11,050 - 8,050 B.C.
Following on the dry late Pleniglacial, the climate of northern South America became wetter. Riverbed fish ponds were submerged. Paleo-Indian tools were deposited at now submerged riverine and estuarine sites.
 
 

Paleo-Indian stemmed projectile point with bilaterally notched edges. Made out of Jasper. Found in the Ireng River. Probably used in spear fishing

8,050 - 6,250 B.C.
In the early centuries, Trinidad still formed part of the South American mainland. The littoral lay farther out to sea with rivers cutting through coastal grass savannas. Bones of a late Pleistocene megafauna in south Trinidad (Natural History Museum, Port-of-Spain) and in Guyana suggest that such animals once grazed these now vanished savannas. In the closing years of the period, the sea reached the emergent rocks of the Guiana Shield. In the Southeastern Subzone, resulting from the proximity of the Essequibo Delta, the Piraka site (Pomeroon River) was occupied in brackish conditions +/-6,250 B.C.

6,250 - 4,050 B.C.
A hypersaline environment immediately preceded culmination of the eustatic sea level rise. The Barabina site (Aruka River) Northwestern Subzone, was occupied +/-4935 B.C.

4,050 - 2,050 B.C.
Culmination of the eustatic sea level rise +/-4,050 B.C. was followed by a relative sea level rise. A perennial spring permitted exploitation of the then hypersaline Waramuri (Moruka River) mudflats, +/-4,010 B.C. Development of the canoe triggered Regional integration, +/-3,300 B.C.

2,050 - 1,600 B.C.
An arid interval supervened. In the stressed environment, pottery was introduced by pre-horticulturists from the lower Amazon to the Aruka River, +/-2,050 B.C.

1,600 - 80 B.C.
Tectonic subsidence ceased locally in the Northwestern Subzone. Salinity dropped below the critical level for reproduction of economic shellfish species. Subsistence-lack stress triggered the shift to food production at Hosororo Creek (Aruka River) +/-1,600 B.C.
 

Ground and polished adz, from Hosororo Creek near Aruka River. Used in food production

80 B.C. - A.D. 1210
The arid interval ended. Salinity stress survived in coastal areas. Coastal horticulturists colonized the rain forest of the Mazaruni (Quartz Island) via its dried-out streams, +/-80 B.C..
 
 

Pottery fragments from Quartz Island, Mazaruni River