The origin of oriented lakes: evidence from the Bolivian Amazon

Lombardo, Umberto; Veit, Heinz (2014). The origin of oriented lakes: evidence from the Bolivian Amazon. Geomorphology, 204, pp. 502-509. Elsevier Science 10.1016/j.geomorph.2013.08.029

[img] Text
1-s2.0-S0169555X13004340-main.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (1MB) | Request a copy

The presence of hundreds of rectangular and oriented lakes is one of the most striking characteristics of the Llanos de Moxos (LM) landscape in the Bolivian Amazon. Oriented lakes also occur in the Arctic coastal plains of Russia, Alaska and Canada and along the Atlantic Coastal Plain from northeast Florida to southeast New Jersey and along the coast of northeast Brazil. Many different mechanisms have been proposed for their formation. In the LM, Plafker's (1964) tectonic model, in which subsidence results from the propagation of bedrock faults through the foreland sediments, is the most accepted. However, this model has not been verified. Here, we present new results from stratigraphic transects across the borders of three rectangular and oriented lakes in the LM. A paleosol buried under mid-Holocene sediments is used as a stratigraphic marker to assess the vertical displacement of sediments on both sides of the alleged faults. Our results show that there is no vertical displacement and, therefore, that Plafker's model can be ruled out. We suggest that, among all the proposed mechanisms behind lake formation, the combined action of wind and waves is the most likely. The evidence from the LM provides new hints for the formation of oriented lakes worldwide.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geography > Physical Geography > Unit Paleo-Geoecology
08 Faculty of Science > Institute of Geography

UniBE Contributor:

Lombardo, Umberto and Veit, Heinz

Subjects:

900 History > 910 Geography & travel

ISSN:

0169-555X

Publisher:

Elsevier Science

Language:

English

Submitter:

Monika Wälti-Stampfli

Date Deposited:

05 Sep 2014 16:33

Last Modified:

19 Oct 2015 09:40

Publisher DOI:

10.1016/j.geomorph.2013.08.029

BORIS DOI:

10.7892/boris.52413

URI:

https://boris.unibe.ch/id/eprint/52413

Actions (login required)

Edit item Edit item
Provide Feedback