RBSE SS Geology case studies
RBSE SS Geology · Put your knowledge to work in context.
The RBSE Senior Secondary Geology qualification is the Class 12 geology stream offered under the Rajasthan Board of Secondary Education (RBSE) framework. It suits students who want a science-flavoured senior secondary certificate with an earth-science focus, and it is typically taken by candidates preparing for university geology, mining, civil engineering or natural-resource careers. The RBSE SS Geology case studies are 5 cases and about 3,778 words.
1Terrace staircase on the Banas: uplift, climate, or both?
During mapping of a 40 km reach of the Banas River you record four strath terraces above the modern channel: T1 at 6 m, T2 at 15 m, T3 at 28 m and T4 at 47 m. OSL ages are 5 ka, 20 ka, 60 ka and 120 ka respectively.
601 words, about 3 min2Two dark phenocrysts in a dyke: augite or hornblende?
A 12 m thick, east-west trending basaltic andesite dyke intrudes gneiss. Phenocrysts from the core reach 4 mm; those from the chilled margin are 0.3 mm.
755 words, about 4 min3A contact aureole in limestone and shale: where is the granite?
A 3 km traverse east of a granite stock crosses a covered interval and then, from west to east, four rock types: massive grey marble with calcite and wollastonite at 0 m; dark, fine-grained hornfels with andalusite porphyroblasts at 40 m; spotted slate with incipient chiastolite at 150 m; and fossiliferous shale with unaffected conodont colour at 400 m. The marble is calcite-rich and shows no dolomite; wollastonite appears only in the first 10 m.
793 words, about 4 min4A 28-degree fault that cuts a fold: thrust or reactivated normal fault?
Construction of a 60 m road cut exposes interbedded sandstone and shale folded into a gentle anticline. Bedding on the north limb strikes 090 degrees and dips 30 degrees north; on the south limb it strikes 090 degrees and dips 25 degrees south, giving an east-west fold axis plunging 8 degrees east.
801 words, about 4 min5A gossan in dolomite: one drill hole, where?
A 1.5 km by 300 m gossan trends north-south along a faulted contact between dolomite and quartz-sericite schist. Limonite, malachite and relic boxwork after pyrite are exposed in old pits.
828 words, about 4 min