Origin of the Mushroom Stone Forest at the southeastern foot of the Little Sangpu Mountain in eastern Guangdong,China: A palaeo-sea-level indicator or not?

The Mushroom Stone Forest, which consists of granite boulders looking like mushrooms with flared sidewalls, is located in eastern Guangdong China, and is a famous scenic spot that draws many tourists each year. The Mushroom Stone Forest has been traditionally recognized as a collection of wave erosion landforms and used for the reconstruction of palaeo-sea-level changes along the coastal areas of eastern Guangdong in previous coastal researches. By combining in situ measurements of the aspect,vertical profile and height of boulder sidewalls,palaeo-coastal wave direction estimation, rock density determination, major elemental analysis, and petrographic thin section analysis, this paper presents an alternative origin for the Mushroom Stone Forest.Our results suggest that wave or wind erosion cannot offer a satisfactory explanation for the formation of the Mushroom Stone Forest; The boulders that make up the Mushroom Stone Forest originated from the corestones in the granite weathering crusts of the Little Sangpu Mountain; When the debris of the weathering crust was removed, the corestones are perched on rocky outcrops or half-buried by weathering debris beneath the natural land surface;The flared sidewall (concave vertical profile) of the boulders is a particular form developed in the foot zone of a half-buried boulder through increased chemical weathering beneath the land surface. A recent exposed half-buried boulder found in the study area provides convincing evidence to support this argument. Sea water reached the foot of the Sangpu Mountain during the Holocene transgression, but it merely provided a mechanism to erode the weathering debris from the bottom of the mushroom rocks and enhanced salt weathering that created tafoni on the boulders. These findings demonstrate that the boulders of the Mushroom Stone Forest are not sea stacks and cannot be served as a palaeo-sea-level indicator.

Design of 15 Gb/s inductorless limiting amplifier with RSSI and LOS indication in 65nm CMOS

A limiting amplifier IC implemented in 65nm CMOS technology and intended for high-speed op- tical fiber communications is described in this paper. The inductorless limiting amplifier incorporates 5-stage 8 dB gain limiting cells with active feedback and negative Miller capacitance, a high speed output buffer with novel third order active feedback, and a high speed full-wave rectifier. The re- ceiver signal strength indictor （RSSI） can detect input signal power with 33dB dynamic range, and the limiting amplifier features a programmable loss of signal （LOS） indication with external resistor. The sensitivity of the limiting amplifier is 5.5mV at BER = 10^ -12 and the layout area is only 0.53 × 0.72 mm^2 because of no passive inductor. The total gain is over 41dB, and bandwidth exceeds 12GHz with 56mW power dissipation.

Experimental Research on Microscopic Indicators of Temperature's Returning-to-Zero in Deformation of Calcite and Discussions of Correlation Problem

In order to determine the degree of returning_to_zero of temperatures of deformed calcite, a series of rock-breaking experiments were designed to test calcite-rich limestone samples under fixed confining pressures and different temperatures. The consolidated deformed samples in their initial state were observed under a microscope and the microscopic indicators in different zero-returning states were put forward, thus providing a microscopic foundation for evaluation of reliability of dating values of deformation in calcite. At last, the correction of dating values of deformation for samples whose temperature has not yet returned to zero is discussed.