scholarly journals Slip history of the La Cruz fault: Development of a late Miocene transform in response to increased rift obliquity in the northern Gulf of California

2016 ◽  
Vol 693 ◽  
pp. 409-435 ◽  
Author(s):  
Scott E.K. Bennett ◽  
Michael E. Oskin ◽  
Alexander Iriondo ◽  
Michael J. Kunk
Keyword(s):  
Late Miocene ◽  
Gulf Of California ◽  
Slip History ◽  
History Of

scholarly journals Late Miocene hinterland crustal shortening in the Longmen Shan thrust belt, the eastern margin of the Tibetan Plateau

2020 ◽  
Author(s):  
Xiaoming Shen ◽  
Yuntao Tian ◽  
Shimin Zhang ◽  
Andrew Carter ◽  
Barry Kohn ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Late Miocene ◽  
Hanging Wall ◽  
The Tibetan Plateau ◽  
Eastern Tibetan Plateau ◽  
Crustal Shortening ◽  
2008 Wenchuan Earthquake ◽  
Slip History ◽  
History Of ◽  
Geodynamic Models

<p>Long‐term (million year time scale) fault‐slip history is crucial for understanding the processes and mechanisms of mountain building in active orogens. Such information remains elusive in the Longmen Shan, the eastern Tibetan Plateau margin affected by the devastating 2008 Wenchuan earthquake. While this event drew attention to fault deformation on the foreland side (the Yingxiu‐Beichuan fault), little is known about the deformation history of the hinterland Wenchuan‐Maoxian fault. To address this gap, thermochronological data were obtained from two vertical transects from the Xuelongbao massif, located in the hanging wall of the Wenchuan‐Maoxian fault. The data record late Miocene rapid cooling and rock exhumation at a rate of 0.9–1.2 km/m.y. from ~13 Ma to present. The exhumation rate is significantly higher than that in the footwall (~0.3–0.5 km/m.y.), indicating a differential exhumation of ~0.6 km/m.y. across the fault. This differential exhumation provides the first and minimum constraint on the long‐term throw rate (~0.6 km/m.y) of the Wenchuan‐Maoxian fault since the late Miocene. This new result implies continuous crustal shortening along the hinterland fault of Longmen Shan, even though it has not been ruptured by major historic earthquakes. Our study lends support to geodynamic models that highlight crustal shortening as dominating deformation along the eastern Tibetan Plateau.</p>

QUATERNARY SLIP HISTORY OF THE SANTA SUSANA FAULT, WESTERN TRANSVERSE RANGES, CALIFORNIA

2019 ◽  
Author(s):  
Reed J. Burgette ◽  
◽  
Jonathan J. Ingram ◽  
Michael P. Reed ◽  
Katherine M. Scharer ◽  
...  
Keyword(s):  
Transverse Ranges ◽  
Slip History ◽  
History Of

Paleoaltitudinal histories for the northern and southern margins of the Tibetan Plateau during the Late Cenozoic: revealed by GDGTs

2021 ◽  
Author(s):  
Chihao Chen ◽  
Yan Bai ◽  
Xiaomin Fang ◽  
Haichao Guo ◽  
Weilin Zhang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Late Miocene ◽  
Global Climate ◽  
The Tibetan Plateau ◽  
Lake Surface ◽  
Terrestrial Organic Matter ◽  
Plant Fossils ◽  
History Of ◽  
Monsoon System ◽  
Uplift History

<p>As an important driver of global climate change during the Cenozoic, the uplift of the Tibetan Plateau (TP) has strongly influenced the origination and evolution of the Asian monsoon system, and therefore the aridification of central Asia. Over the last two decades, the application of stable isotope paleoaltimeters and the discoveries of mammal and plant fossils have greatly promoted the understanding of the uplift history of the TP. However, paleoaltitudinal reconstructions based on different paleoaltimeters have suggested differing outcomes and therefore remain controversial. Novel paleoaltimeters have therefore needed to be developed and applied to constrain the uplift history of the TP more accurately and effectively by comparing and verifying multi-proxies. Paleothermometers based on glyceryl dialkyl glycerol tetraethers (GDGTs) are widely used in terrestrial and ocean temperature reconstructions. In this study, GDGT-based paleothermometers were tentatively applied to the Gyirong Basin on the southern TP, and the Xining Basins on the northern TP, in an attempt to quantitatively reconstruct their paleoaltitudes.</p><p>Both soil and aquatic-typed branched GDGTs have been identified from Late Miocene to Mid-Pliocene (7.0-3.2 Ma) samples taken from the Gyirong Basin; their reconstructed paleotemperatures were 7.5±3.3°C and 14.2±4.5°C, respectively. The former temperature may represent the mean temperature of the terrestrial organic matter input area, while the latter may represent the lake surface temperature. The results would suggest that the lake surface of the Gyirong Basin during the Late Miocene to Mid-Pliocene was 2.5±0.8 km and that the surrounding mountains exceeded 3.6±0.6 km, implying that the central Himalayas underwent a rapid uplift of ~1.5 km after the Mid-Pliocene.</p><p>GDGT-based paleotemperature reconstructions using MBT'<sub>5ME</sub> values show that the Xining Basin dropped in temperature by ~10°C during the ~10.5-8 Ma period, exceeding that in sea surface temperatures and low-altitude terrestrial temperatures during these periods. By combining these results with contemporaneous tectonic and sedimentary records, we infer that these cooling events signaled the regional uplift with the amplitude of ~1 km of the Xining basins. Our results support that the TP was still growing and uplifting substantially since the Late Miocene, which may provide new evidence for understanding the growth, expansion and uplift patterns of the TP.</p>

Ancestors

Horse Nations ◽  
2015 ◽  
Author(s):  
Peter Mitchell
Keyword(s):  
Late Miocene ◽  
Lower Limb ◽  
Greek Myth ◽  
Genetic Studies ◽  
The Third ◽  
Supernatural Power ◽  
History Of ◽  
Key Features ◽  
Similar Body ◽  
Taxonomic Order

In Greek myth the winged horse Pegasus was actually ridden by the hero Bellerophon rather than by Perseus, yet Shakespeare’s words neatly capture the striking combination of supernatural power and tractability that is the horse. This chapter picks up these themes by developing three topics: it describes the evolution of the modern horse, Equus caballus, identifies key features of its biology relevant to subsequent discussions, and reviews the history of human–horse interaction in the Old World, emphasizing the horse’s domestication and subsequent spread. Horses and their relatives, the wild asses and zebras, were once seen as an almost paradigmatic example of how evolution works, although more recent research has shown that their history is more complex and multi-branched than originally thought. Along with tapirs and rhinoceroses, they belong to the taxonomic order Perissodactyla, the odd-toed division of the ungulates or hoofed mammals. The superficial similarities that they share with even-toed antelopes, which belong to the order Artiodactyla, are thus largely the result of evolution converging on similar body plans. In fact, some genetic studies suggest that perissodactyls are closer to carnivores than to the artiodactyls. Like modern tapirs and rhinoceroses, the earliest horses were three-toed, but for the past 40 million years or so all have borne their weight on just the third toe, with ligaments, rather than a fleshy pad, for support. Subsequently, the central metapodial (the bones connecting the digits to the wrist or ankle) was considerably elongated to form a long, slender lower limb and the second and fourth digits were minimized, though still giving support when galloping and jumping. Beginning around 10 million years ago, in the late Miocene period, the remaining side toes were reduced to splints and the animal’s weight came to be carried entirely on a single enlarged hoof. The first perissodactyls were browsers, not grazers. Some 45–34 million years ago, however, temperatures fell at higher latitudes and climate became more seasonal: successful ungulates evolved new adaptations, including the first appearance of both ruminants (which ferment their food in a specialized foregut) and new kinds of ancestral horses such as Mesohippus and its successor Miohippus.

Initiation and Long-Term Slip History of the Altyn Tagh Fault

2001 ◽  
Vol 43 (12) ◽  
pp. 1087-1093 ◽  
Author(s):  
Yongjun Yue ◽  
Bradley D. Ritts ◽  
Stephan A. Graham
Keyword(s):  
Altyn Tagh Fault ◽  
Altyn Tagh ◽  
Slip History ◽  
History Of

HYDROCARBON-RELATED DIAGENETIC ZONES (HRDZs) IN THE VULCAN SUB-BASIN, TIMOR SEA: RECOGNITION AND EXPLORATION IMPLICATIONS

1995 ◽  
Vol 35 (1) ◽  
pp. 220 ◽  
Author(s):  
G.W. O'Brien ◽  
E.P. Woods
Keyword(s):  
Late Miocene ◽  
Predictive Tool ◽  
Hydrocarbon Migration ◽  
Areal Distribution ◽  
Carbon Isotopic ◽  
Individual Structure ◽  
History Of ◽  
Timor Sea ◽  
Two Stages ◽  
Migration Pathways

Within very localised areas of the Vulcan Subbasin, the Eocene Grebe Formation sandstones are strongly cemented with carbonate. These cemented sands are recognisable on seismic data as zones of anomalously high velocity, and result in both time 'pull-up' and deterioration of the stack response in the underlying section.To determine the nature and origin of these cemented zones, their isotopic, mineralogical and petrologic compositions have been characterised, their seismic response and areal distribution established, and these observations integrated with ~2,730 km of AGSO water column geochemical ('sniffer-type') data.The carbon isotopic compositions of the carbonate within the cemented Grebe sands are diagnostic of carbonates formed principally via the oxidation of migrating, thermogenic hydrocarbons. Oxidation of the hydrocarbons took place in two stages: an earlier phase led to calcite precipitation, whereas a later phase produced (generally subsidiary) ferroan dolomite/ankerite cementation.Areas of known, present-day hydrocarbon seepage from the seafloor, such as over major faults on the Skua Horst and along the Vulcan Sub-basin/ Londonderry High boundary zone, are invariably associated with zones of highly cemented Eocene sands. Similarly, areas of known Tertiary hydrocarbon seepage, such as those associated with the residual oil columns on the Eider Horst, also contain strongly cemented Eocene sandstones.These observations have established a causal relationship between the presence of these Hydrocarbon-Related Diagenetic Zones (or HRDZs) in the Eocene sandstones and Tertiary-Quaternary hydrocarbon seepage. It is likely that most of the cementation occurred during the Late Miocene/Early Pliocene, when the Grebe Formation sands were at a shallow depth of burial(Recognition of this causal association has allowed several insights to be gained into the exploration potential and reactivation history of structures within the Vulcan Sub-basin. Mapping of the areal distribution of the cemented zones can effectively define hydrocarbon migration pathways. More importantly, however, predictable relationships exist between the seismic expression of the HRDZs, the total amount of hydrocarbons that have leaked from the traps, and the obliquity between the Jurassic and Late Miocene fault trends over the respective structures. A continuum exists between highintegrity accumulations, in which the fault trends are parallel and the HRDZs are small or absent, and breached accumulations, in which a significant obliquity exists between the respective fault trends and the HRDZs are large and seismically-intense.These observations provide a potential predictive tool for evaluating undrilled structures. It may be possible to determine, from the integration of seismic structural mapping and the characterisation of the seismic expression of the HRDZs, not only whether an individual structure is ever likely to have had a hydrocarbon column, but whether that column is likely to be preserved.

The late Miocene to Pleistocene ice-rafting history of southeast Greenland

Boreas ◽  
2008 ◽  
Vol 31 (1) ◽  
pp. 28-35 ◽  
Author(s):  
KRISTEN E. K. ST. JOHN ◽  
LAWRENCE A. KRISSEK
Keyword(s):  
Late Miocene ◽  
History Of ◽  
Ice Rafting
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