## 1 Introduction  
Massive phosphate deposits of economic interest occur in the southern margin of the Neo-Tethys. These deposits are one of the important natural resources in Jordan and the region [1]. Many prospective areas that contain considerable thicknesses of these deposits are distributed throughout southern Neo-Tethys. Still, despite these highly promising perspectives there are a range of unknowns and uncertainties, in particular with regard to the origin of these huge reserves. Scientists have tried for a long time to understand the genesis of phosphates, but they struggled with the fact that phosphates can be found in divergent oceanic settings; some are found in the open marine system, e.g. [2], others are found in the infratidal to circatidal environments [3] and there is also phosphate deposition in estuaries and semi-restricted embayments [4; 5]. These vast occurrences of phosphates make reaching a consensus on one model that explains the occurrences of phosphatPhosphates are extensive oceanic deposits that resulted from a series of interconnected tectonic, sedimentological, and oceanic conditions [6]. Each case can be studied separately based in differences in land-sea configurations which influence the oceanographic setting and the sedimentological processes. Adding to the previous point, the concentration of phosphorous in the water column, as well as climatic conditions and oxygen content, played major roles in the accumulation. Phosphoric deposits in the ocean are associated primarily with the productivity of surface water that has been detected during the Late Cretaceous period in the southern Neo-Tethys [1; 2; 5; 7]. Primary productivity is considered particularly in upwelling areas, where phosphate is released from the degradation of organic matter in the deep ocean. Upwelling current brought phosphorous and other nutrients to coastal areas and enhanced the primary productivity of these components in the water column [1; 5]. Scientists have focused on the climate as an enrichment factor for phosphate deposits, as it seems to have been accelerated in warm humid climates as a result of a regional sea level rise that caused the establishment of mesotrophic conditions and the enhancement of continental weathering [2; 8; 9]. In such conditions, organic matter can be a source of authigenic phosphate through bio-chemical weathering and direct degradation in the ocean [3; 6; 8]. Phosphate formation requires suboxic and sometimes anoxic alkaline conditions. This can be in restricted basins or in the oxygen minimum zones, where organic matter degraded to produce phosphorus ions directly or from iron oxides [3; 4; 5; 8; 10; 11]. The depositional environments of phosphates and oil shales have been investigated in Jordan, e.g., for phosphates: [1; 12; 13; 14]. The close relation in the formation setting of both of them has been proposed by [PERSON]. [1]. Oil shales have been investigated from 29 boreholes covering most of the oil shale deposits in Jordan [15; 16; 17; 18]. The understanding of oil shale deposition went beyond the enrichment of nutrient and organic productivity during the upwelling; tectonisms and climate also played major roles in controlling the deposition [17]. Since phosphate is associated with the deposition of oil shales, the validity of an oil shale model in the deposition of phosphate was checked in this research work. Ref. [1] interrelated the phosphate deposits in Jordan with the tectonic obstruction, i.e., paleobighs that prevented the upwelling of oceanic currents to pass through eastern Neo-Tethys which resulted in the deposition of phosphate deposits. The upwelling system, tectonisms, paleoclimates, terrigenous inputs, sedimentary environments, and the oceanographic factors must be hypothesized to come up with a comprehensive picture of the deposition of the phosphates. This study aims to establish an age model in order to correlate phosphate deposits across vast areas.