Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1130/B31553.1 |
Growth of the paleo-Orinoco shelf-margin prism: Process regimes, delta evolution, and sediment budget beyond the shelf edge | |
Chen, Si1,2; Steel, Ron2; Olariu, Cornel2,3; Li, Shunli4 | |
2018 | |
发表期刊 | GEOLOGICAL SOCIETY OF AMERICA BULLETIN
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ISSN | 0016-7606 |
EISSN | 1943-2674 |
出版年 | 2018 |
卷号 | 130页码:35-63 |
文章类型 | Article |
语种 | 英语 |
国家 | Peoples R China; USA; Romania |
英文摘要 | The first sedimentological characterization and correlation of onshore outcrop and offshore subsurface data (southern Columbus Basin) are presented for the paleo-Orinoco (Upper Miocene-Pliocene) shelf-margin prism, Trinidad Island, Trinidad and Tobago. The paleo-Orinoco River delta system and associated continental slope, which generated the 10-km-thick sedimentary prism, was a mixed river, tide, wave, and - sediment-gravity flow system that tracked down to deep-water submarine fans. The analysis here includes: (1) an evaluation of delta-plain to deep-water turbidite sedimentary facies, which are seen in spectacular outcrops along the southwest, south, and southeast coasts of Trinidad Island, (2) well-log correlation of the same Upper Miocene-Pliocene strata across southern Trinidad and out to the southern part of the offshore Columbus Basin along an off-axis transect, because the main fairway into the most rapidly subsiding part of Columbus Basin is structurally complex, and few detailed data have been released for publication; and (3) use of published seismic data for reconstruction of clinoform morphology across the relatively undeformed segment of the margin, with quantitative sediment flux calculations and predictions. Paleo-Orinoco shelf-margin growth was generated by repeated (similar to< 100 k.y. time scale) cross-shelf, regressive-transgressive transits (> 100 km) of the Orinoco delta system, with internal variability in clinoform architecture and process-regime changes during shelf-margin construction. The Upper-Miocene-Pliocene prism, with its linkage to the southern Columbus Basin and Columbus Channel, is composed of four progradational clastic wedges, each with a thickness up to 2 km, separated by well-known, Trinidad-wide marine flooding intervals of similar extent, followed by an aggradational wedge with decreased clinothem thickness. The studied sedimentary prism spans an similar to 4 m.y. period and shows an overall rising shelf-edge trajectory, despite an overall and periodic falling eustatic sea level during this global icehouse period. The relationships among the Orinoco paleoflux, shelf-edge trajectory, and clinoform height and shape are discussed for a southeastern segment of the margin that is much less deformed than the main growth-faulted Columbus Basin. However, this off-axis segment was also subject to severe tectonic subsidence, as well as high-frequency sea-level, climate, and sediment supply changes. The estimated sediment flux percentage at the shelf edge shows a similar time trend to that of the well-imaged shelf-edge trajectory. The latter shows three long-term (similar to 0.5 m.y.) trajectory changes, whereas the estimated sediment flux percentage at the shelf edge shows three supply pulses ( with shelf-edge flux varying between 40% and 91% of original sediment discharge) through the early Pliocene, with nearly 76% of the sediment on average transported beyond the shelf edge to the deep-water areas, despite a relatively wide shelf. This sediment flux calculation, and particularly the occurrence of flat segments along the shelf-edge trajectory, predicts significant sediment bypass to slope or basin-floor fans on or beyond the toesets of the paleo-Orinoco shelf margin. At short time scales, the variation in the percentage of sediment budget bypassing the shelf edge depends on a series of shelf parameters. However, at geologic time scale, the total sediment flux bypassing the shelf edge is two thirds to three quarters of the total sediment budget. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000418364200003 |
WOS关键词 | SEQUENCE-STRATIGRAPHIC INTERPRETATION ; MORNE LENFER FORMATION ; SEA-LEVEL CHANGE ; OFFSHORE TRINIDAD ; COLUMBUS BASIN ; WEST-INDIES ; DEPOSITIONAL SYSTEMS ; TECTONIC HISTORY ; PETROLEUM SYSTEM ; SUBMARINE FANS |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/24787 |
专题 | 地球科学 |
作者单位 | 1.China Univ Geosci, Key Lab Tecton & Petr Resources, Minist Educ, Wuhan 430074, Hubei, Peoples R China; 2.Univ Texas Austin, Jackson Sch Geosci, Austin, TX 78712 USA; 3.Natl Inst Marine Geol & Geoecol GEOECOMAR, RO-024053 Bucharest, Romania; 4.China Univ Geosci, Sch Energy Resources, Beijing 100083, Peoples R China |
推荐引用方式 GB/T 7714 | Chen, Si,Steel, Ron,Olariu, Cornel,et al. Growth of the paleo-Orinoco shelf-margin prism: Process regimes, delta evolution, and sediment budget beyond the shelf edge[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2018,130:35-63. |
APA | Chen, Si,Steel, Ron,Olariu, Cornel,&Li, Shunli.(2018).Growth of the paleo-Orinoco shelf-margin prism: Process regimes, delta evolution, and sediment budget beyond the shelf edge.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,130,35-63. |
MLA | Chen, Si,et al."Growth of the paleo-Orinoco shelf-margin prism: Process regimes, delta evolution, and sediment budget beyond the shelf edge".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 130(2018):35-63. |
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