75i Geological Society : — 



It is believed that this main Gondwana outcrop is continued through 

 the Peninsula to Singapore, and on to Banka and Billiton, where it 

 may turn so as to enter Western Borneo, forming an inner arc 

 roughly parallel with the outer volcanic arc of the Malay Archipelago 

 and the Philippines. 



The igneous rocks of the Benom Anticline are less acid than 

 those of the Main Range Anticline, and there is a corresponding 

 difference in mineral products. The area of the Benom Anticline 

 coincides with the i gold-belt ' of the Peninsula. The products of 

 the Main Range Anticline are tin and wolfram. 



Tertiary coal-measures, unconformable on the Gondwana rocks, 

 are known in Selangor. Their exact age cannot be determined, 

 since the flora resembles the existing jungle-flora ; and the same 

 may be said of floras in Borneo coal-measures that are believed to 

 date back to the Eocene Period. An arrangement based on the per- 

 centage of moisture in the coal, however, points to the possibility 

 of their being Miocene. 



Evidence has been found in the Peninsula supplementing the 

 biological evidence described by Dr. A. R. Wallace, of changes in 

 the Archipelago in Tertiary times. When the land-connexion 

 that allowed the migration of the fauna of the Archipelago from 

 the north was destroyed by submergence, the subsidence continued 

 until the Peninsula became an island or group of islands. Sub- 

 sidence then gave place to elevation, which restored the Peninsula 

 and is continuing at the present day. 



Interesting recent deposits are deposits of lignite in ' cups ' 

 formed by solution in the limestone of the Raub Series, and 

 torrential deposits made up of ' core-boulders' derived from weathered 

 granite. 



2. 'On a Mass of Anhydrite in the Magnesian Limestone at 

 Hartlepool.' By Charles Taylor Trechmann, B.Sc. 



The harbour of Hartlepool owes its existence to the erosion of a 

 mass of anhydrite of great thickness, proved by boring and other 

 evidence to exist in close proximity to the Upper Magnesian Lime- 

 stone upon which the towns of Hartlepool and West Hartlepool are 

 built. 



The anhydrite is shown to be included in, and to represent the 

 time-equivalent of part of, the Middle and the greater part of the 

 Upper Limestones. The contrary view, that the anhydrite belongs to 

 the overlying red beds here faulted down, is shown to be erroneous. 



The former presence of sulphates in the Magnesian Limestone is 

 discussed. Tbis formation, wherever protected by overlying com- 

 paratively impervious beds, proves to be more or less gypsiferous 

 throughout its thickness. Evidence is brought to show that very 

 large quantities of anhydrite were originally deposited with the 

 Magnesian Limestone, the subsequent hydration and removal of 

 which is chiefly responsible for the collapse, degradation, brecciation, 

 and other alterations that are such obvious features of the formation 

 in its present condition. 



