Lightsensitive silver halide emulsion, production thereof and silver halide photographic lightsensitive material containing the same

A process for producing a lightsensitive silver halide emulsion comprising silver halide grains, wherein:

• the emulsion contains tabular silver halide grains in an amount of at least 50% of the total projected area of all the silver halide grains, the average iodine content of all the silver halide grains is at least 2 mol %, the tabular silver halide grains have at least 10 dislocation lines per grain, and each of the silver halide grains has a twin face spacing of 0.017 μm or less;
• and
• the process comprises (step 1) set forth below, and the process comprises a step of performing chemical sensitization so that a selenium sensitizer is added in an amount of 2.5×10−6 to 5×10−5 mol/mol silver and comprises a step of performing spectral sensitization:
• (step 1) performing the spectral sensitization in which a spectral sensitizer is added in the presence of 50 ppm or less of calcium, magnesium and strontium, followed by adding at least one water-soluble salt of a metal selected from the group consisting of calcium, magnesium and strontium, so that the concentration of calcium, magnesium and strontium becomes 100-2500 ppm;
• and then the chemical sensitization is started.