In which of the following divisions of the Himalayas is the Karewa formation…

The Himalayas are longitudinally divided into four broad regional belts — the Kashmir Himalayas, the Himachal-Uttarakhand Himalayas, the Darjeeling-Sikkim Himalayas, and the Arunachal Himalayas — each shaped by a distinct set of rivers, rock formations, and depositional history. Karewas are thick, unconsolidated lacustrine (lake-bed) sediments — alternating layers of clay, silt, sand, and glacial debris — laid down when a Pleistocene-age lake occupied a Himalayan valley basin.

This lake-bed sequence is confined to the Kashmir Valley, enclosed between the Pir Panjal range and the main Himalayan range — that is, within the Kashmir Himalayas. The karewa terraces there today support saffron cultivation and orchards, and their layered sediments record the region's Pleistocene glacial and interglacial history.

None of the other three divisions carries this depositional feature:

• Arunachal Himalayas — the easternmost stretch of the range, running from the Bhutan border to the Diphu Pass at the India-Myanmar-China tri-junction, drained by the Kameng, Subansiri, Dihang, and Lohit; it has no lacustrine karewa sequence.

• Darjeeling and Sikkim Himalayas — lie between the Nepal and Bhutan Himalayas, drained by the Tista, with a steep gradient and dense monsoon forest cover; the karewa lake-bed deposits do not occur here.

• Assam Himalayas — the hill ranges east of the Tista toward the Brahmaputra's Dihang bend, marked by very heavy monsoon rainfall and fast-flowing streams; this belt also lacks the karewa sequence.

So the division in which the Karewa formation is found is the Kashmir Himalayas.