Occurrence of Attributes in Original Text
The text related to the cultural heritage 'Ha Long Bay' has mentioned 'Limestone' in the following places:
| Occurrence Sentence | Text Source |
|---|---|
| The bay features thousands of limestone karsts and isles in various shapes and sizes. | WIKI |
| Hxe1xbaxa1 Long Bay has an area of around 1,553xc2xa0km2 (600xc2xa0sqxc2xa0mi), including 1,960xe2x80x932,000 islets, most of which are limestone. | WIKI |
| [1] The limestone in this bay has gone through 500 million years of formation in different conditions and environments. | WIKI |
| The bay consists of a dense cluster of some 1,600[12] limestone monolithic islands each topped with thick jungle vegetation, rising spectacularly from the ocean. | WIKI |
| Another specific feature of Hxe1xbaxa1 Long Bay is the abundance of lakes inside the limestone islands. | WIKI |
| In 2000, UNESCO's World Heritage Committee inscribed Hxe1xbaxa1 Long Bay in the World Heritage List according to its outstanding examples representing major stages of the Earth's history and its original limestone karstic geomorphologic features. | WIKI |
| The limestone karstic geomorphology of the bay was developed since Miocene, especially the cone-shaped hills (fengcong), or isolated high limestone karst towers (fenglin) with many remnants of old phreatic caves, old karstic foot caves, marine notch caves form magnificent limestone karst landforms as unique on the world. | WIKI |
| The present Hxe1xbaxa1 Long Bay, in fact, appeared after the Middle Holocene maximum transgression, leaving ultimate zone of lateral undercutting in the limestone cliffs bearing many shells of oysters, having the 14C age as 2280 to >40,000 y. BP. | WIKI |
| Geological resources are abundant: anthracite, lignite, oil shale, petroleum, phosphate, limestone and cement additives, kaolin, silica sand, dolomite, quartzite of exogenous origin, and antimony, mercury of hydrothermal origin. | WIKI |
| Due to a simultaneous combination of ideal factors such as thick, pale, grey, and strong limestone layers, which are formed by fine-grained materials; hot and moist climate and slow tectonic process as a whole; Ha Long Bay has had a complete karst evolution for 20 million years. | WIKI |
| The sequence of stages in the evolution of a karst landscape over a period of 20 million years requires a combination of several distinct elements including a massive thickness of limestone, a hot wet climate and slow overall tectonic up lift. | WIKI |
| The karst dolines were flooded by the sea, becoming the abundance of lakes that lie within the limestone islands. | WIKI |
| These are not separate evolutionary stages but the result of natural non xe2x80x93 uniform processes in the denudation of a large mass of limestone. | WIKI |
| The marine notch is a feature of limestone coastline but, in Ha Long Bay, it has created the mature landscape. | WIKI |
| Three main types of caves can be recognized in the limestone islands (Waltham, T. 1998): | WIKI |
| Tam Cung is a large phreatic fissure cave that developed in the bedding planes of the limestone dividing the fissure cave into three chambers. | WIKI |
| They may extend back into maze caves of stream caves draining from larger cave systems within the limestone. | WIKI |
| The dissolution process of sea water acting on the limestone and erosion by wave action crates notches at the base of the cliffs. | WIKI |
| In advantageous conditions, dissolution of the limestone allows the cliff notches to be steadily deepened and extended into caves. | WIKI |
| Many of these at sea level extend right though the limestone hills into drowned dolines which are now tidal lakes. | WIKI |
| A distinguishing feature of marine notch caves is an absolutely smooth and horizontal ceiling cut through the limestone. | WIKI |
| The fenglin tower karst, which is the type present in much of Ha Long Bay, is the most extreme form of limestone landscape development. | WIKI |
| If these karst landscapes are broadly compared in terms of their height, steepness and number of their limestone towers, Ha Long Bay is probably second in the entire world only to Yangshou, in China. | WIKI |
| However, Hxe1xbaxa1 Long Bay has also been invaded by the sea so that the geomorphology of its limestone islands are, at least in part, the consequence of marine erosion. | WIKI |
| end of the Devonian Period Due to tectonic activity, the Ha Long area and the entire north-east region were raised from the depths 340,000,000xe2x80x93240,000,000 BC later Carboniferous and Permian periods The formation of the limestone layer more than 1,000 m thick. | WIKI |
| It created two kinds of limestone: the Cxc3xa1t Bxc3xa0 layer of the early Carboniferous period (450 m thick); and the Quang Hanh layer of the middle Carboniferous and the early Permian period (750 m thick). | WIKI |
| The continuation of this erosion has progressively cut the highlands into blocks with altitudes similar to today's mountains 26,000,000xe2x80x9310,000,000 BC Neogene Period The development of the Ha Long depression 2,000,000xe2x80x939000 BC Pleistocene epoch of the Quaternary period The process of erosion began dissolving the limestone-rich region of Ha Long, after that, forming the limestone plain was most active 68,000xe2x80x939000 BC middle and late Pleistocene Epoch Period when the caves and grottoes of the area formed. | WIKI |
| Rainwater flowed into crevices in the limestone that had formed from tectonic activity. | WIKI |
| Covering an area of 43,400 ha and including over 1600 islands and islets, most of which are uninhabitated and unaffected by humans, it forms a spectacular seascape of limestone pillars and is an ideal model of a mature Karst landscape developed during a warm and wet tropical climate. | UNESCO |
| The outstanding value of the property is centered around the drowned limestone karst landforms, displaying spectacular pillars with a variety of coastal erosional features such as arches and caves which form a majestic natural scenery. | UNESCO |
| The repeated regression and transgression of the sea on the limestone karst over geological time has produced a mature landscape of clusters of conical peaks and isolated towers which were modified by sea invasion, adding an extra elemant to the process of lateral undercutting of the limstone towers and islands. | UNESCO |
| Criterion (vii): Comprised of a multitude of limestone islands and islets rising from the sea, in a variety of sizes and shapes and presenting picturesque, unspoiled nature, Ha Long Bay is a spectacular seascape sculpted by nature. | UNESCO |
| Outstanding features of the property include the magnificent towering limestone pillars and associated notches, arches and caves, which are exceptionally well-developed and among the best presented of their type in the world. | UNESCO |