Relations between rulers of Trucial States and Petroleum Development Trucial Coast Company. Code BA file 1531 (papers 12 to end) p.78

FO 371/140224 1959
Frontier of Ajman in the Manama area.

The frontier between Ajman territory on the one hand and
Sharjah territory and Fujairah territory on the other in the
Manama area runs from the junction of Wadi Manassat and Darb
Zahum in the north-east down the Wadi Manassat and Wadi Ghail
Hamama, leaving Jabal Khurus to Fujairah and Ramlat al Hail to
Sharjah, to the south-western point of Ramlat al Hail. Tawi
Bin Hamdan is in Ajman territory. From the south-western point
of Ramlat al Hail the border runs south to a point a quarter of
a mile west of Al Boyadh, which is in Ajman territory. Thence
it goes through Silima to the Darb Sijji, leaving Aud Sidr to
Sharjah. From the point where the frontier meets the Darb Sijji
it runs east, passing between Jabal Ashgar and Tawi Howaira north
of Qurn bin Alwa to Samrat Mansur (Hamad) on Darb Zahum.
Samrat Mansur are in Bujairah territory and the frontier then
runs north from there along the Darb Zahum until it reaches the
Wadi Manassat.

N.B.

Unless otherwise stated, the line divides the places
through which it passes.