RESIDENTS’ PERCEPTION TOWARDS GEOHERITAGE CONSERVATION AND TOURISM DEVELOPMENT: EVIDENCE FROM JODHPUR, INDIA

The Mehrangarh Fort in Jodhpur, India, located at the height of 150 meters above the surrounding sandy plains, is one of the city's most prominent monuments built over the Jodhpur group-Malani-Igneous Suite. The old city, which boasts numerous blue-painted houses, lies adjacent to the Mehrangarh Fort. The residents of the old city play a significant role in keeping the geoheritage and cultural heritage intact. The study investigates the moderating role of residents’ Perception towards support for Geoheritage Tourism and Conservation in and around Mehrangarh Fort. A combination of Weber’s theory of substantive and formal rationality (WTSFR) and Social Exchange Theory (SET) is used to investigate and infer the interposing and moderating role of residents’ perception on the relationship between influencing factors and support for geo-heritage conservation. A PLS evaluation of the SEM reveals a substantial capacity of the residents’ perception to predict support for conservation and tourism development.

Petrology and Geochemistry of Nakora Ring Complex with Emphasis on Tectonics and Magmatism, Neoproterozoic Malani Igneous Suite, Western Rajasthan, India

The present contribution reports on the field, petrographical and geochemical observations of the volcano-plutonic rocks of the Nakora Ring Complex (NRC) from the Neoproterozoic, Malani Igneous Suite (MIS) (Northwestern Peninsular India) and confers about their magmatic evolution and tectonic implications. Three magmatic phases are notable in the NRC which is Extrusive, Intrusive and Dyke phase where with small quantities of basaltic flows was initiated and accompanied by extensive/voluminous acidic flows. Petrographically, rhyolite shows flow bands, porphyritic, spherulitic, aphyritic and perlitic textures whereas basalt flows are distinguished by the presence of labradorite in lath-shaped crystals (plagioclase feldspar) and clinopyroxene (augite). The presence of high silica and total alkalis in NRC rocks, as well as high field strength elements (HFSE), enrichment of trace elements and negative anomalies of Sr., Eu, P, and Ti indicates that the emplacement of the lava flows was controlled by complex magmatic processes such as fractional crystallization, crustal contamination and partial melting. The association of basalt-trachyte-rhyolite means that the magma chamber was supplied a significant amount of heat to the crust before the eruption. Moreover, a volcanic vent was also reported at NRC where rhyolite was associated with agglomerate, volcanic breccia, perlite and tuff. The current research proposed that the Neoproterozoic magmatism at NRC was controlled by rift-related mechanism and produced from crustal source where the heat was supplied by mantle plume.

Petro-Mineralogical and Geochemical Study of the Acid Magmatic Rocks of Tusham Ring Complex, NW Peninsular India

The present contribution reports about the field and petrographical observations which are very important to explain the magmatic evolution and geodynamic setting of Tusham Ring Complex (TRC). TRC is associated with A-type acid volcano-plutonic rock-association which is very common characteristics of Neoproterozoic Malani Igneous Suite (MIS). Based on the geological field information, the investigated rock-types are classified as volcanic phase, plutonic phase and dyke phase. Petrographically, rhyolites show porphyritic, granophyric, glomeroporphyritic, aphyritic, spherulitic and perlitic textures whereas granites show hypidomorphic, granophyric and microgranophyric textures. Based on mineral chemistry and whole-rock geochemistry, the petro-mineralogical results are justified and proposed that the rocks under study belong to A-type affinity, within-plate and anorogenic magmatism. Physiochemical features i.e. F and Cl-rich biotite, pegmatite rim, high mineralized veins, micro-granular enclaves and altered mineralogy indicate rock-fluid interactions which are caused by magmatic origin or secondary metasomatic alteration superimposed on the host rock.

Landslide in rocks of Jodhpur Group at Masuria Hill in Jodhpur, Western Rajasthan, India: Its causes and threat to significant Georesources

The ever first disastrous landslide at Masuria Hill (MH) damaged many houses and properties on 4th October 2019 in surrounding residential colonies of Masuria area in the Jodhpur city, Western Rajasthan India. Present landslide not only created panic among people but also damaged properties and significant georesources which is a serious concern for future. Geologically, MH is represented by rhyolite of Malani igneous suite (MIS) of Cryogenian age which is overlain by siliciclastic rocks of Jodhpur Group (JG) of Ediacaran age of Marwar Supergroup (MSG). Landslide occur in horizontally disposed rocks of Umed Bhawan Formation (UBF) of JG. UBF is divided into 4-18m thick clay dominated soft sediments zone with sheet and release joints at the base. It is followed by 24-72m thick rigid sand zone having orthogonal jointing. This disposition of soft and rigid pattern of sedimentation of UBF is identified as the key horizons responsible for the landslide with shale horizon as the failure plane. Causes of landslide can be explain based on the model of BPSZ (Bedding Parallel Shear Zone). BPSZ is attributed to three main mechanisms: liquefaction, mass wasting and shear stresses that caused the landslide at MH. Study further reveal that residential area surrounding MH and other seven hills having similar geological disposition are under great threat to future landslide in Jodhpur. Paper also embodies characteristics of georesources having educational and cultural values which are under great threat to landslide along with appropriate hazard mitigation measures.

Geochemistry of volcanic flows of Nakora area of Malani igneous suite, Northwestern India: Constraints on magmatic evolution and petrogenesis

The geochemical characteristics of volcanic flows of Nakora area of Malani Igneous Suite have been determined to understand their magmatic evolution and petro-genetic aspects. Geochemically, they are high in silica, total alkalis, high field strength elements (HFSE), low ion lithophile elements (LILE), rare metals and rare earth elements; represent A-type affinity with potential mineralization associations. Here, we carried out average geochemical data bank of representative samples of 44 individual lava flows of isolated hill-locks. The relative enrichment of trace elements and negative anomalies of Sr, Eu, P and Ti in the multi-element spider diagrams suggests that the emplacement of the lava flows was controlled by complex magmatic processes i.e. fractional crystallization, partial melting, magma mixing, crustal contamination and assimilation. Moreover, NRCmagma provides new geochemical approaches to understand geodynamic evolution of MIS and emplaced in plume related extensional geodynamic settings in NW Indian shield. Keywords: Geochemistry; Volcanic flows; Nakora; Malani Igneous Suite; Rajasthan; Rodina