixing, from proximal to distal turbidite, involving volcaniclastic and carbonate sources, in  a bathyal open marine environment. The Early Pliocene Leprak Formation overlies conformably the Menuran Formation, which consists of alternating calcareous sandstones and tuff sandstones deposited in a bathyal open marine environment with proximal turbidite mechanism suggesting that basin depocenter was located to the east. Up to Late Pliocene, the region was dominated by developments proximal turbidite volcanoclastic sedimentation of The Leprak Formation, contemporaneous with increasing volcanic activity in the south. Deformation of Plio-Pleistocene in Java is believed to be the last major tectonic period, which forms the west-east trending structures. In Situbondo area, folding structures in this direction involves the Neogene Menuran Formation, Pacalan Member and Leprak Formation. Volcanic activity persists, and increases, with the activity of Ringgit-Beser volcano in Pleistocene. These late events of magmatism, volcanism and uplift were contributed to the last structural configuration of the area.Keyword : Situbondo, structural geology, volcanic-kendeng zone, stratigraphy


1997 ◽  
Vol 71 (4) ◽  
pp. 610-615 ◽  
Author(s):  
T. J. DeVries ◽  
G. J. Vermeij

The new genus Herminespina comprises extinct South American species of “Thais”-like ocenebrine gastropods with prominent colabral folds and a labral spine. Geographic range extensions into Peru are reported for the late Pliocene H. mirabilis and the late Miocene to Pliocene H. philippii, both previously known only from Chile. A new early Pliocene species, H. saskiae, is described from the Sacaco Basin of southern Peru and compared with an early Miocene muricid from Peru and Chile, Acanthina katzi. Herminespina is one of several genera of Neogene muricids in western South America that bear labral spines.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yan-Yan Yan ◽  
Jia-Fu Zhang ◽  
Gang Hu ◽  
Li-Ping Zhou

AbstractThe precise chronology of the fluvial terraces of the Yellow River in China is essential to understand its geomorphological evolution history. More terrace ages are needed for the correlation of the terraces along the river and the construction of the longitudinal profile. In this study, seven terraces (T1–T7) in the Heiyukou area of the Jinshaan Canyon of the river were identified and were sampled for optical dating. The reliability of the ages was evaluated on the bases of bleachability, comparison of optical ages on fine and coarse grains, stratigraphic consistency of OSL ages, age distribution and geomorphological setting. The results show that the paired T2 terrace was formed at 72 ± 3 ka, and the T4, T5 strath terraces were dated to 108 ± 4 and >141 ± 4 ka, respectively. The ages for the samples from T6 and T7 were significantly underestimated, and the ‘infinitely old’ pre-Quaternary Red-Clay sample on the T7 terrace was dated to 134 ± 6 ka. The long-term river incision rates were calculated to be <0.36, 0.34 and 0.18 mm/a for at least the past 141, 108 and 72 ka, respectively, which also reflect the uplift rates of the Ordos plateau. The implication for dating terrace deposits is that terraces should be systemically sampled and dated using both fine and coarse grain fractions. The reliability of the ages obtained for high terraces should be evaluated using a relative chronology of dated samples on a case-by-case basis, if no independent numerical age controls are available.


1997 ◽  
Vol 45 (3) ◽  
pp. 425 ◽  
Author(s):  
M. K. Macphail

Australian sites that are claimed to preserve evidence of fossil spores and pollen for Late Neogene (Late Miocene, Pliocene) climates, mostly lack one or both of the prerequisites, i.e. accurate dating and continuous preservation of plant microfossils. Nevertheless, the available data confirm that climatic gradients closely parallelled those of the present day in direction although not in strength: broad-scale vegetation successions are ecologically consistent with long-term cooling and (middle to high latitudes) drying trends in global climate. Although it is rarely possible to establish precise meteorological values for the individual sites along these gradients, climatic envelopes can be estimated for many localities. For example, during the Late Miocene–Pliocene, mean annual precipitation along the northern margin appear to range from 600 mm to 1500 mm in the Kimberley region of north-western Western Australia to above 2000–3000 mm on the Atherton Tableland, north-eastern Queensland. If these and other estimates are correct, then environments along the northern margin show only gradual (unidirectional?) change or did not fall below biologically critical thresholds during the Late Miocene and Early Pliocene but began to approach modern values during Late Pliocene time. Whether the observation implies that meteorological controls at this time were similar to modern synoptic scale systems is unknown. Climates along the southern margin were more labile. For example, there is unequivocal evidence that Early Pliocene climates in the Bass Strait region were effectively more humid and warmer than at present, possibly resembling conditions now found on the northern New South Wales and southern Queensland coast. This phase was preceded (weak evidence) and succeeded (strong evidence) by less temperate conditions during the Late Miocene and Late Pliocene respectively. Forcing factors appear to include changes in relative sea level, orographic effects and, speculatively, remote events such as the isolation and reconnection of the Mediterranean Sea to the world ocean. One promising direction for future research is provided by a recently located onshore basin in Western Australia which preserves an extraordinarily long (100 m), detailed sequence of Late Neogene palynofloras.


2008 ◽  
Vol 82 (2) ◽  
pp. 436-441 ◽  
Author(s):  
Raef Minwer-Barakat ◽  
Antonio García-Alix ◽  
Elvira Martín-Suárez ◽  
Matthijs Freudenthal

The Genus Micromys includes a single extant species, Micromys minutus (Pallas, 1771), which lives in Europe and North Asia. This genus is known in the fossil record since the late Miocene; eight fossil species have been described in Europe and Asia, most of them of late Miocene and early Pliocene age. The evolution of this genus during the late Pliocene is barely known. Although it is present in numerous localities of this age, remains of Micromys are usually scarce and generally assigned to the species M. minutus or M. praeminutus Kretzoi, 1959.


2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Adan Alejo Tauber ◽  
Federico Álvarez ◽  
Gastón Martínez ◽  
José Augusto Haro ◽  
Jerónimo Matías Krapovickas ◽  
...  

New fossil remains were found in Neogene and quaternary sedimentary sequences exposed in Alpa Corral and río San Bartolomé localities (Rio Cuarto Department, Córdoba, Argentina). They were assigned to Nopachtus cabrerai (Xenarthra, Cingulata, Glyptodontidae), Notiomastodon platensis (Proboscidea, Gomphotheriidae) and cf. Trigodon gaudryi (Notoungulata, Toxodontidae), and traces of the Scoyenia ichnofacies, as Taenidium barretti, were identified. Based on these findings, we conclude that: 1, the species Nopachtus cabrerai and cf. Trigodon gaudryi are registered for the first time in the Sierras Pampeanas region and support (along with the rest of the known taxa) a clear faunistic similarity to the Pampean region; 2, the beginning of the Neogene sedimentation in the Alpa Corral area (Las Barrancas river and San Bartolome river) would have started during the early Pliocene (Montehermosan Age); 3, the paleoenvironment would have been a fluvial system, with meandering canals interspersed with paleosols developed in floodplains with overflow deposits or abandoned meanders; 4, the paleontological and sedimentary record suggests a well-marked diachronism (from west-southwest to east-northeast) between the beginning of the Neogene sedimentation in the southern sector of San Alberto valley (late Miocene [Huayquerian Age]), the Alpa Corral region (early Pliocene [Monthermosan Age), and Río La Cruz valley (late Pliocene [Chapadmalalan Age]).


2020 ◽  
Vol 3 (1) ◽  
pp. 17 ◽  
Author(s):  
Jia-Fu Zhang ◽  
Wei-Li Qiu ◽  
Gang Hu ◽  
Li-Ping Zhou

Dating fluvial terraces has long been a challenge for geologists and geomorphologists, because terrace straths and treads are not usually directly dated. In this study, the formation ages of the Yellow River terraces in the Baode area in China were determined by dating fluvial deposits overlying bedrock straths using optically stimulated luminescence (OSL) dating techniques. Seven terraces (from the lowest terrace T1 to the highest terrace T7) in the study area were recognized, and they are characterized by thick fluvial terrace deposits overlaid by loess sediments. Twenty-five samples from nine terrace sections were dated to about 2–200 ka. The OSL ages (120–190 ka) of the fluvial samples from higher terraces (T3–T6) seem to be reliable based on their luminescence properties and stratigraphic consistency, but the geomorphologic and stratigraphic evidence show that these ages should be underestimated, because they are generally similar to those of the samples from the lower terrace (T2). The formation ages of the terrace straths and treads for the T1 terrace were deduced to be about 44 ka and 36 ka, respectively, based on the deposition rates of the fluvial terrace deposits, and the T2 terrace has the same strath and tread formation age of about 135 ka. The incision rate was calculated to be about 0.35 mm/ka for the past 135 ka, and the uplift rate pattern suggests that the Ordos Plateau behaves as a rigid block. Based on our previous investigations on the Yellow River terraces and the results in this study, we consider that the formation ages of terrace straths and treads calculated using deposition rates of terrace fluvial sediments can overcome problems associated with age underestimation or overestimation of strath or fill terraces based on the single age of one fluvial terrace sample. The implication is that, for accurate dating of terrace formation, terrace sections should be systematically sampled and dated.


2019 ◽  
Vol 20 (3) ◽  
pp. 143
Author(s):  
Agus Handoyo Harsolumakso ◽  
Dardji Noeradi ◽  
Alfend Rudyawan ◽  
Dadan Amiarsa ◽  
Satryo Wicaksono ◽  
...  

The Tertiary stratigraphy of Situbondo was constructed by a series of volcanoclastic-carbonate turbidite facies of Menuran Formation with Pacalan limestone Member, and Leprak Formation. These formations formed a regional east-west trending circular anticlinorium. The Tertiary formations were covered by Quaternary volcano-clastic Ringgit Formation and subsequent younger Bagor volcanic products. The oldest Tertiary rock units are the Late Miocene-Pliocene Menuran Formation, with Pacalan Limestone Member. Formation is mainly composed of foram-rich marls and calcareous, sometimes tuffaceous sandstones, with conglomerate intercalations. Sedimentation of this formation is interpreted as to be a mixing, from proximal to distal turbidite, involving volcaniclastic and carbonate sources, in  a bathyal open marine environment. The Early Pliocene Leprak Formation overlies conformably the Menuran Formation, which consists of alternating calcareous sandstones and tuff sandstones deposited in a bathyal open marine environment with proximal turbidite mechanism suggesting that basin depocenter was located to the east. Up to Late Pliocene, the region was dominated by developments proximal turbidite volcanoclastic sedimentation of The Leprak Formation, contemporaneous with increasing volcanic activity in the south. Deformation of Plio-Pleistocene in Java is believed to be the last major tectonic period, which forms the west-east trending structures. In Situbondo area, folding structures in this direction involves the Neogene Menuran Formation, Pacalan Member and Leprak Formation. Volcanic activity persists, and increases, with the activity of Ringgit-Beser volcano in Pleistocene. These late events of magmatism, volcanism and uplift were contributed to the last structural configuration of the area.Keyword : Situbondo, structural geology, volcanic-kendeng zone, stratigraphy


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