Fig. 1: Simplified tectonic and geological maps showing the Kangjinla ophiolitic mantle in the Yarlung Zangbo Suture (South Tibet).

Major tectonic units of the Himalayan-Tibetan orogenic system (a; modified from DeCelles et al.⁶⁷), geological sketch map of South Tibet showing the Yarlung Zangbo Suture and major ophiolites (b; modified from Dai et al.⁶⁸), and the simplified geological map illustrating the Luobusa ophiolite and adjacent tectonic units (c; modified from Liang et al.⁶⁹). This study focused on the Kangjinla segment and the southernmost portion of the Xiangkashan segment, both of which display intact occurrence, direct exposure, and minimum alteration. We collected representative peridotites by hammers on the well-exposed outcrops with sampling spacing of several to tens of meters. The studied segments were then reconstructed as four zones (d), from north to south including the northern dunite zone (NDZ), northern harzburgite zone (NHZ), central harzburgite zone (CHZ) and southern lherzolite zone (SLZ). The four zones can represent the major architecture of the ophiolitic mantle, and construct a mantle profile defined as “the Kangjinla ophiolitic mantle” in this study (d). Yellow dashed curves in c and d mark the suggested boundaries between the four zones, and circles with different colors show the sampling positions. YZS Yarlung Zangbo Suture, BNS Bangong-Nujiang Suture, JS Jinsha Suture, AKMS Anyimaqen-Kunlun-Muztagh Suture, NQO North Qaidam Orogen, NQS North Qilian Suture, ATF Altyn Tagh Fault.