نمونه سوالات آزمون های کارشناسی ارشد علوم جغرافیایی زبان عمومی و تخصصی (انگلیسی) سال 1397

The beaches of Puerto Rico contain sand grains derived from several major sources. Erosion of land areas and transport of rock material by rivers to the beach supplies terrigenous sand grains. The composition variances are a function of the source area where the material is eroded and added to the river sand system. Areas of river drainage underlain by basaltic type rocks supply dark minerals and dark igneous rock fragments. Granite rock outcrops supply quartz and feldspar to the beach. Feldspar is a relatively unstable mineral that breaks down to clay minerals. The presence of feldspar in a beach system is indicative of a geologically young environment. Calcium carbonate is supplied to the beach by the shoreward transport of the shells of marine organisms. The composition changes in calcium carbonate and terrigenous material are a function of available supply and transport system. Along parts of the coast containing major rivers, there is an increase in terrigenous content in the beach sands. There is also a shift toward terrigenous beaches where an offshore carbonate source is lacking. By analyzing the availability of supply we can draw conclusions about_the_transport_system_and_beach_dynamics.Larger concentrations of calcium carbonate_can_indicate shoreward_transport. In an area such as Guanajibo Beach (Mayaguez) the absence of carbonate grains in the beach sands coupled with the presence of reefs just offshore shows that shoreward transport of beach material is 16- negligible. This is part of the reason for the erosion on this relatively protected beach environment.

The beaches of Puerto Rico contain sand grains derived from several major sources. Erosion of land areas and transport of rock material by rivers to the beach supplies terrigenous sand grains. The composition variances are a function of the source area where the material is eroded and added to the river sand system. Areas of river drainage underlain by basaltic type rocks supply dark minerals and dark igneous rock fragments. Granite rock outcrops supply quartz and feldspar to the beach. Feldspar is a relatively unstable mineral that breaks down to clay minerals. The presence of feldspar in a beach system is indicative of a geologically young environment. Calcium carbonate is supplied to the beach by the shoreward transport of the shells of marine organisms. The composition changes in calcium carbonate and terrigenous material are a function of available supply and transport system. Along parts of the coast containing major rivers, there is an increase in terrigenous content in the beach sands. There is also a shift toward terrigenous beaches where an offshore carbonate source is lacking. By analyzing the availability of supply we can draw conclusions about_the_transport_system_and_beach_dynamics.Larger concentrations of calcium carbonate_can_indicate shoreward_transport. In an area such as Guanajibo Beach (Mayaguez) the absence of carbonate grains in the beach sands coupled with the presence of reefs just offshore shows that shoreward transport of beach material is 16- negligible. This is part of the reason for the erosion on this relatively protected beach environment.

The beaches of Puerto Rico contain sand grains derived from several major sources. Erosion of land areas and transport of rock material by rivers to the beach supplies terrigenous sand grains. The composition variances are a function of the source area where the material is eroded and added to the river sand system. Areas of river drainage underlain by basaltic type rocks supply dark minerals and dark igneous rock fragments. Granite rock outcrops supply quartz and feldspar to the beach. Feldspar is a relatively unstable mineral that breaks down to clay minerals. The presence of feldspar in a beach system is indicative of a geologically young environment. Calcium carbonate is supplied to the beach by the shoreward transport of the shells of marine organisms. The composition changes in calcium carbonate and terrigenous material are a function of available supply and transport system. Along parts of the coast containing major rivers, there is an increase in terrigenous content in the beach sands. There is also a shift toward terrigenous beaches where an offshore carbonate source is lacking. By analyzing the availability of supply we can draw conclusions about_the_transport_system_and_beach_dynamics.Larger concentrations of calcium carbonate_can_indicate shoreward_transport. In an area such as Guanajibo Beach (Mayaguez) the absence of carbonate grains in the beach sands coupled with the presence of reefs just offshore shows that shoreward transport of beach material is 16- negligible. This is part of the reason for the erosion on this relatively protected beach environment.