KOPRI Repository

Sedimentary Facies and Architecture of a Gigantic Gravelly Submarine Channel System in a Cretaceous Foredeep Trough (the Magallanes Basin, Southern Chile)

Cited 0 time in scopus
Metadata Downloads
Title
Sedimentary Facies and Architecture of a Gigantic Gravelly Submarine Channel System in a Cretaceous Foredeep Trough (the Magallanes Basin, Southern Chile)
Other Titles
칠레 남단 백악기 마젤란 퇴적분지에 발달하는 대규모 역질 심해수로층의 퇴적상과 층구조
Authors
Cheo, Moon Young
Kim, Young-Hwan G.
Jo, Hyung Rae
SOHN, YOUNGKWAN
Woo, Jusun
Subject
Oceanography
Keywords
architectural element; deep-sea conglomerate; foredeep; submarine channel
Issue Date
2017
Citation
Cheo, Moon Young, et al. 2017. "Sedimentary Facies and Architecture of a Gigantic Gravelly Submarine Channel System in a Cretaceous Foredeep Trough (the Magallanes Basin, Southern Chile)". Ocean and Polar Research, 39: 85-106.
Abstract
The Lago Sofia conglomerate in southern Chile is deep-marine gravelly deposits, which are hundreds of meters thick and kilometers wide and extend laterally for more than 100 km, filling the foredeep trough of the Cretaceous Magallanes Basin. For understanding the depositional processes and environments of this gigantic deep-sea conglomerate, detailed analyses on sedimentary facies, architecture and paleoflow patterns were carried out, highlighting the differences between the northern (Lago Pehoe and Lago Goic areas) and southern (Lago Sofia area) parts of the study area. The conglomerate bodies in the northern part occur as relatively thin (< 100 m thick), multiple units intervened by thick mudstone-dominated sequences. They show paleoflows toward ENE and S to SW, displaying a converging drainage pattern. In the southern part, the conglomerate bodies are vertically interconnected and form a thick (> 400 m thick) conglomerate sequence with rare intervening fine-grained deposits. Paleoflows are toward southwest. The north-to-south variations are also distinct in sedimentary facies. The conglomerate bodies in the southern part are mainly composed of clast-supported conglomerate with sandy matrix, which is interpreted to be deposited from highly concentrated bedload layers under turbidity currents. Those in the northern part are dominated by matrix- to clast-supported conglomerate with muddy matrix, which is interpreted as the products of composite mass flows comprising a turbidity current, a gravelly hyperconcentrated flow and a mud-rich debris flow. All these characteristics suggest that the Lago Sofia conglomerate was formed in centripetally converging submarine channels, not in centrifugally diverging channels of submarine fans. The tributaries in the north were dominated by mass flows, probably affected by channel-bank failures or basin-marginal slope instability processes. In contrast, the trunk channel in the south was mostly filled by tractive processes, which resulted in vertical and lateral accretion of gravel bars, deposition of gravel dunes and filling of scours and channels, similar to deposits of terrestrial gravel-bed rivers. The trunk channel developed along the axis of foredeep trough and its confinement within the trough is probably responsible for the thick, interconnected channel fills. The large-scale architecture of the trunk-channel fills shows an eastward offset stacking pattern, suggesting that the channel migrated eastwards most likely due to the uplift of the Andean Cordillera.
URI
http://repository.kopri.re.kr/handle/201206/6541
DOI
http://dx.doi.org/10.4217/OPR.2017.39.2.085
Files in This Item
General Conditions
      ROMEO Green
    Can archive pre-print and post-print or publisher's version/PDF
      ROMEO Blue
    Can archive post-print (ie final draft post-refereeing) or publisher's version/PDF
      ROMEO Yellow
    Can archive pre-print (ie pre-refereeing)
      ROMEO White
    Archiving not formally supported

    qrcode

    Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

    Browse