Llanos de Mojos — Cotoca Northern Causeway (Beni Causeway North, Mojos)
Cotoca North Causeway · Moxos Beni Causeway North · Casarabe Northern Causeway
Casarabe (500–1400 CE)·Casarabe·🇧🇴 Beni, Llanos de Mojos, Cotoca region north of Cotoca main plaza northward to forest island, Bolivia
About
About Llanos de Mojos — Cotoca Northern Causeway (Beni Causeway North, Mojos)
Northern causeway emanating from the Cotoca main plaza in the Llanos de Mojos northward, where the Casarabe four-tier settlement system's northern axis preserves a 1.4 km causeway 10 m wide × 1.2 m high, lateral canals 4 m wide each and terminal forest island 6 ha with 8 m mound surveyed by Lombardo-Prümers 2022 LiDAR. Distinct from the Cedro island western lagoon and Laguna Central East sectors, this Cotoca north causeway forms the primary northern artery of the 147 ha Cotoca polity linking to 315 ha large site. Causeway banks carry terra preta-like soils with maize phytoliths, while canals handle seasonal savanna floods (0.8 m depth). Radiocarbon 800–1200 CE on causeway fill.
Why it mattersNorth causeway proves Cotoca polity four-tier hierarchy; 1.4 km length and canals quantify Casarabe labour and flood-control engineering for maize monoculture.
Open questions
Mysteries & theories
Mysteries
- 01Whether canals are drainage or canoe canals
- 02Attribution of terminal mound to chiefly residence?
Theories
- 01North causeway aligns to wet-season flood flow partitioning
- 02Cotoca 147 ha controlled 500 km2 via north-south causeways
Theories are interpretations, not findings. The seal above tells you how much scholarly weight the place carries.
History
How it came to be
- Built
- c. 600 CE Casarabe causeway initiation; north arm 800–1000 CE
- Period
- Casarabe (500–1400 CE)
- Culture
- Casarabe
- Purpose
- Northern processional causeway and flood-control canal for polity integration
- Abandoned
- c. 1400 CE system collapse
- Rediscovered
- 2022 Lombardo-Prümers LiDAR Cotoca north
- Excavation
- Partially excavated
c. 600 CE
Cotoca polity causeway network initiated
c. 800–1000 CE
1.4 km north causeway, canals and terminal mound built
2022
LiDAR maps north causeway to 0.3 m accuracy
On the ground
Structures & features
14.8000° S · 64.8500° W · 152 m · 3 mapped features
Causeway Embankment (1.4 km×10 m×1.2 m)
causeway1.4 km causeway 10 m wide 1.2 m high north from Cotoca
14.8050° S · 64.8500° WLateral Canals (twin 1.4 km×4 m)
canalTwin canals flanking causeway 4 m wide each
14.8000° S · 64.8500° WTerminal Forest Island Mound (8 m high, 6 ha)
mound6 ha island with 8 m mound terminus
14.7950° S · 64.8500° W