Clarence River (New Zealand)

Clarence River
250px A view over the river mouth near Kaikoura
250px The Clarence River system.
Origin	Lake Tennyson, Saint James Range, Spencer Mountains
Mouth	Pacific Ocean
Progression	Overall east
Basin countries	New Zealand
Location	Canterbury Region, South Island
Length	230 km (140 mi)
Mouth elevation	Sea level
River system	Clarence River system
Left tributaries	Acheron River, Dillon River

The Clarence River is on northeast South Island of New Zealand. It is 230 kilometres (140 mi) long, which makes it the eighth longest river in New Zealand.

For its first 50 kilometres (31 mi), the river runs in a generally southeastern direction. It then turns northeast, running down a long straight valley between the Inland and Seaward Kaikoura Ranges. At the end of the Seaward Kaikouras, the river meanders through undulating hill country before draining into the Pacific Ocean near the town of Clarence.

A large part of the river is within the boundaries of Molesworth Station.

Northern tributaries along the middle segment of Clarence River (e.g., Mead Stream, Dee Stream, Branch Stream, Muzzle Stream) cut through an uplifted, folded and rotated block of limestone and marl that accumulated on the seafloor from the late Cretaceous through the Paleocene and middle Eocene (75–45 million years ago). Exposures of this limestone -- the Amuri Limestone -- provide some of the most complete records for this time interval of Earth's history. They have provided important insights to our understanding of the Paleocene-Eocene Thermal Maximum (PETM), Eocene Thermal Maximum 2 (ETM-2), and other Paleogene hyperthermal events