觀音(yin)(yin)山(shan)(Kuan-yin Mountain),舊(jiu)稱新宜山(shan),別名八(ba)(ba)里坌山(shan)(淡(dan)水(shui)廳(ting)志載)。位于臺灣(wan)省(sheng)新北市五股區、八(ba)(ba)里區交(jiao)界(jie),海(hai)拔標(biao)高616米,由淡(dan)水(shui)河(he)北岸向(xiang)南遙望(wang),全區有十八(ba)(ba)連峰(feng),區內有多座古剎,更增添(tian)觀音(yin)(yin)山(shan)的靈(ling)性,其(qi)中有數間供奉觀世音(yin)(yin)菩薩的觀音(yin)(yin)寺(si)。
觀音(yin)(yin)山(shan),亦有不(bu)少納骨(gu)塔及(ji)墓園錯(cuo)落其(qi)間,該山(shan)西臨臺灣(wan)海峽,東北隔淡水河遠望關渡,昔(xi)日(ri)的“坌嶺(ling)吐霧”為淡水八(ba)大(da)景(jing)之一(yi),山(shan)頂又稱“硬漢(han)嶺(ling)”,全山(shan)屬北海岸及(ji)觀音(yin)(yin)山(shan)風景(jing)區。
觀(guan)(guan)音(yin)(yin)山(shan)自古便(bian)有登(deng)山(shan)活動,目前八里登(deng)觀(guan)(guan)音(yin)(yin)山(shan)的路(lu)(lu)線共有四條(tiao)主要(yao)路(lu)(lu)線,其中以乘車(che)至觀(guan)(guan)音(yin)(yin)山(shan)風景區管(guan)理處,由凌云禪寺旁(pang)鐵漢步道經硬漢嶺拾階而上(shang)登(deng)頂(ding)為(wei)最(zui)熱門路(lu)(lu)線。硬漢嶺為(wei)1961年憲兵學(xue)校300名學(xue)員開辟了一(yi)條(tiao)直達山(shan)頂(ding)的登(deng)山(shan)步道,為(wei)鼓勵學(xue)員學(xue)硬漢而來作硬漢而去,而名硬漢嶺。
硬漢嶺為火山碎屑巖與凝灰角礫巖所(suo)構(gou)成,1992,1993年來時有豪(hao)雨山崩(beng)土石滑(hua)動,步(bu)道毀壞并危及凌云禪寺安全。寄望能有效(xiao)妥(tuo)當的維(wei)護整修以(yi)保持靈(ling)山古剎之(zhi)原有古樸(pu)韻(yun)味。
由于季風吹來臺灣(wan)海(hai)峽的水汽(qi),遇到觀音山嶺的阻擋(dang),便降下化為云(yun)霧(wu),有如(ru)飄綿滾(gun)絮、變幻(huan)無常,蔚(yu)為奇觀.被文人(ren)雅士命名(ming)為“坌(ben)嶺吐霧(wu)”,名(ming)列清代(dai)淡(dan)北八景之一。同治(zhi)年間大龍峒舉人(ren)陳(chen)維英曾題(ti)詩贊曰:“坌(ben)嶺微(wei)茫八里間,連朝(chao)吐霧(wu)罩鴉鬟,此(ci)中定有深(shen)藏貌,未(wei)許分明見一斑(ban)”。
觀音(yin)山在淡(dan)水河河口南畔,東與大屯山群峰隔(ge)河相峙,西南毗接林口臺(tai)地(di)。形(xing)似(si)仰臥之觀音(yin),山頂空曠怡人,立足其上可俯瞰河口及(ji)淡(dan)水鎮(zhen)、臺(tai)北市(shi)郊景(jing)色,為淡(dan)水八景(jing)之一。凌(ling)云(yun)(yun)古剎坐落山腰,后另建新廟于古剎后方約(yue)數百公尺處(即觀音(yin)山腹(fu)),名(ming)曰(yue)凌(ling)云(yun)(yun)禪(chan)寺,是游人休憩處。
觀音(yin)山(shan)(shan)為一(yi)錐狀火(huo)(huo)山(shan)(shan),是大屯火(huo)(huo)山(shan)(shan)匯(hui)最西的(de)一(yi)部分,其北側(ce)以火(huo)(huo)山(shan)(shan)熔(rong)巖為主,南側(ce)以火(huo)(huo)山(shan)(shan)碎(sui)(sui)屑(xie)流(liu)為主,火(huo)(huo)成巖以安山(shan)(shan)巖為主,另外含有(you)一(yi)些早期(qi)噴發的(de)玄武巖,越晚期(qi)的(de)噴發則形(xing)成含角閃(shan)石的(de)安山(shan)(shan)巖。淡水河沿著(zhu)觀音(yin)山(shan)(shan)麓流(liu)入(ru)臺(tai)灣海峽,因兩側(ce)的(de)火(huo)(huo)山(shan)(shan)熔(rong)巖與(yu)碎(sui)(sui)屑(xie)物(wu)漫流(liu)入(ru)海,而(er)形(xing)成火(huo)(huo)山(shan)(shan)海岸。
山(shan)上(shang)(shang)坐落(luo)著不少名剎古寺(si),并(bing)可(ke)溯溪(xi)觀瀑、觀鷹賞鳥、眺望半個臺北(bei)和壯麗的大(da)屯山(shan)列,是一處豐富的自(zi)然觀賞去(qu)處。觀音(yin)山(shan)上(shang)(shang)的山(shan)徑溪(xi)谷四通(tong)八(ba)達,登(deng)山(shan)路線林林總(zong)總(zong)、難易不同,登(deng)山(shan)客可(ke)以揀(jian)挑適合自(zi)己體力的山(shan)徑上(shang)(shang)山(shan)。其中最大(da)眾化的路線是從五股的觀音(yin)山(shan)站牌出發,沿山(shan)階上(shang)(shang)登(deng)凌云禪寺(si),再由寺(si)后(hou)的牌樓往上(shang)(shang)走,約1小時可(ke)抵硬漢嶺(ling)。在此登(deng)高眺覽,視野遼闊,整個臺北(bei)市(shi)自(zi)新光大(da)樓以北(bei)的市(shi)景都在眼(yan)下,而對面的大(da)屯山(shan)列及淡水河(he)口(kou)山(shan)海相映的景象更(geng)是壯觀。
白(bai)天上觀音(yin)山,可隔著門墻老(lao)樹感受楞嚴閣、開山院的古(gu)樸莊嚴,遠眺(tiao)淡水八景之一的“坌領(ling)吐霧”;傍(bang)晚(wan)時分坐觀落日晚(wan)霞,淡水暮(mu)色最令人心動;或于(yu)夜幕低(di)垂(chui)時看淡水河畔夜景,萬家燈火閃爍明(ming)滅(mie),另有一番擾攘人間之美。
在荷蘭(lan)(lan)人統治時代(dai),觀音山叫(jiao)淡水(shui)山(出現在1654年荷蘭(lan)(lan)人‘淡水(shui)與其附(fu)近村社暨雞籠島略圖’中編號37的Tamswijse berch),但漢(han)人習稱八里分(坌)山,系因山邊的原(yuan)住民(min)部落(luo)八里坌社而得名。
康(kang)熙(xi)年間(jian),乃(nai)延用八(ba)里坌山(shan)(shan)的(de)地名(康(kang)熙(xi)二(er)十四年蔣毓英“臺灣府志”)。清朝雍正(zheng)年間(jian)(西元(yuan)1710年代)也曾改為“興直山(shan)(shan)”,但在各(ge)地方史(shi)籍(ji)中仍以“八(ba)里坌山(shan)(shan)”稱之。后來改為觀(guan)(guan)音(yin)(yin)山(shan)(shan)的(de)說法有二(er):一說是(shi)乾隆17年(西元(yuan)1752年)客(ke)家籍(ji)貢生(sheng)胡焯猷(福建(jian)(jian)汀州(zhou)永定人)在山(shan)(shan)路西云巖(yan)籌建(jian)(jian)大士觀(guan)(guan)(今五股區西云巖(yan)寺)而得(de)名,一說是(shi)由于山(shan)(shan)棱(leng)起(qi)伏變化,從關(guan)渡一帶眺望時,山(shan)(shan)型起(qi)伏貌(mao)似觀(guan)(guan)音(yin)(yin)菩薩的(de)面(mian)(mian)容仰天的(de)側面(mian)(mian)而得(de)名。
據(ju)臺灣著(zhu)名(ming)(ming)(ming)的地(di)名(ming)(ming)(ming)學者(zhe)-陳國章教(jiao)授所(suo)著(zhu)的臺灣地(di)名(ming)(ming)(ming)詞(ci)典,認為該(gai)地(di)的地(di)名(ming)(ming)(ming)是因(yin)“形似觀音菩薩(sa)的山”而(er)得名(ming)(ming)(ming)。
1937年(nian)12月27日,日本殖民當局以臺灣寶島山(shan)(shan)水風光秀麗(li)籌(chou)劃(hua)成(cheng)立大屯觀音山(shan)(shan)、次高山(shan)(shan)太魯閣和(he)新高阿(a)里(li)山(shan)(shan)三座公園,并于1941年(nian)3月10日發行紀念郵票、小全張及臺灣公園寫真集(ji),可惜因戰(zhan)爭而延(yan)宕。
二次世界大戰結束后,臺(tai)灣回歸(gui)中國,觀音山優良的屏障、視(shi)野的寬闊好山好水,為(wei)國人(ren)所認為(wei)風水寶(bao)地(di),濫挖濫葬(zang),一(yi)片(pian)零(ling)亂(luan)有礙視(shi)野觀瞻(zhan)。相較(jiao)之(zhi)下,景(jing)觀資源大不如往昔,已失去了(le)成(cheng)為(wei)公園之(zhi)基本要件,十分(fen)可(ke)惜(xi)。
觀音(yin)山(shan)(shan)(shan)(shan)是臺灣北(bei)部火(huo)(huo)(huo)成(cheng)(cheng)巖區中(zhong)最西(xi)北(bei)側之(zhi)火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)單元,以淡水河與大屯火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)群遙遙相(xiang)望,基本上為(wei)單一中(zhong)心噴發的火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)碎(sui)屑、凝灰巖與熔巖交替組成(cheng)(cheng)之(zhi)復(fu)式(shi)火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)。觀音(yin)山(shan)(shan)(shan)(shan)火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)之(zhi)主體可(ke)能(neng)是一中(zhong)央噴發之(zhi)錐狀火(huo)(huo)(huo)山(shan)(shan)(shan)(shan),錐體半(ban)徑約(yue)1~2公里(li),噴發中(zhong)心在(zai)(zai)觀音(yin)山(shan)(shan)(shan)(shan)主峰之(zhi)東南方。在(zai)(zai)凌云山(shan)(shan)(shan)(shan)一帶之(zhi)半(ban)環形之(zhi)連峰可(ke)能(neng)是火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)口壁之(zhi)西(xi)側。
在此以(yi)(yi)東,于石(shi)(shi)壁坑附近之(zhi)(zhi)地(di)形,呈馬(ma)蹄狀之(zhi)(zhi)半圓形凹(ao)陷可能(neng)是(shi)火(huo)(huo)(huo)山(shan)(shan)口所在,但火(huo)(huo)(huo)山(shan)(shan)口之(zhi)(zhi)東壁已經爆破(po)或熔(rong)巖(yan)溢流(liu)巖(yan)漿庫匱空(kong)塌陷而(er)崩塌,其部分碎(sui)屑(xie)構成分布(bu)(bu)于凌(ling)云山(shan)(shan)以(yi)(yi)東地(di)區之(zhi)(zhi)集塊巖(yan)或原先(xian)之(zhi)(zhi)火(huo)(huo)(huo)山(shan)(shan)碎(sui)屑(xie)流(liu)與火(huo)(huo)(huo)山(shan)(shan)礫(li)巖(yan)。觀(guan)(guan)音山(shan)(shan)火(huo)(huo)(huo)山(shan)(shan)活動時可能(neng)不(bu)猛烈(lie),因(yin)而(er)出露之(zhi)(zhi)主(zhu)體并(bing)未(wei)含有可觀(guan)(guan)的(de)火(huo)(huo)(huo)山(shan)(shan)碎(sui)屑(xie)巖(yan),仍(reng)以(yi)(yi)厚層的(de)巖(yan)流(liu)為(wei)(wei)主(zhu)。觀(guan)(guan)音山(shan)(shan)噴出熔(rong)巖(yan)流(liu)也和大(da)屯火(huo)(huo)(huo)山(shan)(shan)群相(xiang)似,均以(yi)(yi)安(an)山(shan)(shan)巖(yan)為(wei)(wei)主(zhu)。一(yi)般安(an)山(shan)(shan)巖(yan)常(chang)呈灰或灰黑色(se),且多呈斑狀結(jie)構,由結(jie)晶(jing)較粗大(da)之(zhi)(zhi)斑晶(jing)散布(bu)(bu)在石(shi)(shi)質細密(mi)之(zhi)(zhi)石(shi)(shi)基中。斑晶(jing)礦(kuang)(kuang)物(wu)(wu)(wu)以(yi)(yi)鎂鐵(tie)礦(kuang)(kuang)物(wu)(wu)(wu)為(wei)(wei)多,包括橄欖石(shi)(shi)、輝石(shi)(shi)、紫蘇輝石(shi)(shi)、角閃(shan)石(shi)(shi)、黑云母(mu)等礦(kuang)(kuang)物(wu)(wu)(wu),此外還有灰白色(se)的(de)斜長(chang)石(shi)(shi)。石(shi)(shi)基以(yi)(yi)斜長(chang)石(shi)(shi)和一(yi)些鎂鐵(tie)礦(kuang)(kuang)物(wu)(wu)(wu)的(de)微(wei)晶(jing)(肉眼不(bu)能(neng)分辨(bian)的(de))和無結(jie)晶(jing)的(de)火(huo)(huo)(huo)山(shan)(shan)玻璃(li)所組成。
本區(qu)安山巖熔巖依噴發(fa)之先后,由下而上(shang)可分別為(wei)三層,各層巖石在組織(zhi)上(shang)和(he)成分上(shang)都有(you)多少不同。
底層(或(huo)(huo)第一層)是(shi)(shi)粗粒(li)普通輝(hui)石(shi)(shi)(shi)(shi)玄武(wu)巖(yan)(yan)(yan)(yan)或(huo)(huo)玄武(wu)巖(yan)(yan)(yan)(yan)質安山(shan)巖(yan)(yan)(yan)(yan)熔(rong)巖(yan)(yan)(yan)(yan)。主要(yao)露出于火(huo)山(shan)錐體(ti)之(zhi)(zhi)中(zhong)心地(di)帶,包括(kuo)石(shi)(shi)(shi)(shi)壁坑及其東側之(zhi)(zhi)米倉村、烏山(shan)頭,至福隆山(shan)等地(di)。安山(shan)巖(yan)(yan)(yan)(yan)顏(yan)色(se)(se)深灰(hui),呈斑(ban)(ban)狀結構(gou)有許(xu)多黑(hei)綠色(se)(se)之(zhi)(zhi)普通輝(hui)石(shi)(shi)(shi)(shi)斑(ban)(ban)晶(jing),散布(bu)在(zai)灰(hui)色(se)(se)細晶(jing)之(zhi)(zhi)石(shi)(shi)(shi)(shi)基中(zhong),斑(ban)(ban)晶(jing)大(da)(da)者可(ke)達5公里左右。在(zai)顯(xian)微(wei)鏡下(xia)觀(guan)(guan)察巖(yan)(yan)(yan)(yan)石(shi)(shi)(shi)(shi)薄片,這些斑(ban)(ban)晶(jing)多成(cheng)雙晶(jing)或(huo)(huo)叢晶(jing)(由數(shu)個晶(jing)體(ti)結集而成(cheng)),輝(hui)石(shi)(shi)(shi)(shi)之(zhi)(zhi)外還有多數(shu)斜(xie)長(chang)石(shi)(shi)(shi)(shi)和少(shao)數(shu)橄(gan)欖石(shi)(shi)(shi)(shi)。中(zhong)層(或(huo)(huo)第二層)的熔(rong)巖(yan)(yan)(yan)(yan)是(shi)(shi)由兩(liang)輝(hui)安山(shan)巖(yan)(yan)(yan)(yan)構(gou)成(cheng)。巖(yan)(yan)(yan)(yan)石(shi)(shi)(shi)(shi)外觀(guan)(guan)灰(hui)色(se)(se),普通輝(hui)石(shi)(shi)(shi)(shi)之(zhi)(zhi)斑(ban)(ban)晶(jing)雖粗大(da)(da)易見但甚稀少(shao),細長(chang)之(zhi)(zhi)紫蘇輝(hui)石(shi)(shi)(shi)(shi)晶(jing)體(ti)頗多但均(jun)細小。本巖(yan)(yan)(yan)(yan)石(shi)(shi)(shi)(shi)之(zhi)(zhi)石(shi)(shi)(shi)(shi)基占量較多,由斜(xie)長(chang)石(shi)(shi)(shi)(shi)和紫蘇輝(hui)石(shi)(shi)(shi)(shi)細晶(jing)以及火(huo)山(shan)玻璃所組成(cheng)。本層是(shi)(shi)觀(guan)(guan)音(yin)山(shan)中(zhong)露出面積最廣的熔(rong)巖(yan)(yan)(yan)(yan),主要(yao)分(fen)布(bu)于觀(guan)(guan)音(yin)山(shan)主峰北側之(zhi)(zhi)山(shan)坡。
第(di)二層(ceng)(ceng)斑(ban)(ban)晶(jing)(jing)稀疏之(zhi)(zhi)兩輝(hui)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan),常(chang)含(han)第(di)一層(ceng)(ceng)輝(hui)石(shi)(shi)(shi)斑(ban)(ban)晶(jing)(jing)多(duo)而聚集成(cheng)叢的普通輝(hui)石(shi)(shi)(shi)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)之(zhi)(zhi)捕獲巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)塊,根據年(nian)代對比的包(bao)裹(guo)定律,即(ji)可(ke)知其(qi)(qi)發生(sheng)之(zhi)(zhi)先后(hou)順(shun)序,乃輝(hui)石(shi)(shi)(shi)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)(第(di)一層(ceng)(ceng))早于兩輝(hui)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)(第(di)二層(ceng)(ceng))。頂層(ceng)(ceng)(第(di)三層(ceng)(ceng))紫(zi)蘇(su)(su)輝(hui)石(shi)(shi)(shi)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)與一部(bu)(bu)分角(jiao)閃石(shi)(shi)(shi)紫(zi)蘇(su)(su)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)為(wei)(wei)其(qi)(qi)特(te)征,顏色淡灰色或(huo)(huo)灰紫(zi),斑(ban)(ban)晶(jing)(jing)細小(xiao)不顯著。有(you)(you)時可(ke)見有(you)(you)細長之(zhi)(zhi)紫(zi)蘇(su)(su)輝(hui)石(shi)(shi)(shi)或(huo)(huo)角(jiao)閃石(shi)(shi)(shi)之(zhi)(zhi)小(xiao)晶(jing)(jing),石(shi)(shi)(shi)基較多(duo)包(bao)含(han)微晶(jing)(jing)與玻(bo)璃質。本層(ceng)(ceng)主(zhu)要分布(bu)在火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)中央(yang)之(zhi)(zhi)頂部(bu)(bu),由觀音(yin)山(shan)(shan)(shan)(shan)主(zhu)峰至崩(beng)山(shan)(shan)(shan)(shan)一帶。在本地(di)區內除上述之(zhi)(zhi)三層(ceng)(ceng)熔巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)流之(zhi)(zhi)外,還(huan)有(you)(you)兩處獨立之(zhi)(zhi)小(xiao)規模(mo)火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)體(ti),一是(shi)在觀音(yin)山(shan)(shan)(shan)(shan)站北側公路旁出露之(zhi)(zhi)黑云母角(jiao)閃安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)脈(mo),為(wei)(wei)一厚約20~40公尺之(zhi)(zhi)脈(mo)狀(zhuang)小(xiao)侵入(ru)體(ti)(或(huo)(huo)稱觀音(yin)坑巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)脈(mo)),穿入(ru)觀音(yin)山(shan)(shan)(shan)(shan)層(ceng)(ceng)之(zhi)(zhi)粉砂巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)之(zhi)(zhi)中。另一處是(shi)突出于成(cheng)子(zi)寮附近低地(di)上之(zhi)(zhi)萬年(nian)塔小(xiao)山(shan)(shan)(shan)(shan),巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)石(shi)(shi)(shi)是(shi)橄(gan)欖(lan)石(shi)(shi)(shi)玄(xuan)武巖(yan)(yan)(yan)(yan)(yan)(yan)(yan),可(ke)能是(shi)一火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)側噴發之(zhi)(zhi)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)體(ti)。萬年(nian)塔所產出者,其(qi)(qi)橄(gan)欖(lan)石(shi)(shi)(shi)含(han)量較普通輝(hui)石(shi)(shi)(shi)為(wei)(wei)多(duo),與福隆山(shan)(shan)(shan)(shan)玄(xuan)武巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)略(lve)有(you)(you)不同。根據結晶(jing)(jing)分化(hua)的效應,玄(xuan)武質巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)漿(jiang)(jiang)經由橄(gan)欖(lan)石(shi)(shi)(shi)、輝(hui)石(shi)(shi)(shi)與斜長石(shi)(shi)(shi)的結晶(jing)(jing)分化(hua)可(ke)以(yi)產生(sheng)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)。同樣(yang)的由混(hun)(hun)染作用,也(ye)就(jiu)是(shi)由基性的巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)漿(jiang)(jiang)與酸(suan)性的巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)漿(jiang)(jiang)混(hun)(hun)合(he),或(huo)(huo)是(shi)由玄(xuan)武質巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)漿(jiang)(jiang),混(hun)(hun)雜了沈積(ji)物或(huo)(huo)地(di)殼(ke)物質都可(ke)能衍生(sheng)成(cheng)安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)。在觀音(yin)山(shan)(shan)(shan)(shan)地(di)區安(an)(an)山(shan)(shan)(shan)(shan)巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)或(huo)(huo)玄(xuan)武巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)中,常(chang)含(han)有(you)(you)火(huo)(huo)(huo)山(shan)(shan)(shan)(shan)體(ti)基底的砂巖(yan)(yan)(yan)(yan)(yan)(yan)(yan)或(huo)(huo)硅質片巖(yan)(yan)(yan)(yan)(yan)(yan)(yan),顯示地(di)殼(ke)物質的混(hun)(hun)染作用具有(you)(you)舉足輕重(zhong)的角(jiao)色。
觀音山(shan)(shan)(shan)(shan)各火(huo)山(shan)(shan)(shan)(shan)體的噴發(fa)(fa)時代,根據鉀-氬(ya)法定年(nian)的結(jie)果來看,觀音山(shan)(shan)(shan)(shan)火(huo)山(shan)(shan)(shan)(shan)之活動盛行于第(di)四紀(ji)。由六十(shi)余萬(wan)年(nian)前開(kai)始(shi);接著是(shi)五十(shi)余萬(wan)年(nian)前底層輝石(shi)玄(xuan)武巖或(huo)玄(xuan)武巖質(zhi)熔(rong)巖之噴發(fa)(fa);其(qi)次(ci)則為四十(shi)余萬(wan)年(nian)前,第(di)二(er)層兩輝安(an)(an)山(shan)(shan)(shan)(shan)巖;再(zai)依次(ci)為三(san)十(shi)余萬(wan)年(nian)前第(di)三(san)層紫蘇輝石(shi)與紫蘇輝石(shi)角(jiao)閃安(an)(an)山(shan)(shan)(shan)(shan)巖之噴發(fa)(fa);最后(hou)以二(er)十(shi)余萬(wan)年(nian)前橄欖(lan)玄(xuan)武巖落幕。由火(huo)山(shan)(shan)(shan)(shan)噴發(fa)(fa)年(nian)代與塌陷(xian)破火(huo)山(shan)(shan)(shan)(shan)口(kou)地貌(mao)看來,觀音山(shan)(shan)(shan)(shan)非為活火(huo)山(shan)(shan)(shan)(shan),有可(ke)能是(shi)座休眠(mian)火(huo)山(shan)(shan)(shan)(shan)或(huo)死火(huo)山(shan)(shan)(shan)(shan)。
1937年(nian)12月27日成(cheng)立大屯公園,觀(guan)音山(shan)(shan)(shan)亦在其中。但戰后成(cheng)立的(de)陽明(ming)山(shan)(shan)(shan)公園剔除觀(guan)音山(shan)(shan)(shan)(2002年(nian)方(fang)另成(cheng)立北海岸及觀(guan)音山(shan)(shan)(shan)風(feng)景(jing)區管理),以及民間認為此山(shan)(shan)(shan)為風(feng)水(shui)寶(bao)地(di),埋(mai)下日后濫(lan)墾濫(lan)葬及水(shui)土保持(chi)的(de)問題。據估計目前(qian)山(shan)(shan)(shan)上非法墓(mu)計4萬(wan)處,成(cheng)為發展阻(zu)礙(ai)。