Mesozoic-Cenozoic denudation history of the Patagonian Andes (southern Chile) and its correlation to different subduction processes

Tectonics ◽  
2001 ◽  
Vol 20 (5) ◽  
pp. 693-711 ◽  
Author(s):  
Stuart N. Thomson ◽  
Francisco Hervé ◽  
Bernhard Stöckhert
Keyword(s):  
Southern Chile ◽  
History Of ◽  
Patagonian Andes

scholarly journals Discovery of Late Triassic fossils in the Chonos Metamorphic Complex, Southern Chile

2010 ◽  
Vol 25 (2) ◽  
pp. 165
Author(s):  
Zong-jie Fang ◽  
Arthur Boucot ◽  
Vladimir Covacevich ◽  
Francisco Herve
Keyword(s):  
Early Carboniferous ◽  
Late Triassic ◽  
Metamorphic Complex ◽  
Southern Chile ◽  
Geologic History ◽  
The North ◽  
Depositional Processes ◽  
History Of ◽  
Southwestern Margin ◽  
Early Late

The late Triassic bivalve Monotis (Pacimonotis) aff. subcircularis Gabb indicative of a Norian (probably early late Norian) age has been collected from the southeastern end of Patranca Island (45º25'S-74º09'W) in the Chonos Archipelago, Southern Chile. Another fossil bivalve, Limidae gen. et sp. indet. has been collected from a small unnamed island (45º25'S-74º10'W) 4 km to the north, and indicates a maximum Early Carboniferous, probably Mesozoic age. The fossil bearing unit is the Potranca Formation (or Potranca Unit) which forms part of the Chonos Metamorphic Complex, interpreted as a subduction complex developed on the southwestern margin of Gondwanaland. As these rocks have been previously considered to be of Paleozoic age (Late Silurian-Early Devonian), the geologic history of this part of the continental margin must be reinterpreted. These fossils provide clear evidence that marine depositional processes persisted within the Chonos Metamorphic Complex during Late Triassic time.

Systematic revision of the South American genus Praocis Eschscholtz, 1829 (Coleoptera: Tenebrionidae). Part 1: Introduction and subgenus Praocis s. str.

Zootaxa ◽  
2012 ◽  
Vol 3336 (1) ◽  
pp. 1 ◽  
Author(s):  
GUSTAVO E. FLORES ◽  
JAIME PIZARRO-ARAYA
Keyword(s):  
South American ◽  
Scanning Electron Micrographs ◽  
Southern Chile ◽  
Systematic Revision ◽  
Distribution Maps ◽  
Representative Species ◽  
Taxonomic Research ◽  
History Of ◽  
Valdivian Forest ◽  
Coleoptera Tenebrionidae

The first part of a revision of the species comprising the genus Praocis Eschscholtz, 1829 (Pimeliinae: Praociini) is present-ed. The history of taxonomic research on Praocis is reviewed. The subgeneric classification is outlined. The subgenusPraocis s. str., distributed in Central and Southern Chile, is revised. Species occur from 26º South to 42º South in the bio-geographic provinces of Atacama, Coquimbo, Santiago, Maule and Valdivian Forest. Included is a redescription of the sub-genus Praocis s. str., redescription of its species, an identification key, habitus photographs of the most representative species,illustrations of external morphology and genital features, scanning electron micrographs of pronotum, head and antenna, as well as distribution maps. Praocis s. str. comprises 18 species, two of which are new: Praocis (Praocis) bicentenario sp.nov. and P. (P.) medvedevi sp. nov. Other species include: Praocis (Praocis) aenea Gay & Solier 1840, P. (P.) costata Gay& Solier 1840, P. (P.) curta Solier 1840, P. (P.) elliptica Philippi & Philippi 1864, P. (P.) hirtella Kulzer 1958, P. (P.) mar-ginata Germain 1855, P. (P.) parva Gay & Solier 1840, P. (P.) quadrisulcata Germain 1855, P. (P.) rufipes Eschscholtz1829 (type species), P. (P.) sanquinolenta Gay & Solier 1840, P. (P.) spinolai Gay & Solier 1840, P. (P.) subaenea Erichson1834, P. (P.) subsulcata Gay & Solier 1840, P. (P.) sulcata Eschscholtz 1829 and P. (P.) tibialis Gay & Solier 1840. Thestatus of P. (P.) bicostata Philippi & Philippi 1864, currently considered a valid name, is discussed. A lectotype is desig-nated for Praocis (P.) laevicosta Curtis 1845 (synonym of P. (P.) subaenea). The subgenus Praocis (Parapraocis) Kulzer 1958 is excluded from Praocis.

Constraints on the timing and isotopic evolution for the 150 my emplacement history of the South Patagonian batholith, Southern Chile

2006 ◽  
Vol 70 (18) ◽  
pp. A164 ◽  
Author(s):  
C.M. Fanning ◽  
F. Hervé ◽  
R.J. Pankhurst ◽  
M. Calderón ◽  
G.M. Yaxley
Keyword(s):  
Southern Chile ◽  
The South ◽  
Isotopic Evolution ◽  
History Of ◽  
History Of The South

scholarly journals Local persistence of Mann’s soft-haired mouse Abrothrix manni (Rodentia, Sigmodontinae) during Quaternary glaciations in southern Chile

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6130 ◽  
Author(s):  
Lourdes Valdez ◽  
Guilermo D’Elía
Keyword(s):  
Demographic History ◽  
Mitochondrial Gene ◽  
Ice Sheets ◽  
Secondary Contact ◽  
Southern Chile ◽  
Geographic Scale ◽  
Climatic Oscillations ◽  
Population Decrease ◽  
History Of ◽  
Valdivian Forest

Quaternary climatic oscillations have impacted Patagonian sigmodontine fauna, leaving traceable genetic footprints. In southern Chile, changes in the landscape included transitions to different vegetation formations as well as the extension of ice sheets. In this study, we focus on the Valdivian forest endemic and recently described sigmodontine species Abrothrix manni. We aim to assess the genetic structure of this species, testing for the existence of intraspecific lineages, and inferring the recent demographic history of the species. Analyses were based on the first 801 bp of the mitochondrial gene Cytocrhome-b from 49 individuals of A. manni collected at 10 localities that covers most part of its geographic distribution. Genealogical analyses recovered two main intraspecific lineages that are geographically segregated and present an intermediate site of secondary contact. Historical demography shows signal of recent population decrease. Based on these results, we proposed that current genetic diversity of A. manni differentiated in at least two distinct refugial areas in southern Chile. This scenario, in addition to be unique among those uncovered for the so far studied Valdivian forest rodents, is noteworthy because of the reduced geographic scale inhabited by the species.

Late Cenozoic geomorphic and tectonic evolution of the Patagonian Andes between latitudes 42°S and 46°S: An appraisal based on fission-track results from the transpressional intra-arc Liquiñe-Ofqui fault zone

2002 ◽  
Vol 114 (9) ◽  
pp. 1159-1173 ◽  
Author(s):  
Stuart N. Thomson
Keyword(s):  
Heat Flow ◽  
Fault Zone ◽  
Tectonic Evolution ◽  
Fission Track ◽  
Strike Slip ◽  
Late Cenozoic ◽  
History Of ◽  
Patagonian Andes ◽  
Digital Landscape ◽  
Fast Rates

Abstract Fission-track (FT) thermochronology has been applied to investigate the low-temperature cooling and denudation history of the Patagonian Andes along the southern part of the intra-arc transpressional Liquiñe-Ofqui fault zone between 42° and 46°S. The Liquiñe-Ofqui fault is shown to have been the focus of enhanced cooling and denudation initiated between ca. 16 and 10 Ma. Several fault blocks with different cooling histories are identified; these are separated by major oblique- or reverse-slip faults proposed to form the eastern part of a major (crustal-scale) dextral transpression zone. Local very fast rates of cooling and denudation between ca. 7 and 2 Ma were coeval with collision of the Chile Rise (an active mid-oceanic ridge) with the Peru-Chile Trench between ∼47° and 48°S. This location is close to the southern termination of the Liquiñe-Ofqui fault, implying that the collision of the ridge was a major force driving late Cenozoic transpression. The lack of significant cooling and denudation before ca. 16 Ma is indicative of pure strike-slip or transtensional movement along the Liquiñe-Ofqui fault before the collision of the ridge. Digital landscape analysis supports glacial and periglacial erosion as the main contributor to denudation since ca. 7 Ma, leading to restriction of topographic development. The combination of transpression-induced rock uplift and glacial erosion is shown to be very effective at causing localized denudation. Anomalously young FT ages along the Liquiñe-Ofqui fault are attributed to the existence of a late Cenozoic localized heat-flow anomaly along the fault.

Sign in / Sign up

Export Citation Format

Share Document