scholarly journals A reconstruction of paleoenvironments and climate change during the Late Holocene in Sierra Nevada: the organic and inorganic geochemistry record from the Borreguil de los Lavaderos de la Reina record (southern Iberian Peninsula)

2020 ◽  
Author(s):  
Alejandro J. López-Avilés ◽  
Antonio García-Alix ◽  
Gonzalo Jiménez-Moreno ◽  
Jaime L. Toney ◽  
R. Scott Anderson
Keyword(s):  
Sierra Nevada ◽  
Late Holocene ◽  
Drainage System ◽  
Human Interaction ◽  
Mountain Range ◽  
Sedimentary Record ◽  
The North ◽  
Southern Iberia ◽  
Geochemical Analyses ◽  
Surrounding Areas

<p>Remote small alpine lakes and wetlands from the Sierra Nevada mountain range (southern Spain) are exceptional ecological sensors of global change and preserve a complete post-glacial Holocene sedimentary record. Several organic and inorganic geochemical analyses carried out in the sedimentary record of the Borreguil de los Lavaderos de la Reina, a small bog located in the north face of the Sierra Nevada at 2421 m, have allowed us to reconstruct climate, vegetation and human interaction in the highest mountain range in southern Iberia in the last 3000 years. This study shows that during the Late Holocene there is a progressive climatic aridification, which produced a reduction in the aquatic environments in Sierra Nevada. The studied peat bog geomorphology and surrounding areas also conditioned the evolution of the local vegetation. An increasing trend in the detrital eolian input from northern Africa, as well as an important anthropic impact in the ecosystems (artificial drainage system among other activities) are observed in the studied record in the last century.</p>

Overview of Naturally Occurring Asbestos in California and Southwestern Nevada

2020 ◽  
Vol 26 (1) ◽  
pp. 9-14
Author(s):  
R. Mark Bailey
Keyword(s):  
Sierra Nevada ◽  
North American ◽  
Volcanic Belt ◽  
Island Arc ◽  
North American Plate ◽  
Mountain Range ◽  
The North ◽  
Rock Types ◽  
Naturally Occurring ◽  
Naturally Occurring Asbestos

ABSTRACT Naturally occurring asbestos (NOA) is being discovered in a widening array of geologic environments. The complex geology of the state of California is an excellent example of the variety of geologic environments and rock types that contain NOA. Notably, the majority of California rocks were emplaced during a continental collision of eastward-subducting oceanic and island arc terranes (Pacific and Farallon plates) with the westward continental margin of the North American plate between 65 and 150 MY BP. This collision and accompanying accretion of oceanic and island arc material from the Pacific plate onto the North American plate, as well as the thermal events caused by emplacement of the large volcanic belt that became today's Sierra Nevada mountain range, are the principal processes that produced the rocks where the majority of NOA-bearing units have been identified.

One Hundred Years of Solitude: rediscovery of Catasticta lycurgus (Godman & Salvin, 1880), a yellow butterfly from the Sierra Nevada de Santa Marta, Colombia (Lepidoptera: Pieridae)

Zootaxa ◽  
2021 ◽  
Vol 4975 (1) ◽  
pp. 176-186
Author(s):  
BLANCA HUERTAS ◽  
CARLOS PRIETO ◽  
FREDY MONTERO ◽  
MIKE ADAMS ◽  
JEAN FRANÇOIS LE CROM ◽  
...  
Keyword(s):  
Sierra Nevada ◽  
High Elevation ◽  
Mountain Range ◽  
Conservation Assessment ◽  
The North ◽  
The Andes ◽  
San Pedro ◽  
Systematic Relationships ◽  
The Uk ◽  
First Time

Catasticta lycurgus is a striking endemic butterfly, restricted to high elevation habitats in the Sierra Nevada de Santa Marta, an isolated mountain range separate from the Andes in the north of Colombia. The type, which for almost a hundred years was the only known specimen, was collected in 1878 by Frederick Simons in the vicinity of Atánquez and was sent to the UK to be described by renowned naturalists Godman and Salvin in 1880. In 1972, explorers Adams and Bernard collected a second specimen of C. lycurgus in the locality of San Pedro at 2,900m of elevation in the Sierra Nevada de Santa Marta. These two specimens were the only known ones for many decades until recently, when Colombian entomologists found the species again in San Pedro de la Sierra and later, when a female was discovered in 2013. Here, we report the rediscovery of this rare and charismatic species, with new specimens collected near the type locality, which have not been reported previously. The female of C. lycurgus is described and illustrated for the first time as well the male genitalia of this species. We combine all information available to provide some insights on the systematic relationships of this species within the genus Catasticta Butler, discuss its distribution and provide a preliminary conservation assessment. Despite the newly collected specimens, the species remains very rare in the field and in collections. 

Sierra Motherlode, Domain 2

2007 ◽  
Author(s):  
Earl B. Alexander ◽  
Roger G. Coleman ◽  
Todd Keeler-Wolfe ◽  
Susan P. Harrison
Keyword(s):  
Sierra Nevada ◽  
Western Slope ◽  
Mountain Range ◽  
Serpentine Soils ◽  
East Side ◽  
The West ◽  
Eastern Side ◽  
The North ◽  
Great Valley ◽  
Block Faulting

The Sierra Motherlode domain is in a series of allochthonous terranes, sometimes called the “Foothill Belt,” along the western edge of the north-northwest–south-southeast trending Sierra Nevada, adjacent to the Great Valley of California. It is a discontinuous belt from the southern Sierra Nevada, in Tulare and Fresno counties, to Butte County in the northern Sierra Nevada , but a branch within the belt is practically continuous from El Dorado County about 140 km north to Plumas County at the north end of the range. Cenozoic block faulting has lifted the Sierra Nevada and tilted the mountain range toward the west; therefore the highest elevations are on the east side of the range. Uplift is more pronounced in the southern than in the northern Sierra Nevada. Altitudes range from <200 m adjacent to the Great Valley to more than 4000 m along the crest of the central to southern part of the mountain range. The highest altitudes in the Sierra Motherlode domain are 1939 m (6360 feet) on Red Mountain and 1935 m (6335 feet) on Red Hill in Plumas County, and even higher on some of the granitic plutons that are within the outer limits of the serpentine domain. These plutons were intruded into the allochthonous terranes after the terranes had been accreted onto the continent. Much of the western slope of the northern Sierra Nevada is an undulating to rolling plateau. This plateau is a remnant from the early Tertiary when its surface was deeply weathered to produce lateritic serpentine soils with silica deposited in the subsoils and in fractures in the bedrock (Rice and Cleveland 1955, Rice 1957). The ancient plateau was capped by volcanic flows that produced a practically continuous cover in the northern Sierra Nevada (Durrell 1966). Uplift along the eastern side of the northern part of the Sierra Nevada to initiate its current relief commenced 4 or 5 Ma ago (Wakabayashi and Sawyer 2001). Since the range began to rise a few million years ago, the larger streams flowing across it have cut deep canyons up to about 600 m below the plateau.

Minimal net incision of the northern Sierra Nevada (California, USA) since the Eocene–early Oligocene

Geology ◽  
2020 ◽  
Vol 48 (10) ◽  
pp. 1023-1027
Author(s):  
Emmanuel J. Gabet ◽  
Daniel P. Miggins
Keyword(s):  
Sierra Nevada ◽  
North American ◽  
Past Century ◽  
Mountain Range ◽  
Late Cenozoic ◽  
North American Cordillera ◽  
The Past ◽  
The North ◽  
Early Oligocene ◽  
Northern Half

Abstract Significant late Cenozoic uplift (&gt;1000 m) of the northern half of the Sierra Nevada (California, USA), a mountain range in the North American Cordillera, has been a dominant paradigm over the past century. This paradigm has been supported by evidence suggesting that in response to this recent uplift, the range’s deep canyons were incised in the past 3–4 m.y. However, paleochannel elevations compiled from a mining report and geological maps demonstrate that while some modern rivers have incised 560 m below their Eocene–early Oligocene riverbeds, incision by others has been &lt;300 m. For example, Eocene–early Oligocene fluvial gravels can be found just 161 m above the modern channel deep within the canyon of the South Fork American River. We conclude that the initiation of late Cenozoic incision was due to a resumption of a period of downcutting that was interrupted in the Eocene when the rivers were buried by fluvial sediment and by later volcanic deposits. This interpretation challenges the hypothesis that recent uplift was responsible for deep canyon incision. Correctly identifying the causes of recent incision in the northern Sierra Nevada has important implications for understanding the geological history of the North American Cordillera because the range is hypothesized to have been the western ramp of the Nevadaplano.

scholarly journals Sedimentary record of coseismic subsidence in Hersek coastal lagoon (Izmit Bay, Turkey) and the late Holocene activity of the North Anatolian Fault

2011 ◽  
Vol 12 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
Sébastien Bertrand ◽  
Lisa Doner ◽  
Sena Akçer Ön ◽  
Ummuhan Sancar ◽  
Ulla Schudack ◽  
...  
Keyword(s):  
Coastal Lagoon ◽  
Late Holocene ◽  
North Anatolian Fault ◽  
Sedimentary Record ◽  
Izmit Bay ◽  
The North ◽  
Holocene Activity ◽  
Coseismic Subsidence

Sedimentary record of late Holocene seismicity and uplift of Hersek restraining bend along the North Anatolian Fault in the Gulf of İzmit

2010 ◽  
Vol 487 (1-4) ◽  
pp. 33-45 ◽  
Author(s):  
Volkan Özaksoy ◽  
Ömer Emre ◽  
Cengiz Yıldırım ◽  
Ahmet Doğan ◽  
Selim Özalp ◽  
...  
Keyword(s):  
Late Holocene ◽  
North Anatolian Fault ◽  
Sedimentary Record ◽  
The North ◽  
Restraining Bend

scholarly journals Hydrogeochemical implications from Ider River in northern Mongolia

2018 ◽  
pp. 45-52
Author(s):  
Alexander Orkhonselenge ◽  
Amgalan-Erdene Nyamjantsan
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Late Holocene ◽  
Drainage Basin ◽  
Solid Wastes ◽  
The North ◽  
Northern Mongolia ◽  
Surface Water Resource ◽  
Anions And Cations ◽  
Geochemical Analyses

This study presents the hydrogeochemical implications resulted from Ider River, one of headwaters of Selenge River in northern Mongolia which is a main headwater of Lake Baikal in southeastern Russia, being included in a drainage basin of the North Arctic Ocean. Surface water and groundwater were collected and estimated with hydrogeochemical analyses of major ionic compositions in order to determine water quality in the catchment of Ider River in northern Mongolia. Result shows that the downstream of Ider River is more polluted than upstream of Ider River and Khunjil River, an inflow of the Ider River. Surface water of Ider River and groundwater in the catchment of the Ider River are comparable with their anions and cations. Ider River is highly enriched with an anion of Cl- in 2-3 times, cations of Na++K+ in 2-3 times and NH4+ in 0.5-1.0 times than those in groundwater in the catchment of Ider River. The hydrogeochemical results show that the surface water of Ider River is mainly polluted by solid wastes along its valley. More investigations with detail geochemical analyses are needed from the large rivers comprising surface water resource in Mongolia to review the hydrological evolution in Mongolia and Central Asia in the late Holocene.

scholarly journals Statherian (ca. 1714–1680 Ma) Extension-Related Magmatism and Deformation in the Southwestern Korean Peninsula and Its Geological Significance: Constraints from the Petrological, Structural, Geochemical and Geochronological Studies of Newly Identified Granitoids

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 557
Author(s):  
Byung-Choon Lee ◽  
Weon-Seo Kee ◽  
Uk-Hwan Byun ◽  
Sung-Won Kim
Keyword(s):  
Korean Peninsula ◽  
Tectonic Setting ◽  
Alkali Feldspar ◽  
Ductile Deformation ◽  
Southwestern Part ◽  
The North ◽  
Deformation Event ◽  
Geochemical Analyses ◽  
A Minor ◽  
T Values

In this study, petrological, structural, geochemical, and geochronological analyses of the Statherian alkali feldspar granite and porphyritic alkali feldspar granite in the southwestern part of the Korean Peninsula were conducted to examine petrogenesis of the granitoids and their tectonic setting. Zircon U-Pb dating revealed that the two granites formed around 1.71 Ga and 1.70–1.68 Ga, respectively. The results of the geochemical analyses showed that both of the granites have a high content of K2O, Nb, Ta, and Y, as well as high FeOt/MgO and Ga/Al ratios. Both granites have alkali-calcic characteristics with a ferroan composition, indicating an A-type affinity. Zircon Lu-Hf isotopic compositions yielded negative εHf(t) values (−3.5 to −10.6), indicating a derivation from ancient crustal materials. Both granite types underwent ductile deformation and exhibited a dextral sense of shear with a minor extension component. Based on field relationships and zircon U-Pb dating, it was considered that the deformation event postdated the emplacement of the alkali feldspar granite and terminated soon after the emplacement of the porphyritic alkali feldspar granite in an extensional setting. These data indicated that there were extension-related magmatic activities accompanying ductile deformation in the southwestern part of the Korean Peninsula during 1.71–1.68 Ga. The Statherian extension-related events are well correlated with those in the midwestern part of the Korean and eastern parts of the North China Craton.

scholarly journals Vulnerability of the North Water ecosystem to climate change

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sofia Ribeiro ◽  
Audrey Limoges ◽  
Guillaume Massé ◽  
Kasper L. Johansen ◽  
William Colgan ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Late Holocene ◽  
Sediment Cores ◽  
Arctic Ecosystems ◽  
Little Auk ◽  
The North ◽  
Water Ecosystem ◽  
North Water

AbstractHigh Arctic ecosystems and Indigenous livelihoods are tightly linked and exposed to climate change, yet assessing their sensitivity requires a long-term perspective. Here, we assess the vulnerability of the North Water polynya, a unique seaice ecosystem that sustains the world’s northernmost Inuit communities and several keystone Arctic species. We reconstruct mid-to-late Holocene changes in sea ice, marine primary production, and little auk colony dynamics through multi-proxy analysis of marine and lake sediment cores. Our results suggest a productive ecosystem by 4400–4200 cal yrs b2k coincident with the arrival of the first humans in Greenland. Climate forcing during the late Holocene, leading to periods of polynya instability and marine productivity decline, is strikingly coeval with the human abandonment of Greenland from c. 2200–1200 cal yrs b2k. Our long-term perspective highlights the future decline of the North Water ecosystem, due to climate warming and changing sea-ice conditions, as an important climate change risk.

scholarly journals Detrital zircon provenance of the Late Triassic Songpan-Ganzi complex: Sedimentary record of collision of the North and South China blocks: Comment and Reply: REPLY

Geology ◽  
2006 ◽  
Vol 34 (1) ◽  
pp. e107-e108
Author(s):  
A. L. Weislogel ◽  
S. A. Graham ◽  
E. Z. Chang ◽  
J. L. Wooden ◽  
G. E. Gehrels ◽  
...  
Keyword(s):  
South China ◽  
Detrital Zircon ◽  
Late Triassic ◽  
Sedimentary Record ◽  
The North ◽  
North And South
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