128 Reviews — Records of the Geological Survey of India. 



metamorphism of an albite-nepheliiie rock originally forming the dyke, 

 since both these minerals are found in conjunction with the jadeite. 

 The region is one where crystalline schists have been invaded by 

 granite. The previous view that the serpentine- jadeite complex is of 

 Tertiary age is also rendered improbable by the fact that these old 

 eruptives, including the jadeite, are prominently represented among 

 the boulders in the Tertiary conglomerate, which is worked expressly 

 for that mineral. The amount raised in 1907 was 3,590 cwts., valued 

 locally at £18,998, and mostly sent to China. 



Paloiontology . — Amongst items of general interest under this heading 

 the discovery of inter-trappean fossils in the Cretaceous of Baluchistan 

 .may be noted. Physa Prinsepii, for instance, so characteristic of the 

 fresh-water beds intercalated in the Deccan Trap, is found to occur in 

 marine beds containing Upper Cretaceous (Maestrichtian) ammonites. 

 These fresh-water shells must have been carried out to sea from the 

 land on which the inter-trappean fossils were laid down, and in this 

 way evidence is obtained fixing the age of the great Deccan Trap 

 eruptions with greater precision than previously. 



Some curious facts are recorded with reference to the so-called 

 * exotic blocks ' of the Kumaon Himalaya, where the later Mesozoic 

 beds are capped in places by massive limestone blocks {Klvppejt), 

 which either appear to rest conformably on the soft Jurassic shales 

 or else are imbedded in them. These blocks are partly of Palaeozoic 

 and partly of Mesozoic age, and their anomalous position among 

 younger strata has given rise to a considerable amount of controversy. 

 It is assumed that the exotic blocks of Kumaon were brought from 

 somewhere further north in the Tibetan region at present unrecognized ; 

 and if so, they must represent the result of one of the most gigantic 

 overthrusts known to geologists. The interest from a palseontological 

 view lies in the fact that there is a remarkable agreement between the 

 fossils of these ' Tibetan ' masses and Alpine Carnic and Liassic fossils, 

 whilst the facies is different from that of the beds of corresponding 

 age in the normal sections within the area in question. Clearly, this 

 is a palseontological puzzle by no means easy of interpretation. 



The examination of the Cambrian fossils from Spiti, collected 

 1898-1901, leads to equally surprising results. The fauna comprises 

 ten genera of Trilobites, five genera of Brachiopods, one genus of 

 Pteropod, one Echinoderm, and one Zoophyte. Six horizons have been 

 recognized in the region whence most of the fossils have been derived, 

 and the fauna of each horizon is peculiar to it, no single species having 

 been found in any two horizons. The only Trilobite that has been 

 identified with a known species is Eedlichia JS'oetlingi, and the presence 

 of this Salt Range species is of interest as the only form known to 

 be common to the two areas. The remaining Trilobites, with the 

 exception of those found in the Olenus -horizo-a, as also the other 

 fossils, are remarkable for their dissimilarity to either Salt Pange 

 or European types. The general conclusion is that the main mass 

 of the beds must be referred to the Middle Cambrian, and that the 

 palseontological affinities of the fossils in these beds are with the 

 Rocky Mountain province of America. Once more, then, we find 

 a palseontological puzzle in the disagreement of these Himalayan 



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